Make const value naming upper snake case

.gitignore

@@ -15,4 +15,7 @@
 vendor/
 .vscode/
 imgui.ini
-*~
+*~
+
+# Custom
+*.pprof

assets/textures.go

@@ -19,7 +19,17 @@ import (
 type ColorFormat int
 
 const (
-	ColorFormat_RGBA8 ColorFormat = iota
+	ColorFormat_Unknown ColorFormat = iota
+	ColorFormat_RGBA8
+)
+
+var (
+	DefaultBlackTexId    Texture
+	DefaultWhiteTexId    Texture
+	DefaultDiffuseTexId  Texture
+	DefaultSpecularTexId Texture
+	DefaultNormalTexId   Texture
+	DefaultEmissionTexId Texture
 )
 
 type Texture struct {

buffers/buf_usage.go

@@ -10,8 +10,10 @@ import (
 type BufUsage int
 
 const (
+	BufUsage_Unknown BufUsage = iota
+
 	//Buffer is set only once and used many times
-	BufUsage_Static BufUsage = iota
+	BufUsage_Static
 	//Buffer is changed a lot and used many times
 	BufUsage_Dynamic
 	//Buffer is set only once and used by the GPU at most a few times

buffers/framebuffer.go

@@ -1,6 +1,7 @@
 package buffers
 
 import (
+	"github.com/bloeys/nmage/assert"
 	"github.com/bloeys/nmage/logging"
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
@@ -10,7 +11,10 @@ type FramebufferAttachmentType int32
 const (
 	FramebufferAttachmentType_Unknown FramebufferAttachmentType = iota
 	FramebufferAttachmentType_Texture
+	FramebufferAttachmentType_Texture_Array
 	FramebufferAttachmentType_Renderbuffer
+	FramebufferAttachmentType_Cubemap
+	FramebufferAttachmentType_Cubemap_Array
 )
 
 func (f FramebufferAttachmentType) IsValid() bool {
@@ -18,7 +22,13 @@ func (f FramebufferAttachmentType) IsValid() bool {
 	switch f {
 	case FramebufferAttachmentType_Texture:
 		fallthrough
+	case FramebufferAttachmentType_Texture_Array:
+		fallthrough
 	case FramebufferAttachmentType_Renderbuffer:
+		fallthrough
+	case FramebufferAttachmentType_Cubemap:
+		fallthrough
+	case FramebufferAttachmentType_Cubemap_Array:
 		return true
 
 	default:
@@ -32,18 +42,22 @@ const (
 	FramebufferAttachmentDataFormat_Unknown FramebufferAttachmentDataFormat = iota
 	FramebufferAttachmentDataFormat_R32Int
 	FramebufferAttachmentDataFormat_RGBA8
+	FramebufferAttachmentDataFormat_RGBAF16
 	FramebufferAttachmentDataFormat_SRGBA
+	FramebufferAttachmentDataFormat_DepthF32
 	FramebufferAttachmentDataFormat_Depth24Stencil8
 )
 
 func (f FramebufferAttachmentDataFormat) IsColorFormat() bool {
 	return f == FramebufferAttachmentDataFormat_R32Int ||
 		f == FramebufferAttachmentDataFormat_RGBA8 ||
-		f == FramebufferAttachmentDataFormat_SRGBA
+		f == FramebufferAttachmentDataFormat_SRGBA ||
+		f == FramebufferAttachmentDataFormat_RGBAF16
 }
 
 func (f FramebufferAttachmentDataFormat) IsDepthFormat() bool {
-	return f == FramebufferAttachmentDataFormat_Depth24Stencil8
+	return f == FramebufferAttachmentDataFormat_Depth24Stencil8 ||
+		f == FramebufferAttachmentDataFormat_DepthF32
 }
 
 func (f FramebufferAttachmentDataFormat) GlInternalFormat() int32 {
@@ -53,8 +67,12 @@ func (f FramebufferAttachmentDataFormat) GlInternalFormat() int32 {
 		return gl.R32I
 	case FramebufferAttachmentDataFormat_RGBA8:
 		return gl.RGB8
+	case FramebufferAttachmentDataFormat_RGBAF16:
+		return gl.RGBA16F
 	case FramebufferAttachmentDataFormat_SRGBA:
 		return gl.SRGB_ALPHA
+	case FramebufferAttachmentDataFormat_DepthF32:
+		return gl.DEPTH_COMPONENT
 	case FramebufferAttachmentDataFormat_Depth24Stencil8:
 		return gl.DEPTH24_STENCIL8
 	default:
@@ -71,9 +89,14 @@ func (f FramebufferAttachmentDataFormat) GlFormat() uint32 {
 
 	case FramebufferAttachmentDataFormat_RGBA8:
 		fallthrough
+	case FramebufferAttachmentDataFormat_RGBAF16:
+		fallthrough
 	case FramebufferAttachmentDataFormat_SRGBA:
 		return gl.RGBA
 
+	case FramebufferAttachmentDataFormat_DepthF32:
+		return gl.DEPTH_COMPONENT
+
 	case FramebufferAttachmentDataFormat_Depth24Stencil8:
 		return gl.DEPTH_STENCIL
 
@@ -83,6 +106,33 @@ func (f FramebufferAttachmentDataFormat) GlFormat() uint32 {
 	}
 }
 
+func (f FramebufferAttachmentDataFormat) GlComponentType() uint32 {
+
+	switch f {
+
+	case FramebufferAttachmentDataFormat_R32Int:
+		return gl.INT
+
+	case FramebufferAttachmentDataFormat_RGBA8:
+		fallthrough
+	case FramebufferAttachmentDataFormat_SRGBA:
+		return gl.UNSIGNED_BYTE
+
+	case FramebufferAttachmentDataFormat_RGBAF16:
+		// Seems this is fine to be float instead of half float
+		fallthrough
+	case FramebufferAttachmentDataFormat_DepthF32:
+		return gl.FLOAT
+
+	case FramebufferAttachmentDataFormat_Depth24Stencil8:
+		return gl.UNSIGNED_INT_24_8
+
+	default:
+		logging.ErrLog.Fatalf("unknown framebuffer attachment data format. Format=%d\n", f)
+		return 0
+	}
+}
+
 type FramebufferAttachment struct {
 	Id     uint32
 	Type   FramebufferAttachmentType
@@ -91,6 +141,7 @@ type FramebufferAttachment struct {
 
 type Framebuffer struct {
 	Id                    uint32
+	ClearFlags            uint32
 	Attachments           []FramebufferAttachment
 	ColorAttachmentsCount uint32
 	Width                 uint32
@@ -106,6 +157,13 @@ func (fbo *Framebuffer) BindWithViewport() {
 	gl.Viewport(0, 0, int32(fbo.Width), int32(fbo.Height))
 }
 
+// Clear calls gl.Clear with the fbo's clear flags.
+// Note that the fbo must be complete and bound.
+// Calling this without a bound fbo will clear something else, like your screen.
+func (fbo *Framebuffer) Clear() {
+	gl.Clear(fbo.ClearFlags)
+}
+
 func (fbo *Framebuffer) UnBind() {
 	gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
 }
@@ -154,6 +212,14 @@ func (fbo *Framebuffer) NewColorAttachment(
 		logging.ErrLog.Fatalf("failed creating color attachment for framebuffer due to unknown attachment type. Type=%d\n", attachType)
 	}
 
+	if attachType == FramebufferAttachmentType_Cubemap || attachType == FramebufferAttachmentType_Cubemap_Array {
+		logging.ErrLog.Fatalf("failed creating color attachment because cubemaps can not be color attachments (at least in this implementation. You might be able to do it manually)\n")
+	}
+
+	if attachType == FramebufferAttachmentType_Texture_Array {
+		logging.ErrLog.Fatalf("failed creating color attachment because texture arrays can not be color attachments (implementation can be updated to support it or you can do it manually)\n")
+	}
+
 	if !attachFormat.IsColorFormat() {
 		logging.ErrLog.Fatalf("failed creating color attachment for framebuffer due to attachment data format not being a valid color type. Data format=%d\n", attachFormat)
 	}
@@ -174,7 +240,17 @@ func (fbo *Framebuffer) NewColorAttachment(
 		}
 
 		gl.BindTexture(gl.TEXTURE_2D, a.Id)
-		gl.TexImage2D(gl.TEXTURE_2D, 0, attachFormat.GlInternalFormat(), int32(fbo.Width), int32(fbo.Height), 0, attachFormat.GlFormat(), gl.UNSIGNED_BYTE, nil)
+		gl.TexImage2D(
+			gl.TEXTURE_2D,
+			0,
+			attachFormat.GlInternalFormat(),
+			int32(fbo.Width),
+			int32(fbo.Height),
+			0,
+			attachFormat.GlFormat(),
+			attachFormat.GlComponentType(),
+			nil,
+		)
 
 		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
 		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
@@ -201,6 +277,269 @@ func (fbo *Framebuffer) NewColorAttachment(
 
 	fbo.UnBind()
 	fbo.ColorAttachmentsCount++
+	fbo.ClearFlags |= gl.COLOR_BUFFER_BIT
+	fbo.Attachments = append(fbo.Attachments, a)
+}
+
+// SetNoColorBuffer sets the read and draw buffers of this fbo to 'NONE',
+// which tells the graphics driver that we don't want a color buffer for this fbo.
+//
+// This is required because normally an fbo must have a color buffer to be considered complete, but by
+// doing this we get marked as complete even without one.
+//
+// Usually used when you only care about some other buffer, like a depth buffer.
+func (fbo *Framebuffer) SetNoColorBuffer() {
+
+	if fbo.HasColorAttachment() {
+		logging.ErrLog.Fatalf("failed SetNoColorBuffer because framebuffer already has a color attachment\n")
+	}
+
+	fbo.Bind()
+	gl.DrawBuffer(gl.NONE)
+	gl.ReadBuffer(gl.NONE)
+	fbo.UnBind()
+}
+
+func (fbo *Framebuffer) NewDepthAttachment(
+	attachType FramebufferAttachmentType,
+	attachFormat FramebufferAttachmentDataFormat,
+) {
+
+	if fbo.HasDepthAttachment() {
+		logging.ErrLog.Fatalf("failed creating depth attachment for framebuffer because a depth attachment already exists\n")
+	}
+
+	if !attachType.IsValid() {
+		logging.ErrLog.Fatalf("failed creating depth attachment for framebuffer due to unknown attachment type. Type=%d\n", attachType)
+	}
+
+	if !attachFormat.IsDepthFormat() {
+		logging.ErrLog.Fatalf("failed creating depth attachment for framebuffer due to attachment data format not being a valid depth-stencil type. Data format=%d\n", attachFormat)
+	}
+
+	if attachType == FramebufferAttachmentType_Cubemap_Array {
+		logging.ErrLog.Fatalf("failed creating cubemap array depth attachment because 'NewDepthCubemapArrayAttachment' must be used for that\n")
+	}
+
+	if attachType == FramebufferAttachmentType_Texture_Array {
+		logging.ErrLog.Fatalf("failed creating texture array depth attachment because 'NewDepthTextureArrayAttachment' must be used for that\n")
+	}
+
+	a := FramebufferAttachment{
+		Type:   attachType,
+		Format: attachFormat,
+	}
+
+	fbo.Bind()
+
+	if attachType == FramebufferAttachmentType_Texture {
+
+		// Create texture
+		gl.GenTextures(1, &a.Id)
+		if a.Id == 0 {
+			logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
+		}
+
+		gl.BindTexture(gl.TEXTURE_2D, a.Id)
+		gl.TexImage2D(
+			gl.TEXTURE_2D,
+			0,
+			attachFormat.GlInternalFormat(),
+			int32(fbo.Width),
+			int32(fbo.Height),
+			0,
+			attachFormat.GlFormat(),
+			attachFormat.GlComponentType(),
+			nil,
+		)
+
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
+
+		// This is so that any sampling outside the depth map gives a full depth value.
+		// Useful for example when doing shadow maps where we want things outside
+		// the range of the texture to not show shadow
+		borderColor := []float32{1, 1, 1, 1}
+		gl.TexParameterfv(gl.TEXTURE_2D, gl.TEXTURE_BORDER_COLOR, &borderColor[0])
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_BORDER)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_BORDER)
+
+		gl.BindTexture(gl.TEXTURE_2D, 0)
+
+		// Attach to fbo
+		gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.TEXTURE_2D, a.Id, 0)
+
+	} else if attachType == FramebufferAttachmentType_Renderbuffer {
+
+		// Create rbo
+		gl.GenRenderbuffers(1, &a.Id)
+		if a.Id == 0 {
+			logging.ErrLog.Fatalf("failed to generate render buffer for framebuffer. GlError=%d\n", gl.GetError())
+		}
+
+		gl.BindRenderbuffer(gl.RENDERBUFFER, a.Id)
+		gl.RenderbufferStorage(gl.RENDERBUFFER, uint32(attachFormat.GlInternalFormat()), int32(fbo.Width), int32(fbo.Height))
+		gl.BindRenderbuffer(gl.RENDERBUFFER, 0)
+
+		// Attach to fbo
+		gl.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, a.Id)
+
+	} else if attachType == FramebufferAttachmentType_Cubemap {
+
+		// Create cubemap
+		gl.GenTextures(1, &a.Id)
+		if a.Id == 0 {
+			logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
+		}
+
+		gl.BindTexture(gl.TEXTURE_CUBE_MAP, a.Id)
+		for i := 0; i < 6; i++ {
+			gl.TexImage2D(
+				uint32(gl.TEXTURE_CUBE_MAP_POSITIVE_X+i),
+				0,
+				attachFormat.GlInternalFormat(),
+				int32(fbo.Width),
+				int32(fbo.Height),
+				0,
+				attachFormat.GlFormat(),
+				attachFormat.GlComponentType(),
+				nil,
+			)
+		}
+
+		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
+		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
+		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+		gl.TexParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
+
+		gl.BindTexture(gl.TEXTURE_2D, 0)
+
+		// Attach to fbo
+		gl.FramebufferTexture(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, a.Id, 0)
+	}
+
+	fbo.UnBind()
+	fbo.ClearFlags |= gl.DEPTH_BUFFER_BIT
+	fbo.Attachments = append(fbo.Attachments, a)
+}
+
+func (fbo *Framebuffer) NewDepthCubemapArrayAttachment(
+	attachFormat FramebufferAttachmentDataFormat,
+	numCubemaps int32,
+) {
+
+	if fbo.HasDepthAttachment() {
+		logging.ErrLog.Fatalf("failed creating cubemap array depth attachment for framebuffer because a depth attachment already exists\n")
+	}
+
+	if !attachFormat.IsDepthFormat() {
+		logging.ErrLog.Fatalf("failed creating depth attachment for framebuffer due to attachment data format not being a valid depth-stencil type. Data format=%d\n", attachFormat)
+	}
+
+	a := FramebufferAttachment{
+		Type:   FramebufferAttachmentType_Cubemap_Array,
+		Format: attachFormat,
+	}
+
+	fbo.Bind()
+
+	// Create cubemap array
+	gl.GenTextures(1, &a.Id)
+	if a.Id == 0 {
+		logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
+	}
+
+	gl.BindTexture(gl.TEXTURE_CUBE_MAP_ARRAY, a.Id)
+
+	gl.TexImage3D(
+		gl.TEXTURE_CUBE_MAP_ARRAY,
+		0,
+		attachFormat.GlInternalFormat(),
+		int32(fbo.Width),
+		int32(fbo.Height),
+		6*numCubemaps,
+		0,
+		attachFormat.GlFormat(),
+		attachFormat.GlComponentType(),
+		nil,
+	)
+
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP_ARRAY, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP_ARRAY, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP_ARRAY, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP_ARRAY, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+	gl.TexParameteri(gl.TEXTURE_CUBE_MAP_ARRAY, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
+
+	gl.BindTexture(gl.TEXTURE_2D, 0)
+
+	// Attach to fbo
+	gl.FramebufferTexture(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, a.Id, 0)
+
+	fbo.UnBind()
+	fbo.ClearFlags |= gl.DEPTH_BUFFER_BIT
+	fbo.Attachments = append(fbo.Attachments, a)
+}
+
+func (fbo *Framebuffer) NewDepthTextureArrayAttachment(
+	attachFormat FramebufferAttachmentDataFormat,
+	numTextures int32,
+) {
+
+	if fbo.HasDepthAttachment() {
+		logging.ErrLog.Fatalf("failed creating texture array depth attachment for framebuffer because a depth attachment already exists\n")
+	}
+
+	if !attachFormat.IsDepthFormat() {
+		logging.ErrLog.Fatalf("failed creating depth attachment for framebuffer due to attachment data format not being a valid depth-stencil type. Data format=%d\n", attachFormat)
+	}
+
+	a := FramebufferAttachment{
+		Type:   FramebufferAttachmentType_Texture_Array,
+		Format: attachFormat,
+	}
+
+	fbo.Bind()
+
+	// Create cubemap array
+	gl.GenTextures(1, &a.Id)
+	if a.Id == 0 {
+		logging.ErrLog.Fatalf("failed to generate texture for framebuffer. GlError=%d\n", gl.GetError())
+	}
+
+	gl.BindTexture(gl.TEXTURE_2D_ARRAY, a.Id)
+
+	gl.TexImage3D(
+		gl.TEXTURE_2D_ARRAY,
+		0,
+		attachFormat.GlInternalFormat(),
+		int32(fbo.Width),
+		int32(fbo.Height),
+		numTextures,
+		0,
+		attachFormat.GlFormat(),
+		attachFormat.GlComponentType(),
+		nil,
+	)
+
+	gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
+	gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
+
+	// This is so that any sampling outside the depth map gives a full depth value.
+	// Useful for example when doing shadow maps where we want things outside
+	// the range of the texture to not show shadow
+	borderColor := []float32{1, 1, 1, 1}
+	gl.TexParameterfv(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_BORDER_COLOR, &borderColor[0])
+	gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_BORDER)
+	gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_BORDER)
+
+	gl.BindTexture(gl.TEXTURE_2D_ARRAY, 0)
+
+	// Attach to fbo
+	gl.FramebufferTexture(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, a.Id, 0)
+
+	fbo.UnBind()
+	fbo.ClearFlags |= gl.DEPTH_BUFFER_BIT
 	fbo.Attachments = append(fbo.Attachments, a)
 }
 
@@ -237,7 +576,17 @@ func (fbo *Framebuffer) NewDepthStencilAttachment(
 		}
 
 		gl.BindTexture(gl.TEXTURE_2D, a.Id)
-		gl.TexImage2D(gl.TEXTURE_2D, 0, attachFormat.GlInternalFormat(), int32(fbo.Width), int32(fbo.Height), 0, attachFormat.GlFormat(), gl.UNSIGNED_INT_24_8, nil)
+		gl.TexImage2D(
+			gl.TEXTURE_2D,
+			0,
+			attachFormat.GlInternalFormat(),
+			int32(fbo.Width),
+			int32(fbo.Height),
+			0,
+			attachFormat.GlFormat(),
+			attachFormat.GlComponentType(),
+			nil,
+		)
 
 		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
 		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
@@ -263,9 +612,32 @@ func (fbo *Framebuffer) NewDepthStencilAttachment(
 	}
 
 	fbo.UnBind()
+	fbo.ClearFlags |= gl.DEPTH_BUFFER_BIT | gl.STENCIL_BUFFER_BIT
 	fbo.Attachments = append(fbo.Attachments, a)
 }
 
+// SetCubemapArrayLayerFace 'binds' a single face of a cubemap from the cubemap
+// array to the fbo, such that rendering only affects that one face and the others inaccessible.
+//
+// If this is not called, the default is that the entire cubemap array and all the faces in it
+// are bound and available for use when binding the fbo.
+func (fbo *Framebuffer) SetCubemapArrayLayerFace(layerFace int32) {
+
+	for i := 0; i < len(fbo.Attachments); i++ {
+
+		a := &fbo.Attachments[i]
+		if a.Type != FramebufferAttachmentType_Cubemap_Array {
+			continue
+		}
+
+		assert.T(a.Format.IsDepthFormat(), "SetCubemapFromArray called but a cubemap array is set on a color attachment, which is not currently handled. Code must be updated!")
+		gl.FramebufferTextureLayer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, a.Id, 0, layerFace)
+		return
+	}
+
+	logging.ErrLog.Fatalf("SetCubemapFromArray failed because no cubemap array attachment was found on fbo. Fbo=%+v\n", *fbo)
+}
+
 func (fbo *Framebuffer) Delete() {
 
 	if fbo.Id == 0 {

camera/camera.go

@@ -41,7 +41,7 @@ func (c *Camera) Update() {
 	c.ViewMat = gglm.LookAtRH(&c.Pos, c.Pos.Clone().Add(&c.Forward), &c.WorldUp).Mat4
 
 	if c.Type == Type_Perspective {
-		c.ProjMat = *gglm.Perspective(c.Fov, c.AspectRatio, c.NearClip, c.FarClip)
+		c.ProjMat = gglm.Perspective(c.Fov, c.AspectRatio, c.NearClip, c.FarClip)
 	} else {
 		c.ProjMat = gglm.Ortho(c.Left, c.Right, c.Top, c.Bottom, c.NearClip, c.FarClip).Mat4
 	}
@@ -59,9 +59,9 @@ func (c *Camera) UpdateRotation(pitch, yaw float32) {
 	c.Update()
 }
 
-func NewPerspective(pos, forward, worldUp *gglm.Vec3, nearClip, farClip, fovRadians, aspectRatio float32) *Camera {
+func NewPerspective(pos, forward, worldUp *gglm.Vec3, nearClip, farClip, fovRadians, aspectRatio float32) Camera {
 
-	cam := &Camera{
+	cam := Camera{
 		Type:    Type_Perspective,
 		Pos:     *pos,
 		Forward: *forward,
@@ -78,9 +78,9 @@ func NewPerspective(pos, forward, worldUp *gglm.Vec3, nearClip, farClip, fovRadi
 	return cam
 }
 
-func NewOrthographic(pos, forward, worldUp *gglm.Vec3, nearClip, farClip, left, right, top, bottom float32) *Camera {
+func NewOrthographic(pos, forward, worldUp *gglm.Vec3, nearClip, farClip, left, right, top, bottom float32) Camera {
 
-	cam := &Camera{
+	cam := Camera{
 		Type:    Type_Orthographic,
 		Pos:     *pos,
 		Forward: *forward,

engine/engine.go

@@ -1,12 +1,14 @@
 package engine
 
 import (
+	"image"
+	"image/color"
 	"runtime"
 
 	imgui "github.com/AllenDang/cimgui-go"
 	"github.com/bloeys/nmage/assert"
+	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/input"
-	"github.com/bloeys/nmage/renderer"
 	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
 	"github.com/go-gl/gl/v4.1-core/gl"
@@ -28,30 +30,16 @@ type Window struct {
 	SDLWin         *sdl.Window
 	GlCtx          sdl.GLContext
 	EventCallbacks []func(sdl.Event)
-	Rend           renderer.Render
 }
 
 func (w *Window) handleInputs() {
 
-	input.EventLoopStart()
 	imIo := imgui.CurrentIO()
 
 	imguiCaptureMouse := imIo.WantCaptureMouse()
 	imguiCaptureKeyboard := imIo.WantCaptureKeyboard()
 
-	// These two are to fix a bug where state isn't cleared
-	// even after imgui captures the keyboard/mouse.
-	//
-	// For example, if player is moving due to key held and then imgui captures the keyboard,
-	// the player keeps moving even when the key is no longer pressed because the input system never
-	// receives the key up event.
-	if imguiCaptureMouse {
-		input.ClearMouseState()
-	}
-
-	if imguiCaptureKeyboard {
-		input.ClearKeyboardState()
-	}
+	input.EventLoopStart(imguiCaptureMouse, imguiCaptureKeyboard)
 
 	for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
 
@@ -65,46 +53,27 @@ func (w *Window) handleInputs() {
 
 		case *sdl.MouseWheelEvent:
 
-			if !imguiCaptureMouse {
-				input.HandleMouseWheelEvent(e)
-			}
-
+			input.HandleMouseWheelEvent(e)
 			imIo.AddMouseWheelDelta(float32(e.X), float32(e.Y))
 
 		case *sdl.KeyboardEvent:
 
-			if !imguiCaptureKeyboard {
-				input.HandleKeyboardEvent(e)
-			}
+			input.HandleKeyboardEvent(e)
+
+			// Send modifier key updates to imgui (based on the imgui SDL backend)
+			imIo.AddKeyEvent(imgui.ModCtrl, e.Keysym.Mod&sdl.KMOD_CTRL != 0)
+			imIo.AddKeyEvent(imgui.ModShift, e.Keysym.Mod&sdl.KMOD_SHIFT != 0)
+			imIo.AddKeyEvent(imgui.ModAlt, e.Keysym.Mod&sdl.KMOD_ALT != 0)
+			imIo.AddKeyEvent(imgui.ModSuper, e.Keysym.Mod&sdl.KMOD_GUI != 0)
 
 			imIo.AddKeyEvent(nmageimgui.SdlScancodeToImGuiKey(e.Keysym.Scancode), e.Type == sdl.KEYDOWN)
 
-			// Send modifier key updates to imgui
-			if e.Keysym.Sym == sdl.K_LCTRL || e.Keysym.Sym == sdl.K_RCTRL {
-				imIo.SetKeyCtrl(e.Type == sdl.KEYDOWN)
-			}
-
-			if e.Keysym.Sym == sdl.K_LSHIFT || e.Keysym.Sym == sdl.K_RSHIFT {
-				imIo.SetKeyShift(e.Type == sdl.KEYDOWN)
-			}
-
-			if e.Keysym.Sym == sdl.K_LALT || e.Keysym.Sym == sdl.K_RALT {
-				imIo.SetKeyAlt(e.Type == sdl.KEYDOWN)
-			}
-
-			if e.Keysym.Sym == sdl.K_LGUI || e.Keysym.Sym == sdl.K_RGUI {
-				imIo.SetKeySuper(e.Type == sdl.KEYDOWN)
-			}
-
 		case *sdl.TextInputEvent:
 			imIo.AddInputCharactersUTF8(e.GetText())
 
 		case *sdl.MouseButtonEvent:
 
-			if !imguiCaptureMouse {
-				input.HandleMouseBtnEvent(e)
-			}
-
+			input.HandleMouseBtnEvent(e)
 			isPressed := e.State == sdl.PRESSED
 
 			if e.Button == sdl.BUTTON_LEFT {
@@ -117,9 +86,7 @@ func (w *Window) handleInputs() {
 
 		case *sdl.MouseMotionEvent:
 
-			if !imguiCaptureMouse {
-				input.HandleMouseMotionEvent(e)
-			}
+			input.HandleMouseMotionEvent(e)
 
 		case *sdl.WindowEvent:
 
@@ -201,38 +168,46 @@ func initSDL() error {
 	return nil
 }
 
-func CreateOpenGLWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
-	return createWindow(title, x, y, width, height, WindowFlags_OPENGL|flags, rend)
+func CreateOpenGLWindow(title string, x, y, width, height int32, flags WindowFlags) (Window, error) {
+	return createWindow(title, x, y, width, height, WindowFlags_OPENGL|flags)
 }
 
-func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
-	return createWindow(title, sdl.WINDOWPOS_CENTERED, sdl.WINDOWPOS_CENTERED, width, height, WindowFlags_OPENGL|flags, rend)
+func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags) (Window, error) {
+	return createWindow(title, sdl.WINDOWPOS_CENTERED, sdl.WINDOWPOS_CENTERED, width, height, WindowFlags_OPENGL|flags)
 }
 
-func createWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
+func createWindow(title string, x, y, width, height int32, flags WindowFlags) (Window, error) {
 
 	assert.T(isInited, "engine.Init() was not called!")
 
-	sdlWin, err := sdl.CreateWindow(title, x, y, width, height, uint32(flags))
-	if err != nil {
-		return nil, err
-	}
-	win := &Window{
-		SDLWin:         sdlWin,
+	win := Window{
+		SDLWin:         nil,
 		EventCallbacks: make([]func(sdl.Event), 0),
-		Rend:           rend,
 	}
 
-	win.GlCtx, err = sdlWin.GLCreateContext()
+	var err error
+
+	win.SDLWin, err = sdl.CreateWindow(title, x, y, width, height, uint32(flags))
 	if err != nil {
-		return nil, err
+		return win, err
+	}
+
+	win.GlCtx, err = win.SDLWin.GLCreateContext()
+	if err != nil {
+		return win, err
 	}
 
 	err = initOpenGL()
 	if err != nil {
-		return nil, err
+		return win, err
 	}
 
+	setupDefaultTextures()
+
+	// Get rid of the blinding white startup screen (unfortunately there is still one frame of white)
+	gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
+	win.SDLWin.GLSwap()
+
 	return win, err
 }
 
@@ -254,6 +229,58 @@ func initOpenGL() error {
 	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
 
 	gl.ClearColor(0, 0, 0, 1)
+
+	return nil
+}
+
+func setupDefaultTextures() error {
+
+	// 1x1 black texture
+	defaultBlackImg := image.NewNRGBA(image.Rect(0, 0, 1, 1))
+	defaultBlackImg.Set(0, 0, color.NRGBA{R: 0, G: 0, B: 0, A: 1})
+	defaultBlackImgTex, err := assets.LoadTextureInMemPngImg(defaultBlackImg, &assets.TextureLoadOptions{NoSrgba: true})
+	if err != nil {
+		return err
+	}
+	assets.DefaultBlackTexId = defaultBlackImgTex
+
+	// 1x1 white texture
+	defaultWhiteImg := image.NewNRGBA(image.Rect(0, 0, 1, 1))
+	defaultWhiteImg.Set(0, 0, color.NRGBA{R: 255, G: 255, B: 255, A: 1})
+	defaultWhiteImgTex, err := assets.LoadTextureInMemPngImg(defaultWhiteImg, &assets.TextureLoadOptions{NoSrgba: true})
+	if err != nil {
+		return err
+	}
+	assets.DefaultWhiteTexId = defaultWhiteImgTex
+
+	// Default diffuse
+	assets.DefaultDiffuseTexId = defaultWhiteImgTex
+
+	// Default specular
+	assets.DefaultSpecularTexId = defaultBlackImgTex
+
+	// Default Normal map which is created to be RGB(0.5,0.5,1), which when multiplied by TBN matrix gives the vertex normal.
+	// 128 is better than 127 for normal maps. See 'Flat Color' section here: http://wiki.polycount.com/wiki/Normal_map
+	// Basically, 127 can create seams while 128 looks correct
+	defaultNormalMapImg := image.NewNRGBA(image.Rect(0, 0, 1, 1))
+	defaultNormalMapImg.Set(0, 0, color.NRGBA{R: 128, G: 128, B: 255, A: 1})
+	defaultNormalMapTex, err := assets.LoadTextureInMemPngImg(defaultNormalMapImg, &assets.TextureLoadOptions{NoSrgba: true})
+	if err != nil {
+		return err
+	}
+
+	assets.DefaultNormalTexId = defaultNormalMapTex
+
+	// Default emission
+	assets.DefaultEmissionTexId = defaultBlackImgTex
+
+	assert.T(assets.DefaultBlackTexId.TexID != 0, "The default black texture handle is zero. Either texture wasn't created or handle wasn't updated")
+	assert.T(assets.DefaultWhiteTexId.TexID != 0, "The default white texture handle is zero. Either texture wasn't created or handle wasn't updated")
+	assert.T(assets.DefaultDiffuseTexId.TexID != 0, "The default diffuse texture handle is zero. Either texture wasn't created or handle wasn't updated")
+	assert.T(assets.DefaultSpecularTexId.TexID != 0, "The default specular texture handle is zero. Either texture wasn't created or handle wasn't updated")
+	assert.T(assets.DefaultNormalTexId.TexID != 0, "The default normal texture handle is zero. Either texture wasn't created or handle wasn't updated")
+	assert.T(assets.DefaultEmissionTexId.TexID != 0, "The default emission texture handle is zero. Either texture wasn't created or handle wasn't updated")
+
 	return nil
 }
 

engine/game.go

@@ -1,6 +1,7 @@
 package engine
 
 import (
+	"github.com/bloeys/nmage/renderer"
 	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
 	"github.com/go-gl/gl/v4.1-core/gl"
@@ -20,7 +21,7 @@ type Game interface {
 	DeInit()
 }
 
-func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
+func Run(g Game, w *Window, rend renderer.Render, ui nmageimgui.ImguiInfo) {
 
 	isRunning = true
 
@@ -56,7 +57,7 @@ func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
 		w.SDLWin.GLSwap()
 
 		g.FrameEnd()
-		w.Rend.FrameEnd()
+		rend.FrameEnd()
 		timing.FrameEnded()
 	}
 

go.mod

@@ -8,7 +8,7 @@ require github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6
 
 require (
 	github.com/bloeys/assimp-go v0.4.4
-	github.com/bloeys/gglm v0.43.0
+	github.com/bloeys/gglm v0.49.0
 )
 
 require (

go.sum

@@ -2,8 +2,8 @@ github.com/AllenDang/cimgui-go v0.0.0-20230720025235-f2ff398a66b2 h1:3HA/5qD8Rim
 github.com/AllenDang/cimgui-go v0.0.0-20230720025235-f2ff398a66b2/go.mod h1:iNfbIyOBN8k3XScMxULbrwYbPsXEAUD0Jb6UwrspQb8=
 github.com/bloeys/assimp-go v0.4.4 h1:Yn5e/RpE0Oes0YMBy8O7KkwAO4R/RpgrZPJCt08dVIU=
 github.com/bloeys/assimp-go v0.4.4/go.mod h1:my3yRxT7CfOztmvi+0svmwbaqw0KFrxaHxncoyaEIP0=
-github.com/bloeys/gglm v0.43.0 h1:ZpOghR3PHfpkigTDh+FqxLsF0gN8CD6s/bWoei6LyxI=
-github.com/bloeys/gglm v0.43.0/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
+github.com/bloeys/gglm v0.49.0 h1:YtbyHpszYhjnxw7KVV0LaCdBktRMqfGx/i37EMomxsE=
+github.com/bloeys/gglm v0.49.0/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
 github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6 h1:zDw5v7qm4yH7N8C8uWd+8Ii9rROdgWxQuGoJ9WDXxfk=
 github.com/go-gl/gl v0.0.0-20211210172815-726fda9656d6/go.mod h1:9YTyiznxEY1fVinfM7RvRcjRHbw2xLBJ3AAGIT0I4Nw=
 github.com/mandykoh/go-parallel v0.1.0 h1:7vJMNMC4dsbgZdkAb2A8tV5ENY1v7VxIO1wzQWZoT8k=

input/input.go

@@ -1,6 +1,23 @@
+// The input package provides an interface to mouse and keyboard inputs
+// like key clicks and releases, along with some higher level constructs like
+// pressed/released this frames, double clicks, and normalized inputs.
+//
+// The input package has two sets of functions for most cases, where one
+// is in the form 'xy' and the other 'xyCaptured'. The captured form
+// always returns normal events even if the mouse or keyboard are captured
+// by the UI system. The 'xy' form however will return zero/false if the
+// respective input device is currently captured (with the exception of mouse position, that is always correctly returned).
+//
+// For most cases, you want to use the 'xy' form. For example, you only want to receive
+// key down events for game character movement when the UI isn't capturing the keyboard,
+// because otherwise the character will move while typing in a UI textbox.
+//
+// The functions IsMouseCaptured and IsKeyboardCaptured are also available.
 package input
 
-import "github.com/veandco/go-sdl2/sdl"
+import (
+	"github.com/veandco/go-sdl2/sdl"
+)
 
 type keyState struct {
 	Key                 sdl.Keycode
@@ -31,15 +48,22 @@ type mouseWheelState struct {
 }
 
 var (
-	keyMap        = make(map[sdl.Keycode]keyState)
-	mouseBtnMap   = make(map[int]mouseBtnState)
-	mouseMotion   = mouseMotionState{}
-	mouseWheel    = mouseWheelState{}
-	quitRequested bool
+	mouseWheel  = mouseWheelState{}
+	mouseMotion = mouseMotionState{}
+	mouseBtnMap = make(map[int]mouseBtnState)
+	keyMap      = make(map[sdl.Keycode]keyState)
+
+	isQuitRequested    bool
+	isMouseCaptured    bool
+	isKeyboardCaptured bool
 )
 
-func EventLoopStart() {
+func EventLoopStart(mouseGotCaptured, keyboardGotCaptured bool) {
 
+	isMouseCaptured = mouseGotCaptured
+	isKeyboardCaptured = keyboardGotCaptured
+
+	// Update per-frame state
 	for k, v := range keyMap {
 		v.IsPressedThisFrame = false
 		v.IsReleasedThisFrame = false
@@ -59,7 +83,7 @@ func EventLoopStart() {
 	mouseWheel.XDelta = 0
 	mouseWheel.YDelta = 0
 
-	quitRequested = false
+	isQuitRequested = false
 }
 
 func ClearKeyboardState() {
@@ -73,11 +97,19 @@ func ClearMouseState() {
 }
 
 func HandleQuitEvent(e *sdl.QuitEvent) {
-	quitRequested = true
+	isQuitRequested = true
+}
+
+func IsMouseCaptured() bool {
+	return isMouseCaptured
+}
+
+func IsKeyboardCaptured() bool {
+	return isKeyboardCaptured
 }
 
 func IsQuitClicked() bool {
-	return quitRequested
+	return isQuitRequested
 }
 
 func HandleKeyboardEvent(e *sdl.KeyboardEvent) {
@@ -123,18 +155,36 @@ func HandleMouseWheelEvent(e *sdl.MouseWheelEvent) {
 	mouseWheel.YDelta = e.Y
 }
 
-// GetMousePos returns the window coordinates of the mouse
+// GetMousePos returns the window coordinates of the mouse regardless of whether the mouse is captured or not
 func GetMousePos() (x, y int32) {
 	return mouseMotion.XPos, mouseMotion.YPos
 }
 
 // GetMouseMotion returns how many pixels were moved last frame
 func GetMouseMotion() (xDelta, yDelta int32) {
+
+	if isMouseCaptured {
+		return 0, 0
+	}
+
+	return GetMouseMotionCaptured()
+}
+
+func GetMouseMotionCaptured() (xDelta, yDelta int32) {
 	return mouseMotion.XDelta, mouseMotion.YDelta
 }
 
 func GetMouseMotionNorm() (xDelta, yDelta int32) {
 
+	if isMouseCaptured {
+		return 0, 0
+	}
+
+	return GetMouseMotionNormCaptured()
+}
+
+func GetMouseMotionNormCaptured() (xDelta, yDelta int32) {
+
 	x, y := mouseMotion.XDelta, mouseMotion.YDelta
 	if x > 0 {
 		x = 1
@@ -152,12 +202,31 @@ func GetMouseMotionNorm() (xDelta, yDelta int32) {
 }
 
 func GetMouseWheelMotion() (xDelta, yDelta int32) {
+
+	if isMouseCaptured {
+		return 0, 0
+	}
+
+	return GetMouseWheelMotionCaptured()
+}
+
+func GetMouseWheelMotionCaptured() (xDelta, yDelta int32) {
 	return mouseWheel.XDelta, mouseWheel.YDelta
 }
 
 // GetMouseWheelXNorm returns 1 if mouse wheel xDelta > 0, -1 if xDelta < 0, and 0 otherwise
 func GetMouseWheelXNorm() int32 {
 
+	if isMouseCaptured {
+		return 0
+	}
+
+	return GetMouseWheelXNormCaptured()
+}
+
+// GetMouseWheelXNormCaptured returns 1 if mouse wheel xDelta > 0, -1 if xDelta < 0, and 0 otherwise
+func GetMouseWheelXNormCaptured() int32 {
+
 	if mouseWheel.XDelta > 0 {
 		return 1
 	} else if mouseWheel.XDelta < 0 {
@@ -167,9 +236,19 @@ func GetMouseWheelXNorm() int32 {
 	return 0
 }
 
-// returns 1 if mouse wheel yDelta > 0, -1 if yDelta < 0, and 0 otherwise
+// GetMouseWheelYNorm returns 1 if mouse wheel yDelta > 0, -1 if yDelta < 0, and 0 otherwise
 func GetMouseWheelYNorm() int32 {
 
+	if isMouseCaptured {
+		return 0
+	}
+
+	return GetMouseWheelYNormCaptured()
+}
+
+// GetMouseWheelYNormCaptured returns 1 if mouse wheel yDelta > 0, -1 if yDelta < 0, and 0 otherwise
+func GetMouseWheelYNormCaptured() int32 {
+
 	if mouseWheel.YDelta > 0 {
 		return 1
 	} else if mouseWheel.YDelta < 0 {
@@ -181,6 +260,15 @@ func GetMouseWheelYNorm() int32 {
 
 func KeyClicked(kc sdl.Keycode) bool {
 
+	if isKeyboardCaptured {
+		return false
+	}
+
+	return KeyClickedCaptured(kc)
+}
+
+func KeyClickedCaptured(kc sdl.Keycode) bool {
+
 	ks, ok := keyMap[kc]
 	if !ok {
 		return false
@@ -191,6 +279,15 @@ func KeyClicked(kc sdl.Keycode) bool {
 
 func KeyReleased(kc sdl.Keycode) bool {
 
+	if isKeyboardCaptured {
+		return false
+	}
+
+	return KeyReleasedCaptured(kc)
+}
+
+func KeyReleasedCaptured(kc sdl.Keycode) bool {
+
 	ks, ok := keyMap[kc]
 	if !ok {
 		return false
@@ -201,6 +298,15 @@ func KeyReleased(kc sdl.Keycode) bool {
 
 func KeyDown(kc sdl.Keycode) bool {
 
+	if isKeyboardCaptured {
+		return false
+	}
+
+	return KeyDownCaptured(kc)
+}
+
+func KeyDownCaptured(kc sdl.Keycode) bool {
+
 	ks, ok := keyMap[kc]
 	if !ok {
 		return false
@@ -211,6 +317,15 @@ func KeyDown(kc sdl.Keycode) bool {
 
 func KeyUp(kc sdl.Keycode) bool {
 
+	if isKeyboardCaptured {
+		return false
+	}
+
+	return KeyUpCaptured(kc)
+}
+
+func KeyUpCaptured(kc sdl.Keycode) bool {
+
 	ks, ok := keyMap[kc]
 	if !ok {
 		return true
@@ -221,6 +336,15 @@ func KeyUp(kc sdl.Keycode) bool {
 
 func MouseClicked(mb int) bool {
 
+	if isMouseCaptured {
+		return false
+	}
+
+	return MouseClickedCaptued(mb)
+}
+
+func MouseClickedCaptued(mb int) bool {
+
 	btn, ok := mouseBtnMap[mb]
 	if !ok {
 		return false
@@ -231,6 +355,15 @@ func MouseClicked(mb int) bool {
 
 func MouseDoubleClicked(mb int) bool {
 
+	if isMouseCaptured {
+		return false
+	}
+
+	return MouseDoubleClickedCaptured(mb)
+}
+
+func MouseDoubleClickedCaptured(mb int) bool {
+
 	btn, ok := mouseBtnMap[mb]
 	if !ok {
 		return false
@@ -240,6 +373,16 @@ func MouseDoubleClicked(mb int) bool {
 }
 
 func MouseReleased(mb int) bool {
+
+	if isMouseCaptured {
+		return false
+	}
+
+	return MouseReleasedCaptured(mb)
+}
+
+func MouseReleasedCaptured(mb int) bool {
+
 	btn, ok := mouseBtnMap[mb]
 	if !ok {
 		return false
@@ -250,6 +393,15 @@ func MouseReleased(mb int) bool {
 
 func MouseDown(mb int) bool {
 
+	if isMouseCaptured {
+		return false
+	}
+
+	return MouseDownCaptued(mb)
+}
+
+func MouseDownCaptued(mb int) bool {
+
 	btn, ok := mouseBtnMap[mb]
 	if !ok {
 		return false
@@ -260,6 +412,15 @@ func MouseDown(mb int) bool {
 
 func MouseUp(mb int) bool {
 
+	if isMouseCaptured {
+		return false
+	}
+
+	return MouseUpCaptured(mb)
+}
+
+func MouseUpCaptured(mb int) bool {
+
 	btn, ok := mouseBtnMap[mb]
 	if !ok {
 		return true

materials/material.go

@@ -1,61 +1,127 @@
 package materials
 
 import (
+	_ "unsafe"
+
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/assert"
+	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/logging"
 	"github.com/bloeys/nmage/shaders"
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
 
+// @TODO: This noescape magic is to avoid heap allocations done when
+// passing vectors or matrices into cgo via set uniform calls.
+//
+// But I would rather this kind of stuff is done on the gl wrapper level.
+// Should we wrap the OpenGL APIs we use ourself?
+
+var (
+	lastMatId uint32
+)
+
+type TextureSlot uint32
+
+const (
+	TextureSlot_Diffuse          TextureSlot = 0
+	TextureSlot_Specular         TextureSlot = 1
+	TextureSlot_Normal           TextureSlot = 2
+	TextureSlot_Emission         TextureSlot = 3
+	TextureSlot_Cubemap          TextureSlot = 10
+	TextureSlot_Cubemap_Array    TextureSlot = 11
+	TextureSlot_ShadowMap1       TextureSlot = 12
+	TextureSlot_ShadowMap_Array1 TextureSlot = 13
+)
+
+type MaterialSettings uint64
+
+const (
+	MaterialSettings_None        MaterialSettings = iota
+	MaterialSettings_HasModelMtx MaterialSettings = 1 << (iota - 1)
+	MaterialSettings_HasNormalMtx
+)
+
+func (ms *MaterialSettings) Set(flags MaterialSettings) {
+	*ms |= flags
+}
+
+func (ms *MaterialSettings) Remove(flags MaterialSettings) {
+	*ms &= ^flags
+}
+
+func (ms *MaterialSettings) Has(flags MaterialSettings) bool {
+	return *ms&flags == flags
+}
+
 type Material struct {
+	Id         uint32
 	Name       string
 	ShaderProg shaders.ShaderProgram
+	Settings   MaterialSettings
 
 	UnifLocs   map[string]int32
 	AttribLocs map[string]int32
 
+	// @TODO: Do this in a better way?. Perhaps something like how we do fbo attachments? Or keep it?
 	// Phong shading
 	DiffuseTex  uint32
 	SpecularTex uint32
 	NormalTex   uint32
 	EmissionTex uint32
 
+	// Shininess of specular highlights
 	Shininess float32
+
+	// Cubemaps
+	CubemapTex      uint32
+	CubemapArrayTex uint32
+
+	// Shadowmaps
+	ShadowMapTex1      uint32
+	ShadowMapTexArray1 uint32
 }
 
 func (m *Material) Bind() {
 
-	gl.UseProgram(m.ShaderProg.ID)
+	m.ShaderProg.Bind()
 
-	gl.ActiveTexture(gl.TEXTURE0)
+	gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Diffuse))
 	gl.BindTexture(gl.TEXTURE_2D, m.DiffuseTex)
 
-	gl.ActiveTexture(gl.TEXTURE1)
+	gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Specular))
 	gl.BindTexture(gl.TEXTURE_2D, m.SpecularTex)
 
-	gl.ActiveTexture(gl.TEXTURE2)
+	gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Normal))
 	gl.BindTexture(gl.TEXTURE_2D, m.NormalTex)
 
-	gl.ActiveTexture(gl.TEXTURE3)
+	gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Emission))
 	gl.BindTexture(gl.TEXTURE_2D, m.EmissionTex)
+
+	// @TODO: Have defaults for these
+	if m.CubemapTex != 0 {
+		gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Cubemap))
+		gl.BindTexture(gl.TEXTURE_CUBE_MAP, m.CubemapTex)
+	}
+
+	if m.CubemapArrayTex != 0 {
+		gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_Cubemap_Array))
+		gl.BindTexture(gl.TEXTURE_CUBE_MAP_ARRAY, m.CubemapArrayTex)
+	}
+
+	if m.ShadowMapTex1 != 0 {
+		gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_ShadowMap1))
+		gl.BindTexture(gl.TEXTURE_2D, m.ShadowMapTex1)
+	}
+
+	if m.ShadowMapTexArray1 != 0 {
+		gl.ActiveTexture(uint32(gl.TEXTURE0 + TextureSlot_ShadowMap_Array1))
+		gl.BindTexture(gl.TEXTURE_2D_ARRAY, m.ShadowMapTexArray1)
+	}
 }
 
 func (m *Material) UnBind() {
 	gl.UseProgram(0)
-
-	//TODO: Should we unbind textures here? Are these two lines needed?
-	// gl.ActiveTexture(gl.TEXTURE0)
-	// gl.BindTexture(gl.TEXTURE_2D, 0)
-
-	// gl.ActiveTexture(gl.TEXTURE1)
-	// gl.BindTexture(gl.TEXTURE_2D, 0)
-
-	// gl.ActiveTexture(gl.TEXTURE2)
-	// gl.BindTexture(gl.TEXTURE_2D, 0)
-
-	// gl.ActiveTexture(gl.TEXTURE3)
-	// gl.BindTexture(gl.TEXTURE_2D, 0)
 }
 
 func (m *Material) GetAttribLoc(attribName string) int32 {
@@ -65,7 +131,7 @@ func (m *Material) GetAttribLoc(attribName string) int32 {
 		return loc
 	}
 
-	loc = gl.GetAttribLocation(m.ShaderProg.ID, gl.Str(attribName+"\x00"))
+	loc = gl.GetAttribLocation(m.ShaderProg.Id, gl.Str(attribName+"\x00"))
 	assert.T(loc != -1, "Attribute '"+attribName+"' doesn't exist on material "+m.Name)
 	m.AttribLocs[attribName] = loc
 	return loc
@@ -78,7 +144,7 @@ func (m *Material) GetUnifLoc(uniformName string) int32 {
 		return loc
 	}
 
-	loc = gl.GetUniformLocation(m.ShaderProg.ID, gl.Str(uniformName+"\x00"))
+	loc = gl.GetUniformLocation(m.ShaderProg.Id, gl.Str(uniformName+"\x00"))
 	assert.T(loc != -1, "Uniform '"+uniformName+"' doesn't exist on material "+m.Name)
 	m.UnifLocs[uniformName] = loc
 	return loc
@@ -93,57 +159,132 @@ func (m *Material) DisableAttribute(attribName string) {
 }
 
 func (m *Material) SetUnifInt32(uniformName string, val int32) {
-	gl.ProgramUniform1i(m.ShaderProg.ID, m.GetUnifLoc(uniformName), val)
+	gl.ProgramUniform1i(m.ShaderProg.Id, m.GetUnifLoc(uniformName), val)
 }
 
 func (m *Material) SetUnifFloat32(uniformName string, val float32) {
-	gl.ProgramUniform1f(m.ShaderProg.ID, m.GetUnifLoc(uniformName), val)
+	gl.ProgramUniform1f(m.ShaderProg.Id, m.GetUnifLoc(uniformName), val)
 }
 
 func (m *Material) SetUnifVec2(uniformName string, vec2 *gglm.Vec2) {
-	gl.ProgramUniform2fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, &vec2.Data[0])
+	internalSetUnifVec2(m.ShaderProg.Id, m.GetUnifLoc(uniformName), vec2)
+}
+
+//go:noescape
+//go:linkname internalSetUnifVec2 github.com/bloeys/nmage/materials.SetUnifVec2
+func internalSetUnifVec2(shaderProgId uint32, unifLoc int32, vec2 *gglm.Vec2)
+
+func SetUnifVec2(shaderProgId uint32, unifLoc int32, vec2 *gglm.Vec2) {
+	gl.ProgramUniform2fv(shaderProgId, unifLoc, 1, &vec2.Data[0])
 }
 
 func (m *Material) SetUnifVec3(uniformName string, vec3 *gglm.Vec3) {
-	gl.ProgramUniform3fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, &vec3.Data[0])
+	internalSetUnifVec3(m.ShaderProg.Id, m.GetUnifLoc(uniformName), vec3)
+}
+
+//go:noescape
+//go:linkname internalSetUnifVec3 github.com/bloeys/nmage/materials.SetUnifVec3
+func internalSetUnifVec3(shaderProgId uint32, unifLoc int32, vec3 *gglm.Vec3)
+
+func SetUnifVec3(shaderProgId uint32, unifLoc int32, vec3 *gglm.Vec3) {
+	gl.ProgramUniform3fv(shaderProgId, unifLoc, 1, &vec3.Data[0])
 }
 
 func (m *Material) SetUnifVec4(uniformName string, vec4 *gglm.Vec4) {
-	gl.ProgramUniform4fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, &vec4.Data[0])
+	internalSetUnifVec4(m.ShaderProg.Id, m.GetUnifLoc(uniformName), vec4)
+}
+
+//go:noescape
+//go:linkname internalSetUnifVec4 github.com/bloeys/nmage/materials.SetUnifVec4
+func internalSetUnifVec4(shaderProgId uint32, unifLoc int32, vec4 *gglm.Vec4)
+
+func SetUnifVec4(shaderProgId uint32, unifLoc int32, vec4 *gglm.Vec4) {
+	gl.ProgramUniform4fv(shaderProgId, unifLoc, 1, &vec4.Data[0])
 }
 
 func (m *Material) SetUnifMat2(uniformName string, mat2 *gglm.Mat2) {
-	gl.ProgramUniformMatrix2fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, false, &mat2.Data[0][0])
+	internalSetUnifMat2(m.ShaderProg.Id, m.GetUnifLoc(uniformName), mat2)
+}
+
+//go:noescape
+//go:linkname internalSetUnifMat2 github.com/bloeys/nmage/materials.SetUnifMat2
+func internalSetUnifMat2(shaderProgId uint32, unifLoc int32, mat2 *gglm.Mat2)
+
+func SetUnifMat2(shaderProgId uint32, unifLoc int32, mat2 *gglm.Mat2) {
+	gl.ProgramUniformMatrix2fv(shaderProgId, unifLoc, 1, false, &mat2.Data[0][0])
 }
 
 func (m *Material) SetUnifMat3(uniformName string, mat3 *gglm.Mat3) {
-	gl.ProgramUniformMatrix3fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, false, &mat3.Data[0][0])
+	internalSetUnifMat3(m.ShaderProg.Id, m.GetUnifLoc(uniformName), mat3)
+}
+
+//go:noescape
+//go:linkname internalSetUnifMat3 github.com/bloeys/nmage/materials.SetUnifMat3
+func internalSetUnifMat3(shaderProgId uint32, unifLoc int32, mat3 *gglm.Mat3)
+
+func SetUnifMat3(shaderProgId uint32, unifLoc int32, mat3 *gglm.Mat3) {
+	gl.ProgramUniformMatrix3fv(shaderProgId, unifLoc, 1, false, &mat3.Data[0][0])
 }
 
 func (m *Material) SetUnifMat4(uniformName string, mat4 *gglm.Mat4) {
-	gl.ProgramUniformMatrix4fv(m.ShaderProg.ID, m.GetUnifLoc(uniformName), 1, false, &mat4.Data[0][0])
+	internalSetUnifMat4(m.ShaderProg.Id, m.GetUnifLoc(uniformName), mat4)
+}
+
+//go:noescape
+//go:linkname internalSetUnifMat4 github.com/bloeys/nmage/materials.SetUnifMat4
+func internalSetUnifMat4(shaderProgId uint32, unifLoc int32, mat4 *gglm.Mat4)
+
+func SetUnifMat4(shaderProgId uint32, unifLoc int32, mat4 *gglm.Mat4) {
+	gl.ProgramUniformMatrix4fv(shaderProgId, unifLoc, 1, false, &mat4.Data[0][0])
 }
 
 func (m *Material) Delete() {
-	gl.DeleteProgram(m.ShaderProg.ID)
+	gl.DeleteProgram(m.ShaderProg.Id)
 }
 
-func NewMaterial(matName, shaderPath string) *Material {
+func getNewMatId() uint32 {
+	lastMatId++
+	return lastMatId
+}
+
+func NewMaterial(matName, shaderPath string) Material {
 
 	shdrProg, err := shaders.LoadAndCompileCombinedShader(shaderPath)
 	if err != nil {
-		logging.ErrLog.Fatalln("Failed to create new material. Err: ", err)
+		logging.ErrLog.Fatalf("Failed to create new material '%s'. Err: %s\n", matName, err.Error())
 	}
 
-	return &Material{Name: matName, ShaderProg: shdrProg, UnifLocs: make(map[string]int32), AttribLocs: make(map[string]int32)}
+	return Material{
+		Id:         getNewMatId(),
+		Name:       matName,
+		ShaderProg: shdrProg,
+		UnifLocs:   make(map[string]int32),
+		AttribLocs: make(map[string]int32),
+
+		DiffuseTex:  assets.DefaultDiffuseTexId.TexID,
+		SpecularTex: assets.DefaultSpecularTexId.TexID,
+		NormalTex:   assets.DefaultNormalTexId.TexID,
+		EmissionTex: assets.DefaultEmissionTexId.TexID,
+	}
 }
 
-func NewMaterialSrc(matName string, shaderSrc []byte) *Material {
+func NewMaterialSrc(matName string, shaderSrc []byte) Material {
 
 	shdrProg, err := shaders.LoadAndCompileCombinedShaderSrc(shaderSrc)
 	if err != nil {
-		logging.ErrLog.Fatalln("Failed to create new material. Err: ", err)
+		logging.ErrLog.Fatalf("Failed to create new material '%s'. Err: %s\n", matName, err.Error())
 	}
 
-	return &Material{Name: matName, ShaderProg: shdrProg, UnifLocs: make(map[string]int32), AttribLocs: make(map[string]int32)}
+	return Material{
+		Id:         getNewMatId(),
+		Name:       matName,
+		ShaderProg: shdrProg,
+		UnifLocs:   make(map[string]int32),
+		AttribLocs: make(map[string]int32),
+
+		DiffuseTex:  assets.DefaultDiffuseTexId.TexID,
+		SpecularTex: assets.DefaultSpecularTexId.TexID,
+		NormalTex:   assets.DefaultNormalTexId.TexID,
+		EmissionTex: assets.DefaultEmissionTexId.TexID,
+	}
 }

meshes/mesh.go

@@ -16,24 +16,48 @@ type SubMesh struct {
 }
 
 type Mesh struct {
-	Name      string
+	Name string
+	/*
+		Vao has the following shader attribute layout:
+			- Loc0: Pos
+			- Loc1: Normal
+			- Loc2: UV0
+			- Loc3: Tangent
+			- (Optional) Color
+
+		Optional stuff appear in the order in this list, depending on what other optional stuff exists.
+
+		For example:
+			- If color exists it will be in Loc3, otherwise it is unset
+	*/
 	Vao       buffers.VertexArray
 	SubMeshes []SubMesh
 }
 
-func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh, error) {
+var (
+	// DefaultMeshLoadFlags are the flags always applied when loading a new mesh regardless
+	// of what post process flags are used when loading a mesh.
+	//
+	// Defaults to: asig.PostProcessTriangulate | asig.PostProcessCalcTangentSpace;
+	// Note: changing this will break the normal lit shaders, which expect tangents to be there
+	DefaultMeshLoadFlags asig.PostProcess = asig.PostProcessTriangulate | asig.PostProcessCalcTangentSpace
+)
 
-	scene, release, err := asig.ImportFile(modelPath, asig.PostProcessTriangulate|postProcessFlags)
+func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (Mesh, error) {
+
+	finalPostProcessFlags := DefaultMeshLoadFlags | postProcessFlags
+
+	scene, release, err := asig.ImportFile(modelPath, finalPostProcessFlags)
 	if err != nil {
-		return nil, errors.New("Failed to load model. Err: " + err.Error())
+		return Mesh{}, errors.New("Failed to load model. Err: " + err.Error())
 	}
 	defer release()
 
 	if len(scene.Meshes) == 0 {
-		return nil, errors.New("No meshes found in file: " + modelPath)
+		return Mesh{}, errors.New("No meshes found in file: " + modelPath)
 	}
 
-	mesh := &Mesh{
+	mesh := Mesh{
 		Name:      name,
 		Vao:       buffers.NewVertexArray(),
 		SubMeshes: make([]SubMesh, 0, 1),
@@ -42,8 +66,17 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 	vbo := buffers.NewVertexBuffer()
 	ibo := buffers.NewIndexBuffer()
 
-	// Initial sizes assuming one submesh that has vertex pos+normals+texCoords, and 3 indices per face
-	var vertexBufData []float32 = make([]float32, 0, len(scene.Meshes[0].Vertices)*3*3*2)
+	// Estimate a useful prealloc capacity based on the first submesh that has vertex pos+normals+tangents+texCoords
+	vertexBufDataCapacity := len(scene.Meshes[0].Vertices) * 3 * 3 * 3 * 2
+
+	// Increase capacity depending on what the mesh has
+	if len(scene.Meshes[0].ColorSets) > 0 && len(scene.Meshes[0].ColorSets[0]) > 0 {
+		vertexBufDataCapacity *= 4
+	}
+
+	var vertexBufData []float32 = make([]float32, 0, vertexBufDataCapacity)
+
+	// Initial size assumes 3 indices per face
 	var indexBufData []uint32 = make([]uint32, 0, len(scene.Meshes[0].Faces)*3)
 
 	// fmt.Printf("\nMesh %s has %d meshe(s) with first mesh having %d vertices\n", name, len(scene.Meshes), len(scene.Meshes[0].Vertices))
@@ -52,12 +85,25 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 
 		sceneMesh := scene.Meshes[i]
 
+		// We always want tangents and UV0
+		if len(sceneMesh.Tangents) == 0 {
+			sceneMesh.Tangents = make([]gglm.Vec3, len(sceneMesh.Vertices))
+		}
+
 		if len(sceneMesh.TexCoords[0]) == 0 {
 			sceneMesh.TexCoords[0] = make([]gglm.Vec3, len(sceneMesh.Vertices))
 		}
 
-		layoutToUse := []buffers.Element{{ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec2}}
-		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
+		hasColorSet0 := len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0
+
+		layoutToUse := []buffers.Element{
+			{ElementType: buffers.DataTypeVec3}, // Position
+			{ElementType: buffers.DataTypeVec3}, // Normals
+			{ElementType: buffers.DataTypeVec3}, // Tangents
+			{ElementType: buffers.DataTypeVec2}, // UV0
+		}
+
+		if hasColorSet0 {
 			layoutToUse = append(layoutToUse, buffers.Element{ElementType: buffers.DataTypeVec4})
 		}
 
@@ -79,8 +125,14 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 			}
 		}
 
-		arrs := []arrToInterleave{{V3s: sceneMesh.Vertices}, {V3s: sceneMesh.Normals}, {V2s: v3sToV2s(sceneMesh.TexCoords[0])}}
-		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
+		arrs := []arrToInterleave{
+			{V3s: sceneMesh.Vertices},
+			{V3s: sceneMesh.Normals},
+			{V3s: sceneMesh.Tangents},
+			{V2s: v3sToV2s(sceneMesh.TexCoords[0])},
+		}
+
+		if hasColorSet0 {
 			arrs = append(arrs, arrToInterleave{V4s: sceneMesh.ColorSets[0]})
 		}
 

renderer/rend3dgl/rend3dgl.go

@@ -2,6 +2,7 @@ package rend3dgl
 
 import (
 	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/buffers"
 	"github.com/bloeys/nmage/materials"
 	"github.com/bloeys/nmage/meshes"
 	"github.com/bloeys/nmage/renderer"
@@ -11,23 +12,63 @@ import (
 var _ renderer.Render = &Rend3DGL{}
 
 type Rend3DGL struct {
-	BoundMesh *meshes.Mesh
-	BoundMat  *materials.Material
+	BoundVaoId     uint32
+	BoundMatId     uint32
+	BoundMeshVaoId uint32
 }
 
-func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material) {
+func (r *Rend3DGL) DrawMesh(mesh *meshes.Mesh, modelMat *gglm.TrMat, mat *materials.Material) {
 
-	if mesh != r3d.BoundMesh {
+	if mesh.Vao.Id != r.BoundMeshVaoId {
 		mesh.Vao.Bind()
-		r3d.BoundMesh = mesh
+		r.BoundMeshVaoId = mesh.Vao.Id
 	}
 
-	if mat != r3d.BoundMat {
+	if mat.Id != r.BoundMatId {
 		mat.Bind()
-		r3d.BoundMat = mat
+		r.BoundMatId = mat.Id
 	}
 
-	mat.SetUnifMat4("modelMat", &trMat.Mat4)
+	if mat.Settings.Has(materials.MaterialSettings_HasModelMtx) {
+		mat.SetUnifMat4("modelMat", &modelMat.Mat4)
+	}
+
+	if mat.Settings.Has(materials.MaterialSettings_HasNormalMtx) {
+		normalMat := modelMat.Clone().InvertAndTranspose().ToMat3()
+		mat.SetUnifMat3("normalMat", &normalMat)
+	}
+
+	for i := 0; i < len(mesh.SubMeshes); i++ {
+		gl.DrawElementsBaseVertexWithOffset(gl.TRIANGLES, mesh.SubMeshes[i].IndexCount, gl.UNSIGNED_INT, uintptr(mesh.SubMeshes[i].BaseIndex), mesh.SubMeshes[i].BaseVertex)
+	}
+}
+
+func (r *Rend3DGL) DrawVertexArray(mat *materials.Material, vao *buffers.VertexArray, firstElement int32, elementCount int32) {
+
+	if vao.Id != r.BoundVaoId {
+		vao.Bind()
+		r.BoundVaoId = vao.Id
+	}
+
+	if mat.Id != r.BoundMatId {
+		mat.Bind()
+		r.BoundMatId = mat.Id
+	}
+
+	gl.DrawArrays(gl.TRIANGLES, firstElement, elementCount)
+}
+
+func (r *Rend3DGL) DrawCubemap(mesh *meshes.Mesh, mat *materials.Material) {
+
+	if mesh.Vao.Id != r.BoundMeshVaoId {
+		mesh.Vao.Bind()
+		r.BoundMeshVaoId = mesh.Vao.Id
+	}
+
+	if mat.Id != r.BoundMatId {
+		mat.Bind()
+		r.BoundMatId = mat.Id
+	}
 
 	for i := 0; i < len(mesh.SubMeshes); i++ {
 		gl.DrawElementsBaseVertexWithOffset(gl.TRIANGLES, mesh.SubMeshes[i].IndexCount, gl.UNSIGNED_INT, uintptr(mesh.SubMeshes[i].BaseIndex), mesh.SubMeshes[i].BaseVertex)
@@ -35,8 +76,9 @@ func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.M
 }
 
 func (r3d *Rend3DGL) FrameEnd() {
-	r3d.BoundMesh = nil
-	r3d.BoundMat = nil
+	r3d.BoundVaoId = 0
+	r3d.BoundMatId = 0
+	r3d.BoundMeshVaoId = 0
 }
 
 func NewRend3DGL() *Rend3DGL {

renderer/renderer.go

@@ -2,11 +2,14 @@ package renderer
 
 import (
 	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/buffers"
 	"github.com/bloeys/nmage/materials"
 	"github.com/bloeys/nmage/meshes"
 )
 
 type Render interface {
-	Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material)
+	DrawMesh(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material)
+	DrawVertexArray(mat *materials.Material, vao *buffers.VertexArray, firstElement int32, count int32)
+	DrawCubemap(mesh *meshes.Mesh, mat *materials.Material)
 	FrameEnd()
 }

res/shaders/array-depth-map.glsl

@@ -0,0 +1,54 @@
+//shader:vertex
+#version 410
+
+layout(location=0) in vec3 vertPosIn;
+
+uniform mat4 modelMat;
+
+void main()
+{
+    gl_Position = modelMat * vec4(vertPosIn, 1);
+}
+
+//shader:geometry
+#version 410
+
+layout (triangles) in;
+
+#define NUM_PROJ_VIEW_MATS 4
+
+// 3 * NUM_PROJ_VIEW_MATS
+layout (triangle_strip, max_vertices=12) out;
+
+// This is the same number as max spot lights or whatever else is being rendered
+uniform mat4 projViewMats[NUM_PROJ_VIEW_MATS];
+
+out vec4 FragPos;
+
+void main()
+{
+    for(int projViewMatIndex = 0; projViewMatIndex < NUM_PROJ_VIEW_MATS; projViewMatIndex++){
+
+        gl_Layer = projViewMatIndex;
+        mat4 projViewMat = projViewMats[projViewMatIndex];
+
+        for(int i = 0; i < 3; i++)
+        {
+            FragPos = gl_in[i].gl_Position;
+            gl_Position = projViewMat * FragPos;
+            EmitVertex();
+        }
+        EndPrimitive();
+    }
+}
+
+//shader:fragment
+#version 410
+
+in vec4 FragPos;
+
+void main()
+{
+    // This implicitly writes to the depth buffer with no color operations
+    // Equivalent: gl_FragDepth = gl_FragCoord.z;
+}

res/shaders/debug-depth.glsl

@@ -2,35 +2,32 @@
 #version 410
 
 layout(location=0) in vec3 vertPosIn;
-layout(location=1) in vec3 vertNormalIn;
-layout(location=2) in vec2 vertUV0In;
-layout(location=3) in vec3 vertColorIn;
+layout(location=2) in vec3 vertTangentIn;
+layout(location=3) in vec2 vertUV0In;
+layout(location=4) in vec3 vertColorIn;
 
-out vec3 vertNormal;
 out vec2 vertUV0;
 out vec3 vertColor;
 out vec3 fragPos;
 
-//MVP = Model View Projection
 uniform mat4 modelMat;
-uniform mat4 viewMat;
-uniform mat4 projMat;
+uniform mat4 projViewMat;
 
 void main()
 {
-    vertNormal = mat3(transpose(inverse(modelMat))) * vertNormalIn;
     vertUV0 = vertUV0In;
     vertColor = vertColorIn;
-    fragPos = vec3(modelMat * vec4(vertPosIn, 1.0));
 
-    gl_Position = projMat * viewMat * modelMat * vec4(vertPosIn, 1.0);
+    vec4 modelVert = modelMat * vec4(vertPosIn, 1);
+    fragPos = modelVert.xyz;
+
+    gl_Position = projViewMat * modelVert;
 }
 
 //shader:fragment
 #version 410
 
 in vec3 vertColor;
-in vec3 vertNormal;
 in vec2 vertUV0;
 in vec3 fragPos;
 

res/shaders/depth-map.glsl

@@ -0,0 +1,21 @@
+//shader:vertex
+#version 410
+
+layout(location=0) in vec3 vertPosIn;
+
+uniform mat4 modelMat;
+uniform mat4 projViewMat;
+
+void main()
+{
+    gl_Position = projViewMat * modelMat * vec4(vertPosIn, 1);
+}
+
+//shader:fragment
+#version 410
+
+void main()
+{
+    // This implicitly writes to the depth buffer with no color operations
+    // Equivalent: gl_FragDepth = gl_FragCoord.z;
+}

res/shaders/omnidirectional-depth-map.glsl

@@ -0,0 +1,65 @@
+//shader:vertex
+#version 410
+
+layout(location=0) in vec3 vertPosIn;
+
+uniform mat4 modelMat;
+
+void main()
+{
+    gl_Position = modelMat * vec4(vertPosIn, 1);
+}
+
+//shader:geometry
+#version 410
+
+layout (triangles) in;
+
+// Cubemap means 6 faces, and the
+// input 3 triangle vertices are drawn once per face, so 6*3=18
+layout (triangle_strip, max_vertices=18) out;
+
+uniform int cubemapIndex;
+uniform mat4 cubemapProjViewMats[6];
+
+out vec4 FragPos;
+
+void main()
+{
+    for(int face = 0; face < 6; ++face)
+    {
+        // Built in variable that specifies which cubemap face we are rendering to
+        // and only works when a cubemap is attached to the active fbo.
+        //
+        // We use an additional index here because our fbo has a cubemap array
+        gl_Layer = (cubemapIndex * 6) + face;
+
+        // Transform each triangle vertex
+        for(int i = 0; i < 3; ++i)
+        {
+            FragPos = gl_in[i].gl_Position;
+            gl_Position = cubemapProjViewMats[face] * FragPos;
+            EmitVertex();
+        }
+        EndPrimitive();
+    }
+}
+
+//shader:fragment
+#version 410
+
+in vec4 FragPos;
+
+uniform vec3 lightPos;
+uniform float farPlane;
+
+void main()
+{
+    // Get distance between fragment and light source
+    float lightDistance = length(FragPos.xyz - lightPos);
+
+    // Map to [0, 1] by dividing by far plane and use it as our depth
+    lightDistance = lightDistance / farPlane;
+
+    gl_FragDepth = lightDistance;
+}

res/shaders/simple-unlit.glsl

@@ -3,32 +3,25 @@
 
 layout(location=0) in vec3 vertPosIn;
 layout(location=1) in vec3 vertNormalIn;
-layout(location=2) in vec2 vertUV0In;
-layout(location=3) in vec3 vertColorIn;
+layout(location=2) in vec3 vertTangentIn;
+layout(location=3) in vec2 vertUV0In;
+layout(location=4) in vec3 vertColorIn;
 
-out vec3 vertNormal;
 out vec2 vertUV0;
 out vec3 vertColor;
 out vec3 fragPos;
 
-//MVP = Model View Projection
 uniform mat4 modelMat;
-uniform mat4 viewMat;
-uniform mat4 projMat;
+uniform mat4 projViewMat;
 
 void main()
 {
-    // @TODO: Calculate this on the CPU and send it as a uniform
-
-    // This produces the normal matrix that multiplies with the model normal to produce the
-    // world space normal. Based on 'One last thing' section from: https://learnopengl.com/Lighting/Basic-Lighting
-    vertNormal = mat3(transpose(inverse(modelMat))) * vertNormalIn;
-    
     vertUV0 = vertUV0In;
     vertColor = vertColorIn;
-    fragPos = vec3(modelMat * vec4(vertPosIn, 1.0));
 
-    gl_Position = projMat * viewMat * modelMat * vec4(vertPosIn, 1.0);
+    vec4 modelVert = modelMat * vec4(vertPosIn, 1);
+    fragPos = modelVert.xyz;
+    gl_Position = projViewMat * modelVert;
 }
 
 //shader:fragment
@@ -41,7 +34,6 @@ struct Material {
 uniform Material material;
 
 in vec3 vertColor;
-in vec3 vertNormal;
 in vec2 vertUV0;
 in vec3 fragPos;
 

res/shaders/simple.glsl

@@ -1,55 +1,34 @@
 //shader:vertex
 #version 410
 
+#define NUM_SPOT_LIGHTS 4
+#define NUM_POINT_LIGHTS 8
+
+//
+// Inputs
+//
 layout(location=0) in vec3 vertPosIn;
 layout(location=1) in vec3 vertNormalIn;
-layout(location=2) in vec2 vertUV0In;
-layout(location=3) in vec3 vertColorIn;
+layout(location=2) in vec3 vertTangentIn;
+layout(location=3) in vec2 vertUV0In;
+layout(location=4) in vec3 vertColorIn;
 
-out vec3 vertNormal;
-out vec2 vertUV0;
-out vec3 vertColor;
-out vec3 fragPos;
-
-//MVP = Model View Projection
+//
+// Uniforms
+//
+uniform vec3 camPos;
 uniform mat4 modelMat;
-uniform mat4 viewMat;
-uniform mat4 projMat;
-
-void main()
-{
-    // @TODO: Calculate this on the CPU and send it as a uniform
-
-    // This produces the normal matrix that multiplies with the model normal to produce the
-    // world space normal. Based on 'One last thing' section from: https://learnopengl.com/Lighting/Basic-Lighting
-    vertNormal = mat3(transpose(inverse(modelMat))) * vertNormalIn;
-    
-    vertUV0 = vertUV0In;
-    vertColor = vertColorIn;
-    fragPos = vec3(modelMat * vec4(vertPosIn, 1.0));
-
-    gl_Position = projMat * viewMat * modelMat * vec4(vertPosIn, 1.0);
-}
-
-//shader:fragment
-#version 410
-
-struct Material {
-    sampler2D diffuse;
-    sampler2D specular;
-    // sampler2D normal;
-    sampler2D emission;
-    float shininess;
-};
-
-uniform Material material;
+uniform mat3 normalMat;
+uniform mat4 projViewMat;
+uniform mat4 dirLightProjViewMat;
+uniform mat4 spotLightProjViewMats[NUM_SPOT_LIGHTS];
 
 struct DirLight {
     vec3 dir;
     vec3 diffuseColor;
     vec3 specularColor;
+    sampler2D shadowMap;
 };
-
 uniform DirLight dirLight;
 
 struct PointLight {
@@ -59,9 +38,8 @@ struct PointLight {
     float constant;
     float linear;
     float quadratic;
+    float farPlane;
 };
-
-#define NUM_POINT_LIGHTS 16
 uniform PointLight pointLights[NUM_POINT_LIGHTS];
 
 struct SpotLight {
@@ -72,81 +50,311 @@ struct SpotLight {
     float innerCutoff;
     float outerCutoff;
 };
-
-#define NUM_SPOT_LIGHTS 4
 uniform SpotLight spotLights[NUM_SPOT_LIGHTS];
 
-uniform vec3 camPos;
+//
+// Outputs
+//
+out vec2 vertUV0;
+out vec3 vertColor;
+
+out vec3 fragPos;
+out vec3 fragPosDirLight;
+out vec4 fragPosSpotLight[NUM_SPOT_LIGHTS];
+
+out vec3 tangentCamPos;
+out vec3 tangentFragPos;
+out vec3 tangentDirLightDir;
+out vec3 tangentSpotLightPositions[NUM_SPOT_LIGHTS];
+out vec3 tangentSpotLightDirections[NUM_SPOT_LIGHTS];
+out vec3 tangentPointLightPositions[NUM_POINT_LIGHTS];
+
+void main()
+{
+    vertUV0 = vertUV0In;
+    vertColor = vertColorIn;
+    vec4 modelVert = modelMat * vec4(vertPosIn, 1);
+
+    // Tangent-BiTangent-Normal matrix for normal mapping
+    vec3 T = normalize(vec3(modelMat * vec4(vertTangentIn,   0.0)));
+    vec3 N = normalize(vec3(modelMat * vec4(vertNormalIn,    0.0)));
+
+    // Ensure T is orthogonal with respect to N
+    T = normalize(T - dot(T, N) * N);
+
+    vec3 B = cross(N, T);
+    mat3 tbnMtx = transpose(mat3(T, B, N));
+
+    // Lighting related
+    fragPos = modelVert.xyz;
+    fragPosDirLight = vec3(dirLightProjViewMat * vec4(fragPos, 1));
+
+    tangentCamPos = tbnMtx * camPos;
+    tangentFragPos = tbnMtx * fragPos;
+    tangentDirLightDir = tbnMtx * dirLight.dir;
+
+    for (int i = 0; i < NUM_POINT_LIGHTS; i++)
+        tangentPointLightPositions[i] = tbnMtx * pointLights[i].pos;
+
+    for (int i = 0; i < NUM_SPOT_LIGHTS; i++)
+    {
+        fragPosSpotLight[i] = spotLightProjViewMats[i] * vec4(fragPos, 1);
+
+        tangentSpotLightPositions[i] = tbnMtx * spotLights[i].pos;
+        tangentSpotLightDirections[i] = tbnMtx * spotLights[i].dir;
+    }
+
+    gl_Position = projViewMat * modelVert;
+}
+
+//shader:fragment
+#version 410
+
+/*
+    Note that while all lighting calculations are done in tangent space,
+    shadow mapping is done in world space.
+
+    The exception is the bias calculation. Since the bias relies on the normal
+    and the normal is in tangent space, we use a tangent space fragment position
+    with it, but the rest of shadow processing is in world space.
+*/
+
+#define NUM_SPOT_LIGHTS 4
+#define NUM_POINT_LIGHTS 8
+
+//
+// Inputs
+//
+in vec3 fragPos;
+in vec2 vertUV0;
+in vec3 vertColor;
+in vec3 fragPosDirLight;
+in vec4 fragPosSpotLight[NUM_SPOT_LIGHTS];
+
+in vec3 tangentCamPos;
+in vec3 tangentFragPos;
+in vec3 tangentDirLightDir;
+in vec3 tangentSpotLightPositions[NUM_SPOT_LIGHTS];
+in vec3 tangentSpotLightDirections[NUM_SPOT_LIGHTS];
+in vec3 tangentPointLightPositions[NUM_POINT_LIGHTS];
+
+//
+// Uniforms
+//
+struct Material {
+    sampler2D diffuse;
+    sampler2D specular;
+    sampler2D normal;
+    sampler2D emission;
+    float shininess;
+};
+uniform Material material;
+
+struct DirLight {
+    vec3 dir;
+    vec3 diffuseColor;
+    vec3 specularColor;
+    sampler2D shadowMap;
+};
+uniform DirLight dirLight;
+
+struct PointLight {
+    vec3 pos;
+    vec3 diffuseColor;
+    vec3 specularColor;
+    float constant;
+    float linear;
+    float quadratic;
+    float farPlane;
+};
+uniform PointLight pointLights[NUM_POINT_LIGHTS];
+uniform samplerCubeArray pointLightCubeShadowMaps;
+
+struct SpotLight {
+    vec3 pos;
+    vec3 dir;
+    vec3 diffuseColor;
+    vec3 specularColor;
+    float innerCutoff;
+    float outerCutoff;
+};
+uniform SpotLight spotLights[NUM_SPOT_LIGHTS];
+uniform sampler2DArray spotLightShadowMaps;
+
 uniform vec3 ambientColor = vec3(0.2, 0.2, 0.2);
 
-in vec3 vertColor;
-in vec3 vertNormal;
-in vec2 vertUV0;
-in vec3 fragPos;
-
+//
+// Outputs
+//
 out vec4 fragColor;
 
+//
 // Global variables used as cache for lighting calculations
+//
+vec3 tangentViewDir;
 vec4 diffuseTexColor;
 vec4 specularTexColor;
 vec4 emissionTexColor;
 vec3 normalizedVertNorm;
-vec3 viewDir;
+
+float CalcDirShadow(sampler2D shadowMap, vec3 tangentLightDir)
+{
+    // Move from [-1,1] to [0, 1]
+    vec3 projCoords = fragPosDirLight * 0.5 + 0.5;
+
+    // If sampling outside the depth texture then force 'no shadow'
+    if(projCoords.z > 1)
+        return 0;
+
+    // currentDepth is the fragment depth from the light's perspective
+    float currentDepth = projCoords.z;
+
+    // Bias in the range [0.005, 0.05] depending on the angle, where a higher
+    // angle gives a higher bias, as shadow acne gets worse with angle
+    float bias = max(0.05 * (1 - dot(normalizedVertNorm, tangentLightDir)), 0.005);
+
+    // 'Percentage Close Filtering'.
+    // Basically get soft shadows by averaging this texel and surrounding ones
+    float shadow = 0;
+    vec2 texelSize = 1 / textureSize(shadowMap, 0);
+    for(int x = -1; x <= 1; x++)
+    {
+        for(int y = -1; y <= 1; y++)
+        {
+            float pcfDepth = texture(shadowMap, projCoords.xy + vec2(x, y) * texelSize).r; 
+
+            // If our depth is larger than the lights closest depth at the texel we checked (projCoords),
+            // then there is something closer to the light than us, and so we are in shadow
+            shadow += currentDepth - bias > pcfDepth ? 1 : 0;
+        }
+    }
+
+    shadow /= 9;
+
+    return shadow;
+}
 
 vec3 CalcDirLight()
 {
-    vec3 lightDir = normalize(-dirLight.dir);
+    vec3 lightDir = normalize(-tangentDirLightDir);
 
     // Diffuse
     float diffuseAmount = max(0.0, dot(normalizedVertNorm, lightDir));
     vec3 finalDiffuse = diffuseAmount * dirLight.diffuseColor * diffuseTexColor.rgb;
 
     // Specular
-    vec3 halfwayDir = normalize(lightDir + viewDir);
+    vec3 halfwayDir = normalize(lightDir + tangentViewDir);
     float specularAmount = pow(max(dot(normalizedVertNorm, halfwayDir), 0.0), material.shininess);
     vec3 finalSpecular = specularAmount * dirLight.specularColor * specularTexColor.rgb;
 
-    return finalDiffuse + finalSpecular;
+    // Shadow
+    float shadow = CalcDirShadow(dirLight.shadowMap, lightDir);
+
+    return (finalDiffuse + finalSpecular) * (1 - shadow);
 }
 
-vec3 CalcPointLight(PointLight pointLight)
+float CalcPointShadow(int lightIndex, vec3 worldLightPos, vec3 tangentLightDir, float farPlane) {
+
+    vec3 lightToFrag = fragPos - worldLightPos;
+
+    float closestDepth = texture(pointLightCubeShadowMaps, vec4(lightToFrag, lightIndex)).r;
+
+    // We stored depth in the cubemap in the range [0, 1], so now we move back to [0, farPlane]
+    closestDepth *= farPlane;
+
+    // Get depth of current fragment
+    float currentDepth = length(lightToFrag);
+
+    float bias = max(0.05 * (1 - dot(normalizedVertNorm, tangentLightDir)), 0.005);
+
+    float shadow = currentDepth -  bias > closestDepth ? 1.0 : 0.0;
+
+    return shadow;
+}
+
+vec3 CalcPointLight(PointLight pointLight, int lightIndex)
 {
     // Ignore unset lights
     if (pointLight.constant == 0){
         return vec3(0);
     }
 
-    vec3 lightDir = normalize(pointLight.pos - fragPos);
+    vec3 tangentLightPos = tangentPointLightPositions[lightIndex];
+    vec3 tangentLightDir = normalize(tangentLightPos - tangentFragPos);
 
     // Diffuse
-    float diffuseAmount = max(0.0, dot(normalizedVertNorm, lightDir));
+    float diffuseAmount = max(0.0, dot(normalizedVertNorm, tangentLightDir));
     vec3 finalDiffuse = diffuseAmount * pointLight.diffuseColor * diffuseTexColor.rgb;
 
     // Specular
-    vec3 halfwayDir = normalize(lightDir + viewDir);
+    vec3 halfwayDir = normalize(tangentLightDir + tangentViewDir);
     float specularAmount = pow(max(dot(normalizedVertNorm, halfwayDir), 0.0), material.shininess);
     vec3 finalSpecular = specularAmount * pointLight.specularColor * specularTexColor.rgb;
 
-    // attenuation
-    float distToLight = length(pointLight.pos - fragPos);
-    float attenuation = 1.0 / (pointLight.constant + pointLight.linear * distToLight + pointLight.quadratic * (distToLight * distToLight));  
+    // Attenuation
+    float distToLight = length(tangentLightPos - tangentFragPos);
+    float attenuation = 1 / (pointLight.constant + pointLight.linear * distToLight + pointLight.quadratic * (distToLight * distToLight));  
 
-    return (finalDiffuse + finalSpecular) * attenuation;
+    // Shadow
+    float shadow = CalcPointShadow(lightIndex, pointLight.pos, tangentLightDir, pointLight.farPlane);
+
+    return (finalDiffuse + finalSpecular) * attenuation * (1 - shadow);
 }
 
-vec3 CalcSpotLight(SpotLight light)
+float CalcSpotShadow(vec3 tangentLightDir, int lightIndex)
+{
+    // Move from clip space to NDC
+    vec3 projCoords = fragPosSpotLight[lightIndex].xyz / fragPosSpotLight[lightIndex].w;
+
+    // Move from [-1,1] to [0, 1]
+    projCoords = projCoords * 0.5 + 0.5;
+
+    // If sampling outside the depth texture then force 'no shadow'
+    if(projCoords.z > 1)
+        return 0;
+
+    // currentDepth is the fragment depth from the light's perspective
+    float currentDepth = projCoords.z;
+
+    // Bias in the range [0.005, 0.05] depending on the angle, where a higher
+    // angle gives a higher bias, as shadow acne gets worse with angle
+    float bias = max(0.05 * (1 - dot(normalizedVertNorm, tangentLightDir)), 0.005);
+
+    // 'Percentage Close Filtering'.
+    // Basically get soft shadows by averaging this texel and surrounding ones
+    float shadow = 0;
+    vec2 texelSize = 1 / textureSize(spotLightShadowMaps, 0).xy;
+    for(int x = -1; x <= 1; x++)
+    {
+        for(int y = -1; y <= 1; y++)
+        {
+            float pcfDepth = texture(spotLightShadowMaps, vec3(projCoords.xy + vec2(x, y) * texelSize, lightIndex)).r; 
+
+            // If our depth is larger than the lights closest depth at the texel we checked (projCoords),
+            // then there is something closer to the light than us, and so we are in shadow
+            shadow += currentDepth - bias > pcfDepth ? 1 : 0;
+        }
+    }
+
+    shadow /= 9;
+
+    return shadow;
+}
+
+vec3 CalcSpotLight(SpotLight light, int lightIndex)
 {
     if (light.innerCutoff == 0)
         return vec3(0);
 
-    vec3 fragToLightDir = normalize(light.pos - fragPos);
+    vec3 tangentLightDir = tangentSpotLightDirections[lightIndex];
+    vec3 fragToLightDir = normalize(tangentSpotLightPositions[lightIndex] - tangentFragPos);
 
     // Spot light cone with full intensity within inner cutoff,
     // and falloff between inner-outer cutoffs, and zero
     // light after outer cutoff
-    float theta = dot(fragToLightDir, normalize(-light.dir));
+    float theta = dot(fragToLightDir, normalize(-tangentLightDir));
     float epsilon = (light.innerCutoff - light.outerCutoff);
-    float intensity = clamp((theta - light.outerCutoff) / epsilon, 0.0, 1.0);
+    float intensity = clamp((theta - light.outerCutoff) / epsilon, float(0), float(1));
 
     if (intensity == 0)
         return vec3(0);
@@ -156,38 +364,52 @@ vec3 CalcSpotLight(SpotLight light)
     vec3 finalDiffuse = diffuseAmount * light.diffuseColor * diffuseTexColor.rgb;
 
     // Specular
-    vec3 halfwayDir = normalize(fragToLightDir + viewDir);
+    vec3 halfwayDir = normalize(fragToLightDir + tangentViewDir);
     float specularAmount = pow(max(dot(normalizedVertNorm, halfwayDir), 0.0), material.shininess);
     vec3 finalSpecular = specularAmount * light.specularColor * specularTexColor.rgb;
 
-    return (finalDiffuse + finalSpecular) * intensity;
+    // Shadow
+    float shadow = CalcSpotShadow(fragToLightDir, lightIndex);
+
+    return (finalDiffuse + finalSpecular) * intensity * (1 - shadow);
 }
 
+#define DRAW_NORMALS false
+
 void main()
 {
     // Shared values
+    tangentViewDir = normalize(tangentCamPos - tangentFragPos);
     diffuseTexColor = texture(material.diffuse, vertUV0);
     specularTexColor = texture(material.specular, vertUV0);
     emissionTexColor = texture(material.emission, vertUV0);
 
-    normalizedVertNorm = normalize(vertNormal);
-    viewDir = normalize(camPos - fragPos);
+    // Read normal data encoded [0,1]
+    normalizedVertNorm = texture(material.normal, vertUV0).rgb;
+
+    // Remap normal to [-1,1]
+    normalizedVertNorm = normalize(normalizedVertNorm * 2.0 - 1.0);
 
     // Light contributions
     vec3 finalColor = CalcDirLight();
 
     for (int i = 0; i < NUM_POINT_LIGHTS; i++)
     {
-        finalColor += CalcPointLight(pointLights[i]);
+        finalColor += CalcPointLight(pointLights[i], i);
     }
 
     for (int i = 0; i < NUM_SPOT_LIGHTS; i++)
     {
-        finalColor += CalcSpotLight(spotLights[i]);
+        finalColor += CalcSpotLight(spotLights[i], i);
     }
 
     vec3 finalEmission = emissionTexColor.rgb;
     vec3 finalAmbient = ambientColor * diffuseTexColor.rgb;
 
     fragColor = vec4(finalColor + finalAmbient + finalEmission, 1);
+
+    if (DRAW_NORMALS)
+    {
+        fragColor = vec4(texture(material.normal, vertUV0).rgb, 1);
+    }
 }

res/shaders/skybox.glsl

@@ -3,18 +3,18 @@
 
 layout(location=0) in vec3 vertPosIn;
 layout(location=1) in vec3 vertNormalIn;
-layout(location=2) in vec2 vertUV0In;
-layout(location=3) in vec3 vertColorIn;
+layout(location=2) in vec3 vertTangentIn;
+layout(location=3) in vec2 vertUV0In;
+layout(location=4) in vec3 vertColorIn;
 
 out vec3 vertUV0;
 
-uniform mat4 viewMat;
-uniform mat4 projMat;
+uniform mat4 projViewMat;
 
 void main()
 {
     vertUV0 = vec3(vertPosIn.x, vertPosIn.y, -vertPosIn.z);
-    vec4 pos = projMat * viewMat * vec4(vertPosIn, 1.0);
+    vec4 pos = projViewMat * vec4(vertPosIn, 1.0);
     gl_Position = pos.xyww;
 }
 

res/shaders/tonemapped-screen-quad.glsl

@@ -0,0 +1,50 @@
+//shader:vertex
+#version 410
+
+out vec2 vertUV0;
+
+// Hardcoded vertex positions for a fullscreen quad.
+// Format: vec4(pos.x, pos.y, uv0.x, uv0.y)
+vec4 quadData[6] = vec4[](
+    vec4(-1.0,  1.0, 0.0, 1.0),
+    vec4(-1.0, -1.0, 0.0, 0.0),
+    vec4(1.0, -1.0, 1.0, 0.0),
+    vec4(-1.0,  1.0, 0.0, 1.0),
+    vec4(1.0, -1.0, 1.0, 0.0),
+    vec4(1.0,  1.0, 1.0, 1.0)
+);
+
+void main()
+{
+    vec4 vertData = quadData[gl_VertexID];
+
+    vertUV0 = vertData.zw;
+    gl_Position = vec4(vertData.xy, 0.0, 1.0);
+}
+
+//shader:fragment
+#version 410
+
+struct Material {
+    sampler2D diffuse;
+};
+
+uniform float exposure = 1;
+uniform Material material;
+
+in vec2 vertUV0;
+
+out vec4 fragColor;
+
+void main()
+{
+    vec4 diffuseTexColor = texture(material.diffuse, vertUV0);
+
+    // Reinhard tone mapping
+    // vec3 mappedColor = diffuseTexColor.rgb / (diffuseTexColor.rgb + vec3(1.0));
+
+    // Exposure tone mapping
+    vec3 mappedColor = vec3(1.0) - exp(-diffuseTexColor.rgb * exposure);
+
+    fragColor = vec4(mappedColor, 1);
+}

shaders/shader_program.go

@@ -6,32 +6,48 @@ import (
 )
 
 type ShaderProgram struct {
-	ID           uint32
-	VertShaderID uint32
-	FragShaderID uint32
+	Id           uint32
+	VertShaderId uint32
+	FragShaderId uint32
+	GeomShaderId uint32
 }
 
 func (sp *ShaderProgram) AttachShader(shader Shader) {
 
-	gl.AttachShader(sp.ID, shader.ID)
-	switch shader.ShaderType {
-	case VertexShaderType:
-		sp.VertShaderID = shader.ID
-	case FragmentShaderType:
-		sp.FragShaderID = shader.ID
+	gl.AttachShader(sp.Id, shader.Id)
+	switch shader.Type {
+	case ShaderType_Vertex:
+		sp.VertShaderId = shader.Id
+	case ShaderType_Fragment:
+		sp.FragShaderId = shader.Id
+	case ShaderType_Geometry:
+		sp.GeomShaderId = shader.Id
 	default:
-		logging.ErrLog.Println("Unknown shader type ", shader.ShaderType, " for ID ", shader.ID)
+		logging.ErrLog.Fatalf("Unknown shader type '%d' for shader id '%d'\n", shader.Type, shader.Id)
 	}
 }
 
 func (sp *ShaderProgram) Link() {
 
-	gl.LinkProgram(sp.ID)
+	gl.LinkProgram(sp.Id)
 
-	if sp.VertShaderID != 0 {
-		gl.DeleteShader(sp.VertShaderID)
+	if sp.VertShaderId != 0 {
+		gl.DeleteShader(sp.VertShaderId)
 	}
-	if sp.FragShaderID != 0 {
-		gl.DeleteShader(sp.FragShaderID)
+
+	if sp.FragShaderId != 0 {
+		gl.DeleteShader(sp.FragShaderId)
+	}
+
+	if sp.GeomShaderId != 0 {
+		gl.DeleteShader(sp.GeomShaderId)
 	}
 }
+
+func (s *ShaderProgram) Bind() {
+	gl.UseProgram(s.Id)
+}
+
+func (s *ShaderProgram) UnBind() {
+	gl.UseProgram(0)
+}

shaders/shader_types.go

@@ -1,10 +1,31 @@
 package shaders
 
-import "github.com/go-gl/gl/v4.1-core/gl"
+import (
+	"github.com/bloeys/nmage/logging"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
 
-type ShaderType int
+type ShaderType int32
+
+func (s ShaderType) ToGl() uint32 {
+
+	switch s {
+	case ShaderType_Vertex:
+		return gl.VERTEX_SHADER
+	case ShaderType_Fragment:
+		return gl.FRAGMENT_SHADER
+	case ShaderType_Geometry:
+		return gl.GEOMETRY_SHADER
+
+	default:
+		logging.ErrLog.Fatalf("Unknown shader type '%d'\n", s)
+		return 0
+	}
+}
 
 const (
-	VertexShaderType   ShaderType = gl.VERTEX_SHADER
-	FragmentShaderType ShaderType = gl.FRAGMENT_SHADER
+	ShaderType_Unknown ShaderType = iota
+	ShaderType_Vertex
+	ShaderType_Fragment
+	ShaderType_Geometry
 )

shaders/shaders.go

@@ -3,6 +3,7 @@ package shaders
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"os"
 	"strings"
 
@@ -11,12 +12,13 @@ import (
 )
 
 type Shader struct {
-	ID         uint32
-	ShaderType ShaderType
+	Id   uint32
+	Type ShaderType
 }
 
-func (s Shader) Delete() {
-	gl.DeleteShader(s.ID)
+func (s *Shader) Delete() {
+	gl.DeleteShader(s.Id)
+	s.Id = 0
 }
 
 func NewShaderProgram() (ShaderProgram, error) {
@@ -26,7 +28,7 @@ func NewShaderProgram() (ShaderProgram, error) {
 		return ShaderProgram{}, errors.New("failed to create shader program")
 	}
 
-	return ShaderProgram{ID: id}, nil
+	return ShaderProgram{Id: id}, nil
 }
 
 func LoadAndCompileCombinedShader(shaderPath string) (ShaderProgram, error) {
@@ -43,8 +45,8 @@ func LoadAndCompileCombinedShader(shaderPath string) (ShaderProgram, error) {
 func LoadAndCompileCombinedShaderSrc(shaderSrc []byte) (ShaderProgram, error) {
 
 	shaderSources := bytes.Split(shaderSrc, []byte("//shader:"))
-	if len(shaderSources) == 1 {
-		return ShaderProgram{}, errors.New("failed to read combined shader. Did not find '//shader:vertex' or '//shader:fragment'")
+	if len(shaderSources) < 2 {
+		return ShaderProgram{}, errors.New("failed to read combined shader. The minimum shader types to have are '//shader:vertex' and '//shader:fragment'")
 	}
 
 	shdrProg, err := NewShaderProgram()
@@ -65,12 +67,15 @@ func LoadAndCompileCombinedShaderSrc(shaderSrc []byte) (ShaderProgram, error) {
 		var shdrType ShaderType
 		if bytes.HasPrefix(src, []byte("vertex")) {
 			src = src[6:]
-			shdrType = VertexShaderType
+			shdrType = ShaderType_Vertex
 		} else if bytes.HasPrefix(src, []byte("fragment")) {
 			src = src[8:]
-			shdrType = FragmentShaderType
+			shdrType = ShaderType_Fragment
+		} else if bytes.HasPrefix(src, []byte("geometry")) {
+			src = src[8:]
+			shdrType = ShaderType_Geometry
 		} else {
-			return ShaderProgram{}, errors.New("unknown shader type. Must be '//shader:vertex' or '//shader:fragment'")
+			return ShaderProgram{}, errors.New("unknown shader type. Must be '//shader:vertex' or '//shader:fragment' or '//shader:geometry'")
 		}
 
 		shdr, err := CompileShaderOfType(src, shdrType)
@@ -83,7 +88,15 @@ func LoadAndCompileCombinedShaderSrc(shaderSrc []byte) (ShaderProgram, error) {
 	}
 
 	if loadedShdrCount == 0 {
-		return ShaderProgram{}, errors.New("no valid shaders found. Please put '//shader:vertex' or '//shader:fragment' before your shaders")
+		return ShaderProgram{}, errors.New("no valid shaders found. Please put '//shader:vertex' or '//shader:fragment' or '//shader:geometry' before your shaders")
+	}
+
+	if shdrProg.VertShaderId == 0 {
+		return ShaderProgram{}, errors.New("no valid vertex shader found. Please put '//shader:vertex' before your vertex shader")
+	}
+
+	if shdrProg.FragShaderId == 0 {
+		return ShaderProgram{}, errors.New("no valid fragment shader found. Please put '//shader:fragment' before your vertex shader")
 	}
 
 	shdrProg.Link()
@@ -92,41 +105,40 @@ func LoadAndCompileCombinedShaderSrc(shaderSrc []byte) (ShaderProgram, error) {
 
 func CompileShaderOfType(shaderSource []byte, shaderType ShaderType) (Shader, error) {
 
-	shaderID := gl.CreateShader(uint32(shaderType))
-	if shaderID == 0 {
-		logging.ErrLog.Println("Failed to create shader.")
-		return Shader{}, errors.New("failed to create shader")
+	shaderId := gl.CreateShader(shaderType.ToGl())
+	if shaderId == 0 {
+		return Shader{}, fmt.Errorf("failed to create OpenGl shader. OpenGl Error=%d", gl.GetError())
 	}
 
 	//Load shader source and compile
 	shaderCStr, shaderFree := gl.Strs(string(shaderSource) + "\x00")
 	defer shaderFree()
-	gl.ShaderSource(shaderID, 1, shaderCStr, nil)
+	gl.ShaderSource(shaderId, 1, shaderCStr, nil)
 
-	gl.CompileShader(shaderID)
-	if err := getShaderCompileErrors(shaderID); err != nil {
-		gl.DeleteShader(shaderID)
+	gl.CompileShader(shaderId)
+	if err := getShaderCompileErrors(shaderId); err != nil {
+		gl.DeleteShader(shaderId)
 		return Shader{}, err
 	}
 
-	return Shader{ID: shaderID, ShaderType: shaderType}, nil
+	return Shader{Id: shaderId, Type: shaderType}, nil
 }
 
-func getShaderCompileErrors(shaderID uint32) error {
+func getShaderCompileErrors(shaderId uint32) error {
 
 	var compiledSuccessfully int32
-	gl.GetShaderiv(shaderID, gl.COMPILE_STATUS, &compiledSuccessfully)
+	gl.GetShaderiv(shaderId, gl.COMPILE_STATUS, &compiledSuccessfully)
 	if compiledSuccessfully == gl.TRUE {
 		return nil
 	}
 
 	var logLength int32
-	gl.GetShaderiv(shaderID, gl.INFO_LOG_LENGTH, &logLength)
+	gl.GetShaderiv(shaderId, gl.INFO_LOG_LENGTH, &logLength)
 
 	log := gl.Str(strings.Repeat("\x00", int(logLength)))
-	gl.GetShaderInfoLog(shaderID, logLength, nil, log)
+	gl.GetShaderInfoLog(shaderId, logLength, nil, log)
 
 	errMsg := gl.GoStr(log)
-	logging.ErrLog.Println("Compilation of shader with id ", shaderID, " failed. Err: ", errMsg)
+	logging.ErrLog.Println("Compilation of shader with id ", shaderId, " failed. Err: ", errMsg)
 	return errors.New(errMsg)
 }

ui/imgui/imgui.go

@@ -12,7 +12,7 @@ import (
 type ImguiInfo struct {
 	ImCtx imgui.Context
 
-	Mat        *materials.Material
+	Mat        materials.Material
 	VaoID      uint32
 	VboID      uint32
 	IndexBufID uint32
@@ -204,7 +204,7 @@ void main()
 // If the path is empty a default nMage shader is used
 func NewImGui(shaderPath string) ImguiInfo {
 
-	var imguiMat *materials.Material
+	var imguiMat materials.Material
 	if shaderPath == "" {
 		imguiMat = materials.NewMaterialSrc("ImGUI Mat", []byte(DefaultImguiShader))
 	} else {