Support arrays and slices in buffers.(SetData/SetIndexBufData)

assets/assets.go

@@ -5,23 +5,28 @@ var (
 	TexturePaths map[string]uint32  = make(map[string]uint32)
 )
 
-func SetTexture(t Texture) {
+func AddTextureToCache(t Texture) {
 
-	if _, ok := TexturePaths[t.Path]; ok {
+	if t.Path != "" {
+		if _, ok := TexturePaths[t.Path]; ok {
+			return
+		}
+		println("Loaded texture from path:", t.Path)
+		Textures[t.TexID] = t
+		TexturePaths[t.Path] = t.TexID
 		return
 	}
 
-	println("Loaded texture:", t.Path)
-	Textures[t.TexID] = t
+	println("Loaded in-mem texture with ID:", t.TexID)
 	TexturePaths[t.Path] = t.TexID
 }
 
-func GetTexture(texID uint32) (Texture, bool) {
+func GetTextureFromCacheID(texID uint32) (Texture, bool) {
 	tex, ok := Textures[texID]
 	return tex, ok
 }
 
-func GetTexturePath(path string) (Texture, bool) {
+func GetTextureFromCachePath(path string) (Texture, bool) {
 	tex, ok := Textures[TexturePaths[path]]
 	return tex, ok
 }

assets/textures.go

@@ -2,6 +2,7 @@ package assets
 
 import (
 	"bytes"
+	"image"
 	"image/color"
 	"image/png"
 	"os"
@@ -17,6 +18,7 @@ const (
 )
 
 type Texture struct {
+	//Path only exists for textures loaded from disk
 	Path   string
 	TexID  uint32
 	Width  int32
@@ -24,10 +26,22 @@ type Texture struct {
 	Pixels []byte
 }
 
-func LoadPNGTexture(file string) (Texture, error) {
+type TextureLoadOptions struct {
+	TryLoadFromCache bool
+	WriteToCache     bool
+	GenMipMaps       bool
+}
 
-	if tex, ok := GetTexturePath(file); ok {
-		return tex, nil
+func LoadTexturePNG(file string, loadOptions *TextureLoadOptions) (Texture, error) {
+
+	if loadOptions == nil {
+		loadOptions = &TextureLoadOptions{}
+	}
+
+	if loadOptions.TryLoadFromCache {
+		if tex, ok := GetTextureFromCachePath(file); ok {
+			return tex, nil
+		}
 	}
 
 	//Load from disk
@@ -72,14 +86,72 @@ func LoadPNGTexture(file string) (Texture, error) {
 	// set the texture wrapping/filtering options (on the currently bound texture object)
 	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT)
 	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT)
-	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
 	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
 
 	// load and generate the texture
 	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, tex.Width, tex.Height, 0, gl.RGBA, gl.UNSIGNED_BYTE, unsafe.Pointer(&tex.Pixels[0]))
-	gl.GenerateMipmap(gl.TEXTURE_2D)
 
-	SetTexture(tex)
+	if loadOptions.GenMipMaps {
+		gl.GenerateMipmap(tex.TexID)
+	}
+
+	if loadOptions.WriteToCache {
+		AddTextureToCache(tex)
+	}
+
+	return tex, nil
+}
+
+func LoadTextureInMemImg(img image.Image, loadOptions *TextureLoadOptions) (Texture, error) {
+
+	if loadOptions == nil {
+		loadOptions = &TextureLoadOptions{}
+	}
+
+	tex := Texture{
+		Width:  int32(img.Bounds().Dx()),
+		Height: int32(img.Bounds().Dy()),
+		Pixels: make([]byte, img.Bounds().Dx()*img.Bounds().Dy()*4),
+	}
+
+	//NOTE: Load bottom left to top right because this is the texture coordinate system used by OpenGL
+	//NOTE: We only support 8-bit channels (32-bit colors) for now
+	i := 0
+	for y := img.Bounds().Dy() - 1; y >= 0; y-- {
+		for x := 0; x < img.Bounds().Dx(); x++ {
+
+			c := color.NRGBAModel.Convert(img.At(x, y)).(color.NRGBA)
+
+			tex.Pixels[i] = c.R
+			tex.Pixels[i+1] = c.G
+			tex.Pixels[i+2] = c.B
+			tex.Pixels[i+3] = c.A
+
+			i += 4
+		}
+	}
+
+	//Prepare opengl stuff
+	gl.GenTextures(1, &tex.TexID)
+	gl.BindTexture(gl.TEXTURE_2D, tex.TexID)
+
+	// set the texture wrapping/filtering options (on the currently bound texture object)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
+	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
+
+	// load and generate the texture
+	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, tex.Width, tex.Height, 0, gl.RGBA, gl.UNSIGNED_BYTE, unsafe.Pointer(&tex.Pixels[0]))
+
+	if loadOptions.GenMipMaps {
+		gl.GenerateMipmap(tex.TexID)
+	}
+
+	if loadOptions.WriteToCache {
+		AddTextureToCache(tex)
+	}
 
 	return tex, nil
 }

buffers/buffers.go

@@ -30,7 +30,12 @@ func (b *Buffer) SetData(values []float32) {
 	gl.BindVertexArray(b.VAOID)
 	gl.BindBuffer(gl.ARRAY_BUFFER, b.BufID)
 
-	gl.BufferData(gl.ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsage_Static.ToGL())
+	sizeInBytes := len(values) * 4
+	if sizeInBytes == 0 {
+		gl.BufferData(gl.ARRAY_BUFFER, 0, gl.Ptr(nil), BufUsage_Static.ToGL())
+	} else {
+		gl.BufferData(gl.ARRAY_BUFFER, sizeInBytes, gl.Ptr(&values[0]), BufUsage_Static.ToGL())
+	}
 
 	gl.BindVertexArray(0)
 	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
@@ -42,7 +47,12 @@ func (b *Buffer) SetIndexBufData(values []uint32) {
 	gl.BindVertexArray(b.VAOID)
 	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.IndexBufID)
 
-	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(values)*4, gl.Ptr(values), BufUsage_Static.ToGL())
+	sizeInBytes := len(values) * 4
+	if sizeInBytes == 0 {
+		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, 0, gl.Ptr(nil), BufUsage_Static.ToGL())
+	} else {
+		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, sizeInBytes, gl.Ptr(&values[0]), BufUsage_Static.ToGL())
+	}
 
 	gl.BindVertexArray(0)
 	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
@@ -54,6 +64,8 @@ func (b *Buffer) GetLayout() []Element {
 	return e
 }
 
+//SetLayout updates the layout object and the corresponding vertex attributes.
+//Vertex attributes are also enabled.
 func (b *Buffer) SetLayout(layout ...Element) {
 
 	b.layout = layout
@@ -64,6 +76,20 @@ func (b *Buffer) SetLayout(layout ...Element) {
 		b.layout[i].Offset = int(b.Stride)
 		b.Stride += b.layout[i].Size()
 	}
+
+	//Set opengl stuff
+	b.Bind()
+
+	//NOTE: VBOs are only bound at 'VertexAttribPointer', not BindBUffer, so we need to bind the buffer and vao here
+	gl.BindBuffer(gl.ARRAY_BUFFER, b.BufID)
+
+	for i := 0; i < len(layout); i++ {
+		gl.EnableVertexAttribArray(uint32(i))
+		gl.VertexAttribPointer(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, b.Stride, gl.PtrOffset(layout[i].Offset))
+	}
+
+	b.UnBind()
+	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
 }
 
 func NewBuffer(layout ...Element) Buffer {

engine/engine.go

@@ -1,17 +1,26 @@
 package engine
 
 import (
+	"runtime"
+
+	"github.com/bloeys/nmage/asserts"
 	"github.com/bloeys/nmage/input"
+	"github.com/bloeys/nmage/renderer"
 	"github.com/bloeys/nmage/timing"
 	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
+var (
+	isInited = false
+)
+
 type Window struct {
 	SDLWin         *sdl.Window
 	GlCtx          sdl.GLContext
 	EventCallbacks []func(sdl.Event)
+	Rend           renderer.Render
 }
 
 func (w *Window) handleInputs() {
@@ -92,6 +101,9 @@ func (w *Window) Destroy() error {
 
 func Init() error {
 
+	isInited = true
+
+	runtime.LockOSThread()
 	timing.Init()
 	err := initSDL()
 
@@ -124,16 +136,17 @@ func initSDL() error {
 	return nil
 }
 
-func CreateOpenGLWindow(title string, x, y, width, height int32, flags WindowFlags) (*Window, error) {
-	return createWindow(title, x, y, width, height, WindowFlags_OPENGL|flags)
+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 CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags) (*Window, error) {
-	return createWindow(title, -1, -1, width, height, WindowFlags_OPENGL|flags)
+func CreateOpenGLWindowCentered(title string, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
+	return createWindow(title, -1, -1, width, height, WindowFlags_OPENGL|flags, rend)
 }
 
-func createWindow(title string, x, y, width, height int32, flags WindowFlags) (*Window, error) {
+func createWindow(title string, x, y, width, height int32, flags WindowFlags, rend renderer.Render) (*Window, error) {
 
+	asserts.T(isInited, "engine.Init was not called!")
 	if x == -1 && y == -1 {
 		x = sdl.WINDOWPOS_CENTERED
 		y = sdl.WINDOWPOS_CENTERED
@@ -143,7 +156,11 @@ func createWindow(title string, x, y, width, height int32, flags WindowFlags) (*
 	if err != nil {
 		return nil, err
 	}
-	win := &Window{SDLWin: sdlWin, EventCallbacks: make([]func(sdl.Event), 0)}
+	win := &Window{
+		SDLWin:         sdlWin,
+		EventCallbacks: make([]func(sdl.Event), 0),
+		Rend:           rend,
+	}
 
 	win.GlCtx, err = sdlWin.GLCreateContext()
 	if err != nil {
@@ -169,11 +186,16 @@ func initOpenGL() error {
 	gl.CullFace(gl.BACK)
 	gl.FrontFace(gl.CCW)
 
+	gl.Enable(gl.BLEND)
+	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
+
 	gl.ClearColor(0, 0, 0, 1)
 	return nil
 }
 
 func SetVSync(enabled bool) {
+	asserts.T(isInited, "engine.Init was not called!")
+
 	if enabled {
 		sdl.GLSetSwapInterval(1)
 	} else {

engine/game.go

@@ -6,29 +6,34 @@ import (
 	"github.com/go-gl/gl/v4.1-core/gl"
 )
 
+var (
+	isRunning = false
+)
+
 type Game interface {
 	Init()
 
-	FrameStart()
 	Update()
 	Render()
 	FrameEnd()
-	ShouldRun() bool
 
-	GetWindow() *Window
-	GetImGUI() nmageimgui.ImguiInfo
-
-	Deinit()
+	DeInit()
 }
 
-func Run(g Game) {
+func Run(g Game, w *Window, ui nmageimgui.ImguiInfo) {
 
+	isRunning = true
 	g.Init()
 
-	w := g.GetWindow()
-	ui := g.GetImGUI()
-	for g.ShouldRun() {
+	//Simulate an imgui frame during init so any imgui calls are allowed within init
+	tempWidth, tempHeight := w.SDLWin.GetSize()
+	tempFBWidth, tempFBHeight := w.SDLWin.GLGetDrawableSize()
+	ui.FrameStart(float32(tempWidth), float32(tempHeight))
+	ui.Render(float32(tempWidth), float32(tempHeight), tempFBWidth, tempFBHeight)
 
+	for isRunning {
+
+		//PERF: Cache these
 		width, height := w.SDLWin.GetSize()
 		fbWidth, fbHeight := w.SDLWin.GLGetDrawableSize()
 
@@ -36,8 +41,6 @@ func Run(g Game) {
 		w.handleInputs()
 		ui.FrameStart(float32(width), float32(height))
 
-		g.FrameStart()
-
 		g.Update()
 
 		gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
@@ -46,8 +49,13 @@ func Run(g Game) {
 		w.SDLWin.GLSwap()
 
 		g.FrameEnd()
+		w.Rend.FrameEnd()
 		timing.FrameEnded()
 	}
 
-	g.Deinit()
+	g.DeInit()
+}
+
+func Quit() {
+	isRunning = false
 }

go.mod

@@ -8,6 +8,6 @@ require github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784
 
 require (
 	github.com/bloeys/assimp-go v0.4.2
-	github.com/bloeys/gglm v0.3.1
+	github.com/bloeys/gglm v0.41.10
 	github.com/inkyblackness/imgui-go/v4 v4.3.0
 )

go.sum

@@ -2,6 +2,8 @@ github.com/bloeys/assimp-go v0.4.2 h1:ArVK74BCFcTO/rCGj2NgZG9xtbjnJdEn5npIeJx1Z0
 github.com/bloeys/assimp-go v0.4.2/go.mod h1:my3yRxT7CfOztmvi+0svmwbaqw0KFrxaHxncoyaEIP0=
 github.com/bloeys/gglm v0.3.1 h1:Sy9upW7SBsBfDXrSmEhid3aQ+7J7itej+upwcxOnPMQ=
 github.com/bloeys/gglm v0.3.1/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
+github.com/bloeys/gglm v0.41.10 h1:R9FMiI+VQVXAI+vDwCB7z9xqzy5VAR1657u8TQTDNKA=
+github.com/bloeys/gglm v0.41.10/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-gl/gl v0.0.0-20211025173605-bda47ffaa784 h1:1Zi56D0LNfvkzM+BdoxKryvUEdyWO7LP8oRT+oSYJW0=

main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"runtime"
 
 	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
@@ -12,28 +11,28 @@ import (
 	"github.com/bloeys/nmage/logging"
 	"github.com/bloeys/nmage/materials"
 	"github.com/bloeys/nmage/meshes"
+	"github.com/bloeys/nmage/renderer/rend3dgl"
 	"github.com/bloeys/nmage/timing"
 	nmageimgui "github.com/bloeys/nmage/ui/imgui"
-	"github.com/go-gl/gl/v4.1-core/gl"
 	"github.com/inkyblackness/imgui-go/v4"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
 //TODO: Tasks:
-//Proper rendering setup
-//Entities and components
-//Camera class
-//Audio
-//Flesh out the material system
-
-//Low Priority:
+// Camera class
+// Entities and components
+// Integrate physx
+// Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
+// Renderer batching
+// Scene graph
+// Separate engine loop from rendering loop? or leave it to the user?
 // Abstract keys enum away from sdl
-// Abstract UI
 // Proper Asset loading
+// Frustum culling
+// Material system editor with fields automatically extracted from the shader
 
 var (
-	isRunning bool = true
-	window    *engine.Window
+	window *engine.Window
 
 	simpleMat *materials.Material
 	cubeMesh  *meshes.Mesh
@@ -50,13 +49,12 @@ var (
 type OurGame struct {
 	Win       *engine.Window
 	ImGUIInfo nmageimgui.ImguiInfo
-	Quitting  bool
 }
 
 func (g *OurGame) Init() {
 
 	//Create materials
-	simpleMat = materials.NewMaterial("Simple Mat", "./res/shaders/simple")
+	simpleMat = materials.NewMaterial("Simple Mat", "./res/shaders/simple.glsl")
 
 	//Load meshes
 	var err error
@@ -66,19 +64,13 @@ func (g *OurGame) Init() {
 	}
 
 	//Load textures
-	tex, err := assets.LoadPNGTexture("./res/textures/Low poly planet.png")
+	tex, err := assets.LoadTexturePNG("./res/textures/Low poly planet.png", nil)
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to load texture. Err: ", err)
 	}
-	cubeMesh.AddTexture(tex)
 
-	//Set mesh textures on material
-	for _, v := range cubeMesh.TextureIDs {
-		simpleMat.AddTextureID(v)
-	}
-
-	//Enable vertex attributes
-	simpleMat.SetAttribute(cubeMesh.Buf)
+	//Configure material
+	simpleMat.DiffuseTex = tex.TexID
 
 	//Movement, scale and rotation
 	translationMat := gglm.NewTranslationMat(gglm.NewVec3(0, 0, 0))
@@ -100,13 +92,10 @@ func (g *OurGame) Init() {
 	simpleMat.SetUnifVec3("lightColor1", lightColor1)
 }
 
-func (g *OurGame) FrameStart() {
-}
-
 func (g *OurGame) Update() {
 
-	if input.IsQuitClicked() {
-		g.Quitting = true
+	if input.IsQuitClicked() || input.KeyClicked(sdl.K_ESCAPE) {
+		engine.Quit()
 	}
 
 	winWidth, winHeight := g.Win.SDLWin.GetSize()
@@ -149,64 +138,31 @@ func (g *OurGame) Update() {
 	imgui.DragFloat3("Cam Pos", &camPos.Data)
 }
 
-var dtAccum float32 = 0
-var lastElapsedTime uint64 = 0
-var framesSinceLastFPSUpdate uint = 0
-
 func (g *OurGame) Render() {
 
-	simpleMat.Bind()
-	cubeMesh.Buf.Bind()
 	tempModelMat := modelMat.Clone()
 
 	rowSize := 100
 	for y := 0; y < rowSize; y++ {
 		for x := 0; x < rowSize; x++ {
-			simpleMat.SetUnifMat4("modelMat", &tempModelMat.Translate(gglm.NewVec3(-1, 0, 0)).Mat4)
-			gl.DrawElements(gl.TRIANGLES, cubeMesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+			tempModelMat.Translate(gglm.NewVec3(-1, 0, 0))
+			window.Rend.Draw(cubeMesh, tempModelMat, simpleMat)
 		}
-		simpleMat.SetUnifMat4("modelMat", &tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0)).Mat4)
-	}
-	simpleMat.SetUnifMat4("modelMat", &modelMat.Mat4)
-
-	dtAccum += timing.DT()
-	framesSinceLastFPSUpdate++
-	if timing.ElapsedTime() > lastElapsedTime {
-
-		avgDT := dtAccum / float32(framesSinceLastFPSUpdate)
-		g.GetWindow().SDLWin.SetTitle(fmt.Sprint("nMage (", 1/avgDT, " fps)"))
-
-		dtAccum = 0
-		framesSinceLastFPSUpdate = 0
+		tempModelMat.Translate(gglm.NewVec3(float32(rowSize), -1, 0))
 	}
 
-	lastElapsedTime = timing.ElapsedTime()
+	g.Win.SDLWin.SetTitle(fmt.Sprint("nMage (", timing.GetAvgFPS(), " fps)"))
 }
 
 func (g *OurGame) FrameEnd() {
-
 }
 
-func (g *OurGame) ShouldRun() bool {
-	return !g.Quitting
-}
-
-func (g *OurGame) GetWindow() *engine.Window {
-	return g.Win
-}
-
-func (g *OurGame) GetImGUI() nmageimgui.ImguiInfo {
-	return g.ImGUIInfo
-}
-
-func (g *OurGame) Deinit() {
+func (g *OurGame) DeInit() {
 	g.Win.Destroy()
 }
 
 func main() {
 
-	runtime.LockOSThread()
-
 	//Init engine
 	err := engine.Init()
 	if err != nil {
@@ -214,7 +170,7 @@ func main() {
 	}
 
 	//Create window
-	window, err = engine.CreateOpenGLWindowCentered("nMage", 1280, 720, engine.WindowFlags_RESIZABLE)
+	window, err = engine.CreateOpenGLWindowCentered("nMage", 1280, 720, engine.WindowFlags_RESIZABLE, rend3dgl.NewRend3DGL())
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to create window. Err: ", err)
 	}
@@ -227,8 +183,7 @@ func main() {
 		ImGUIInfo: nmageimgui.NewImGUI(),
 	}
 
-	engine.Run(game)
-	return
+	engine.Run(game, window, game.ImGUIInfo)
 }
 
 func updateViewMat() {

materials/material.go

@@ -3,7 +3,6 @@ package materials
 import (
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/asserts"
-	"github.com/bloeys/nmage/buffers"
 	"github.com/bloeys/nmage/logging"
 	"github.com/bloeys/nmage/shaders"
 	"github.com/go-gl/gl/v4.1-core/gl"
@@ -12,7 +11,8 @@ import (
 type Material struct {
 	Name       string
 	ShaderProg shaders.ShaderProgram
-	TexIDs     []uint32
+
+	DiffuseTex uint32
 
 	UnifLocs   map[string]int32
 	AttribLocs map[string]int32
@@ -21,19 +21,17 @@ type Material struct {
 func (m *Material) Bind() {
 
 	gl.UseProgram(m.ShaderProg.ID)
-	for i, v := range m.TexIDs {
-		gl.ActiveTexture(gl.TEXTURE0 + uint32(i))
-		gl.BindTexture(gl.TEXTURE_2D, v)
-	}
+
+	gl.ActiveTexture(gl.TEXTURE0)
+	gl.BindTexture(gl.TEXTURE_2D, m.DiffuseTex)
 }
 
 func (m *Material) UnBind() {
-
 	gl.UseProgram(0)
-	for i := range m.TexIDs {
-		gl.ActiveTexture(gl.TEXTURE0 + uint32(i))
-		gl.BindTexture(gl.TEXTURE_2D, 0)
-	}
+
+	//TODO: Should we unbind textures here? Are these two lines needed?
+	// gl.ActiveTexture(gl.TEXTURE0)
+	// gl.BindTexture(gl.TEXTURE_2D, 0)
 }
 
 func (m *Material) GetAttribLoc(attribName string) int32 {
@@ -62,27 +60,6 @@ func (m *Material) GetUnifLoc(uniformName string) int32 {
 	return loc
 }
 
-func (m *Material) SetAttribute(bufObj buffers.Buffer) {
-
-	bufObj.Bind()
-
-	//NOTE: VBOs are only bound at 'VertexAttribPointer', not BindBUffer, so we need to bind the buffer and vao here
-	gl.BindBuffer(gl.ARRAY_BUFFER, bufObj.BufID)
-
-	layout := bufObj.GetLayout()
-	for i := 0; i < len(layout); i++ {
-		gl.EnableVertexAttribArray(uint32(i))
-		gl.VertexAttribPointer(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, bufObj.Stride, gl.PtrOffset(layout[i].Offset))
-	}
-
-	bufObj.UnBind()
-	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
-}
-
-func (m *Material) AddTextureID(texID uint32) {
-	m.TexIDs = append(m.TexIDs, texID)
-}
-
 func (m *Material) EnableAttribute(attribName string) {
 	gl.EnableVertexAttribArray(uint32(m.GetAttribLoc(attribName)))
 }
@@ -129,24 +106,20 @@ func (m *Material) Delete() {
 
 func NewMaterial(matName, shaderPath string) *Material {
 
-	shdrProg, err := shaders.NewShaderProgram()
+	shdrProg, err := shaders.LoadAndCompileCombinedShader(shaderPath)
 	if err != nil {
-		logging.ErrLog.Fatalln("Failed to create new shader program. Err: ", err)
+		logging.ErrLog.Fatalln("Failed to create new material. Err: ", err)
+	}
+
+	return &Material{Name: matName, ShaderProg: shdrProg, UnifLocs: make(map[string]int32), AttribLocs: make(map[string]int32)}
+}
+
+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)
 	}
 
-	vertShader, err := shaders.LoadAndCompilerShader(shaderPath+".vert.glsl", shaders.VertexShaderType)
-	if err != nil {
-		logging.ErrLog.Fatalln("Failed to load and create vertex shader. Err: ", err)
-	}
-
-	fragShader, err := shaders.LoadAndCompilerShader(shaderPath+".frag.glsl", shaders.FragmentShaderType)
-	if err != nil {
-		logging.ErrLog.Fatalln("Failed to load and create fragment shader. Err: ", err)
-	}
-
-	shdrProg.AttachShader(vertShader)
-	shdrProg.AttachShader(fragShader)
-	shdrProg.Link()
-
 	return &Material{Name: matName, ShaderProg: shdrProg, UnifLocs: make(map[string]int32), AttribLocs: make(map[string]int32)}
 }

meshes/mesh.go

@@ -7,18 +7,12 @@ import (
 	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/asserts"
-	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/buffers"
 )
 
 type Mesh struct {
-	Name       string
-	TextureIDs []uint32
-	Buf        buffers.Buffer
-}
-
-func (m *Mesh) AddTexture(tex assets.Texture) {
-	m.TextureIDs = append(m.TextureIDs, tex.TexID)
+	Name string
+	Buf  buffers.Buffer
 }
 
 func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh, error) {

renderer/rend3dgl/rend3dgl.go

@@ -0,0 +1,41 @@
+package rend3dgl
+
+import (
+	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/materials"
+	"github.com/bloeys/nmage/meshes"
+	"github.com/bloeys/nmage/renderer"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+var _ renderer.Render = &Rend3DGL{}
+
+type Rend3DGL struct {
+	BoundMesh *meshes.Mesh
+	BoundMat  *materials.Material
+}
+
+func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material) {
+
+	if mesh != r3d.BoundMesh {
+		mesh.Buf.Bind()
+		r3d.BoundMesh = mesh
+	}
+
+	if mat != r3d.BoundMat {
+		mat.Bind()
+		r3d.BoundMat = mat
+	}
+
+	mat.SetUnifMat4("modelMat", &trMat.Mat4)
+	gl.DrawElements(gl.TRIANGLES, mesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+}
+
+func (r3d *Rend3DGL) FrameEnd() {
+	r3d.BoundMesh = nil
+	r3d.BoundMat = nil
+}
+
+func NewRend3DGL() *Rend3DGL {
+	return &Rend3DGL{}
+}

renderer/renderer.go

@@ -0,0 +1,12 @@
+package renderer
+
+import (
+	"github.com/bloeys/gglm/gglm"
+	"github.com/bloeys/nmage/materials"
+	"github.com/bloeys/nmage/meshes"
+)
+
+type Render interface {
+	Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material)
+	FrameEnd()
+}

res/shaders/imgui.frag.glsl

@@ -1,13 +0,0 @@
-#version 410
-
-uniform sampler2D Texture;
-
-in vec2 Frag_UV;
-in vec4 Frag_Color;
-
-out vec4 Out_Color;
-
-void main()
-{
-    Out_Color = vec4(Frag_Color.rgb, Frag_Color.a * texture(Texture, Frag_UV.st).r);
-}

res/shaders/imgui.vert.glsl

@@ -1,17 +0,0 @@
-#version 410
-
-uniform mat4 ProjMtx;
-
-in vec2 Position;
-in vec2 UV;
-in vec4 Color;
-
-out vec2 Frag_UV;
-out vec4 Frag_Color;
-
-void main()
-{
-    Frag_UV = UV;
-    Frag_Color = Color;
-    gl_Position = ProjMtx * vec4(Position.xy, 0, 1);
-}

res/shaders/simple.frag.glsl

@@ -1,26 +0,0 @@
-#version 410
-
-uniform float ambientStrength = 0.1;
-uniform vec3 ambientLightColor = vec3(1, 1, 1);
-
-uniform vec3 lightPos1;
-uniform vec3 lightColor1;
-
-uniform sampler2D diffTex;
-
-in vec3 vertColor;
-in vec3 vertNormal;
-in vec2 vertUV0;
-in vec3 fragPos;
-
-out vec4 fragColor;
-
-void main()
-{
-    vec3 lightDir = normalize(lightPos1 - fragPos);  
-    float diffStrength = max(0.0, dot(normalize(vertNormal), lightDir));
-
-    vec3 finalAmbientColor = ambientLightColor * ambientStrength;
-    vec4 texColor = texture(diffTex, vertUV0);
-    fragColor = vec4(texColor.rgb * vertColor * (finalAmbientColor + diffStrength*lightColor1) , texColor.a);
-} 

res/shaders/simple.glsl

@@ -0,0 +1,55 @@
+//shader:vertex
+#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;
+
+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;
+
+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);
+}
+
+//shader:fragment
+#version 410
+
+uniform float ambientStrength = 0.1;
+uniform vec3 ambientLightColor = vec3(1, 1, 1);
+
+uniform vec3 lightPos1;
+uniform vec3 lightColor1;
+
+uniform sampler2D diffTex;
+
+in vec3 vertColor;
+in vec3 vertNormal;
+in vec2 vertUV0;
+in vec3 fragPos;
+
+out vec4 fragColor;
+
+void main()
+{
+    vec3 lightDir = normalize(lightPos1 - fragPos);  
+    float diffStrength = max(0.0, dot(normalize(vertNormal), lightDir));
+
+    vec3 finalAmbientColor = ambientLightColor * ambientStrength;
+    vec4 texColor = texture(diffTex, vertUV0);
+    fragColor = vec4(texColor.rgb * vertColor * (finalAmbientColor + diffStrength*lightColor1) , texColor.a);
+} 

res/shaders/simple.vert.glsl

@@ -1,26 +0,0 @@
-#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;
-
-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;
-
-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);
-}

shaders/shaders.go

@@ -1,6 +1,7 @@
 package shaders
 
 import (
+	"bytes"
 	"errors"
 	"os"
 	"strings"
@@ -28,14 +29,69 @@ func NewShaderProgram() (ShaderProgram, error) {
 	return ShaderProgram{ID: id}, nil
 }
 
-func LoadAndCompilerShader(shaderPath string, shaderType ShaderType) (Shader, error) {
+func LoadAndCompileCombinedShader(shaderPath string) (ShaderProgram, error) {
 
-	shaderSource, err := os.ReadFile(shaderPath)
+	combinedSource, err := os.ReadFile(shaderPath)
 	if err != nil {
 		logging.ErrLog.Println("Failed to read shader. Err: ", err)
-		return Shader{}, err
+		return ShaderProgram{}, err
 	}
 
+	return LoadAndCompileCombinedShaderSrc(combinedSource)
+
+}
+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'")
+	}
+
+	shdrProg, err := NewShaderProgram()
+	if err != nil {
+		return ShaderProgram{}, errors.New("failed to create new shader program. Err: " + err.Error())
+	}
+
+	loadedShdrCount := 0
+	for i := 0; i < len(shaderSources); i++ {
+
+		src := shaderSources[i]
+
+		//This can happen when the shader type is at the start of the file
+		if len(bytes.TrimSpace(src)) == 0 {
+			continue
+		}
+
+		var shdrType ShaderType
+		if bytes.HasPrefix(src, []byte("vertex")) {
+			src = src[6:]
+			shdrType = VertexShaderType
+		} else if bytes.HasPrefix(src, []byte("fragment")) {
+			src = src[8:]
+			shdrType = FragmentShaderType
+		} else {
+			return ShaderProgram{}, errors.New("unknown shader type. Must be '//shader:vertex' or '//shader:fragment'")
+		}
+
+		shdr, err := CompileShaderOfType(src, shdrType)
+		if err != nil {
+			return ShaderProgram{}, err
+		}
+
+		loadedShdrCount++
+		shdrProg.AttachShader(shdr)
+	}
+
+	if loadedShdrCount == 0 {
+		return ShaderProgram{}, errors.New("no valid shaders found. Please put '//shader:vertex' or '//shader:fragment' before your shaders")
+	}
+
+	shdrProg.Link()
+	return shdrProg, nil
+}
+
+func CompileShaderOfType(shaderSource []byte, shaderType ShaderType) (Shader, error) {
+
 	shaderID := gl.CreateShader(uint32(shaderType))
 	if shaderID == 0 {
 		logging.ErrLog.Println("Failed to create shader.")

timing/timing.go

@@ -8,6 +8,12 @@ var (
 	dt         float32 = 0.01
 	frameStart time.Time
 	startTime  time.Time
+
+	//fps calculator vars
+	dtAccum                  float32 = 1
+	lastElapsedTime          uint64  = 0
+	framesSinceLastFPSUpdate uint    = 0
+	avgFps                   float32 = 1
 )
 
 func Init() {
@@ -15,14 +21,29 @@ func Init() {
 }
 
 func FrameStarted() {
+
 	frameStart = time.Now()
+
+	//fps stuff
+	dtAccum += dt
+	framesSinceLastFPSUpdate++
+	et := ElapsedTime()
+	if et > lastElapsedTime {
+		avgDT := dtAccum / float32(framesSinceLastFPSUpdate)
+		avgFps = 1 / avgDT
+
+		dtAccum = 0
+		framesSinceLastFPSUpdate = 0
+	}
+	lastElapsedTime = et
 }
 
 func FrameEnded() {
 
+	//Calculate new dt
 	dt = float32(time.Since(frameStart).Seconds())
 	if dt == 0 {
-		dt = float32(time.Microsecond)
+		dt = float32(time.Microsecond.Seconds())
 	}
 }
 
@@ -31,6 +52,11 @@ func DT() float32 {
 	return dt
 }
 
+//GetAvgFPS returns the fps averaged over 1 second
+func GetAvgFPS() float32 {
+	return avgFps
+}
+
 //ElapsedTime is time since game start
 func ElapsedTime() uint64 {
 	return uint64(time.Since(startTime).Seconds())

ui/imgui/imgui.go

@@ -120,7 +120,6 @@ func (i *ImguiInfo) Render(winWidth, winHeight float32, fbWidth, fbHeight int32)
 	}
 
 	//Reset gl state
-	gl.Disable(gl.BLEND)
 	gl.Disable(gl.SCISSOR_TEST)
 	gl.Enable(gl.CULL_FACE)
 	gl.Enable(gl.DEPTH_TEST)
@@ -150,11 +149,47 @@ func (i *ImguiInfo) AddFontTTF(fontPath string, fontSize float32, fontConfig *im
 	return f
 }
 
+const imguiShdrSrc = `
+//shader:vertex
+#version 410
+
+uniform mat4 ProjMtx;
+
+in vec2 Position;
+in vec2 UV;
+in vec4 Color;
+
+out vec2 Frag_UV;
+out vec4 Frag_Color;
+
+void main()
+{
+    Frag_UV = UV;
+    Frag_Color = Color;
+    gl_Position = ProjMtx * vec4(Position.xy, 0, 1);
+}
+
+//shader:fragment
+#version 410
+
+uniform sampler2D Texture;
+
+in vec2 Frag_UV;
+in vec4 Frag_Color;
+
+out vec4 Out_Color;
+
+void main()
+{
+    Out_Color = vec4(Frag_Color.rgb, Frag_Color.a * texture(Texture, Frag_UV.st).r);
+}
+`
+
 func NewImGUI() ImguiInfo {
 
 	imguiInfo := ImguiInfo{
 		ImCtx: imgui.CreateContext(nil),
-		Mat:   materials.NewMaterial("ImGUI Mat", "./res/shaders/imgui"),
+		Mat:   materials.NewMaterialSrc("ImGUI Mat", []byte(imguiShdrSrc)),
 	}
 
 	imIO := imgui.CurrentIO()