Split buffer struct into VAO+VBO+IBO structs

buffers/buffers.go

@@ -1,134 +0,0 @@
-package buffers
-
-import (
-	"github.com/bloeys/nmage/logging"
-	"github.com/go-gl/gl/v4.1-core/gl"
-)
-
-type Buffer struct {
-	VAOID uint32
-	// BufID is the ID of the VBO
-	BufID uint32
-	// IndexBufID is the ID of the index/element buffer
-	IndexBufID uint32
-	// IndexBufCount is the number of elements in the index buffer
-	// Updated on SetIndexBufData
-	IndexBufCount int32
-	// IndexBufCount int32
-	Stride int32
-
-	layout []Element
-}
-
-func (b *Buffer) Bind() {
-	gl.BindVertexArray(b.VAOID)
-}
-
-func (b *Buffer) UnBind() {
-	gl.BindVertexArray(0)
-}
-
-func (b *Buffer) SetData(values []float32) {
-
-	gl.BindVertexArray(b.VAOID)
-	gl.BindBuffer(gl.ARRAY_BUFFER, b.BufID)
-
-	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)
-}
-
-func (b *Buffer) SetDataWithUsage(values []float32, usage BufUsage) {
-
-	gl.BindVertexArray(b.VAOID)
-	gl.BindBuffer(gl.ARRAY_BUFFER, b.BufID)
-
-	sizeInBytes := len(values) * 4
-	if sizeInBytes == 0 {
-		gl.BufferData(gl.ARRAY_BUFFER, 0, gl.Ptr(nil), usage.ToGL())
-	} else {
-		gl.BufferData(gl.ARRAY_BUFFER, sizeInBytes, gl.Ptr(&values[0]), usage.ToGL())
-	}
-
-	gl.BindVertexArray(0)
-	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
-}
-
-func (b *Buffer) SetIndexBufData(values []uint32) {
-
-	b.IndexBufCount = int32(len(values))
-	gl.BindVertexArray(b.VAOID)
-	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.IndexBufID)
-
-	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)
-}
-
-func (b *Buffer) GetLayout() []Element {
-	e := make([]Element, len(b.layout))
-	copy(e, b.layout)
-	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
-
-	b.Stride = 0
-	for i := 0; i < len(b.layout); i++ {
-
-		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.VertexAttribPointerWithOffset(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, b.Stride, uintptr(layout[i].Offset))
-	}
-
-	b.UnBind()
-	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
-}
-
-func NewBuffer(layout ...Element) Buffer {
-
-	b := Buffer{}
-	gl.GenVertexArrays(1, &b.VAOID)
-	if b.VAOID == 0 {
-		logging.ErrLog.Println("Failed to create openGL vertex array object")
-	}
-
-	gl.GenBuffers(1, &b.BufID)
-	if b.BufID == 0 {
-		logging.ErrLog.Println("Failed to create openGL buffer")
-	}
-
-	gl.GenBuffers(1, &b.IndexBufID)
-	if b.IndexBufID == 0 {
-		logging.ErrLog.Println("Failed to create openGL buffer")
-	}
-
-	b.SetLayout(layout...)
-	return b
-}

buffers/index_buffer.go

@@ -0,0 +1,46 @@
+package buffers
+
+import (
+	"github.com/bloeys/nmage/logging"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+type IndexBuffer struct {
+	Id uint32
+	// IndexBufCount is the number of elements in the index buffer. Updated in IndexBuffer.SetData
+	IndexBufCount int32
+}
+
+func (ib *IndexBuffer) Bind() {
+	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ib.Id)
+}
+
+func (ib *IndexBuffer) UnBind() {
+	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
+}
+
+func (ib *IndexBuffer) SetData(values []uint32) {
+
+	ib.Bind()
+
+	sizeInBytes := len(values) * 4
+	ib.IndexBufCount = int32(len(values))
+
+	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())
+	}
+}
+
+func NewIndexBuffer() IndexBuffer {
+
+	ib := IndexBuffer{}
+
+	gl.GenBuffers(1, &ib.Id)
+	if ib.Id == 0 {
+		logging.ErrLog.Println("Failed to create OpenGL buffer")
+	}
+
+	return ib
+}

buffers/vertex_array.go

@@ -0,0 +1,54 @@
+package buffers
+
+import (
+	"github.com/bloeys/nmage/logging"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+type VertexArray struct {
+	Id          uint32
+	Vbos        []VertexBuffer
+	IndexBuffer IndexBuffer
+}
+
+func (va *VertexArray) Bind() {
+	gl.BindVertexArray(va.Id)
+}
+
+func (va *VertexArray) UnBind() {
+	gl.BindVertexArray(0)
+}
+
+func (va *VertexArray) AddVertexBuffer(vbo VertexBuffer) {
+
+	// NOTE: VBOs are only bound at 'VertexAttribPointer' (and related) calls
+
+	va.Bind()
+	vbo.Bind()
+
+	for i := 0; i < len(vbo.layout); i++ {
+
+		l := &vbo.layout[i]
+
+		gl.EnableVertexAttribArray(uint32(i))
+		gl.VertexAttribPointerWithOffset(uint32(i), l.ElementType.CompCount(), l.ElementType.GLType(), false, vbo.Stride, uintptr(l.Offset))
+	}
+}
+
+func (va *VertexArray) SetIndexBuffer(ib IndexBuffer) {
+	va.Bind()
+	ib.Bind()
+	va.IndexBuffer = ib
+}
+
+func NewVertexArray() VertexArray {
+
+	vao := VertexArray{}
+
+	gl.GenVertexArrays(1, &vao.Id)
+	if vao.Id == 0 {
+		logging.ErrLog.Println("Failed to create OpenGL vertex array object")
+	}
+
+	return vao
+}

buffers/vertex_buffer.go

@@ -0,0 +1,63 @@
+package buffers
+
+import (
+	"github.com/bloeys/nmage/logging"
+	"github.com/go-gl/gl/v4.1-core/gl"
+)
+
+type VertexBuffer struct {
+	Id     uint32
+	Stride int32
+	layout []Element
+}
+
+func (vb *VertexBuffer) Bind() {
+	gl.BindBuffer(gl.ARRAY_BUFFER, vb.Id)
+}
+
+func (vb *VertexBuffer) UnBind() {
+	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
+}
+
+func (vb *VertexBuffer) SetData(values []float32, usage BufUsage) {
+
+	vb.Bind()
+
+	sizeInBytes := len(values) * 4
+	if sizeInBytes == 0 {
+		gl.BufferData(gl.ARRAY_BUFFER, 0, gl.Ptr(nil), usage.ToGL())
+	} else {
+		gl.BufferData(gl.ARRAY_BUFFER, sizeInBytes, gl.Ptr(&values[0]), usage.ToGL())
+	}
+}
+
+func (vb *VertexBuffer) GetLayout() []Element {
+	e := make([]Element, len(vb.layout))
+	copy(e, vb.layout)
+	return e
+}
+
+func (vb *VertexBuffer) SetLayout(layout ...Element) {
+
+	vb.Stride = 0
+	vb.layout = layout
+
+	for i := 0; i < len(vb.layout); i++ {
+
+		vb.layout[i].Offset = int(vb.Stride)
+		vb.Stride += vb.layout[i].Size()
+	}
+}
+
+func NewVertexBuffer(layout ...Element) VertexBuffer {
+
+	vb := VertexBuffer{}
+
+	gl.GenBuffers(1, &vb.Id)
+	if vb.Id == 0 {
+		logging.ErrLog.Println("Failed to create OpenGL buffer")
+	}
+
+	vb.SetLayout(layout...)
+	return vb
+}

main.go

@@ -34,7 +34,7 @@ import (
 		- Cascaded shadow mapping
 		- Skeletal animations
 	- Proper model loading (i.e. load model by reading all its meshes, textures, and so on together)
-	- Create VAO struct independent from VBO to support multi-VBO use cases (e.g. instancing)
+	- 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?
@@ -812,7 +812,7 @@ func (g *Game) DrawSkybox() {
 
 	gl.Disable(gl.CULL_FACE)
 	gl.DepthFunc(gl.LEQUAL)
-	skyboxMesh.Buf.Bind()
+	skyboxMesh.Vao.Bind()
 	skyboxMat.Bind()
 	gl.ActiveTexture(gl.TEXTURE0)
 	gl.BindTexture(gl.TEXTURE_CUBE_MAP, skyboxCmap.TexID)

meshes/mesh.go

@@ -2,7 +2,6 @@ package meshes
 
 import (
 	"errors"
-	"fmt"
 
 	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
@@ -18,7 +17,7 @@ type SubMesh struct {
 
 type Mesh struct {
 	Name      string
-	Buf       buffers.Buffer
+	Vao       buffers.VertexArray
 	SubMeshes []SubMesh
 }
 
@@ -36,21 +35,25 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 
 	mesh := &Mesh{
 		Name:      name,
-		Buf:       buffers.NewBuffer(),
+		Vao:       buffers.NewVertexArray(),
 		SubMeshes: make([]SubMesh, 0, 1),
 	}
 
+	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)
 	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))
+
 	for i := 0; i < len(scene.Meshes); i++ {
 
 		sceneMesh := scene.Meshes[i]
 
 		if len(sceneMesh.TexCoords[0]) == 0 {
 			sceneMesh.TexCoords[0] = make([]gglm.Vec3, len(sceneMesh.Vertices))
-			println("Zeroing tex coords for submesh", i)
 		}
 
 		layoutToUse := []buffers.Element{{ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec3}, {ElementType: buffers.DataTypeVec2}}
@@ -59,10 +62,16 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 		}
 
 		if i == 0 {
-			mesh.Buf.SetLayout(layoutToUse...)
+			vbo.SetLayout(layoutToUse...)
 		} else {
 
-			firstSubmeshLayout := mesh.Buf.GetLayout()
+			// @TODO @NOTE: This requirement is because we are using one VAO+VBO for all
+			// the meshes and so the buffer must have one format.
+			//
+			// If we want to allow different layouts then we can simply create one vbo per layout and put
+			// meshes of the same layout in the same vbo, and we store the index of the vbo the mesh
+			// uses in the submesh struct.
+			firstSubmeshLayout := vbo.GetLayout()
 			assert.T(len(firstSubmeshLayout) == len(layoutToUse), "Vertex layout of submesh '%d' of mesh '%s' at path '%s' does not equal vertex layout of the first submesh. Original layout: %v; This layout: %v", i, name, modelPath, firstSubmeshLayout, layoutToUse)
 
 			for i := 0; i < len(firstSubmeshLayout); i++ {
@@ -79,7 +88,7 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 		mesh.SubMeshes = append(mesh.SubMeshes, SubMesh{
 
 			// Index of the vertex to start from (e.g. if index buffer says use vertex 5, and BaseVertex=3, the vertex used will be vertex 8)
-			BaseVertex: int32(len(vertexBufData)*4) / mesh.Buf.Stride,
+			BaseVertex: int32(len(vertexBufData)*4) / vbo.Stride,
 			// Which index (in the index buffer) to start from
 			BaseIndex: uint32(len(indexBufData)),
 			// How many indices in this submesh
@@ -90,9 +99,16 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 		indexBufData = append(indexBufData, indices...)
 	}
 
-	// fmt.Printf("!!! Vertex count: %d; Submeshes: %+v\n", len(vertexBufData)*4/int(mesh.Buf.Stride), mesh.SubMeshes)
-	mesh.Buf.SetData(vertexBufData)
-	mesh.Buf.SetIndexBufData(indexBufData)
+	vbo.SetData(vertexBufData, buffers.BufUsage_Static)
+	ibo.SetData(indexBufData)
+
+	mesh.Vao.AddVertexBuffer(vbo)
+	mesh.Vao.SetIndexBuffer(ibo)
+
+	// This is needed so that if you load meshes one after the other the
+	// following mesh doesn't attach its vbo/ibo to this vao
+	mesh.Vao.UnBind()
+
 	return mesh, nil
 }
 
@@ -170,7 +186,7 @@ func interleave(arrs ...arrToInterleave) []float32 {
 
 func flattenFaces(faces []asig.Face) []uint32 {
 
-	assert.T(len(faces[0].Indices) == 3, fmt.Sprintf("Face doesn't have 3 indices. Index count: %v\n", len(faces[0].Indices)))
+	assert.T(len(faces[0].Indices) == 3, "Face doesn't have 3 indices. Index count: %v\n", len(faces[0].Indices))
 
 	uints := make([]uint32, len(faces)*3)
 	for i := 0; i < len(faces); i++ {

renderer/rend3dgl/rend3dgl.go

@@ -18,7 +18,7 @@ type Rend3DGL struct {
 func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.Material) {
 
 	if mesh != r3d.BoundMesh {
-		mesh.Buf.Bind()
+		mesh.Vao.Bind()
 		r3d.BoundMesh = mesh
 	}