Basic submeshe support

buffers/buffers.go

@@ -11,7 +11,7 @@ type Buffer struct {
 	BufID uint32
 	//IndexBufID is the ID of the index/element buffer
 	IndexBufID uint32
-	IndexBufCount int32
+	// IndexBufCount int32
 	Stride int32
 
 	layout []Element
@@ -59,7 +59,7 @@ func (b *Buffer) SetDataWithUsage(values []float32, usage BufUsage) {
 
 func (b *Buffer) SetIndexBufData(values []uint32) {
 
-	b.IndexBufCount = int32(len(values))
+	// b.IndexBufCount = int32(len(values))
 	gl.BindVertexArray(b.VAOID)
 	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.IndexBufID)
 
@@ -101,7 +101,7 @@ func (b *Buffer) SetLayout(layout ...Element) {
 
 	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))
+		gl.VertexAttribPointerWithOffset(uint32(i), layout[i].ElementType.CompCount(), layout[i].ElementType.GLType(), false, b.Stride, uintptr(layout[i].Offset))
 	}
 
 	b.UnBind()

main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 
-	"github.com/bloeys/assimp-go/asig"
 	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/nmage/assets"
 	"github.com/bloeys/nmage/camera"
@@ -153,7 +152,8 @@ func (g *OurGame) Init() {
 
 	//Load meshes
 	var err error
-	cubeMesh, err = meshes.NewMesh("Cube", "./res/models/tex-cube.fbx", asig.PostProcess(0))
+	// cubeMesh, err = meshes.NewMesh("Cube", "./res/models/Wolf.fbx", 0)
+	cubeMesh, err = meshes.NewMesh("Cube", "./res/models/tex-cube.fbx", 0)
 	if err != nil {
 		logging.ErrLog.Fatalln("Failed to load cube mesh. Err: ", err)
 	}
@@ -181,7 +181,7 @@ func (g *OurGame) Init() {
 		gglm.NewVec3(0, 0, 10),
 		gglm.NewVec3(0, 0, -1),
 		gglm.NewVec3(0, 1, 0),
-		0.1, 20,
+		0.1, 200,
 		45*gglm.Deg2Rad,
 		float32(winWidth)/float32(winHeight),
 	)
@@ -292,8 +292,9 @@ func (g *OurGame) updateCameraPos() {
 func (g *OurGame) Render() {
 
 	tempModelMat := cubeModelMat.Clone()
+	// window.Rend.Draw(cubeMesh, tempModelMat, simpleMat)
 
-	rowSize := 100
+	rowSize := 10
 	for y := 0; y < rowSize; y++ {
 		for x := 0; x < rowSize; x++ {
 			tempModelMat.Translate(gglm.NewVec3(-1, 0, 0))

meshes/mesh.go

@@ -10,9 +10,16 @@ import (
 	"github.com/bloeys/nmage/buffers"
 )
 
+type SubMesh struct {
+	BaseVertex int32
+	BaseIndex  uint32
+	IndexCount int32
+}
+
 type Mesh struct {
 	Name      string
 	Buf       buffers.Buffer
+	SubMeshes []SubMesh
 }
 
 func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh, error) {
@@ -27,32 +34,68 @@ func NewMesh(name, modelPath string, postProcessFlags asig.PostProcess) (*Mesh,
 		return nil, errors.New("No meshes found in file: " + modelPath)
 	}
 
-	mesh := &Mesh{Name: name}
-	sceneMesh := scene.Meshes[0]
-	mesh.Buf = buffers.NewBuffer()
+	mesh := &Mesh{
+		Name:      name,
+		Buf:       buffers.NewBuffer(),
+		SubMeshes: make([]SubMesh, 0, 1),
+	}
+
+	// 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)
+
+	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}}
-
 		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
 			layoutToUse = append(layoutToUse, buffers.Element{ElementType: buffers.DataTypeVec4})
 		}
+
+		if i == 0 {
 			mesh.Buf.SetLayout(layoutToUse...)
+		} else {
+
+			// @NOTE: Require that all submeshes have the same vertex buffer layout
+			firstSubmeshLayout := mesh.Buf.GetLayout()
+			assert.T(len(firstSubmeshLayout) == len(layoutToUse), fmt.Sprintf("Vertex layout of submesh %d does not equal vertex layout of the first submesh. Original layout: %v; This layout: %v", i, firstSubmeshLayout, layoutToUse))
+
+			for i := 0; i < len(firstSubmeshLayout); i++ {
+				if firstSubmeshLayout[i].ElementType != layoutToUse[i].ElementType {
+					panic(fmt.Sprintf("Vertex layout of submesh %d does not equal vertex layout of the first submesh. Original layout: %v; This layout: %v", i, firstSubmeshLayout, layoutToUse))
+				}
+			}
+		}
 
-	var values []float32
 		arrs := []arrToInterleave{{V3s: sceneMesh.Vertices}, {V3s: sceneMesh.Normals}, {V2s: v3sToV2s(sceneMesh.TexCoords[0])}}
-
 		if len(sceneMesh.ColorSets) > 0 && len(sceneMesh.ColorSets[0]) > 0 {
 			arrs = append(arrs, arrToInterleave{V4s: sceneMesh.ColorSets[0]})
 		}
 
-	values = interleave(arrs...)
+		indices := flattenFaces(sceneMesh.Faces)
+		mesh.SubMeshes = append(mesh.SubMeshes, SubMesh{
 
-	mesh.Buf.SetData(values)
-	mesh.Buf.SetIndexBufData(flattenFaces(sceneMesh.Faces))
+			// 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,
+			// Which index (in the index buffer) to start from
+			BaseIndex: uint32(len(indexBufData)),
+			// How many indices in this submesh
+			IndexCount: int32(len(indices)),
+		})
+
+		vertexBufData = append(vertexBufData, interleave(arrs...)...)
+		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)
 	return mesh, nil
 }
 

renderer/rend3dgl/rend3dgl.go

@@ -28,7 +28,10 @@ func (r3d *Rend3DGL) Draw(mesh *meshes.Mesh, trMat *gglm.TrMat, mat *materials.M
 	}
 
 	mat.SetUnifMat4("modelMat", &trMat.Mat4)
-	gl.DrawElements(gl.TRIANGLES, mesh.Buf.IndexBufCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
+
+	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 (r3d *Rend3DGL) FrameEnd() {