Ep5: Obj file loading+indexed drawing+uniforms

buffers/buffers.go

@@ -2,39 +2,58 @@ package buffers
 
 import (
 	"github.com/bloeys/go-sdl-engine/logging"
-	"github.com/go-gl/gl/v4.6-compatibility/gl"
+	"github.com/go-gl/gl/v4.6-core/gl"
 )
 
-type BufferType int
+type BufGLType int
 
 const (
-	BufTypeUnknown BufferType = iota
+	BufGLTypeUnknown BufGLType = 0
+	//Generic array of data. Should be used for most data like vertex positions, vertex colors etc.
+	BufGLTypeArray   BufGLType = gl.ARRAY_BUFFER
+	BufGLTypeIndices BufGLType = gl.ELEMENT_ARRAY_BUFFER
+)
+
+type BufType int
+
+const (
+	BufTypeUnknown BufType = iota
 	BufTypeVertPos
 	BufTypeColor
+	BufTypeIndex
 )
 
-type BufferGLType int
+func (bt BufType) GetBufferGLType() BufGLType {
+	switch bt {
 
-const (
+	case BufTypeColor:
-	//Generic array of data. Should be used for most data like vertex positions, vertex colors etc.
+		fallthrough
-	BufGLTypeArrayBuffer BufferGLType = gl.ARRAY_BUFFER
+	case BufTypeVertPos:
-)
+		return BufGLTypeArray
 
-type BufferUsage int
+	case BufTypeIndex:
+		return BufGLTypeIndices
+	default:
+		logging.WarnLog.Println("Unknown BufferType. BufferType: ", bt)
+		return BufGLTypeUnknown
+	}
+}
+
+type BufUsage int
 
 const (
 	//Buffer is set only once and used many times
-	BufUsageStatic BufferUsage = gl.STATIC_DRAW
+	BufUsageStatic BufUsage = gl.STATIC_DRAW
 	//Buffer is changed a lot and used many times
-	BufUsageDynamic BufferUsage = gl.DYNAMIC_DRAW
+	BufUsageDynamic BufUsage = gl.DYNAMIC_DRAW
 	//Buffer is set only once and used by the GPU at most a few times
-	BufUsageStream BufferUsage = gl.STREAM_DRAW
+	BufUsageStream BufUsage = gl.STREAM_DRAW
 )
 
 type Buffer struct {
 	ID     uint32
-	Type   BufferType
+	Type   BufType
-	GLType BufferGLType
+	GLType BufGLType
 	DataTypeInfo
 }
 
@@ -50,9 +69,10 @@ type BufferObject struct {
 	VAOID      uint32
 	VertPosBuf *Buffer
 	ColorBuf   *Buffer
+	IndexBuf   *Buffer
 }
 
-func (bo *BufferObject) GenBuffer(data []float32, bufUsage BufferUsage, bufType BufferType, bufDataType DataType) {
+func (bo *BufferObject) GenBuffer(data []float32, bufUsage BufUsage, bufType BufType, bufDataType DataType) {
 
 	gl.BindVertexArray(bo.VAOID)
 
@@ -66,7 +86,35 @@ func (bo *BufferObject) GenBuffer(data []float32, bufUsage BufferUsage, bufType
 	buf := &Buffer{
 		ID:           vboID,
 		Type:         bufType,
-		GLType:       BufGLTypeArrayBuffer,
+		GLType:       bufType.GetBufferGLType(),
+		DataTypeInfo: GetDataTypeInfo(bufDataType),
+	}
+	bo.SetBuffer(buf)
+
+	//Fill buffer with data
+	gl.BindBuffer(uint32(buf.GLType), buf.ID)
+	gl.BufferData(uint32(buf.GLType), int(buf.DataTypeInfo.ElementSize)*len(data), gl.Ptr(data), uint32(bufUsage))
+
+	//Unbind everything
+	gl.BindVertexArray(0)
+	gl.BindBuffer(uint32(buf.GLType), 0)
+}
+
+func (bo *BufferObject) GenBufferUint32(data []uint32, bufUsage BufUsage, bufType BufType, bufDataType DataType) {
+
+	gl.BindVertexArray(bo.VAOID)
+
+	//Create vertex buffer object
+	var vboID uint32
+	gl.CreateBuffers(1, &vboID)
+	if vboID == 0 {
+		logging.ErrLog.Println("Failed to create openGL buffer")
+	}
+
+	buf := &Buffer{
+		ID:           vboID,
+		Type:         bufType,
+		GLType:       bufType.GetBufferGLType(),
 		DataTypeInfo: GetDataTypeInfo(bufDataType),
 	}
 	bo.SetBuffer(buf)
@@ -87,6 +135,8 @@ func (bo *BufferObject) SetBuffer(buf *Buffer) {
 		bo.VertPosBuf = buf
 	case BufTypeColor:
 		bo.ColorBuf = buf
+	case BufTypeIndex:
+		bo.IndexBuf = buf
 	default:
 		logging.WarnLog.Println("Unknown buffer type in SetBuffer. Type:", buf.Type)
 	}

buffers/dataType.go

@@ -2,13 +2,14 @@ package buffers
 
 import (
 	"github.com/bloeys/go-sdl-engine/logging"
-	"github.com/go-gl/gl/v4.6-compatibility/gl"
+	"github.com/go-gl/gl/v4.6-core/gl"
 )
 
 type DataType int
 
 const (
-	DataTypeUnknown = iota
+	DataTypeUnknown DataType = iota
+	DataTypeUint32
 	DataTypeInt32
 	DataTypeFloat32
 	DataTypeFloat64
@@ -37,6 +38,8 @@ func (dti *DataTypeInfo) GetSize() int32 {
 func GetDataTypeInfo(dt DataType) DataTypeInfo {
 
 	switch dt {
+	case DataTypeUint32:
+		fallthrough
 	case DataTypeInt32:
 		return DataTypeInfo{
 			ElementSize:  4,

go.mod

@@ -5,3 +5,5 @@ go 1.17
 require github.com/veandco/go-sdl2 v0.4.10
 
 require github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259
+
+require github.com/bloeys/gglm v0.1.1 // indirect

go.sum

@@ -1,3 +1,5 @@
+github.com/bloeys/gglm v0.1.1 h1:juLE2OqobKKamMq7IKkplOJcZaM45CAcmbS0rCND3Hc=
+github.com/bloeys/gglm v0.1.1/go.mod h1:qwJQ0WzV191wAMwlGicbfbChbKoSedMk7gFFX6GnyOk=
 github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259 h1:8q7+xl2D2qHPLTII1t4vSMNP2VKwDcn+Avf2WXvdB1A=
 github.com/go-gl/gl v0.0.0-20210905235341-f7a045908259/go.mod h1:wjpnOv6ONl2SuJSxqCPVaPZibGFdSci9HFocT9qtVYM=
 github.com/veandco/go-sdl2 v0.4.10 h1:8QoD2bhWl7SbQDflIAUYWfl9Vq+mT8/boJFAUzAScgY=

main.go

@@ -1,11 +1,13 @@
 package main
 
 import (
+	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/go-sdl-engine/buffers"
 	"github.com/bloeys/go-sdl-engine/input"
 	"github.com/bloeys/go-sdl-engine/logging"
+	"github.com/bloeys/go-sdl-engine/res/models"
 	"github.com/bloeys/go-sdl-engine/shaders"
-	"github.com/go-gl/gl/v4.6-compatibility/gl"
+	"github.com/go-gl/gl/v4.6-core/gl"
 	"github.com/veandco/go-sdl2/sdl"
 )
 
@@ -48,8 +50,16 @@ func main() {
 	simpleShader.SetAttribute("vertPos", bo, bo.VertPosBuf)
 	simpleShader.EnableAttribute("vertPos")
 
-	simpleShader.SetAttribute("vertColor", bo, bo.ColorBuf)
+	// simpleShader.SetAttribute("vertColor", bo, bo.ColorBuf)
-	simpleShader.EnableAttribute("vertColor")
+	// simpleShader.EnableAttribute("vertColor")
+
+	modelMat := gglm.NewTrMatId()
+	translationMat := gglm.NewTranslationMat(gglm.NewVec3(-0.5, 0, 0))
+	scaleMat := gglm.NewScaleMat(gglm.NewVec3(0.25, 0.25, 0.25))
+	rotMat := gglm.NewRotMat(gglm.NewQuatEuler(gglm.NewVec3(0, 0, 0).AsRad()))
+
+	modelMat.Mul(translationMat.Mul(rotMat.Mul(scaleMat)))
+	simpleShader.SetUnifMat4("modelMat", &modelMat.Mat4)
 
 	//Game loop
 	for isRunning {
@@ -109,27 +119,32 @@ func loadBuffers() {
 
 	vertices := []float32{
 		-0.5, 0.5, 0,
-		0.5, 0.5, 0,
-		-0.5, -0.5, 0,
-
 		0.5, 0.5, 0,
 		0.5, -0.5, 0,
 		-0.5, -0.5, 0,
 	}
+	// colors := []float32{
+	// 	1, 0, 0,
+	// 	0, 0, 1,
+	// 	0, 0, 1,
+	// 	0, 0, 1,
+	// }
+	indices := []uint32{0, 1, 3, 1, 2, 3}
 
-	colors := []float32{
+	//Load obj
-		1, 0, 0,
+	objInfo, err := models.LoadObj("./res/models/obj.obj")
-		0, 0, 1,
+	if err != nil {
-		0, 0, 1,
+		panic(err)
-
-		0, 0, 1,
-		0, 0, 1,
-		0, 0, 1,
 	}
+	logging.InfoLog.Printf("%v", objInfo.TriIndices)
+
+	vertices = objInfo.VertPos
+	indices = objInfo.TriIndices
 
 	bo = buffers.NewBufferObject()
 	bo.GenBuffer(vertices, buffers.BufUsageStatic, buffers.BufTypeVertPos, buffers.DataTypeVec3)
-	bo.GenBuffer(colors, buffers.BufUsageStatic, buffers.BufTypeColor, buffers.DataTypeVec3)
+	// bo.GenBuffer(colors, buffers.BufUsageStatic, buffers.BufTypeColor, buffers.DataTypeVec3)
+	bo.GenBufferUint32(indices, buffers.BufUsageStatic, buffers.BufTypeIndex, buffers.DataTypeUint32)
 }
 
 func handleInputs() {
@@ -162,7 +177,7 @@ func draw() {
 
 	//DRAW
 	bo.Activate()
-	gl.DrawArrays(gl.TRIANGLES, 0, 6)
+	gl.DrawElements(gl.TRIANGLES, 36, gl.UNSIGNED_INT, gl.PtrOffset(0))
 	bo.Deactivate()
 
 	window.GLSwap()

res/models/loader.go

@@ -0,0 +1,73 @@
+package models
+
+import (
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/bloeys/go-sdl-engine/logging"
+)
+
+type ObjInfo struct {
+	VertPos    []float32
+	TriIndices []uint32
+}
+
+func LoadObj(file string) (objInfo ObjInfo, err error) {
+
+	b, err := os.ReadFile(file)
+	if err != nil {
+		return objInfo, err
+	}
+
+	lines := strings.Split(string(b), "\n")
+	for i := 0; i < len(lines); i++ {
+
+		s := strings.SplitN(lines[i], " ", 2)
+		switch s[0] {
+		case "v":
+
+			vertPosStrings := strings.Split(s[1], " ")
+
+			f, err := strconv.ParseFloat(vertPosStrings[0], 32)
+			if err != nil {
+				return objInfo, err
+			}
+			objInfo.VertPos = append(objInfo.VertPos, float32(f))
+
+			f, err = strconv.ParseFloat(vertPosStrings[1], 32)
+			if err != nil {
+				return objInfo, err
+			}
+			objInfo.VertPos = append(objInfo.VertPos, float32(f))
+
+			f, err = strconv.ParseFloat(vertPosStrings[2], 32)
+			if err != nil {
+				return objInfo, err
+			}
+			objInfo.VertPos = append(objInfo.VertPos, float32(f))
+
+		case "f":
+
+			facesStrings := strings.Split(s[1], " ")
+			objInfo.TriIndices = append(objInfo.TriIndices, getVertIndexFromFace(facesStrings[0]))
+			objInfo.TriIndices = append(objInfo.TriIndices, getVertIndexFromFace(facesStrings[1]))
+			objInfo.TriIndices = append(objInfo.TriIndices, getVertIndexFromFace(facesStrings[2]))
+
+		default:
+		}
+	}
+
+	return objInfo, nil
+}
+
+func getVertIndexFromFace(f string) uint32 {
+
+	indxStr := strings.SplitN(f, "/", 2)[0]
+	index, err := strconv.Atoi(indxStr)
+	if err != nil {
+		logging.ErrLog.Printf("Invalid face index '%v'. Err: %v", indxStr, err)
+		return 0
+	}
+	return uint32(index) - 1
+}

res/models/obj.obj

@@ -0,0 +1,46 @@
+# Blender v2.92.0 OBJ File: ''
+# www.blender.org
+mtllib obj.mtl
+o Cube
+v 2.275618 1.000000 0.349413
+v 3.520138 -1.000000 0.102233
+v 2.275618 1.000000 0.752820
+v 3.520138 -1.000000 1.000000
+v 0.244520 1.000000 0.349413
+v -1.000000 -1.000000 0.102233
+v 0.244520 1.000000 0.752820
+v -1.000000 -1.000000 1.000000
+vt 0.806168 0.568832
+vt 0.693832 0.681168
+vt 0.693832 0.568832
+vt 0.375000 1.000000
+vt 0.375000 0.750000
+vt 0.375000 0.000000
+vt 0.625000 0.250000
+vt 0.375000 0.250000
+vt 0.375000 0.500000
+vt 0.125000 0.750000
+vt 0.125000 0.500000
+vt 0.806168 0.681168
+vt 0.625000 0.931168
+vt 0.625000 0.068832
+vn 0.0000 1.0000 0.0000
+vn 0.0000 0.1227 0.9924
+vn -0.8490 0.5283 0.0000
+vn 0.0000 -1.0000 0.0000
+vn 0.8490 0.5283 0.0000
+vn 0.0000 0.1227 -0.9924
+usemtl Material
+s off
+f 5/1/1 3/2/1 1/3/1
+f 3/2/2 8/4/2 4/5/2
+f 8/6/3 5/7/3 6/8/3
+f 2/9/4 8/10/4 6/11/4
+f 1/3/5 4/5/5 2/9/5
+f 5/7/6 2/9/6 6/8/6
+f 5/1/1 7/12/1 3/2/1
+f 3/2/2 7/13/2 8/4/2
+f 8/6/3 7/14/3 5/7/3
+f 2/9/4 4/5/4 8/10/4
+f 1/3/5 3/2/5 4/5/5
+f 5/7/6 1/3/6 2/9/6

res/shaders/simple.frag.glsl

@@ -6,5 +6,6 @@ out vec4 fragColor;
 
 void main()
 {
-    fragColor = vec4(outColor, 1.0);
+    fragColor = vec4(1,1,1, 1.0);
+    // fragColor = vec4(outColor, 1.0);
 } 

res/shaders/simple.vert.glsl

@@ -5,8 +5,10 @@ in vec3 vertColor;
 
 out vec3 outColor;
 
+uniform mat4 modelMat;
+
 void main()
 {
     outColor = vertColor;
-    gl_Position = vec4(vertPos, 1.0); // vec4(vertPos.x, vertPos.y, vertPos.z, 1.0)
+    gl_Position = modelMat * (vec4(vertPos, 1.0)); // vec4(vertPos.x, vertPos.y, vertPos.z, 1.0)
 }

shaders/shader_program.go

@@ -1,9 +1,10 @@
 package shaders
 
 import (
+	"github.com/bloeys/gglm/gglm"
 	"github.com/bloeys/go-sdl-engine/buffers"
 	"github.com/bloeys/go-sdl-engine/logging"
-	"github.com/go-gl/gl/v4.6-compatibility/gl"
+	"github.com/go-gl/gl/v4.6-core/gl"
 )
 
 type ShaderProgram struct {
@@ -69,6 +70,36 @@ func (sp *ShaderProgram) DisableAttribute(attribName string) {
 	gl.DisableVertexAttribArray(uint32(sp.GetAttribLoc(attribName)))
 }
 
+func (sp *ShaderProgram) SetUnifVec2(uniformName string, vec2 *gglm.Vec2) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniform2fv(sp.ID, loc, 1, &vec2.Data[0])
+}
+
+func (sp *ShaderProgram) SetUnifVec3(uniformName string, vec3 *gglm.Vec3) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniform3fv(sp.ID, loc, 1, &vec3.Data[0])
+}
+
+func (sp *ShaderProgram) SetUnifVec4(uniformName string, vec4 *gglm.Vec4) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniform4fv(sp.ID, loc, 1, &vec4.Data[0])
+}
+
+func (sp *ShaderProgram) SetUnifMat2(uniformName string, mat2 *gglm.Mat2) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniformMatrix2fv(sp.ID, loc, 1, true, &mat2.Data[0])
+}
+
+func (sp *ShaderProgram) SetUnifMat3(uniformName string, mat3 *gglm.Mat3) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniformMatrix3fv(sp.ID, loc, 1, true, &mat3.Data[0])
+}
+
+func (sp *ShaderProgram) SetUnifMat4(uniformName string, mat4 *gglm.Mat4) {
+	loc := gl.GetUniformLocation(sp.ID, gl.Str(uniformName+"\x00"))
+	gl.ProgramUniformMatrix4fv(sp.ID, loc, 1, true, &mat4.Data[0])
+}
+
 func (sp *ShaderProgram) Delete() {
 	gl.DeleteProgram(sp.ID)
 }

shaders/shader_types.go

@@ -1,6 +1,6 @@
 package shaders
 
-import "github.com/go-gl/gl/v4.6-compatibility/gl"
+import "github.com/go-gl/gl/v4.6-core/gl"
 
 type ShaderType int
 

shaders/shaders.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 
 	"github.com/bloeys/go-sdl-engine/logging"
-	"github.com/go-gl/gl/v4.6-compatibility/gl"
+	"github.com/go-gl/gl/v4.6-core/gl"
 )
 
 type Shader struct {