Checkpoint cube example in a really, really rough state.

.gitignore

@@ -25,6 +25,7 @@ glow
 
 # Temporary/output directories
 examples/test
+examples/cube/cube
 egl
 gl
 gles1
@@ -35,3 +36,4 @@ xml
 
 # Vim
 *.swp
+*.swo

examples/cube/cube.go

@@ -0,0 +1,316 @@
+// Command cube demonstrates simple Glow binding usage.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"github.com/errcw/glow/gl/3.3/gl"
+	"github.com/errcw/glow/glt"
+	"github.com/fzipp/geom"
+	glfw "github.com/go-gl/glfw3"
+	"runtime"
+	"strings"
+	"unsafe"
+)
+
+func init() {
+	// GLFW event handling must run on the main OS thread
+	runtime.LockOSThread()
+}
+
+func glfwErrorCallback(err glfw.ErrorCode, desc string) {
+	fmt.Printf("GLFW error %v: %v\n", err, desc)
+}
+
+func checkerr() {
+	e := gl.GetError()
+	if e != gl.NO_ERROR {
+		panic(e)
+	}
+}
+
+func main() {
+	// Initialize GLFW for window management
+	glfw.SetErrorCallback(glfwErrorCallback)
+	if !glfw.Init() {
+		panic("failed to initialize glfw")
+	}
+	defer glfw.Terminate()
+
+	glfw.WindowHint(glfw.Resizable, glfw.False)
+	glfw.WindowHint(glfw.ContextVersionMajor, 3)
+	glfw.WindowHint(glfw.ContextVersionMinor, 3)
+	glfw.WindowHint(glfw.OpenglForwardCompatible, glfw.True)    // Necessary for OS X
+	glfw.WindowHint(glfw.OpenglProfile, glfw.OpenglCoreProfile) // Necessary for OS X
+	window, err := glfw.CreateWindow(640, 480, "Cube", nil, nil)
+	if err != nil {
+		panic(err)
+	}
+	window.MakeContextCurrent()
+
+	// Initialize Glow
+	if err := gl.Init(); err != nil {
+		panic(err)
+	}
+
+	version := glt.GoStr(gl.GetString(gl.VERSION))
+	fmt.Println("OpenGL version", version)
+
+	// Configure the scene
+	program, err := newProgram(vertexShader, fragmentShader)
+	if err != nil {
+		panic(err)
+	}
+	gl.UseProgram(program)
+
+	var projection geom.Mat4
+	projection.Perspective(50.0, 640.0/480.0, 0.1, 10.0)
+	projectionUniform := gl.GetUniformLocation(program, glt.Str("projection\x00"))
+	gl.UniformMatrix4fv(projectionUniform, 1, true, toRowMajorFloats(&projection))
+	checkerr()
+
+	var camera geom.Mat4
+	camera.LookAt(geom.V3(3, 3, 3), geom.V3(0, 0, 0), geom.V3(0, 1, 0))
+	cameraUniform := gl.GetUniformLocation(program, glt.Str("camera\x00"))
+	gl.UniformMatrix4fv(cameraUniform, 1, true, toRowMajorFloats(&camera))
+	checkerr()
+
+	var model geom.Mat4
+	model.ID()
+	modelUniform := gl.GetUniformLocation(program, glt.Str("model\x00"))
+	gl.UniformMatrix4fv(modelUniform, 1, true, toRowMajorFloats(&model))
+	checkerr()
+
+	/*
+		var texture uint32
+		gl.GenTextures(1, &texture)
+		gl.ActiveTexture(gl.TEXTURE0)
+		gl.BindTexture(gl.TEXTURE_2D, texture)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+		gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+
+		textureUniform := gl.GetUniformLocation(program, glt.Str("tex\x00"))
+		gl.Uniform1i(textureUniform, 0)
+	*/
+
+	var vao uint32
+	gl.GenVertexArrays(1, &vao)
+	checkerr()
+	gl.BindVertexArray(vao)
+	checkerr()
+
+	var vbo uint32
+	gl.GenBuffers(1, &vbo)
+	checkerr()
+	gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
+	checkerr()
+	gl.BufferData(gl.ARRAY_BUFFER, len(cube)*4, glt.Ptr(cube), gl.STATIC_DRAW)
+	checkerr()
+
+	vertAttrib := uint32(gl.GetAttribLocation(program, glt.Str("vert\x00")))
+	checkerr()
+	gl.EnableVertexAttribArray(vertAttrib)
+	checkerr()
+	gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, 0)
+	checkerr()
+
+	texCoordAttrib := uint32(gl.GetAttribLocation(program, glt.Str("vertTexCoord\x00")))
+	checkerr()
+	gl.EnableVertexAttribArray(texCoordAttrib)
+	checkerr()
+	gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 5*4, 3*4)
+	checkerr()
+
+	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
+
+	gl.Enable(gl.DEPTH_TEST)
+	checkerr()
+	gl.DepthFunc(gl.LESS)
+	checkerr()
+
+	gl.Viewport(0, 0, 640, 480)
+	checkerr()
+	gl.ClearColor(1.0, 1.0, 1.0, 1.0)
+	checkerr()
+
+	frames := 0
+	for !window.ShouldClose() {
+		gl.Clear(gl.COLOR_BUFFER_BIT)
+		checkerr()
+
+		gl.UseProgram(program)
+		checkerr()
+		gl.BindVertexArray(vao)
+		checkerr()
+
+		gl.ValidateProgram(program)
+		var status int32
+		gl.GetProgramiv(program, gl.VALIDATE_STATUS, &status)
+		fmt.Println("Got validate status", status)
+
+		gl.DrawArrays(gl.TRIANGLES, 0, 6*2*3)
+		checkerr()
+
+		// Maintenance
+		window.SwapBuffers()
+		glfw.PollEvents()
+
+		frames++
+	}
+}
+
+func newProgram(vertexShaderSource, fragmentShaderSource string) (uint32, error) {
+	vertexShader, err := compileShader(vertexShaderSource, gl.VERTEX_SHADER)
+	if err != nil {
+		return 0, err
+	}
+
+	fragmentShader, err := compileShader(fragmentShaderSource, gl.FRAGMENT_SHADER)
+	if err != nil {
+		return 0, err
+	}
+
+	program := gl.CreateProgram()
+	checkerr()
+
+	gl.AttachShader(program, vertexShader)
+	checkerr()
+	gl.AttachShader(program, fragmentShader)
+	checkerr()
+	gl.LinkProgram(program)
+	checkerr()
+
+	var status int32
+	gl.GetProgramiv(program, gl.LINK_STATUS, &status)
+	checkerr()
+	if status == gl.FALSE {
+		var logLength int32
+		gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)
+
+		log := strings.Repeat("\x00", int(logLength+1))
+		gl.GetProgramInfoLog(program, logLength, nil, glt.Str(log))
+
+		return 0, errors.New(fmt.Sprintf("failed to link program: %v", log))
+	}
+
+	//gl.DeleteShader(vertexShader)
+	//gl.DeleteShader(fragmentShader)
+
+	return program, nil
+}
+
+func compileShader(source string, shaderType uint32) (uint32, error) {
+	shader := gl.CreateShader(shaderType)
+	checkerr()
+
+	csource := glt.Str(source)
+	gl.ShaderSource(shader, 1, &csource, nil)
+	checkerr()
+	gl.CompileShader(shader)
+
+	checkerr()
+	var status int32
+	gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
+	checkerr()
+	if status == gl.FALSE {
+		var logLength int32
+		gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)
+
+		log := strings.Repeat("\x00", int(logLength+1))
+		gl.GetShaderInfoLog(shader, logLength, nil, glt.Str(log))
+
+		return 0, errors.New(fmt.Sprintf("failed to compile %v: %v", source, log))
+	}
+
+	return shader, nil
+}
+
+func toRowMajorFloats(m *geom.Mat4) *float32 {
+	return (*float32)(unsafe.Pointer(m))
+}
+
+var vertexShader string = `
+#version 330
+
+uniform mat4 projection;
+uniform mat4 camera;
+uniform mat4 model;
+
+in vec3 vert;
+in vec2 vertTexCoord;
+
+out vec2 fragTexCoord;
+
+void main() {
+    fragTexCoord = vertTexCoord;
+    gl_Position = projection * camera * model * vec4(vert, 1);
+}
+` + "\x00"
+
+var fragmentShader = `
+#version 330
+
+//uniform sampler2D tex;
+
+in vec2 fragTexCoord;
+
+out vec4 finalColor;
+
+void main() {
+    //finalColor = texture(tex, fragTexCoord);
+    finalColor = vec4(0, 0, 0, 0);
+}
+` + "\x00"
+
+var cube = []float32{
+	//  X, Y, Z, U, V
+	// Bottom
+	-1.0, -1.0, -1.0, 0.0, 0.0,
+	1.0, -1.0, -1.0, 1.0, 0.0,
+	-1.0, -1.0, 1.0, 0.0, 1.0,
+	1.0, -1.0, -1.0, 1.0, 0.0,
+	1.0, -1.0, 1.0, 1.0, 1.0,
+	-1.0, -1.0, 1.0, 0.0, 1.0,
+
+	// Top
+	-1.0, 1.0, -1.0, 0.0, 0.0,
+	-1.0, 1.0, 1.0, 0.0, 1.0,
+	1.0, 1.0, -1.0, 1.0, 0.0,
+	1.0, 1.0, -1.0, 1.0, 0.0,
+	-1.0, 1.0, 1.0, 0.0, 1.0,
+	1.0, 1.0, 1.0, 1.0, 1.0,
+
+	// Front
+	-1.0, -1.0, 1.0, 1.0, 0.0,
+	1.0, -1.0, 1.0, 0.0, 0.0,
+	-1.0, 1.0, 1.0, 1.0, 1.0,
+	1.0, -1.0, 1.0, 0.0, 0.0,
+	1.0, 1.0, 1.0, 0.0, 1.0,
+	-1.0, 1.0, 1.0, 1.0, 1.0,
+
+	// Back
+	-1.0, -1.0, -1.0, 0.0, 0.0,
+	-1.0, 1.0, -1.0, 0.0, 1.0,
+	1.0, -1.0, -1.0, 1.0, 0.0,
+	1.0, -1.0, -1.0, 1.0, 0.0,
+	-1.0, 1.0, -1.0, 0.0, 1.0,
+	1.0, 1.0, -1.0, 1.0, 1.0,
+
+	// Left
+	-1.0, -1.0, 1.0, 0.0, 1.0,
+	-1.0, 1.0, -1.0, 1.0, 0.0,
+	-1.0, -1.0, -1.0, 0.0, 0.0,
+	-1.0, -1.0, 1.0, 0.0, 1.0,
+	-1.0, 1.0, 1.0, 1.0, 1.0,
+	-1.0, 1.0, -1.0, 1.0, 0.0,
+
+	// Right
+	1.0, -1.0, 1.0, 1.0, 1.0,
+	1.0, -1.0, -1.0, 1.0, 0.0,
+	1.0, 1.0, -1.0, 0.0, 0.0,
+	1.0, -1.0, 1.0, 1.0, 1.0,
+	1.0, 1.0, -1.0, 0.0, 0.0,
+	1.0, 1.0, 1.0, 0.0, 1.0,
+}