func initResources() {
var err error
// Load shaders
vs, err = createShader("triangle.v.glsl", VertexShaderType)
if err != nil {
fmt.Printf("Shader: %s\n", err)
return
}
fs, err = createShader("triangle.f.glsl", FragmentShaderType)
if err != nil {
fmt.Printf("Shader: %s\n", err)
return
}
// Create GLSL program with loaded shaders
var compileOk gl.Int
program = gl.CreateProgram()
gl.AttachShader(program, vs)
gl.AttachShader(program, fs)
gl.LinkProgram(program)
gl.GetProgramiv(program, gl.LINK_STATUS, &compileOk)
if compileOk == 0 {
fmt.Printf("Error in program.\n")
}
// Generate a buffer for the VertexBufferObject
gl.GenBuffers(1, &vboTriangle)
gl.BindBuffer(gl.ARRAY_BUFFER, vboTriangle)
// Submit the vertices of the triangle to the graphic card
gl.BufferData(gl.ARRAY_BUFFER, gl.Sizeiptr(len(triangleVertices)*4), gl.Pointer(&triangleVertices[0]), gl.STATIC_DRAW)
// Unset the active buffer
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Generate a buffer for the Color-VBO
gl.GenBuffers(1, &vboTriangleColors)
gl.BindBuffer(gl.ARRAY_BUFFER, vboTriangleColors)
gl.BufferData(gl.ARRAY_BUFFER, gl.Sizeiptr(len(triangleColors)*4), gl.Pointer(&triangleColors[0]), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Get the attribute location from the GLSL program (here from the vertex shader)
attributeName := gl.GLString("coord2d")
defer gl.GLStringFree(attributeName)
attributeTemp := gl.GetAttribLocation(program, attributeName)
if attributeTemp == -1 {
fmt.Printf("Could not bind attribute %s\n", gl.GoString(attributeName))
}
attributeCoord2d = gl.Uint(attributeTemp)
attributeName = gl.GLString("v_color")
defer gl.GLStringFree(attributeName)
attributeTemp = gl.GetAttribLocation(program, attributeName)
if attributeTemp == -1 {
fmt.Printf("Could not bind attribute %s\n", gl.GoString(attributeName))
}
attributeColor = gl.Uint(attributeTemp)
}
func createprogram() gl.Uint {
// VERTEX SHADER
vs := gl.CreateShader(gl.VERTEX_SHADER)
vs_source := gl.GLString(vertexShaderSource)
gl.ShaderSource(vs, 1, &vs_source, nil)
gl.CompileShader(vs)
var vs_status gl.Int
gl.GetShaderiv(vs, gl.COMPILE_STATUS, &vs_status)
fmt.Printf("Compiled Vertex Shader: %v\n", vs_status)
// FRAGMENT SHADER
fs := gl.CreateShader(gl.FRAGMENT_SHADER)
fs_source := gl.GLString(fragmentShaderSource)
gl.ShaderSource(fs, 1, &fs_source, nil)
gl.CompileShader(fs)
var fstatus gl.Int
gl.GetShaderiv(fs, gl.COMPILE_STATUS, &fstatus)
fmt.Printf("Compiled Fragment Shader: %v\n", fstatus)
// CREATE PROGRAM
program := gl.CreateProgram()
gl.AttachShader(program, vs)
gl.AttachShader(program, fs)
fragoutstring := gl.GLString("outColor")
defer gl.GLStringFree(fragoutstring)
gl.BindFragDataLocation(program, gl.Uint(0), fragoutstring)
gl.LinkProgram(program)
var linkstatus gl.Int
gl.GetProgramiv(program, gl.LINK_STATUS, &linkstatus)
fmt.Printf("Program Link: %v\n", linkstatus)
return program
}
func (p *Program) GetAttributeLocation(name string) (*AttributeLocation, error) {
attributeName := gl.GLString(name)
defer gl.GLStringFree(attributeName)
attributeTemp := gl.GetAttribLocation(p.id, attributeName)
if attributeTemp == -1 {
return nil, errors.New(fmt.Sprintf("Could not bind attribute %s\n", gl.GoString(attributeName)))
}
return &AttributeLocation{id: gl.Uint(attributeTemp)}, nil
}
func initResources() {
var compileOk gl.Int
// Vertex Shader
vs = gl.CreateShader(gl.VERTEX_SHADER)
vsSrc := gl.GLStringArray(vsSource)
defer gl.GLStringArrayFree(vsSrc)
gl.ShaderSource(vs, gl.Sizei(len(vsSrc)), &vsSrc[0], nil)
gl.CompileShader(vs)
gl.GetShaderiv(vs, gl.COMPILE_STATUS, &compileOk)
if compileOk == 0 {
errNum := gl.GetError()
fmt.Printf("Error in vertex shader: %d\n", errNum)
}
// Fragment Shader
fs = gl.CreateShader(gl.FRAGMENT_SHADER)
fsSrc := gl.GLStringArray(fsSource)
defer gl.GLStringArrayFree(fsSrc)
gl.ShaderSource(fs, gl.Sizei(1), &fsSrc[0], nil)
gl.CompileShader(fs)
gl.GetShaderiv(fs, gl.COMPILE_STATUS, &compileOk)
if compileOk == 0 {
errNum := gl.GetError()
fmt.Printf("Error in fragment shader: %d\n", errNum)
}
// GLSL program
program = gl.CreateProgram()
gl.AttachShader(program, vs)
gl.AttachShader(program, fs)
gl.LinkProgram(program)
gl.GetProgramiv(program, gl.LINK_STATUS, &compileOk)
if compileOk == 0 {
fmt.Printf("Error in program.\n")
}
// Get the attribute location from the GLSL program (here from the vertex shader)
attributeName := gl.GLString("coord2d")
defer gl.GLStringFree(attributeName)
attributeTemp := gl.GetAttribLocation(program, attributeName)
if attributeTemp == -1 {
fmt.Printf("Could not bind attribute %s\n", gl.GoString(attributeName))
}
attributeCoord2d = gl.Uint(attributeTemp)
}
func NewMesh(attrs interface{}, indicies []uint32) *Mesh {
mesh := new(Mesh)
mesh.Attrs = attrs
mesh.Indicies = indicies
gl33.GenVertexArrays(1, &mesh.vao)
gl33.BindVertexArray(mesh.vao)
attrsValue := reflect.ValueOf(attrs)
mesh.vertexBO = NewBuffer(gl33.ARRAY_BUFFER, gl33.STATIC_DRAW, attrs)
vertexSpec := attrsValue.Type().Elem()
if vertexSpec.Kind() != reflect.Struct && vertexSpec.Kind() != reflect.Array {
panic("attrs is not a slice of structs or arrays")
}
var num int
if vertexSpec.Kind() == reflect.Struct {
num = vertexSpec.NumField()
} else {
num = vertexSpec.Len()
}
for i, offset := 0, uintptr(0); i < num; i++ {
var field reflect.Type
var type_ gl33.Enum
var dimensions int
if vertexSpec.Kind() == reflect.Struct {
field = vertexSpec.Field(i).Type
} else {
field = vertexSpec.Elem()
}
if field.Kind() == reflect.Array {
type_ = glType(field.Elem().Kind())
dimensions = field.Len()
} else {
type_ = glType(field.Kind())
dimensions = 1
}
setupAttrib(gl33.Uint(i), type_, dimensions, offset, int(vertexSpec.Size()))
offset += field.Size()
}
mesh.indexBO = NewBuffer(gl33.ELEMENT_ARRAY_BUFFER, gl33.STATIC_DRAW, indicies)
return mesh
}
