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 (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)
}