func (s *Shader) initShader(t gl.Enum, str string, shader *gl.Uint) {
*shader = gl.CreateShader(t)
if *shader == 0 {
fmt.Println("error creating shader of type ", t)
}
src := gl.GLStringArray(str)
defer gl.GLStringArrayFree(src)
gl.ShaderSource(*shader, 1, &src[0], nil)
gl.CompileShader(*shader)
var (
status gl.Int
info_length gl.Int
message *gl.Char
)
gl.GetShaderiv(*shader, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
fmt.Println("Error compiling shader")
gl.GetShaderiv(*shader, gl.INFO_LOG_LENGTH, &info_length)
message = gl.GLStringAlloc(gl.Sizei(info_length))
gl.GetShaderInfoLog(*shader, gl.Sizei(info_length), nil, message)
fmt.Println(gl.GoString(message))
gl.GLStringFree(message)
}
}
func (s *Shader) initWithString(vert_shader string, frag_shader string) {
s.initShader(gl.VERTEX_SHADER, vert_shader, &s.vert_shader)
s.initShader(gl.FRAGMENT_SHADER, frag_shader, &s.frag_shader)
s.program = gl.CreateProgram()
gl.AttachShader(s.program, s.vert_shader)
gl.AttachShader(s.program, s.frag_shader)
gl.LinkProgram(s.program)
var (
status gl.Int
info_length gl.Int
message *gl.Char
)
gl.GetProgramiv(s.program, gl.LINK_STATUS, &status)
if status == gl.FALSE {
fmt.Println("Error linking program")
gl.GetProgramiv(s.program, gl.INFO_LOG_LENGTH, &info_length)
message = gl.GLStringAlloc(gl.Sizei(info_length))
gl.GetProgramInfoLog(s.program, gl.Sizei(info_length), nil, message)
fmt.Println(gl.GoString(message))
gl.GLStringFree(message)
}
s.initAttributes()
s.initUniforms()
}
func (s *Shader) initUniform(name string, uni *gl.Int) {
uni_name := gl.GLString(name)
defer gl.GLStringFree(uni_name)
*uni = gl.GetUniformLocation(s.program, uni_name)
if *uni == -1 {
fmt.Println("Error in getting uniform", gl.GoString(uni_name))
}
}
func (s *Shader) initAttribute(name string, att *gl.Uint) {
att_name := gl.GLString(name)
defer gl.GLStringFree(att_name)
att_tmp := gl.GetAttribLocation(s.program, att_name)
if att_tmp == -1 {
fmt.Println("Error in getting attribute ", gl.GoString(att_name))
} else {
*att = gl.Uint(att_tmp)
}
}