func compileShaders() (err error) {
var glStatus gl.Int
makeShader := func(stage gl.Enum, src string) (shader gl.Uint) {
shader = gl.CreateShader(stage)
logLastGlError("gl.CreateShader()")
glStr := gl.Util.CStringArray(src)
defer gl.Util.CStringArrayFree(glStr)
gl.ShaderSource(shader, gl.Sizei(len(glStr)), &glStr[0], nil)
logLastGlError("gl.ShaderSource()")
gl.CompileShader(shader)
if gl.GetShaderiv(shader, gl.COMPILE_STATUS, &glStatus); glStatus == 0 {
panic("Shader compilation failed: " + src)
}
return
}
glVertShader := makeShader(gl.VERTEX_SHADER, srcVertShader)
defer gl.DeleteShader(glVertShader)
glFragShader := makeShader(gl.FRAGMENT_SHADER, srcFragShader)
defer gl.DeleteShader(glFragShader)
shaderProg = gl.CreateProgram()
for stageName, shader := range map[string]gl.Uint{"vert": glVertShader, "frag": glFragShader} {
gl.AttachShader(shaderProg, shader)
logLastGlError("gl.AttachShader " + stageName)
defer gl.DetachShader(shaderProg, shader)
}
gl.LinkProgram(shaderProg)
if gl.GetProgramiv(shaderProg, gl.LINK_STATUS, &glStatus); glStatus == 0 {
panic("Program linking failed...")
}
glAttName := gl.Util.CString("aPos")
defer gl.Util.CStringFree(glAttName)
progPosAttrLoc = gl.Uint(gl.GetAttribLocation(shaderProg, glAttName))
logLastGlError("gl.GetAttribLocation()")
return
}
// Calls gl.AttachShader() and yields the err returned by Util.LastError(), if any.
func (_ GlTry) AttachShader(program gl.Uint, shader gl.Uint) (err error) {
gl.AttachShader(program, shader)
err = Util.LastError("gl.AttachShader()")
return
}