func (self *ShaderInfo) CompileShader() (uint32, error) {
content, err := ioutil.ReadFile(self.Path)
if err != nil {
return 0, err
}
contentString := bytes.NewBuffer(content).String()
glContentString := gl.Str(contentString + "\x00")
shader := gl.CreateShader(self.ShaderType)
gl.ShaderSource(shader, 1, &glContentString, nil)
gl.CompileShader(shader)
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
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, gl.Str(log))
return 0, fmt.Errorf("failed to compile %v: %v", contentString, log)
}
return shader, nil
}
// loads shader objects and then attaches them to a program
func LoadShaderProgram(vertShader string, fragShader string, attribs []string) (*Program, error) {
// create the program
var prog uint32 = gl.CreateProgram()
var p *Program = &Program{prog, make(map[string]int32)}
// create the vertex shader
var vs uint32 = gl.CreateShader(gl.VERTEX_SHADER)
ShaderSource(vs, vertShader)
gl.CompileShader(vs)
var success int32 = gl.FALSE
gl.GetShaderiv(vs, gl.COMPILE_STATUS, &success)
if success == gl.FALSE {
return nil, fmt.Errorf("Failed to compile the vertex shader!\n%s", GetShaderInfoLog(vs))
}
// create the fragment shader
var fs uint32 = gl.CreateShader(gl.FRAGMENT_SHADER)
ShaderSource(fs, fragShader)
gl.CompileShader(fs)
success = gl.FALSE
gl.GetShaderiv(fs, gl.COMPILE_STATUS, &success)
if success == gl.FALSE {
return nil, fmt.Errorf("Failed to compile the fragment shader!\n%s", GetShaderInfoLog(fs))
}
// attach the shaders to the program and link
gl.AttachShader(prog, vs)
gl.AttachShader(prog, fs)
for i := 1; i <= len(attribs); i++ {
var attr_array []uint8 = StringToArray(attribs[i-1])
gl.BindAttribLocation(prog, uint32(i), &attr_array[0])
}
gl.LinkProgram(prog)
success = gl.FALSE
gl.GetProgramiv(prog, gl.LINK_STATUS, &success)
if success == gl.FALSE {
return nil, fmt.Errorf("Failed to link the program!\n%s", p.GetProgramInfoLog())
}
// at this point the shaders can be deleted
gl.DeleteShader(vs)
gl.DeleteShader(fs)
return p, nil
}
func GetShaderInfoLog(shader uint32) string {
var logSize int32 = 0
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logSize)
var infoLog []uint8 = make([]uint8, logSize)
gl.GetShaderInfoLog(shader, logSize, &logSize, &infoLog[0])
return gl.GoStr(&infoLog[0])
}
func compileShader(source string, shaderType uint32) (uint32, error) {
shader := gl.CreateShader(shaderType)
csource := gl.Str(source)
gl.ShaderSource(shader, 1, &csource, nil)
gl.CompileShader(shader)
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
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, gl.Str(log))
return 0, fmt.Errorf("failed to compile %v: %v", source, log)
}
return shader, nil
}
