//
// Build Shader
// Creates and compiles a shader
//
// @param source (string) the path to the shader file
// @param shaderType (uint32) the shader type
//
// @return shader (uint32) the pointer to the shader
// @return error (error) the error (if any)
//
func BuildShader(source string, shaderType uint32) (uint32, error) {
// Creates the Shader Object
shader := gl.CreateShader(shaderType)
// Reads the File
fileContents := FileToString(source)
// Converts the file contents into a valid C String
csource := gl.Str(fileContents)
// Loads the Shader's Source
gl.ShaderSource(shader, 1, &csource, nil)
// Compiles the Shader
gl.CompileShader(shader)
// Gets any errors that happened when building the Shader
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
// If there was an error, parse the C Error into a Go Error and return it
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)
}
// Returns the shader if everything is OK
return shader, nil
}
func compileShader(source string, shaderType uint32) (uint32, error) {
shader := gl.CreateShader(shaderType)
csource := gl.Str(source)
gl.ShaderSource(shader, 1, &csource, nil)
if e := gl.GetError(); e != gl.NO_ERROR {
panic(fmt.Sprintf("before resizing: %d", e))
}
gl.CompileShader(shader)
if e := gl.GetError(); e != gl.NO_ERROR {
panic(fmt.Sprintf("before resizing: %d", e))
}
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
}
func makeShader(shaderType uint32, source string) uint32 {
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))
x(fmt.Errorf("failed to compile %v: %v", source, log))
}
return shader
}
