Golang C.glGetProgramiv函数代码示例

func (program *Program) Link() {
	C.glLinkProgram(program.id)

	status := C.GLint(0)
	C.glGetProgramiv(program.id, C.GL_LINK_STATUS, &status)

	if status != C.GL_TRUE {
		loglen := C.GLint(0)
		C.glGetProgramiv(program.id, C.GL_INFO_LOG_LENGTH, &loglen)
		log := (*C.GLchar)(C.malloc(C.size_t(loglen)))
		defer C.free(unsafe.Pointer(log))
		C.glGetProgramInfoLog(program.id, C.GLsizei(loglen), nil, log)
		panic(fmt.Errorf("Failed to link shader: %s", C.GoString((*C.char)(log))))
	}
}

func GetProgramiv(
	program uint32, pname Enum, params *int32) {
	C.glGetProgramiv(
		C.GLuint(program),
		C.GLenum(pname),
		(*C.GLint)(params))

}

func (program Program) GetAttachedShaders() []Object {
	var len C.GLint
	C.glGetProgramiv(C.GLuint(program), C.GLenum(ACTIVE_UNIFORM_MAX_LENGTH), &len)

	objects := make([]Object, len)
	C.glGetAttachedShaders(C.GLuint(program), C.GLsizei(len), nil, *((**C.GLuint)(unsafe.Pointer(&objects))))
	return objects
}

func GetProgrami(p Program, pname Enum) (r0 int) {
	defer func() {
		errstr := errDrain()
		log.Printf("gl.GetProgrami(%v, %v) %v%v", p, pname, r0, errstr)
	}()
	var params C.GLint
	C.glGetProgramiv(p.c(), pname.c(), &params)
	return int(params)
}

func (program *Program) Shaders() []Shader {
	if !program.shadersValid {
		nshaders := C.GLint(0)
		C.glGetProgramiv(program.id, C.GL_ATTACHED_SHADERS, &nshaders)
		program.shaders = make([]Shader, nshaders)
		C.glGetAttachedShaders(program.id, C.GLsizei(nshaders), nil, (*C.GLuint)(&program.shaders[0]))
		program.shadersValid = true
	}
	return program.shaders
}

// Link links the attached shader objects
func (p *Program) Link() error {
	var val, val2 C.GLint
	C.glLinkProgram(p.i)
	C.glGetProgramiv(p.i, LINK_STATUS, &val)
	if val != TRUE {
		C.glGetProgramiv(p.i, INFO_LOG_LENGTH, &val)
		buf := make([]C.GLchar, val+1)
		C.glGetProgramInfoLog(p.i, C.GLsizei(val), nil, &buf[0])
		return errors.New(C.GoString((*C.char)(&buf[0])))
	}
	p.attr = make(map[string]C.GLuint)
	C.glGetProgramiv(p.i, ACTIVE_ATTRIBUTES, &val)
	C.glGetProgramiv(p.i, ACTIVE_ATTRIBUTE_MAX_LENGTH, &val2)
	buf := make([]C.char, val2)
	for i := C.GLuint(0); i < C.GLuint(val); i++ {
		C.glGetActiveAttrib(p.i, i, C.GLsizei(val2), nil, nil, nil, (*C.GLchar)(&buf[0]))
		p.attr[C.GoString(&buf[0])] = C.GLuint(C.glGetAttribLocation(p.i, (*C.GLchar)(&buf[0])))
	}
	p.uni = make(map[string]C.GLint)
	C.glGetProgramiv(p.i, ACTIVE_UNIFORMS, &val)
	C.glGetProgramiv(p.i, ACTIVE_UNIFORM_MAX_LENGTH, &val2)
	buf = make([]C.char, val2)
	for i := C.GLuint(0); i < C.GLuint(val); i++ {
		C.glGetActiveUniform(p.i, i, C.GLsizei(val2), nil, nil, nil, (*C.GLchar)(&buf[0]))
		p.uni[C.GoString(&buf[0])] = C.glGetUniformLocation(p.i, (*C.GLchar)(&buf[0]))
	}
	return nil
}

func GetProgramInfoLog(program C.GLuint) string {
	var logLen C.GLint
	C.glGetProgramiv(program, C.GL_INFO_LOG_LENGTH, &logLen)
	var c C.GLchar
	logLenBytes := int(logLen) * int(unsafe.Sizeof(c))
	log := C.malloc(C.size_t(logLenBytes))
	if log == nil {
		panic("Failed to allocate shader log buffer")
	}
	defer C.free(log)
	C.glGetProgramInfoLog(C.GLuint(program), C.GLsizei(logLen), (*C.GLsizei)(unsafe.Pointer(nil)), (*C.GLchar)(log))
	return string(C.GoBytes(log, C.int(logLenBytes)))
}

func (program Program) GetInfoLog() string {
	var length C.GLint
	C.glGetProgramiv(C.GLuint(program), C.GLenum(INFO_LOG_LENGTH), &length)
	// length is buffer size including null character

	if length > 1 {
		log := C.malloc(C.size_t(length))
		defer C.free(log)
		C.glGetProgramInfoLog(C.GLuint(program), C.GLsizei(length), nil, (*C.GLchar)(log))
		return C.GoString((*C.char)(log))
	}
	return ""

}

func createProgram(vertShaderSrc string, fragShaderSrc string) C.GLuint {
	vertShader := loadShader(C.GL_VERTEX_SHADER, vertShaderSrc)
	fragShader := loadShader(C.GL_FRAGMENT_SHADER, fragShaderSrc)
	prog := C.glCreateProgram()
	if prog == 0 {
		panic("Failed to create shader program")
	}
	C.glAttachShader(prog, vertShader)
	checkGLError()
	C.glAttachShader(prog, fragShader)
	checkGLError()
	C.glLinkProgram(prog)
	var linkStatus C.GLint
	C.glGetProgramiv(prog, C.GL_LINK_STATUS, &linkStatus)
	if linkStatus != C.GL_TRUE {
		log := GetProgramInfoLog(prog)
		panic(fmt.Errorf("Failed to link program: %v", log))
	}
	return prog
}

func GetProgrami(p Program, pname Enum) int {
	var params C.GLint
	C.glGetProgramiv(p.c(), pname.c(), &params)
	return int(params)
}

// Get returns a parameter from a program object.
func (p Program) Get(parm ProgramParameter) int {
	var vl C.GLint
	C.glGetProgramiv(C.GLuint(p), C.GLenum(parm), &vl)
	return int(vl)
}

func (program Program) Get(param GLenum) int {
	var rv C.GLint

	C.glGetProgramiv(C.GLuint(program), C.GLenum(param), &rv)
	return int(rv)
}

func GetProgramiv(program, pname uint, params []int32) []int32 {
	C.glGetProgramiv(C.GLuint(program), C.GLenum(pname), (*C.GLint)(unsafe.Pointer(&params[0])))
	return params
}