func NewProgram(vertexSource, fragmentSource string) (*Program, error) {
vertexId, err := newShader(vertexSource, gl.VERTEX_SHADER)
if err != nil {
return nil, err
}
fragmentId, err := newShader(fragmentSource, gl.FRAGMENT_SHADER)
if err != nil {
gl.DeleteShader(vertexId)
return nil, err
}
id := gl.CreateProgram()
if id == 0 {
gl.DeleteShader(vertexId)
gl.DeleteShader(fragmentId)
return nil, fmt.Errorf("Unable to allocate program")
}
gl.AttachShader(id, vertexId)
gl.AttachShader(id, fragmentId)
gl.LinkProgram(id)
var result int32
gl.GetProgramiv(id, gl.LINK_STATUS, &result)
if result == int32(gl.FALSE) {
var loglength int32
gl.GetProgramiv(id, gl.INFO_LOG_LENGTH, &loglength)
log := make([]byte, loglength)
var length int32
gl.GetProgramInfoLog(id, loglength, &length, &log[0])
gl.DeleteShader(vertexId)
gl.DeleteShader(fragmentId)
gl.DeleteProgram(id)
return nil, fmt.Errorf("Unable to link program: %s", log[:length])
}
return &Program{
id: id,
vertId: vertexId,
fragId: fragmentId,
uniforms: uniforms(id),
}, nil
}
// CreateShader creates a shader object from a source file.
func CreateShader(filename string, xtype uint32) uint32 {
data, err := ioutil.ReadFile(filename)
if err != nil {
log.Fatal(err)
}
dataString := "#version 120\n" + string(data) + "\x00"
dataSrc := gl.Str(dataString)
res := gl.CreateShader(xtype)
gl.ShaderSource(res, 1, &dataSrc, nil)
gl.CompileShader(res)
var compileOk int32
gl.GetShaderiv(res, gl.COMPILE_STATUS, &compileOk)
if compileOk == gl.FALSE {
PrintLog(res)
gl.DeleteShader(res)
}
return res
}
func newShader(source string, shaderType uint32) (uint32, error) {
id := gl.CreateShader(shaderType)
if id == 0 {
return 0, fmt.Errorf("Unable to allocate shader")
}
ptr, free := convc.StringToC(source)
defer free()
gl.ShaderSource(id, 1, &ptr, nil)
gl.CompileShader(id)
var result int32
gl.GetShaderiv(id, gl.COMPILE_STATUS, &result)
if result == int32(gl.FALSE) {
var loglength int32
gl.GetShaderiv(id, gl.INFO_LOG_LENGTH, &loglength)
log := make([]byte, loglength)
var length int32
gl.GetShaderInfoLog(id, loglength, &length, &log[0])
gl.DeleteShader(id)
return 0, fmt.Errorf("Unable to compile shader: %s", log[:length])
}
return id, nil
}
// DeleteShader deletes shader s.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glDeleteShader.xhtml
func DeleteShader(s Shader) {
gl.DeleteShader(s.Value)
}
func (c *Context) DeleteShader(s Shader) {
gl.DeleteShader(uint32(s))
}
// DeleteShader will free the shader memory. You should call this in case of
// a compilation error to avoid leaking memory
func (c *Context) DeleteShader(shader *Shader) {
gl.DeleteShader(shader.uint32)
}
func (c *Context) DeleteShader(s Shader) {
_ = c.runOnContextThread(func() error {
gl.DeleteShader(uint32(s))
return nil
})
}
func (program *Program) Delete() {
gl.DeleteProgram(program.id)
gl.DeleteShader(program.vertId)
gl.DeleteShader(program.fragId)
}