func (s *Shader) getProgramInfoLog(context string) error {
var logLength int32
gl.GetProgramiv(s.program, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(s.program, logLength, nil, gl.Str(log))
return fmt.Errorf("%s: %s", context, log)
}
func (s *Shader) getProgramInfoLog(context string) error {
var logLength int32
gl.GetProgramiv(s.program, gl.INFO_LOG_LENGTH, &logLength)
cLog, free := gl.Strs(strings.Repeat("\x00", int(logLength+1)))
defer free()
gl.GetProgramInfoLog(s.program, logLength, nil, *cLog)
return fmt.Errorf("%s: %s", context, cLog)
}
// GetProgramInfoLog returns the information log for a program.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glGetProgramInfoLog.xhtml
func GetProgramInfoLog(p Program) string {
var logLength int32
gl.GetProgramiv(p.Value, gl.INFO_LOG_LENGTH, &logLength)
if logLength == 0 {
return ""
}
logBuffer := make([]uint8, logLength)
gl.GetProgramInfoLog(p.Value, logLength, nil, &logBuffer[0])
return gl.GoStr(&logBuffer[0])
}
func (*backend) LinkProgram(p *gg.Program) error {
pv := p.Value.(uint32)
gl.LinkProgram(pv)
var status int32
gl.GetProgramiv(pv, gl.LINK_STATUS, &status)
if status == gl.TRUE {
return nil
}
var logLength int32
gl.GetProgramiv(pv, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(pv, logLength, nil, gl.Str(log))
return fmt.Errorf("link program: %s", log)
}
// PrintLog prints the error log for an object
func PrintLog(object uint32) {
var logLength int32
if gl.IsShader(object) {
gl.GetShaderiv(object, gl.INFO_LOG_LENGTH, &logLength)
} else if gl.IsProgram(object) {
gl.GetProgramiv(object, gl.INFO_LOG_LENGTH, &logLength)
} else {
log.Fatal("PrintLog: not a shader or program")
}
infoLog := strings.Repeat("\x00", int(logLength+1))
if gl.IsShader(object) {
gl.GetShaderInfoLog(object, logLength, nil, gl.Str(infoLog))
} else if gl.IsProgram(object) {
gl.GetProgramInfoLog(object, logLength, nil, gl.Str(infoLog))
}
log.Fatal(infoLog)
}
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
}