func (c *Context) GetUniformLocation(p Program, location string) UniformLocation {
u := UniformLocation(gl.GetUniformLocation(uint32(p), gl.Str(location+"\x00")))
if u == -1 {
panic("invalid uniform location: " + location)
}
return u
}
func (*backend) GetUniformLocation(p *gg.Program, name string) (*gg.Uniform, error) {
u := gl.GetUniformLocation(p.Value.(uint32), gl.Str(name+"\x00"))
if u < 0 {
return nil, fmt.Errorf("gg: no uniform named " + name)
}
return &gg.Uniform{Value: u}, nil
}
func (c *Context) getUniformLocationImpl(p Program, location string) uniformLocation {
uniform := uniformLocation(gl.GetUniformLocation(uint32(p), gl.Str(location+"\x00")))
if uniform == -1 {
panic("opengl: invalid uniform location: " + location)
}
return uniform
}
func initResources() uint32 {
vs := CreateShader("triangle.v.glsl", gl.VERTEX_SHADER)
fs := CreateShader("triangle.f.glsl", gl.FRAGMENT_SHADER)
var linkOk int32
program := gl.CreateProgram()
gl.AttachShader(program, vs)
gl.AttachShader(program, fs)
gl.LinkProgram(program)
gl.GetProgramiv(program, gl.LINK_STATUS, &linkOk)
if linkOk == 0 {
log.Fatal("gl.LinkProgram")
}
gl.GenBuffers(1, &vboTriangle)
gl.BindBuffer(gl.ARRAY_BUFFER, vboTriangle)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(triangleAttributes), gl.Ptr(triangleAttributes), gl.STATIC_DRAW)
attributeCoord2d = gl.GetAttribLocation(program, gl.Str("coord2d\x00"))
if attributeCoord2d == -1 {
log.Fatal("failed to bind attribute")
}
attributeVColor = gl.GetAttribLocation(program, gl.Str("v_color\x00"))
if attributeVColor == -1 {
log.Fatal("could not bind attribute v_color")
}
uniformFade = gl.GetUniformLocation(program, gl.Str("fade\x00"))
if uniformFade == -1 {
log.Fatal("could not bind uniform fade")
}
return program
}
func (s *Shader) addUniform(uniformName string) error {
uniformLocation := gl.GetUniformLocation(s.program, gl.Str(uniformName+"\000"))
if uniformLocation == -1 {
return fmt.Errorf("could not find uniform: %s", uniformName)
}
s.uniforms[uniformName] = uniformLocation
return nil
}
func (s *Shader) addUniform(uniformName string) error {
csource, free := gl.Strs(uniformName + "\000")
defer free()
uniformLocation := gl.GetUniformLocation(s.program, *csource)
if uniformLocation == -1 {
return fmt.Errorf("could not find uniform: %s", uniformName)
}
s.uniforms[uniformName] = uniformLocation
return nil
}
func uniforms(id uint32) map[string]Uniform {
var maxlength int32
gl.GetProgramiv(id, gl.ACTIVE_UNIFORM_MAX_LENGTH, &maxlength)
var numuniforms int32
gl.GetProgramiv(id, gl.ACTIVE_UNIFORMS, &numuniforms)
buf := make([]byte, maxlength)
m := make(map[string]Uniform)
for index := uint32(0); index < uint32(numuniforms); index++ {
name, dt, siz := uniform(id, index, buf)
loc := gl.GetUniformLocation(id, &buf[0])
if loc == -1 {
panic(fmt.Errorf("Expected location for indexed uniform '%s'", name))
}
m[name] = Uniform{
name: name,
location: loc,
typ: dt,
siz: siz,
}
}
return m
}
// GetUniformLocation returns the location of a uniform variable.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glGetUniformLocation.xhtml
func GetUniformLocation(p Program, name string) Uniform {
return Uniform{Value: gl.GetUniformLocation(p.Value, gl.Str(name+"\x00"))}
}
func (c *Context) GetUniformLocation(program *Program, name string) *UniformLocation {
return &UniformLocation{gl.GetUniformLocation(program.uint32, gl.Str(name+"\x00"))}
}
func (c *Context) GetUniformLocation(program *Program, name string) *UniformLocation {
strptr, free := gl.Strs(name + "\x00")
defer free()
return &UniformLocation{gl.GetUniformLocation(program.uint32, *strptr)}
}
