func (a *app) draw(t time.Time) {
gl.Clear(gl.COLOR_BUFFER_BIT)
img := a.img
w := img.Rect.Dx()
h := img.Rect.Dy()
gl.ActiveTexture(gl.TEXTURE0)
upload(1, img.Y, img.YStride, w, h)
gl.ActiveTexture(gl.TEXTURE1)
upload(2, img.Cb, img.CStride, w/2, h/2)
gl.ActiveTexture(gl.TEXTURE2)
upload(3, img.Cr, img.CStride, w/2, h/2)
if *blend {
pimg := a.pimg
gl.Uniform1f(a.factorloc, factor(t,
a.tbase.Add(pimg.Timecode),
a.tbase.Add(img.Timecode)))
gl.ActiveTexture(gl.TEXTURE3)
upload(4, pimg.Y, pimg.YStride, w, h)
gl.ActiveTexture(gl.TEXTURE4)
upload(5, pimg.Cb, pimg.CStride, w/2, h/2)
gl.ActiveTexture(gl.TEXTURE5)
upload(6, pimg.Cr, pimg.CStride, w/2, h/2)
}
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
}
func SetUniformF(shader, variable string, f float32) error {
prog, ok := shader_progs[shader]
if !ok {
return shaderError(fmt.Sprintf("Tried to set a uniform in an unknown shader '%s'", shader))
}
bvariable := []byte(fmt.Sprintf("%s\x00", variable))
loc := gl.GetUniformLocation(prog, (*gl.Char)(unsafe.Pointer(&bvariable[0])))
gl.Uniform1f(loc, gl.Float(f))
return nil
}
func SetUniformF(shader, variable string, f float32) {
prog, ok := shader_progs[shader]
if !ok {
if !warned_names[shader] {
Warn().Printf("Tried to set a uniform in an unknown shader '%s'", shader)
warned_names[shader] = true
}
return
}
bvariable := []byte(fmt.Sprintf("%s\x00", variable))
loc := gl.GetUniformLocation(prog, (*gl.Char)(unsafe.Pointer(&bvariable[0])))
gl.Uniform1f(loc, f)
}
// SetVariablef sets a specified variable to the supplied integer to be passed
// into an effect.
func (effect *Effect) SetVariablef(variable string, val float32) error {
var currEffect gl.Int
gl.GetIntegerv(gl.CURRENT_PROGRAM, &currEffect)
if gl.Uint(currEffect) != effect.program {
return errors.New("effect is not currently in use")
}
effect.checkUniformVariable(variable)
gl.Uniform1f(effect.uniforms[variable], gl.Float(val))
return nil
}