//NewShadowFBO will create a new FBO, a new depth texture and the program needed to generate shadow map
//currently not optimized, we should probably reuse the FBO and absolutely reuse the program.
func NewShadowFBO(width, height int32) (*ShadowFBO, error) {
sfbo := ShadowFBO{}
fbo := gl2.GenFramebuffer()
sfbo.width, sfbo.height = width, height
sfbo.framebuffer = fbo
fbo.Bind(gl2.FRAMEBUFFER)
defer fbo.Unbind(gl2.FRAMEBUFFER)
shadowtex := gl2.GenTexture2D()
sfbo.texture = shadowtex
shadowtex.Bind()
defer shadowtex.Unbind()
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_COMPARE_MODE, gl.COMPARE_REF_TO_TEXTURE)
shadowtex.TexParameteriv(gl.TEXTURE_2D, gl.TEXTURE_COMPARE_FUNC, gl.LEQUAL)
shadowtex.TexImage2D(0, gl.DEPTH_COMPONENT16, width, height, 0, gl.DEPTH_COMPONENT, gl.FLOAT, nil)
fbo.Texture(gl2.FRAMEBUFFER, gl2.DEPTH_ATTACHMENT, shadowtex, 0 /*level*/)
fbo.DrawBuffer(gl2.NONE)
fbo.ReadBuffer(gl2.NONE)
if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
return &sfbo, errors.New("framebuffer incomplete")
}
vs, err := CompileShader(_shadowFboVertexShader, gl2.VERTEX_SHADER)
if err != nil {
return &sfbo, err
}
defer vs.Delete()
fs, err := CompileShader(_shadowFboFragmentShader, gl2.FRAGMENT_SHADER)
if err != nil {
return &sfbo, err
}
defer fs.Delete()
prog, err := NewProgram(vs, fs)
if err != nil {
return &sfbo, err
}
sfbo.program = prog
prog.Use()
sfbo.mvpUni = prog.GetUniformLocation("mvp")
return &sfbo, nil
}
func (r *EffectsRenderer) GetError() error {
if e := gl.GetError(); e != 0 {
return fmt.Errorf("OpenGL error: %X", e)
}
var status = gl.CheckFramebufferStatus(gl.DRAW_FRAMEBUFFER)
switch status {
case gl.FRAMEBUFFER_COMPLETE:
return nil
case gl.FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
return fmt.Errorf("Attachment point unconnected")
case gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
return fmt.Errorf("Missing attachment")
case gl.FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
return fmt.Errorf("Draw buffer")
case gl.FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
return fmt.Errorf("Read buffer")
case gl.FRAMEBUFFER_UNSUPPORTED:
return fmt.Errorf("Unsupported config")
default:
return fmt.Errorf("Unknown framebuffer error: %X", status)
}
}
//NewPostProcessFramebuffer creates a new PostProcessFramebuffer and allocated all the ressources.
//You do not control the vertex shader but you can give a fragment shader. The fragment shader must have the following uniforms:
// -resolution: float vec2, representing the size of the texture
// -time: float, glfw time since the begining of the program
// -tex: sampler2D, the input texture to this post process pass
func NewPostProcessFramebuffer(width, height int32, fragmentSource string) (*PostProcessFramebuffer, error) {
ppf := PostProcessFramebuffer{}
vs, err := CompileShader(_fullscreenVertexShader, gl2.VERTEX_SHADER)
if err != nil {
return &ppf, err
}
defer vs.Delete()
fs, err := CompileShader(fragmentSource, gl2.FRAGMENT_SHADER)
if err != nil {
return &ppf, err
}
defer fs.Delete()
prog, err := NewProgram(vs, fs)
if err != nil {
return &ppf, err
}
ppf.Prog = prog
prog.Use()
res := prog.GetUniformLocation("resolution")
ppf.source = prog.GetUniformLocation("tex")
res.Uniform2f(float32(width), float32(height))
ppf.time = prog.GetUniformLocation("time")
ppf.Fb = gl2.GenFramebuffer()
ppf.Tex = GenRGBTexture2D(width, height)
ppf.Fb.Bind(gl2.FRAMEBUFFER)
defer ppf.Fb.Unbind(gl2.FRAMEBUFFER)
ppf.Fb.Texture(gl2.FRAMEBUFFER, gl2.COLOR_ATTACHMENT0, ppf.Tex, 0)
ppf.Fb.DrawBuffers(gl2.COLOR_ATTACHMENT0)
if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
return &ppf, errors.New("framebuffer incomplete")
}
return &ppf, nil
}