func (r *EffectsRenderer) Bind() error {
gl.BindFramebuffer(gl.FRAMEBUFFER, r.framebuffer)
gl.Enable(gl.STENCIL_TEST)
gl.Viewport(0, 0, int32(r.width), int32(r.height))
gl.ClearStencil(0)
gl.ClearColor(0.0, 0.0, 0.0, 0.0)
gl.StencilMask(0xFF) // Write to buffer
gl.Clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT)
gl.StencilMask(0x00) // Don't write to buffer
return nil
}
func (r *EffectsRenderer) EnableOutput() {
gl.ColorMask(true, true, true, true)
gl.StencilMask(0x00) // No more writing
gl.StencilFunc(gl.EQUAL, 0, 0xFF) // Only pass where stencil is 0
}
func (r *EffectsRenderer) DisableOutput() {
gl.ColorMask(false, false, false, false)
gl.StencilFunc(gl.NEVER, 1, 0xFF) // Never pass
gl.StencilOp(gl.REPLACE, gl.REPLACE, gl.REPLACE) // Replace to ref=1
gl.StencilMask(0xFF) // Write to buffer
}
func InitGL() error {
defer tlog.FuncLog(tlog.Func("InitGL"))
err := gl.Init()
if err != nil {
return err
}
gl.GetError() // cleanup gl error state
version := gl.GoStr(gl.GetString(gl.VERSION))
tlog.Println("OpenGL version", version)
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
Check()
gl.ReadBuffer(gl.BACK)
Check()
gl.DrawBuffer(gl.BACK)
Check()
gl.FrontFace(gl.CW)
Check()
gl.CullFace(gl.BACK)
Check()
gl.Disable(gl.CULL_FACE)
Check()
gl.ClearColor(1, 1, 0.5, 0)
Check()
gl.ClearDepth(1.0)
Check()
gl.ClearStencil(0)
Check()
gl.Disable(gl.STENCIL_TEST)
Check()
gl.StencilMask(0xFFFFFFFF)
Check()
gl.StencilFunc(gl.EQUAL, 0x00000000, 0x00000001)
Check()
gl.StencilOp(gl.KEEP, gl.KEEP, gl.KEEP)
Check()
gl.Disable(gl.DITHER)
Check()
gl.Enable(gl.DEPTH_TEST)
Check()
gl.DepthFunc(gl.LEQUAL)
Check()
gl.DepthMask(true)
Check()
gl.DepthRange(0., 1.)
Check()
gl.Enable(gl.DEPTH_CLAMP)
Check()
gl.Enable(gl.BLEND)
Check()
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
ForceCheck()
return nil
}