Example #1
0
func main() {
	initialWidth, initialHeight := 1280, 720
	runtime.LockOSThread()
	if sdlInit := sdl.Init(sdl.INIT_VIDEO); sdlInit != 0 {
		panic("SDL init error")
	}
	reinitScreen(initialWidth, initialHeight)
	defer cleanExit(true, false)
	if err := gl.Init(); err != nil {
		panic(err)
	}
	gl.Enable(gl.BLEND)
	gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
	gl.Enable(gl.DEPTH)
	defer cleanExit(false, true)
	glSetupShaderProg(&shaderTextureCreator, false)
	glSetupShaderProg(&shaderTextureDisplay, true)
	glFillBuffer(rttVerts, &rttVertBuf)
	glFillBuffer(dispVerts, &dispVertBuf)
	gl.GenTextures(1, &rttFrameTex)
	gl.BindTexture(gl.TEXTURE_2D, rttFrameTex)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT)
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT)
	if doRtt {
		gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, texSize, texSize, 0, gl.RGBA, gl.UNSIGNED_BYTE, nil)
		gl.GenFramebuffers(1, &rttFrameBuf)
		gl.BindFramebuffer(gl.FRAMEBUFFER, rttFrameBuf)
		gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, rttFrameTex, 0)
		gl.BindFramebuffer(gl.FRAMEBUFFER, 0)
	} else {
		glFillTextureFromImageFile("texture.jpg")
	}
	gl.BindTexture(gl.TEXTURE_2D, 0)
	gl.ClearColor(0.3, 0.6, 0.9, 1)
	gl.Clear(gl.COLOR_BUFFER_BIT)
	gl.ActiveTexture(gl.TEXTURE0)
	for {
		if evt := sdl.PollEvent(); evt != nil {
			switch event := evt.(type) {
			case *sdl.ResizeEvent:
				reinitScreen(int(event.W), int(event.H))
			case *sdl.QuitEvent:
				return
			}
		} else {
			if doRtt {
				renderToTexture()
			}
			renderToScreen()
			sdl.GL_SwapBuffers()
		}
	}

	sdl.Quit()
}
Example #2
0
func renderToTexture() {
	gl.BindFramebuffer(gl.FRAMEBUFFER, rttFrameBuf)
	gl.Viewport(0, 0, texSize, texSize)
	gl.ClearColor(0.9, 0.6, 0.3, 1)
	gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
	gl.UseProgram(shaderTextureCreator.glProg)
	gl.BindBuffer(gl.ARRAY_BUFFER, rttVertBuf)
	gl.EnableVertexAttribArray(shaderTextureCreator.attrPos)
	gl.VertexAttribPointer(shaderTextureCreator.attrPos, 2, gl.FLOAT, gl.FALSE, 0, gl.Pointer(nil))
	gl.DrawArrays(gl.TRIANGLE_FAN, 0, 4)
	gl.DisableVertexAttribArray(shaderTextureCreator.attrPos)
	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}