I am trying to combine a light shader with a water shader in libgdx. Shader programming is not one of my strengths at all.
This is the water effect rendering nicely: 
And when I have added the flickering light code I am getting this: 
The light is meant to be a flickering white circle and the water should show up. It doesn't. What I have done so far is try to re-arrange texture binding, combine drawing in one pass. I can render the other scene content on top of the water but the water has to be the top-most item. That is what I am failing to do,
Here is my wall of code (just the render function):
public void render() { float dt = Gdx.graphics.getDeltaTime(); // water time += dt; float angle = time * (2 * MathUtils.PI); if (angle > (2 * MathUtils.PI)) angle -= (2 * MathUtils.PI); // light zAngle += dt * zSpeed; while (zAngle > PI2) zAngle -= PI2; fbo.begin(); batch.setProjectionMatrix(cam.combined); batch.setShader(defaultShader); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.begin(); float lightSize = 140.75f + 0.25f * (float) Math.sin(zAngle) + 27.2f * MathUtils.random(); batch.draw(lighttex, 400 - lightSize * 0.5f + 0.5f, 300 + 0.5f - lightSize * 0.5f, lightSize, lightSize); batch.end(); fbo.end(); // draw the actual scene Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); batch.setProjectionMatrix(cam.combined); batch.setShader(finalShader); batch.begin(); fbo.getColorBufferTexture().bind(1); lighttex.bind(0); batch.draw(map1BgTex, 0, 0, 960, 540); batch.setShader(waterShader); waterShader.setUniformMatrix("u_worldView", cam.combined); batch.end(); Gdx.gl20.glBlendFunc(GL20.GL_SRC_ALPHA, GL20.GL_ONE_MINUS_SRC_ALPHA); Gdx.gl20.glEnable(GL20.GL_BLEND); watertex.bind(1); waterdisptex.bind(2); defWaterShader.begin(); defWaterShader.setUniformMatrix("u_worldView", matrix); defWaterShader.setUniformi("u_texture", 2); defWaterShader.setUniformi("u_texture2", 3); defWaterShader.setUniformf("timedelta", -angle); waterMesh.render(defWaterShader, GL20.GL_TRIANGLE_FAN); defWaterShader.end(); } I uploaded a more complete source file and the shaders to my server, I hope it's not too inconvenient - http://agexdev.com/files/shaders.tar.xz
