Libgdx - FrameBuffer rendering and FitViewport

Question

I use ortho camera and FitViewport at my project.

In my render() method i create a fremeBuffer to store actual state of my game, then create a pixmap of that buffer and finally i set a new shader and do my postprocess stuff with that frame:

//--- render frame to buffer
screenBuffer.begin();
camera.update();
Gdx.gl.glClearColor(1, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.setProjectionMatrix(camera.combined);
batch.begin();
batch.draw(img, 0, 0);
batch.end();
stage.draw();
//--- create pixmap from that buffer
pixmap = ScreenUtils.getFrameBufferPixmap(0, 0,screenBuffer.getWidth(), screenBuffer.getHeight());
batch.flush();
screenBuffer.end();
//--- create texture from pixmap   
renderedScreenTexture = new Texture(pixmap);
//--- finally render frame with postprocess shader
camera.update();
Gdx.gl.glClearColor(1, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.setShader(monoShader);
batch.setProjectionMatrix(camera.combined);
batch.begin();
batch.draw(renderedScreenTexture, 0,0);
batch.draw(renderedScreenTexture, 0, 0, 640, 320, 0, 0, 640, 320, false, true);
batch.end();

At my resize method I have:

viewport.update(width, height);
camera.position.set(camera.viewportWidth / 2,camera.viewportHeight / 2, 0);

The problem is that after resizing a window FitViewport doesen't work. When i remove a creating frameBuffer from render method FitViewport works fine. Can anybody tell me what is wrong with my code or whole concept?

Answer 1

You may have to call fitViewport.apply() before drawing your frameBuffer.