gistfile1.cpp

#include "cinder/app/AppBasic.h"
#include "cinder/gl/gl.h"
#include "cinder/gl/Fbo.h"
#include "cinder/gl/Texture.h"

using namespace ci;
using namespace ci::app;
using namespace std;

class MirroredFboApp : public AppBasic {
public:
	void setup(); 
	void update();
	void draw();

	gl::Fbo fbo1, fbo2;
};

void MirroredFboApp::setup()
{
	gl::enableAlphaBlending(); 
	fbo1 = gl::Fbo( getWindowWidth()/2, getWindowHeight() );
	fbo2 = gl::Fbo( getWindowWidth(), getWindowHeight() );
} 

void MirroredFboApp::update()
{ 
	fbo1.bindFramebuffer();
	gl::color(Color(255,255,255));
	gl::drawSolidCircle(getWindowCenter(), 200);
	fbo1.unbindFramebuffer();

	//fbo2.bindFramebuffer();
	//gl::color(Color(255,0,0));
	//gl::drawSolidCircle(getWindowCenter(), 200);
	//fbo2.unbindFramebuffer();

	//fbo2.getTexture().enableAndBind();
	//glEnable(GL_SCISSOR_TEST);
	fbo2.bindTexture();
	gl::enable(GL_SCISSOR_TEST);
	glScissor( 0,0,fbo2.getWidth(),fbo2.getHeight() );
	gl::color(Color(1.0,0.0,0.0));
	gl::drawSolidCircle(getWindowCenter(), 200);
	gl::disable(GL_SCISSOR_TEST);
	fbo2.unbindTexture();
}

void MirroredFboApp::draw()
{ 
	gl::clear( Color( 0, 0, 0 ) );  
	gl::color(Color(1,1,1));
	//gl::draw(fbo1.getTexture(),Vec2f::zero());
	//gl::draw(fbo2.getTexture(), Rectf(fbo1.getWidth()/2,0,fbo1.getWidth(),fbo1.getHeight() ));
	gl::draw(fbo2.getTexture(),Vec2f(0,0));
}

CINDER_APP_BASIC( MirroredFboApp, RendererGl )