Shows how to render a dynamic scene as 6 faces of a cube map (horizontal cross)

CubeMapApp.cpp

#include "cinder/app/App.h"
#include "cinder/app/RendererGl.h"
#include "cinder/gl/gl.h"
#include "cinder/Camera.h"
#include "cinder/Rand.h"

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

class CubeMapApp : public App {
public:
	static void prepare( Settings *settings );

	void setup() override;
	void update() override;
	void draw() override;

	void render();

private:
	gl::BatchRef  mTorus;
};

void CubeMapApp::prepare( Settings * settings )
{
	settings->setWindowSize( 800, 600 );
	settings->setResizable( false );
}

void CubeMapApp::setup()
{
	auto mesh = gl::VboMesh::create( geom::Torus().colors().radius( 1.0f, 0.95f ).subdivisionsAxis( 60.0f ).subdivisionsHeight( 60.0f ) );
	auto shader = gl::getStockShader( gl::ShaderDef().color() );
	mTorus = gl::Batch::create( mesh, shader );
}

void CubeMapApp::update()
{
}

void CubeMapApp::draw()
{
	gl::clear( Color::gray( 0.25f ) );

	gl::ScopedDepth depth( true, true );

	gl::ScopedColor color( 1, 1, 1 );
	gl::ScopedMatrices mat;

	CameraPersp cam;
	cam.setPerspective( 90.0f, 1.0f, 0.01f, 100.0f );
		
	// Left
	{
		gl::ScopedViewport viewport( ivec2( 0, 200 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( -1, 0, 0 ), vec3( 0, 1, 0 ) );
		gl::setMatrices( cam );

		render();
	}

	// Front
	{
		gl::ScopedViewport viewport( ivec2( 200, 200 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( 0, 0, -1 ), vec3( 0, 1, 0 ) );
		gl::setMatrices( cam );

		render();
	}

	// Right
	{
		gl::ScopedViewport viewport( ivec2( 400, 200 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( 1, 0, 0 ), vec3( 0, 1, 0 ) );
		gl::setMatrices( cam );

		render();
	}

	// Back
	{
		gl::ScopedViewport viewport( ivec2( 600, 200 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( 0, 0, 1 ), vec3( 0, 1, 0 ) );
		gl::setMatrices( cam );

		render();
	}

	// Top
	{
		gl::ScopedViewport viewport( ivec2( 200, 400 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( 0, 1, 0 ), vec3( 0, 0, 1 ) );
		gl::setMatrices( cam );

		render();
	}

	// Bottom
	{
		gl::ScopedViewport viewport( ivec2( 200, 0 ), ivec2( 200, 200 ) );

		cam.lookAt( vec3( 0 ), vec3( 0, -1, 0 ), vec3( 0, 0, -1 ) );
		gl::setMatrices( cam );

		render();
	}
}

void CubeMapApp::render()
{
	// Draw a cube. It will show where the faces of our map are.
	gl::drawStrokedCube( vec3( 0 ), vec3( 1 ) );

	// Draw several torii.
	Rand::randSeed( 12345678 );
	for(int i = 0; i < 100; ++i) {
		auto transform = glm::translate( Rand::randFloat( 1.2f, 3.6f ) * Rand::randVec3() );
		transform *= glm::rotate( (float)getElapsedSeconds() * Rand::randFloat( 0.5f, 2.0f ), Rand::randVec3() );

		gl::setModelMatrix( transform );
		mTorus->draw();
	}

}

CINDER_APP( CubeMapApp, RendererGl( RendererGl::Options().msaa( 4 ) ), &CubeMapApp::prepare )