#include "Renderer.h"
#include "App.h"
#include "Scene.h"
#include "MeshNode.h"


//=====================================================================================================================================
// init                                                                                                                               =
//=====================================================================================================================================
void Renderer::Is::Sm::init()
{
	// create FBO
	fbo.create();
	fbo.bind();

	// texture
	shadowMap.createEmpty2D( resolution, resolution, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT );
	shadowMap.texParameter( GL_TEXTURE_MIN_FILTER, GL_NEAREST );
	if( bilinearEnabled )
	{
		shadowMap.texParameter( GL_TEXTURE_MAG_FILTER, GL_LINEAR );
	}
	else
	{
		shadowMap.texParameter( GL_TEXTURE_MAG_FILTER, GL_NEAREST );
	}
	shadowMap.texParameter( GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE );
	shadowMap.texParameter( GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL );
	/*
	 * If you dont want to use the FFP for comparing the shadwomap (the above two lines) then you can make the comparision inside the
	 * glsl shader. The GL_LEQUAL means that: shadow = ( R <= Dt ) ? 1.0 : 0.0; . The R is given by: R = _tex_coord2.z/_tex_coord2.w;
	 * and the Dt = shadow2D(shadow_depth_map, _shadow_uv ).r (see lp_generic.frag). Hardware filters like GL_LINEAR cannot be applied.
	 */

	// inform the we wont write to color buffers
	fbo.setNumOfColorAttachements( 0 );

	// attach the texture
	glFramebufferTexture2DEXT( GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, shadowMap.getGlId(), 0 );

	// test if success
	if( !fbo.isGood() )
		FATAL( "Cannot create shadowmapping FBO" );

	// unbind
	fbo.unbind();
}


//=====================================================================================================================================
// run                                                                                                                                =
//=====================================================================================================================================
void Renderer::Is::Sm::run( const Camera& cam )
{
	// FBO
	fbo.bind();

	// push attribs
	/// @todo remove the matrices
	glMatrixMode( GL_PROJECTION );
	glPushMatrix();
	glMatrixMode( GL_MODELVIEW );
	glPushMatrix();
	glPushAttrib( GL_VIEWPORT_BIT );


	glClear( GL_DEPTH_BUFFER_BIT );
	r.setProjectionViewMatrices( cam );
	Renderer::setViewport( 0, 0, resolution, resolution );

	// disable color & blend & enable depth test
	glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
	glEnable( GL_DEPTH_TEST );
	glDisable( GL_BLEND );

	// for artifacts
	glPolygonOffset( 2.0, 2.0 ); // keep the values as low as possible!!!!
	glEnable( GL_POLYGON_OFFSET_FILL );

	// render all meshes
	for( uint i=0; i<app->getScene()->meshNodes.size(); i++ )
	{
		MeshNode* meshNode = app->getScene()->meshNodes[i];
		if( meshNode->material->blends || meshNode->material->refracts ) continue;

		DEBUG_ERR( meshNode->material->dpMtl == NULL );

		//meshNode->material->dpMtl->setup();
		//meshNode->renderDepth();
		r.setupMaterial( *meshNode->material, *meshNode, cam );
		meshNode->render();
	}

	glDisable( GL_POLYGON_OFFSET_FILL );

	glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );

	// restore attribs
	glPopAttrib();
	glMatrixMode( GL_MODELVIEW );
	glPopMatrix();
	glMatrixMode( GL_PROJECTION );
	glPopMatrix();

	// FBO
	fbo.unbind();
}