Method BeginFrame

neo/renderer/RenderSystem.cpp:577–656

==================== BeginFrame ==================== */

====================
*/
void idRenderSystemLocal::BeginFrame( int windowWidth, int windowHeight ) {
	setBufferCommand_t	*cmd;

	if ( !glConfig.isInitialized ) {
		return;
	}

	// DG: r_lockSurfaces only works properly if r_useScissor is disabled
	if ( r_lockSurfaces.IsModified() ) {
		static bool origUseScissor = true;
		r_lockSurfaces.ClearModified();
		if ( r_lockSurfaces.GetBool() ) {
			origUseScissor = r_useScissor.GetBool();
			r_useScissor.SetBool( false );
		} else {
			r_useScissor.SetBool( origUseScissor );
		}
	} // DG end

	// determine which back end we will use
	SetBackEndRenderer();

	guiModel->Clear();

	// for the larger-than-window tiled rendering screenshots
	if ( tiledViewport[0] ) {
		windowWidth = tiledViewport[0];
		windowHeight = tiledViewport[1];
	}

	// DG: save the original size, so editors don't mess up the game viewport
	//     with their tiny (texture-preview etc) viewports.
	origWidth = glConfig.vidWidth;
	origHeight = glConfig.vidHeight;

	glConfig.vidWidth = windowWidth;
	glConfig.vidHeight = windowHeight;

	renderCrops[0].x = 0;
	renderCrops[0].y = 0;
	renderCrops[0].width = windowWidth;
	renderCrops[0].height = windowHeight;
	currentRenderCrop = 0;

	// screenFraction is just for quickly testing fill rate limitations
	if ( r_screenFraction.GetInteger() != 100 ) {
		int	w = SCREEN_WIDTH * r_screenFraction.GetInteger() / 100.0f;
		int h = SCREEN_HEIGHT * r_screenFraction.GetInteger() / 100.0f;
		CropRenderSize( w, h );
	}


	// this is the ONLY place this is modified
	frameCount++;

	// just in case we did a common->Error while this
	// was set
	guiRecursionLevel = 0;