Method updateTemplateCache

src/gui/map/map_widget.cpp:1305–1346

}

void MapWidget::updateTemplateCache(QImage& cache, QRect& dirty_rect, int first_template, int last_template, bool use_background)
{
	Q_ASSERT(containsVisibleTemplate(first_template, last_template));
	
	if (cache.isNull())
	{
		// Lazy allocation of cache image
		cache = QImage(size(), QImage::Format_ARGB32_Premultiplied);
		dirty_rect = rect();
	}
	else
	{
		// Make sure not to use a bigger draw rect than necessary
		dirty_rect = dirty_rect.intersected(rect());
	}
		
	// Start drawing
	QPainter painter(&cache);
	painter.setClipRect(dirty_rect);
	
	// Fill with background color (TODO: make configurable)
	if (use_background)
		painter.fillRect(dirty_rect, Qt::white);
	else
	{
		QPainter::CompositionMode mode = painter.compositionMode();
		painter.setCompositionMode(QPainter::CompositionMode_Clear);
		painter.fillRect(dirty_rect, Qt::transparent);
		painter.setCompositionMode(mode);
	}
	
	// Draw templates
	painter.translate(width() / 2.0, height() / 2.0);
	painter.setWorldTransform(view->worldTransform(), true);
	
	Map* map = view->getMap();
	QRectF map_view_rect = view->calculateViewedRect(viewportToView(dirty_rect));
	
	map->drawTemplates(&painter, map_view_rect, first_template, last_template, view, true);
	
	dirty_rect.setWidth(-1); // => !dirty_rect.isValid()
}

void MapWidget::updateMapCache(bool use_background)
{