// This file is part of the "Irrlicht Engine".
// written by Reinhard Ostermeier, reinhard@nospam.r-ostermeier.de
// modified by Thomas Alten

#include "CGUIImageList.h"

namespace irr
{
namespace gui
{

//! constructor
CGUIImageList::CGUIImageList(video::IVideoDriver *driver) :
		Driver(driver),
		Texture(0),
		ImageCount(0),
		ImageSize(0, 0),
		ImagesPerRow(0),
		UseAlphaChannel(false)
{
	if (Driver) {
		Driver->grab();
	}
}

//! destructor
CGUIImageList::~CGUIImageList()
{
	if (Driver) {
		Driver->drop();
	}

	if (Texture) {
		Texture->drop();
	}
}

//! Creates the image list from texture.
bool CGUIImageList::createImageList(video::ITexture *texture,
		core::dimension2d<s32> imageSize,
		bool useAlphaChannel)
{
	if (!texture) {
		return false;
	}

	Texture = texture;
	Texture->grab();

	ImageSize = imageSize;

	ImagesPerRow = Texture->getSize().Width / ImageSize.Width;
	ImageCount = ImagesPerRow * Texture->getSize().Height / ImageSize.Height;

	UseAlphaChannel = useAlphaChannel;

	return true;
}

//! Draws an image and clips it to the specified rectangle if wanted
void CGUIImageList::draw(s32 index, const core::position2d<s32> &destPos,
		const core::rect<s32> *clip /*= 0*/)
{
	core::rect<s32> sourceRect;

	if (!Driver || index < 0 || index >= ImageCount) {
		return;
	}

	sourceRect.UpperLeftCorner.X = (index % ImagesPerRow) * ImageSize.Width;
	sourceRect.UpperLeftCorner.Y = (index / ImagesPerRow) * ImageSize.Height;
	sourceRect.LowerRightCorner.X = sourceRect.UpperLeftCorner.X + ImageSize.Width;
	sourceRect.LowerRightCorner.Y = sourceRect.UpperLeftCorner.Y + ImageSize.Height;

	Driver->draw2DImage(Texture, destPos, sourceRect, clip,
			video::SColor(255, 255, 255, 255), UseAlphaChannel);
}

} // end namespace gui
} // end namespace irr
