/*******************************************************************************

 Copyright (c) 2009, Charles McGarvey
 All rights reserved.
 
 Redistribution   and   use  in  source  and  binary  forms,  with  or  without
 modification, are permitted provided that the following conditions are met:
 
   * Redistributions  of  source  code  must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * Redistributions  in binary form must reproduce the above copyright notice,
     this  list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
 
 THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES  (INCLUDING,  BUT  NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 SERVICES;  LOSS  OF  USE,  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 CAUSED  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*******************************************************************************/

#include <Moof/Library.hh>
#include <Moof/OpenGL.hh>
#include <Moof/Script.hh>

#include "Tilemap.hh"


struct Tilemap::Impl : public Mf::Library<Impl>
{
	Impl(const std::string& name) :
		Mf::Library<Impl>(name),
		mMagFilter(GL_NEAREST),
		mMinFilter(GL_NEAREST),
		mTilesS(1),
		mTilesT(1),
		mWrapS(GL_CLAMP),
		mWrapT(GL_CLAMP)
	{
		loadFromFile();
	}


	static void bindScriptConstants(Mf::Script& script)
	{
		script.push(GL_CLAMP); script.set("CLAMP");
		script.push(GL_REPEAT); script.set("REPEAT");
		script.push(GL_LINEAR); script.set("LINEAR");
		script.push(GL_NEAREST); script.set("NEAREST");
		script.push(GL_LINEAR_MIPMAP_LINEAR); script.set("LINEAR_MIPMAP_LINEAR");
		script.push(GL_LINEAR_MIPMAP_NEAREST); script.set("LINEAR_MIPMAP_NEAREST");
		script.push(GL_NEAREST_MIPMAP_LINEAR); script.set("NEAREST_MIPMAP_LINEAR");
		script.push(GL_NEAREST_MIPMAP_NEAREST); script.set("NEAREST_MIPMAP_NEAREST");
	}

	void loadFromFile()
	{
		Mf::Script script;
		std::string filePath = Tilemap::getPath(getName());

		script.importStandardLibraries();
		importLogFunctions(script);
		bindScriptConstants(script);

		if (script.doFile(filePath) != Mf::Script::SUCCESS)
		{
			std::string str;
			script[-1].get(str);
			Mf::logWarning(str);
			return;		// TODO needs a better exit strategy
		}

		Mf::logInfo << "loading tiles from tilemap " << filePath << std::endl;

		Mf::Script::Slot globals = script.getGlobalTable();
		Mf::Script::Slot top = script[-1];

		globals.pushField("tiles_s");
		top.get(mTilesS);

		globals.pushField("tiles_t");
		top.get(mTilesT);

		globals.pushField("min_filter");
		top.get(mMinFilter);

		globals.pushField("mag_filter");
		top.get(mMagFilter);

		globals.pushField("wrap_s");
		top.get(mWrapS);

		globals.pushField("wrap_t");
		top.get(mWrapT);
	}


	bool getTileCoords(Tilemap::Index index, Mf::Scalar coords[8]) const
	{
		// make sure the index represents a real tile
		if (index >= mTilesS * mTilesT) return false;

		Mf::Scalar w = 1.0 / Mf::Scalar(mTilesS);
		Mf::Scalar h = 1.0 / Mf::Scalar(mTilesT);

		coords[0] = Mf::Scalar(index % mTilesS) * w;
		coords[1] = (Mf::Scalar(mTilesT - 1) -
				Mf::Scalar(index / mTilesS)) * h;
		coords[2] = coords[0] + w;
		coords[3] = coords[1];
		coords[4] = coords[2];
		coords[5] = coords[1] + h;
		coords[6] = coords[0];
		coords[7] = coords[5];

		return true;
	}


	GLuint		mMagFilter;
	GLuint		mMinFilter;
	unsigned	mTilesS;
	unsigned	mTilesT;
	GLuint		mWrapS;
	GLuint		mWrapT;
};


Tilemap::Tilemap(const std::string& name) :
	Texture(name),
	mImpl(Tilemap::Impl::getInstance(name))
{
	setMinFilter(mImpl->mMinFilter);
	setMagFilter(mImpl->mMagFilter);
	setWrapS(mImpl->mWrapS);
	setWrapT(mImpl->mWrapT);
}


bool Tilemap::getTileCoords(Index index, Mf::Scalar coords[8]) const
{
	// pass through
	return mImpl->getTileCoords(index, coords);
}

bool Tilemap::getTileCoords(Index index, Mf::Scalar coords[8],
		Orientation orientation) const
{
	if (getTileCoords(index, coords))
	{
		if (orientation & FLIP)
		{
			// this looks kinda weird, but it's just swapping in a way that
			// doesn't require an intermediate variable
			coords[1] = coords[5];
			coords[5] = coords[3];
			coords[3] = coords[7];
			coords[7] = coords[5];
		}
		if (orientation & REVERSE)
		{
			coords[0] = coords[2];
			coords[2] = coords[6];
			coords[4] = coords[6];
			coords[6] = coords[0];
		}

		return true;
	}

	return false;
}


std::string Tilemap::getPath(const std::string& name)
{
	return Resource::getPath("tilemaps/" + name + ".lua");
}


/** vim: set ts=4 sw=4 tw=80: *************************************************/