#include <memory></memory>

#include "ext/meshtexturizer.h"

// TnzCore includes

#include "tgl.h" // OpenGL includes

// Qt includes

#include <qreadwritelock></qreadwritelock>

#include <qreadlocker></qreadlocker>

#include <qwritelocker></qwritelocker>

// tcg includes

#include "tcg/tcg_macros.h"

#include "tcg/tcg_list.h"

#include "tcg/tcg_misc.h"

#define COPIED_BORDER 1								 // Amount of tile border from the original image

#define TRANSP_BORDER 1								 // Amount of transparent tile border

#define NONPREM_BORDER 1							 // Amount of nonpremultiplied copied transparent border

#define TOTAL_BORDER (COPIED_BORDER + TRANSP_BORDER) // Overall border to texture tiles above

#define TOTAL_BORDER_2 (2 * TOTAL_BORDER)			 // Twice the above

TCG_STATIC_ASSERT(COPIED_BORDER > 0);				// Due to GL_LINEAR alpha blending on tile seams

TCG_STATIC_ASSERT(TRANSP_BORDER > 0);				// Due to GL_CLAMP beyond tile limits

TCG_STATIC_ASSERT(NONPREM_BORDER <= TRANSP_BORDER); // The nonpremultiplied border is transparent

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

//    MeshTexturizer::Imp  definition

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

class MeshTexturizer::Imp

{

	typedef MeshTexturizer::TextureData TextureData;

public:

	QReadWriteLock m_lock;									  //!< Lock for synchronized access

	tcg::list<std::shared_ptr<texturedata>> m_textureDatas; //!< Pool of texture datas</std::shared_ptr<texturedata>

public:

	Imp() : m_lock(QReadWriteLock::Recursive) {}

	bool testTextureAlloc(int lx, int ly);

	GLuint textureAlloc(const TRaster32P &ras, const TRaster32P &aux,

						int x, int y, int textureLx, int textureLy,

						bool premultiplied);

	void allocateTextures(int groupIdx, const TRaster32P &ras, const TRaster32P &aux,

						  int x, int y, int textureLx, int textureLy,

						  bool premultiplied);

	TextureData *getTextureData(int groupIdx);

};

//---------------------------------------------------------------------------------

bool MeshTexturizer::Imp::testTextureAlloc(int lx, int ly)

{

	lx += TOTAL_BORDER_2, ly += TOTAL_BORDER_2; // Add border

	glTexImage2D(GL_PROXY_TEXTURE_2D,

				 0,				   // one level only

				 GL_RGBA,		   // number of pixel channels

				 lx,			   // width

				 ly,			   // height

				 0,				   // border size

				 TGL_FMT,		   // pixel format

				 GL_UNSIGNED_BYTE, // pixel data type

				 0);

	int outLx;

	glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &outLx);

	return (lx == outLx);

}

//---------------------------------------------------------------------------------

GLuint MeshTexturizer::Imp::textureAlloc(const TRaster32P &ras, const TRaster32P &aux,

										 int x, int y, int textureLx, int textureLy,

										 bool premultiplied)

{

	struct locals {

		static void clearMatte(const TRaster32P &ras, int xBegin, int yBegin, int xEnd, int yEnd)

		{

			for (int y = yBegin; y != yEnd; ++y) {

				TPixel32 *line = ras->pixels(y), *pixEnd = line + xEnd;

				for (TPixel32 *pix = line + xBegin; pix != pixEnd; ++pix)

					pix->m = 0;

			}

		}

		static void clearMatte_border(const TRaster32P &ras, int border0, int border1)

		{

			assert(border0 < border1);

			// Horizontal

			clearMatte(ras, border0, border0, ras->getLx() - border0, border1);

			clearMatte(ras, border0, ras->getLy() - border1, ras->getLx() - border0, ras->getLy() - border0);

			// Vertical

			clearMatte(ras, border0, border1, border1, ras->getLy() - border1);

			clearMatte(ras, ras->getLx() - border1, border1, ras->getLx() - border0, ras->getLy() - border1);

		}

	}; // locals

	// Prepare the texture tile

	assert(aux->getLx() >= textureLx + TOTAL_BORDER_2 && aux->getLy() >= textureLy + TOTAL_BORDER_2);

	TRect rasRect(x, y, x + textureLx - 1, y + textureLy - 1);

	rasRect = rasRect.enlarge(premultiplied ? COPIED_BORDER : COPIED_BORDER + NONPREM_BORDER);

	rasRect = rasRect * ras->getBounds();

	TRect auxRect(rasRect - TPoint(x - TOTAL_BORDER, y - TOTAL_BORDER));

	// An auxiliary raster must be used to supply the transparent border

	TRaster32P tex(aux->extract(0, 0, textureLx + TOTAL_BORDER_2 - 1, textureLy + TOTAL_BORDER_2 - 1));

	tex->clear();

	aux->extract(auxRect)->copy(ras->extract(rasRect));

	if (!premultiplied && NONPREM_BORDER > 0)

		locals::clearMatte_border(aux, TRANSP_BORDER - NONPREM_BORDER, TRANSP_BORDER);

	// Pass the raster into VRAM

	GLuint texId;

	glGenTextures(1, &texId);

	glBindTexture(GL_TEXTURE_2D, texId);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);	  // These must be used on a bound texture,

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);	  // and are remembered in the OpenGL context.

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // They can be set here, no need for

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); // the user to do it.

	glPixelStorei(GL_UNPACK_ROW_LENGTH, tex->getWrap());

	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

	glTexImage2D(GL_TEXTURE_2D,

				 0,				   // one level only

				 GL_RGBA,		   // pixel channels count

				 tex->getLx(),	 // width

				 tex->getLy(),	 // height

				 0,				   // border size

				 TGL_FMT,		   // pixel format

				 GL_UNSIGNED_BYTE, // pixel data type

				 (GLvoid *)tex->getRawData());

	return texId;

}

//---------------------------------------------------------------------------------

void MeshTexturizer::Imp::allocateTextures(int groupIdx, const TRaster32P &ras, const TRaster32P &aux,

										   int x, int y, int textureLx, int textureLy,

										   bool premultiplied)

{

	TextureData *data = m_textureDatas[groupIdx].get();

	// Test the specified texture allocation

	if (testTextureAlloc(textureLx, textureLy)) {

		TPointD scale(data->m_geom.getLx() / (double)ras->getLx(),

					  data->m_geom.getLy() / (double)ras->getLy());

		TRectD tileGeom(

			TRectD(

				scale.x * (x - TOTAL_BORDER), scale.y * (y - TOTAL_BORDER),

				scale.x * (x + textureLx + TOTAL_BORDER), scale.y * (y + textureLy + TOTAL_BORDER)) +

			data->m_geom.getP00());

		GLuint texId = textureAlloc(ras, aux, x, y, textureLx, textureLy, premultiplied);

		TextureData::TileData td = {texId, tileGeom};

		data->m_tileDatas.push_back(td);

		return;

	}

	if (textureLx <= 1 && textureLy <= 1)

		return; // No texture can be allocated

	// The texture could not be allocated. Then, bisecate and branch.

	if (textureLx > textureLy) {

		int textureLx_2 = textureLx >> 1;

		allocateTextures(groupIdx, ras, aux, x, y, textureLx_2, textureLy, premultiplied);

		allocateTextures(groupIdx, ras, aux, x + textureLx_2, y, textureLx_2, textureLy, premultiplied);

	} else {

		int textureLy_2 = textureLy >> 1;

		allocateTextures(groupIdx, ras, aux, x, y, textureLx, textureLy_2, premultiplied);

		allocateTextures(groupIdx, ras, aux, x, y + textureLy_2, textureLx, textureLy_2, premultiplied);

	}

}

//---------------------------------------------------------------------------------

MeshTexturizer::TextureData *MeshTexturizer::Imp::getTextureData(int groupIdx)

{

	typedef MeshTexturizer::TextureData TextureData;

	// Copy tile datas container

	return m_textureDatas[groupIdx].get();

}

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

//    MeshTexturizer  implementation

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

MeshTexturizer::MeshTexturizer()

	: m_imp(new Imp)

{

}

//---------------------------------------------------------------------------------

MeshTexturizer::~MeshTexturizer()

{

}

//---------------------------------------------------------------------------------

int MeshTexturizer::bindTexture(const TRaster32P &ras, const TRectD &geom,

								PremultMode premultiplyMode)

{

	QWriteLocker locker(&m_imp->m_lock);

	// Backup the state of some specific OpenGL variables that will be changed throughout the code

	int row_length, alignment;

	glGetIntegerv(GL_UNPACK_ROW_LENGTH, &row_length);

	glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);

	// Initialize a new texture data

	int dataIdx = m_imp->m_textureDatas.push_back(std::make_shared<texturedata>(geom));</texturedata>

	// Textures must have 2-power sizes. So, let's start with the smallest 2 power

	// >= ras's sizes.

	int textureLx = tcg::numeric_ops::GE_2Power((unsigned int)ras->getLx() + TOTAL_BORDER_2);

	int textureLy = tcg::numeric_ops::GE_2Power((unsigned int)ras->getLy() + TOTAL_BORDER_2);

	// We'll assume a strict granularity max of 512 x 512 textures

	textureLx = tmin(textureLx, 1 << 9);

	textureLy = tmin(textureLy, 1 << 9);

	// Allocate a suitable texture raster. The texture will include a transparent 1-pix border

	// that is needed to perform texture mapping with GL_CLAMP transparent wrapping

	TRaster32P tex(textureLx, textureLy);

	// Now, let's tile the specified raster. We'll start from the lower-left corner in case

	// the raster can be completely included in just one tile

	int lx = ras->getLx(), ly = ras->getLy();

	int tileLx = textureLx - TOTAL_BORDER_2, tileLy = textureLy - TOTAL_BORDER_2; // Texture size without border

	int xEntireCells = (lx - 1) / tileLx, yEntireCells = (ly - 1) / tileLy; // +1 so in case l == tileL, we get the remainder case

	int lastTexLx = tcg::numeric_ops::GE_2Power((unsigned int)(lx - xEntireCells * tileLx + TOTAL_BORDER_2));

	int lastTexLy = tcg::numeric_ops::GE_2Power((unsigned int)(ly - yEntireCells * tileLy + TOTAL_BORDER_2));

	int lastTileLx = lastTexLx - TOTAL_BORDER_2, lastTileLy = lastTexLy - TOTAL_BORDER_2;

	bool premultiplied = (premultiplyMode == PREMULTIPLIED);

	int i, j;

	for (i = 0; i < yEntireCells; ++i) {

		for (j = 0; j < xEntireCells; ++j)

			// Perform a (possibly subdividing) allocation of the specified tile

			m_imp->allocateTextures(dataIdx, ras, tex, j * tileLx, i * tileLy, tileLx, tileLy, premultiplied);

		m_imp->allocateTextures(dataIdx, ras, tex, j * tileLx, i * tileLy, lastTileLx, tileLy, premultiplied);

	}

	for (j = 0; j < xEntireCells; ++j)

		m_imp->allocateTextures(dataIdx, ras, tex, j * tileLx, i * tileLy, tileLx, lastTileLy, premultiplied);

	m_imp->allocateTextures(dataIdx, ras, tex, j * tileLx, i * tileLy, lastTileLx, lastTileLy, premultiplied);

	// Restore OpenGL variables

	glPixelStorei(GL_UNPACK_ROW_LENGTH, row_length);

	glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);

	return dataIdx;

}

//---------------------------------------------------------------------------------

void MeshTexturizer::rebindTexture(int texId, const TRaster32P &ras, const TRectD &geom,

								   PremultMode premultiplyMode)

{

	QWriteLocker locker(&m_imp->m_lock);

	unbindTexture(texId);

	int newTexId = bindTexture(ras, geom, premultiplyMode);

	assert(texId == newTexId);

}

//---------------------------------------------------------------------------------

void MeshTexturizer::unbindTexture(int texId)

{

	QWriteLocker locker(&m_imp->m_lock);

	m_imp->m_textureDatas.erase(texId);

}

//---------------------------------------------------------------------------------

MeshTexturizer::TextureData *MeshTexturizer::getTextureData(int textureId)

{

	QReadLocker locker(&m_imp->m_lock);

	return m_imp->getTextureData(textureId);

}