#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"

#include "trop.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

namespace {

int getMaxTextureTileSize() {

  static int maxTexSize = -1;

  if (maxTexSize == -1) {

    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTexSize);

    maxTexSize = std::min(maxTexSize, 1 << 11);

  }

  return maxTexSize;

}

};

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

//    MeshTexturizer::Imp  definition

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

class MeshTexturizer::Imp {

  typedef MeshTexturizer::TextureData TextureData;

public:

  QReadWriteLock m_lock;  //!< Lock for synchronized access

  tcg::list<std::shared_ptr<texturedata>></std::shared_ptr<texturedata>

      m_textureDatas;  //!< Pool of texture datas

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) {

  GLuint texName;

  glEnable(GL_TEXTURE_2D);

  glGenTextures(1, &texName);

  glBindTexture(GL_TEXTURE_2D, texName);

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

  int max_texture_size;

  glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size);

  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);

  glDeleteTextures(1, &texName);

  assert(glGetError() == GL_NO_ERROR);

  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(tex, TRANSP_BORDER - NONPREM_BORDER,

                              TRANSP_BORDER);

    TRop::expandColor(tex, true);  // precise is always true for now

  }

  // 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());

  assert(glGetError() == GL_NO_ERROR);

  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);

    assert(glGetError() == GL_NO_ERROR);

    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 2048 x 2048 textures, if it is

  // possible.

  textureLx = std::min(textureLx, getMaxTextureTileSize());

  textureLy = std::min(textureLy, getMaxTextureTileSize());

  // 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);

}