text: /*
   * Copyright (c) 2010-2013 OTClient <https://github.com/edubart/otclient>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include "texture.h"
  #include "graphics.h"
  #include "framebuffer.h"
  #include "image.h"
  
  #include <framework/core/application.h>
  
  Texture::Texture()
  {
      m_id = 0;
      m_time = 0;
  }
  
  Texture::Texture(const Size& size)
  {
      m_id = 0;
      m_time = 0;
  
      if(!setupSize(size))
          return;
  
      createTexture();
      bind();
      setupPixels(0, m_glSize, nullptr, 4);
      setupWrap();
      setupFilters();
  }
  
  Texture::Texture(const ImagePtr& image, bool buildMipmaps, bool compress)
  {
      m_id = 0;
      m_time = 0;
  
      createTexture();
  
      uploadPixels(image, buildMipmaps, compress);
  }
  
  Texture::~Texture()
  {
  #ifndef NDEBUG
      assert(!g_app.isTerminated());
  #endif
      // free texture from gl memory
      if(g_graphics.ok() && m_id != 0)
          glDeleteTextures(1, &m_id);
  }
  
  void Texture::uploadPixels(const ImagePtr& image, bool buildMipmaps, bool compress)
  {
      if(!setupSize(image->getSize(), buildMipmaps))
          return;
  
      ImagePtr glImage = image;
      if(m_size != m_glSize) {
          glImage = ImagePtr(new Image(m_glSize, image->getBpp()));
          glImage->paste(image);
      } else
          glImage = image;
  
      bind();
  
      if(buildMipmaps) {
          int level = 0;
          do {
              setupPixels(level++, glImage->getSize(), glImage->getPixelData(), glImage->getBpp(), compress);
          } while(glImage->nextMipmap());
          m_hasMipmaps = true;
      } else
          setupPixels(0, glImage->getSize(), glImage->getPixelData(), glImage->getBpp(), compress);
  
      setupWrap();
      setupFilters();
  }
  
  void Texture::bind()
  {
      // must reset painter texture state
      g_painter->setTexture(this);
      glBindTexture(GL_TEXTURE_2D, m_id);
  }
  
  void Texture::copyFromScreen(const Rect& screenRect)
  {
      bind();
      glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, screenRect.x(), screenRect.y(), screenRect.width(), screenRect.height());
  }
  
  bool Texture::buildHardwareMipmaps()
  {
      if(!g_graphics.canUseHardwareMipmaps())
          return false;
  
      bind();
  
      if(!m_hasMipmaps) {
          m_hasMipmaps = true;
          setupFilters();
      }
  
      glGenerateMipmap(GL_TEXTURE_2D);
      return true;
  }
  
  void Texture::setSmooth(bool smooth)
  {
      if(smooth && !g_graphics.canUseBilinearFiltering())
          return;
  
      if(smooth == m_smooth)
          return;
  
      m_smooth = smooth;
      bind();
      setupFilters();
  }
  
  void Texture::setRepeat(bool repeat)
  {
      if(m_repeat == repeat)
          return;
  
      m_repeat = repeat;
      bind();
      setupWrap();
  }
  
  void Texture::setUpsideDown(bool upsideDown)
  {
      if(m_upsideDown == upsideDown)
          return;
      m_upsideDown = upsideDown;
      setupTranformMatrix();
  }
  
  void Texture::createTexture()
  {
      glGenTextures(1, &m_id);
      assert(m_id != 0);
  }
  
  bool Texture::setupSize(const Size& size, bool forcePowerOfTwo)
  {
      Size glSize;
      if(!g_graphics.canUseNonPowerOfTwoTextures() || forcePowerOfTwo)
          glSize.resize(stdext::to_power_of_two(size.width()), stdext::to_power_of_two(size.height()));
      else
          glSize = size;
  
      // checks texture max size
      if(std::max(glSize.width(), glSize.height()) > g_graphics.getMaxTextureSize()) {
          g_logger.error(stdext::format("loading texture with size %dx%d failed, "
                   "the maximum size allowed by the graphics card is %dx%d,"
                   "to prevent crashes the texture will be displayed as a blank texture",
                   size.width(), size.height(), g_graphics.getMaxTextureSize(), g_graphics.getMaxTextureSize()));
          return false;
      }
  
      m_size = size;
      m_glSize = glSize;
      setupTranformMatrix();
      return true;
  }
  
  void Texture::setupWrap()
  {
      int texParam;
      if(!m_repeat && g_graphics.canUseClampToEdge())
          texParam = GL_CLAMP_TO_EDGE;
      else
          texParam = GL_REPEAT;
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, texParam);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, texParam);
  }
  
  void Texture::setupFilters()
  {
      int minFilter;
      int magFilter;
      if(m_smooth) {
          minFilter = m_hasMipmaps ? GL_LINEAR_MIPMAP_LINEAR : GL_LINEAR;
          magFilter = GL_LINEAR;
      } else {
          minFilter = m_hasMipmaps ? GL_NEAREST_MIPMAP_NEAREST : GL_NEAREST;
          magFilter = GL_NEAREST;
      }
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minFilter);
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magFilter);
  }
  
  void Texture::setupTranformMatrix()
  {
      if(m_upsideDown) {
          m_transformMatrix = { 1.0f/m_glSize.width(),  0.0f,                                     0.0f,
                                0.0f,                  -1.0f/m_glSize.height(),                   0.0f,
                                0.0f,                   m_size.height()/(float)m_glSize.height(), 1.0f };
      } else {
          m_transformMatrix = { 1.0f/m_glSize.width(),  0.0f,                    0.0f,
                                0.0f,                   1.0f/m_glSize.height(),  0.0f,
                                0.0f,                   0.0f,                    1.0f };
      }
  }
  
  void Texture::setupPixels(int level, const Size& size, uchar* pixels, int channels, bool compress)
  {
      GLenum format = 0;
      switch(channels) {
          case 4:
              format = GL_RGBA;
              break;
          case 3:
              format = GL_RGB;
              break;
          case 2:
              format = GL_LUMINANCE_ALPHA;
              break;
          case 1:
              format = GL_LUMINANCE;
              break;
      }
  
      GLenum internalFormat = GL_RGBA;
  
  #ifdef OPENGL_ES
      //TODO
  #else
      if(compress)
          internalFormat = GL_COMPRESSED_RGBA;
  #endif
  
      glTexImage2D(GL_TEXTURE_2D, level, internalFormat, size.width(), size.height(), 0, format, GL_UNSIGNED_BYTE, pixels);
  }
  