Esempio n. 1
0
void GfxGlEngine::drawPicture(const Picture &picture, const int dx, const int dy, Rect* clipRect)
{
   GLuint aTextureID = picture.getGlTextureID();
   float x0 = (float)( dx+picture.getOffset().getX());
   float x1 = x0+picture.getWidth();
   float y0 = (float)(dy-picture.getOffset().getY());
   float y1 = y0+picture.getHeight();


   // Bind the texture to which subsequent calls refer to
   glBindTexture( GL_TEXTURE_2D, aTextureID);

   glBegin( GL_QUADS );

   //Bottom-left vertex (corner)
   glTexCoord2i( 0, 0 );
   glVertex2f( x0, y0 );

   //Bottom-right vertex (corner)
   glTexCoord2i( 1, 0 );
   glVertex2f( x1, y0 );

   //Top-right vertex (corner)
   glTexCoord2i( 1, 1 );
   glVertex2f( x1, y1 );

   //Top-left vertex (corner)
   glTexCoord2i( 0, 1 );
   glVertex2f( x0, y1 );

   glEnd();
}
Esempio n. 2
0
void GfxGlEngine::unloadPicture(Picture &ioPicture)
{
  const GLuint& texture = (GLuint)ioPicture.getGlTextureID();
  glDeleteTextures(1, &texture );
  SDL_FreeSurface(ioPicture.getSurface());

  ioPicture = Picture();
}
Esempio n. 3
0
void GfxGlEngine::loadPicture(Picture& ioPicture)
{
   GLuint& texture(ioPicture.getGlTextureID());
   SDL_Surface *surface = ioPicture.getSurface();
   GLenum texture_format;
   GLint nOfColors;

   // SDL_Surface *surface2
   // get the number of channels in the SDL surface
   nOfColors = surface->format->BytesPerPixel;
   if (nOfColors == 4)     // contains an alpha channel
   {
      if (surface->format->Rmask == 0x000000ff)
         texture_format = GL_RGBA;
      else
         texture_format = GL_BGRA;
   }
   else if (nOfColors == 3)     // no alpha channel
   {
      if (surface->format->Rmask == 0x000000ff)
         texture_format = GL_RGB;
      else
         texture_format = GL_BGR;
   }
   else
   {
      THROW("Invalid image format");
   }

   if (texture == 0)
   {
      // the picture has no texture ID!
      // generate a texture ID
      glGenTextures( 1, &texture );
   }

   // Bind the texture object
   glBindTexture( GL_TEXTURE_2D, texture );

   // Set the texture's stretching properties
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );

   // Edit the texture object's image data using the information SDL_Surface gives us
   ioPicture.lock();
   glTexImage2D( GL_TEXTURE_2D, 0, nOfColors, surface->w, surface->h, 0,
                 texture_format, GL_UNSIGNED_BYTE, surface->pixels );
   ioPicture.unlock();
}