src/video/gl/gl_texture.cpp

   1 //  SuperTux
   2 //  Copyright (C) 2006 Matthias Braun <matze@braunis.de>
   3 //
   4 //  This program is free software: you can redistribute it and/or modify
   5 //  it under the terms of the GNU General Public License as published by
   6 //  the Free Software Foundation, either version 3 of the License, or
   7 //  (at your option) any later version.
   8 //
   9 //  This program is distributed in the hope that it will be useful,
  10 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 //  GNU General Public License for more details.
  13 //
  14 //  You should have received a copy of the GNU General Public License
  15 //  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 #include "supertux/gameconfig.hpp"
  18 #include "video/gl/gl_texture.hpp"
  19
  20 namespace {
  21
  22 inline bool is_power_of_2(int v)
  23 {
  24   return (v & (v-1)) == 0;
  25 }
  26
  27 inline int next_power_of_two(int val)
  28 {
  29   int result = 1;
  30   while(result < val)
  31     result *= 2;
  32   return result;
  33 }
  34
  35 } // namespace
  36
  37 GLTexture::GLTexture(unsigned int width, unsigned int height) :
  38   handle(),
  39   texture_width(),
  40   texture_height(),
  41   image_width(),
  42   image_height()
  43 {
  44   assert(is_power_of_2(width));
  45   assert(is_power_of_2(height));
  46   texture_width  = width;
  47   texture_height = height;
  48   image_width  = width;
  49   image_height = height;
  50
  51   assert_gl("before creating texture");
  52   glGenTextures(1, &handle);
  53
  54   try {
  55     glBindTexture(GL_TEXTURE_2D, handle);
  56
  57     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width,
  58                  texture_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  59
  60     set_texture_params();
  61   } catch(...) {
  62     glDeleteTextures(1, &handle);
  63     throw;
  64   }
  65 }
  66
  67 GLTexture::GLTexture(SDL_Surface* image) :
  68   handle(),
  69   texture_width(),
  70   texture_height(),
  71   image_width(),
  72   image_height()
  73 {
  74   texture_width = next_power_of_two(image->w);
  75   texture_height = next_power_of_two(image->h);
  76   image_width = image->w;
  77   image_height = image->h;
  78
  79 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
  80   SDL_Surface* convert = SDL_CreateRGBSurface(SDL_SWSURFACE,
  81                                               texture_width, texture_height, 32,
  82                                               0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff);
  83 #else
  84   SDL_Surface* convert = SDL_CreateRGBSurface(SDL_SWSURFACE,
  85                                               texture_width, texture_height, 32,
  86                                               0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000);
  87 #endif
  88
  89   if(convert == 0) {
  90     throw std::runtime_error("Couldn't create texture: out of memory");
  91   }
  92
  93   SDL_SetAlpha(image, 0, 0);
  94   SDL_BlitSurface(image, 0, convert, 0);
  95
  96   assert_gl("before creating texture");
  97   glGenTextures(1, &handle);
  98
  99   try {
 100     GLenum sdl_format;
 101     if(convert->format->BytesPerPixel == 3)
 102       sdl_format = GL_RGB;
 103     else if(convert->format->BytesPerPixel == 4)
 104       sdl_format = GL_RGBA;
 105     else
 106       assert(false);
 107
 108     glBindTexture(GL_TEXTURE_2D, handle);
 109     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 110 #ifdef GL_UNPACK_ROW_LENGTH
 111     glPixelStorei(GL_UNPACK_ROW_LENGTH, convert->pitch/convert->format->BytesPerPixel);
 112 #else
 113     /* OpenGL ES doesn't support UNPACK_ROW_LENGTH, let's hope SDL didn't add
 114      * padding bytes, otherwise we need some extra code here... */
 115     assert(convert->pitch == texture_width * convert->format->BytesPerPixel);
 116 #endif
 117
 118     if(SDL_MUSTLOCK(convert))
 119     {
 120       SDL_LockSurface(convert);
 121     }
 122     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width,
 123                  texture_height, 0, sdl_format,
 124                  GL_UNSIGNED_BYTE, convert->pixels);
 125     if(SDL_MUSTLOCK(convert))
 126     {
 127       SDL_UnlockSurface(convert);
 128     }
 129
 130     assert_gl("creating texture");
 131
 132     set_texture_params();
 133   } catch(...) {
 134     glDeleteTextures(1, &handle);
 135     SDL_FreeSurface(convert);
 136     throw;
 137   }
 138   SDL_FreeSurface(convert);
 139 }
 140
 141 GLTexture::~GLTexture()
 142 {
 143   glDeleteTextures(1, &handle);
 144 }
 145
 146 void
 147 GLTexture::set_texture_params()
 148 {
 149   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 150   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 151 #ifdef GL_CLAMP
 152   /* OpenGL ES doesn't support it */
 153   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 154   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 155 #endif
 156
 157   assert_gl("set texture params");
 158 }
 159
 160 /* EOF */