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 #ifdef GL_VERSION_ES_CM_1_0
  45   assert(is_power_of_2(width));
  46   assert(is_power_of_2(height));
  47 #endif
  48   texture_width  = width;
  49   texture_height = height;
  50   image_width  = width;
  51   image_height = height;
  52
  53   assert_gl("before creating texture");
  54   glGenTextures(1, &handle);
  55
  56   try {
  57     glBindTexture(GL_TEXTURE_2D, handle);
  58
  59     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width,
  60                  texture_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  61
  62     set_texture_params();
  63   } catch(...) {
  64     glDeleteTextures(1, &handle);
  65     throw;
  66   }
  67 }
  68
  69 GLTexture::GLTexture(SDL_Surface* image) :
  70   handle(),
  71   texture_width(),
  72   texture_height(),
  73   image_width(),
  74   image_height()
  75 {
  76 #ifdef GL_VERSION_ES_CM_1_0
  77   texture_width = next_power_of_two(image->w);
  78   texture_height = next_power_of_two(image->h);
  79 #else
  80   texture_width  = image->w;
  81   texture_height = image->h;
  82 #endif
  83
  84   image_width  = image->w;
  85   image_height = image->h;
  86
  87 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
  88   SDL_Surface* convert = SDL_CreateRGBSurface(SDL_SWSURFACE,
  89                                               texture_width, texture_height, 32,
  90                                               0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff);
  91 #else
  92   SDL_Surface* convert = SDL_CreateRGBSurface(SDL_SWSURFACE,
  93                                               texture_width, texture_height, 32,
  94                                               0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000);
  95 #endif
  96
  97   if(convert == 0) {
  98     throw std::runtime_error("Couldn't create texture: out of memory");
  99   }
 100
 101   SDL_SetAlpha(image, 0, 0);
 102   SDL_BlitSurface(image, 0, convert, 0);
 103
 104   assert_gl("before creating texture");
 105   glGenTextures(1, &handle);
 106
 107   try {
 108     GLenum sdl_format;
 109     if(convert->format->BytesPerPixel == 3)
 110       sdl_format = GL_RGB;
 111     else if(convert->format->BytesPerPixel == 4)
 112       sdl_format = GL_RGBA;
 113     else
 114       assert(false);
 115
 116     glBindTexture(GL_TEXTURE_2D, handle);
 117     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 118 #ifdef GL_UNPACK_ROW_LENGTH
 119     glPixelStorei(GL_UNPACK_ROW_LENGTH, convert->pitch/convert->format->BytesPerPixel);
 120 #else
 121     /* OpenGL ES doesn't support UNPACK_ROW_LENGTH, let's hope SDL didn't add
 122      * padding bytes, otherwise we need some extra code here... */
 123     assert(convert->pitch == texture_width * convert->format->BytesPerPixel);
 124 #endif
 125
 126     if(SDL_MUSTLOCK(convert))
 127     {
 128       SDL_LockSurface(convert);
 129     }
 130     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texture_width,
 131                  texture_height, 0, sdl_format,
 132                  GL_UNSIGNED_BYTE, convert->pixels);
 133     if(SDL_MUSTLOCK(convert))
 134     {
 135       SDL_UnlockSurface(convert);
 136     }
 137
 138     assert_gl("creating texture");
 139
 140     set_texture_params();
 141   } catch(...) {
 142     glDeleteTextures(1, &handle);
 143     SDL_FreeSurface(convert);
 144     throw;
 145   }
 146   SDL_FreeSurface(convert);
 147 }
 148
 149 GLTexture::~GLTexture()
 150 {
 151   glDeleteTextures(1, &handle);
 152 }
 153
 154 void
 155 GLTexture::set_texture_params()
 156 {
 157   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 158   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 159 #ifdef GL_CLAMP
 160   /* OpenGL ES doesn't support it */
 161   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
 162   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
 163 #endif
 164
 165   assert_gl("set texture params");
 166 }
 167
 168 /* EOF */