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