src/backend/texture.c

   1 /************************************************************************
   2     This file is part of NE.
   3
   4     NE 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     NE 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 NE.  If not, see <http://www.gnu.org/licenses/>.
  16 ************************************************************************/
  17
  18 #include "texture.h"
  19 #include "error.h"
  20 #include "video.h"
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <GL/gl.h>
  25 #include <GL/glu.h>
  26 #include <SDL/SDL_image.h>
  27
  28 void t_init()
  29 {
  30         static int init = 0;
  31         if (init) return;
  32         init = 1;
  33
  34         glMatrixMode(GL_TEXTURE);
  35         glLoadIdentity();
  36         //glScalef(-1,1,1);
  37 }
  38
  39 struct texture *t_create()
  40 {
  41         struct texture *t = (struct texture*)malloc(sizeof(struct texture));
  42
  43         t->ready = 0;
  44         t->gl_handle = 0;
  45
  46         return t;
  47 }
  48
  49 void t_destroy(struct texture *t)
  50 {
  51         t_unload(t);
  52         free(t);
  53 }
  54
  55 int t_ready(struct texture *t)
  56 {
  57         return t->ready;
  58 }
  59
  60 void t_load(struct texture *t, const char *filename)
  61 {
  62         t_unload(t);
  63         t->ready = 0;
  64
  65         SDL_Surface *img = IMG_Load(filename);
  66
  67         if (!img)
  68         {
  69                 fprintf(stderr, "Texture load error: %s\n", IMG_GetError());
  70                 return;
  71         }
  72
  73         if (img->format->BytesPerPixel < 2)
  74         {
  75                 fprintf(stderr, "Texture load error: %s is not true color\n", filename);
  76                 return;
  77         }
  78
  79         glGenTextures(1, &t->gl_handle);
  80         glBindTexture(GL_TEXTURE_2D, t->gl_handle);
  81
  82         t->width = img->w;
  83         t->height = img->h;
  84
  85         t->u = t->v = 1.0; // TODO: change this when textures are scaled to pow2
  86
  87         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  88         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  89
  90         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  91         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  92
  93         GLuint mode = GL_RGB;
  94         if (img->format->BytesPerPixel == 4) mode = GL_RGBA;
  95
  96         int mipmap = 0;
  97
  98         if (!mipmap)
  99         {
 100                 glTexImage2D(GL_TEXTURE_2D, 0, img->format->BytesPerPixel,
 101                                          img->w, img->h, 0, mode, GL_UNSIGNED_BYTE, img->pixels);
 102         }
 103         else
 104         {
 105                 glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
 106                 gluBuild2DMipmaps(GL_TEXTURE_2D, img->format->BytesPerPixel, img->w, img->h,
 107                                                   mode, GL_UNSIGNED_BYTE, img->pixels);
 108         }
 109
 110     SDL_FreeSurface(img);
 111
 112         t->ready = 1;
 113 }
 114
 115 void t_unload(struct texture *t)
 116 {
 117         if (t_ready(t))
 118         {
 119                 glDeleteTextures(1, &t->gl_handle);
 120         }
 121 }
 122
 123 void t_apply(struct texture *t)
 124 {
 125         glBindTexture(GL_TEXTURE_2D, t->gl_handle);
 126 }
 127
 128 void t_set(struct texture *t, GLuint name, GLuint value)
 129 {
 130         t_apply(t);
 131         glTexParameteri(GL_TEXTURE_2D,name,value);
 132 }
 133
 134 struct texture *t_screenshot()
 135 {
 136         struct texture *t = t_create();
 137
 138         glGenTextures(1, &t->gl_handle);
 139         glBindTexture(GL_TEXTURE_2D, t->gl_handle);
 140
 141         const struct video_info* vi = v_info();
 142
 143         // TODO: figure out what old cards can't render non pow2 textures...
 144         t->width = vi->width;
 145         t->height = vi->height;
 146
 147         t->u = t->v = 1.0;
 148
 149         glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, t->width, t->height, 0);
 150
 151         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 152         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 153
 154         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 155         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 156
 157         t->ready = 1;
 158
 159         return t;
 160 }
 161