git.mutantstargoat.com Git - laserbrain_demo/blob - src/post.cc

   1 #include "opengl.h"
   2 #include "app.h"
   3 #include "texture.h"    // next_pow2
   4
   5 static void update_fbtex();
   6
   7 static unsigned int fb_tex;
   8 static int fb_tex_width, fb_tex_height;
   9
  10 void slow_post(unsigned int sdr)
  11 {
  12         update_fbtex();
  13
  14         glBindTexture(GL_TEXTURE_2D, fb_tex);
  15         glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, win_width, win_height);
  16
  17         glPushAttrib(GL_ENABLE_BIT);
  18         glDisable(GL_DEPTH_TEST);
  19         glDisable(GL_LIGHTING);
  20
  21         glUseProgram(sdr);
  22
  23         float umax = (float)win_width / (float)fb_tex_width;
  24         float vmax = (float)win_height / (float)fb_tex_height;
  25
  26         glBegin(GL_QUADS);
  27         glTexCoord2f(0, 0);
  28         glVertex2f(-1, -1);
  29         glTexCoord2f(umax, 0);
  30         glVertex2f(1, -1);
  31         glTexCoord2f(umax, vmax);
  32         glVertex2f(1, 1);
  33         glTexCoord2f(0, vmax);
  34         glVertex2f(-1, 1);
  35         glEnd();
  36
  37         glPopAttrib();
  38 }
  39
  40 static void update_fbtex()
  41 {
  42         if(win_width <= fb_tex_width && win_height <= fb_tex_height) {
  43                 return;         // nothing to do
  44         }
  45         if(!fb_tex) {
  46                 glGenTextures(1, &fb_tex);
  47                 glBindTexture(GL_TEXTURE_2D, fb_tex);
  48                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  49                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  50         } else {
  51                 glBindTexture(GL_TEXTURE_2D, fb_tex);
  52         }
  53
  54         fb_tex_width = next_pow2(win_width);
  55         fb_tex_height = next_pow2(win_height);
  56         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, fb_tex_width, fb_tex_height, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
  57 }