summaryrefslogtreecommitdiffstats
path: root/progs/xdemos/glxpbdemo.c
blob: 91fd30dcaa693afc949229407323a472033e837d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430

/*
 * This program demonstrates how to do "off-screen" rendering using
 * the GLX pixel buffer extension.
 *
 * Written by Brian Paul for the "OpenGL and Window System Integration"
 * course presented at SIGGRAPH '97.  Updated on 5 October 2002.
 *
 * Updated on 31 January 2004 to use native GLX by
 * Andrew P. Lentvorski, Jr. <bsder@allcaps.org>
 *
 * Usage:
 *   glxpbdemo width height imgfile
 * Where:
 *   width is the width, in pixels, of the image to generate.
 *   height is the height, in pixels, of the image to generate.
 *   imgfile is the name of the PPM image file to write.
 *
 *
 * This demo draws 3-D boxes with random orientation.
 *
 * On machines such as the SGI Indigo you may have to reconfigure your
 * display/X server to enable pbuffers.  Look in the /usr/gfx/ucode/MGRAS/vof/
 * directory for display configurations with the _pbuf suffix.  Use
 * setmon -x <vof> to configure your X server and display for pbuffers.
 *
 * O2 systems seem to support pbuffers well.
 *
 */

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>
#include <GL/glx.h>

/* Some ugly global vars */
static GLXFBConfig gFBconfig = 0;
static Display *gDpy = NULL;
static int gScreen = 0;
static GLXPbuffer gPBuffer = 0;
static int gWidth, gHeight;


/*
 * Test for appropriate version of GLX to run this program
 * Input:  dpy - the X display
 *         screen - screen number
 * Return:  0 = GLX not available.
 *          1 = GLX available.
 */
static int
RuntimeQueryGLXVersion(Display *dpy, int screen)
{
#if defined(GLX_VERSION_1_3) || defined(GLX_VERSION_1_4)
   char *glxversion;
 
   glxversion = (char *) glXGetClientString(dpy, GLX_VERSION);
   if (!(strstr(glxversion, "1.3") || strstr(glxversion, "1.4")))
      return 0;

   glxversion = (char *) glXQueryServerString(dpy, screen, GLX_VERSION);
   if (!(strstr(glxversion, "1.3") || strstr(glxversion, "1.4")))
      return 0;

   return 1;
#else
   return 0;
#endif
}



/*
 * Create the pbuffer and return a GLXPbuffer handle.
 */
static GLXPbuffer
MakePbuffer( Display *dpy, int screen, int width, int height )
{
   GLXFBConfig *fbConfigs;
   GLXFBConfig chosenFBConfig;
   GLXPbuffer pBuffer = None;

   int nConfigs;
   int fbconfigid;

   int fbAttribs[] = {
      GLX_RENDER_TYPE, GLX_RGBA_BIT,
      GLX_DEPTH_SIZE, 1,
      GLX_DRAWABLE_TYPE, GLX_PIXMAP_BIT | GLX_PBUFFER_BIT,
      None
   };

   int pbAttribs[] = {
      GLX_PBUFFER_WIDTH, 0,
      GLX_PBUFFER_HEIGHT, 0,
      GLX_LARGEST_PBUFFER, False,
      GLX_PRESERVED_CONTENTS, False,
      None
   };

   pbAttribs[1] = width;
   pbAttribs[3] = height;

   fbConfigs = glXChooseFBConfig(dpy, screen, fbAttribs, &nConfigs);

   if (0 == nConfigs || !fbConfigs) {
      printf("Error: glxChooseFBConfig failed\n");
      XCloseDisplay(dpy);
      return 0;
   }

   chosenFBConfig = fbConfigs[0];

   glXGetFBConfigAttrib(dpy, chosenFBConfig, GLX_FBCONFIG_ID, &fbconfigid);
   printf("Chose 0x%x as fbconfigid\n", fbconfigid);

   /* Create the pbuffer using first fbConfig in the list that works. */
   pBuffer = glXCreatePbuffer(dpy, chosenFBConfig, pbAttribs);

   if (pBuffer) {
      gFBconfig = chosenFBConfig;
      gWidth = width;
      gHeight = height;
   }

   XFree(fbConfigs);

   return pBuffer;
}



/*
 * Do all the X / GLX setup stuff.
 */
static int
Setup(int width, int height)
{
#if defined(GLX_VERSION_1_3) || defined(GLX_VERSION_1_4)
   GLXContext glCtx;

   /* Open the X display */
   gDpy = XOpenDisplay(NULL);
   if (!gDpy) {
      printf("Error: couldn't open default X display.\n");
      return 0;
   }

   /* Get default screen */
   gScreen = DefaultScreen(gDpy);

   /* Test that GLX is available */
   if (!RuntimeQueryGLXVersion(gDpy, gScreen)) {
     printf("Error: GLX 1.3 or 1.4 not available\n");
     XCloseDisplay(gDpy);
     return 0;
   }

   /* Create Pbuffer */
   gPBuffer = MakePbuffer( gDpy, gScreen, width, height );
   if (gPBuffer==None) {
      printf("Error: couldn't create pbuffer\n");
      XCloseDisplay(gDpy);
      return 0;
   }

   /* Create GLX context */
   glCtx = glXCreateNewContext(gDpy, gFBconfig, GLX_RGBA_TYPE, NULL, True);
   if (glCtx) {
      if (!glXIsDirect(gDpy, glCtx)) {
         printf("Warning: using indirect GLXContext\n");
      }
   }
   else {
      printf("Error: Couldn't create GLXContext\n");
      XCloseDisplay(gDpy);
      return 0;
   }

   /* Bind context to pbuffer */
   if (!glXMakeCurrent(gDpy, gPBuffer, glCtx)) {
      printf("Error: glXMakeCurrent failed\n");
      XCloseDisplay(gDpy);
      return 0;
   }

   return 1;  /* Success!! */
#else
   printf("Error: GLX version 1.3 or 1.4 not available at compile time\n");
   return 0;
#endif
}



/* One-time GL setup */
static void
InitGL(void)
{
   static GLfloat pos[4] = {0.0, 0.0, 10.0, 0.0};
   glEnable(GL_LIGHTING);
   glEnable(GL_LIGHT0);
   glLightfv(GL_LIGHT0, GL_POSITION, pos);
   glEnable(GL_NORMALIZE);
   glEnable(GL_DEPTH_TEST);
   glEnable(GL_CULL_FACE);

   glViewport(0, 0, gWidth, gHeight);
   glMatrixMode( GL_PROJECTION );
   glLoadIdentity();
   glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
   glMatrixMode( GL_MODELVIEW );
   glLoadIdentity();
   glTranslatef( 0.0, 0.0, -15.0 );

}


/* Return random float in [0,1] */
static float
Random(void)
{
   int i = rand();
   return (float) (i % 1000) / 1000.0;
}


static void
RandomColor(void)
{
   GLfloat c[4];
   c[0] = Random();
   c[1] = Random();
   c[2] = Random();
   c[3] = 1.0;
   glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, c);
}


/* This function borrowed from Mark Kilgard's GLUT */
static void
drawBox(GLfloat x0, GLfloat x1, GLfloat y0, GLfloat y1,
        GLfloat z0, GLfloat z1, GLenum type)
{
  static GLfloat n[6][3] =
  {
    {-1.0, 0.0, 0.0},
    {0.0, 1.0, 0.0},
    {1.0, 0.0, 0.0},
    {0.0, -1.0, 0.0},
    {0.0, 0.0, 1.0},
    {0.0, 0.0, -1.0}
  };
  static GLint faces[6][4] =
  {
    {0, 1, 2, 3},
    {3, 2, 6, 7},
    {7, 6, 5, 4},
    {4, 5, 1, 0},
    {5, 6, 2, 1},
    {7, 4, 0, 3}
  };
  GLfloat v[8][3], tmp;
  GLint i;

  if (x0 > x1) {
    tmp = x0;
    x0 = x1;
    x1 = tmp;
  }
  if (y0 > y1) {
    tmp = y0;
    y0 = y1;
    y1 = tmp;
  }
  if (z0 > z1) {
    tmp = z0;
    z0 = z1;
    z1 = tmp;
  }
  v[0][0] = v[1][0] = v[2][0] = v[3][0] = x0;
  v[4][0] = v[5][0] = v[6][0] = v[7][0] = x1;
  v[0][1] = v[1][1] = v[4][1] = v[5][1] = y0;
  v[2][1] = v[3][1] = v[6][1] = v[7][1] = y1;
  v[0][2] = v[3][2] = v[4][2] = v[7][2] = z0;
  v[1][2] = v[2][2] = v[5][2] = v[6][2] = z1;

  for (i = 0; i < 6; i++) {
    glBegin(type);
    glNormal3fv(&n[i][0]);
    glVertex3fv(&v[faces[i][0]][0]);
    glVertex3fv(&v[faces[i][1]][0]);
    glVertex3fv(&v[faces[i][2]][0]);
    glVertex3fv(&v[faces[i][3]][0]);
    glEnd();
  }
}



/* Render a scene */
static void
Render(void)
{
   int NumBoxes = 100;
   int i;

   InitGL();
   glClearColor(0.2, 0.2, 0.9, 0.0);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   for (i=0;i<NumBoxes;i++) {
      float tx = -2.0 + 4.0 * Random();
      float ty = -2.0 + 4.0 * Random();
      float tz =  4.0 - 16.0 * Random();
      float sx = 0.1 + Random() * 0.4;
      float sy = 0.1 + Random() * 0.4;
      float sz = 0.1 + Random() * 0.4;
      float rx = Random();
      float ry = Random();
      float rz = Random();
      float ra = Random() * 360.0;
      glPushMatrix();
      glTranslatef(tx, ty, tz);
      glRotatef(ra, rx, ry, rz);
      glScalef(sx, sy, sz);
      RandomColor();
      drawBox(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0, GL_POLYGON);
      glPopMatrix();
   }

   glFinish();
}



static void
WriteFile(const char *filename)
{
   FILE *f;
   GLubyte *image;
   int i;

   image = malloc(gWidth * gHeight * 3 * sizeof(GLubyte));
   if (!image) {
      printf("Error: couldn't allocate image buffer\n");
      return;
   }

   glPixelStorei(GL_PACK_ALIGNMENT, 1);
   glReadPixels(0, 0, gWidth, gHeight, GL_RGB, GL_UNSIGNED_BYTE, image);

   f = fopen(filename, "w");
   if (!f) {
      printf("Couldn't open image file: %s\n", filename);
      return;
   }
   fprintf(f,"P6\n");
   fprintf(f,"# ppm-file created by %s\n", "trdemo2");
   fprintf(f,"%i %i\n", gWidth, gHeight);
   fprintf(f,"255\n");
   fclose(f);
   f = fopen(filename, "ab");  /* now append binary data */
   if (!f) {
      printf("Couldn't append to image file: %s\n", filename);
      return;
   }

   for (i=0;i<gHeight;i++) {
      GLubyte *rowPtr;
      /* Remember, OpenGL images are bottom to top.  Have to reverse. */
      rowPtr = image + (gHeight-1-i) * gWidth*3;
      fwrite(rowPtr, 1, gWidth*3, f);
   }

   fclose(f);
   free(image);

   printf("Wrote %d by %d image file: %s\n", gWidth, gHeight, filename);
}



/*
 * Print message describing command line parameters.
 */
static void
Usage(const char *appName)
{
   printf("Usage:\n");
   printf("  %s width height imgfile\n", appName);
   printf("Where imgfile is a ppm file\n");
}



int
main(int argc, char *argv[])
{
   if (argc!=4) {
      Usage(argv[0]);
   }
   else {
      int width = atoi(argv[1]);
      int height = atoi(argv[2]);
      char *fileName = argv[3];
      if (width<=0) {
         printf("Error: width parameter must be at least 1.\n");
         return 1;
      }
      if (height<=0) {
         printf("Error: height parameter must be at least 1.\n");
         return 1;
      }
      if (!Setup(width, height)) {
         return 1;
      }

      printf("Setup completed\n");
      Render();
      printf("Render completed.\n");
      WriteFile(fileName);
      printf("File write completed.\n");

      glXDestroyPbuffer( gDpy, gPBuffer );
   }
   return 0;
}