1/*
2 * Test AUX buffer rendering
3 * Use GLX since GLUT doesn't support AUX buffers
4 */
5
6
7/*
8 * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a
11 * copy of this software and associated documentation files (the "Software"),
12 * to deal in the Software without restriction, including without limitation
13 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
14 * and/or sell copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included
18 * in all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
21 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
23 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
24 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
25 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 */
27
28/*
29 * This is a port of the infamous "gears" demo to straight GLX (i.e. no GLUT)
30 * Port by Brian Paul  23 March 2001
31 *
32 * Command line options:
33 *    -info      print GL implementation information
34 *
35 */
36
37
38#include <math.h>
39#include <stdlib.h>
40#include <stdio.h>
41#include <string.h>
42#include <X11/Xlib.h>
43#include <X11/keysym.h>
44#include <GL/glew.h>
45#include <GL/glx.h>
46
47
48static int
49current_time(void)
50{
51   return 0;
52}
53
54
55
56
57#ifndef M_PI
58#define M_PI 3.14159265
59#endif
60
61static int WinWidth = 300, WinHeight = 300;
62static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
63static GLint gear1, gear2, gear3;
64static GLfloat angle = 0.0;
65
66
67/*
68 *
69 *  Draw a gear wheel.  You'll probably want to call this function when
70 *  building a display list since we do a lot of trig here.
71 *
72 *  Input:  inner_radius - radius of hole at center
73 *          outer_radius - radius at center of teeth
74 *          width - width of gear
75 *          teeth - number of teeth
76 *          tooth_depth - depth of tooth
77 */
78static void
79gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
80     GLint teeth, GLfloat tooth_depth)
81{
82   GLint i;
83   GLfloat r0, r1, r2;
84   GLfloat angle, da;
85   GLfloat u, v, len;
86
87   r0 = inner_radius;
88   r1 = outer_radius - tooth_depth / 2.0;
89   r2 = outer_radius + tooth_depth / 2.0;
90
91   da = 2.0 * M_PI / teeth / 4.0;
92
93   glShadeModel(GL_FLAT);
94
95   glNormal3f(0.0, 0.0, 1.0);
96
97   /* draw front face */
98   glBegin(GL_QUAD_STRIP);
99   for (i = 0; i <= teeth; i++) {
100      angle = i * 2.0 * M_PI / teeth;
101      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
102      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
103      if (i < teeth) {
104	 glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
105	 glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
106		    width * 0.5);
107      }
108   }
109   glEnd();
110
111   /* draw front sides of teeth */
112   glBegin(GL_QUADS);
113   da = 2.0 * M_PI / teeth / 4.0;
114   for (i = 0; i < teeth; i++) {
115      angle = i * 2.0 * M_PI / teeth;
116
117      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
118      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
119      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
120		 width * 0.5);
121      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
122		 width * 0.5);
123   }
124   glEnd();
125
126   glNormal3f(0.0, 0.0, -1.0);
127
128   /* draw back face */
129   glBegin(GL_QUAD_STRIP);
130   for (i = 0; i <= teeth; i++) {
131      angle = i * 2.0 * M_PI / teeth;
132      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
133      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
134      if (i < teeth) {
135	 glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
136		    -width * 0.5);
137	 glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
138      }
139   }
140   glEnd();
141
142   /* draw back sides of teeth */
143   glBegin(GL_QUADS);
144   da = 2.0 * M_PI / teeth / 4.0;
145   for (i = 0; i < teeth; i++) {
146      angle = i * 2.0 * M_PI / teeth;
147
148      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
149		 -width * 0.5);
150      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
151		 -width * 0.5);
152      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
153      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
154   }
155   glEnd();
156
157   /* draw outward faces of teeth */
158   glBegin(GL_QUAD_STRIP);
159   for (i = 0; i < teeth; i++) {
160      angle = i * 2.0 * M_PI / teeth;
161
162      glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
163      glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
164      u = r2 * cos(angle + da) - r1 * cos(angle);
165      v = r2 * sin(angle + da) - r1 * sin(angle);
166      len = sqrt(u * u + v * v);
167      u /= len;
168      v /= len;
169      glNormal3f(v, -u, 0.0);
170      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
171      glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
172      glNormal3f(cos(angle), sin(angle), 0.0);
173      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
174		 width * 0.5);
175      glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
176		 -width * 0.5);
177      u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
178      v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
179      glNormal3f(v, -u, 0.0);
180      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
181		 width * 0.5);
182      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
183		 -width * 0.5);
184      glNormal3f(cos(angle), sin(angle), 0.0);
185   }
186
187   glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
188   glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
189
190   glEnd();
191
192   glShadeModel(GL_SMOOTH);
193
194   /* draw inside radius cylinder */
195   glBegin(GL_QUAD_STRIP);
196   for (i = 0; i <= teeth; i++) {
197      angle = i * 2.0 * M_PI / teeth;
198      glNormal3f(-cos(angle), -sin(angle), 0.0);
199      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
200      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
201   }
202   glEnd();
203}
204
205
206static void
207draw(void)
208{
209   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
210
211   glPushMatrix();
212   glRotatef(view_rotx, 1.0, 0.0, 0.0);
213   glRotatef(view_roty, 0.0, 1.0, 0.0);
214   glRotatef(view_rotz, 0.0, 0.0, 1.0);
215
216   glPushMatrix();
217   glTranslatef(-3.0, -2.0, 0.0);
218   glRotatef(angle, 0.0, 0.0, 1.0);
219   glCallList(gear1);
220   glPopMatrix();
221
222   glPushMatrix();
223   glTranslatef(3.1, -2.0, 0.0);
224   glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
225   glCallList(gear2);
226   glPopMatrix();
227
228   glPushMatrix();
229   glTranslatef(-3.1, 4.2, 0.0);
230   glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
231   glCallList(gear3);
232   glPopMatrix();
233
234   glPopMatrix();
235}
236
237
238/* new window size or exposure */
239static void
240reshape(int width, int height)
241{
242   GLfloat h = (GLfloat) height / (GLfloat) width;
243
244   WinWidth = width;
245   WinHeight = height;
246   glViewport(0, 0, (GLint) width, (GLint) height);
247   glMatrixMode(GL_PROJECTION);
248   glLoadIdentity();
249   glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
250   glMatrixMode(GL_MODELVIEW);
251   glLoadIdentity();
252   glTranslatef(0.0, 0.0, -40.0);
253}
254
255
256static void
257init(void)
258{
259   static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
260   static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
261   static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
262   static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
263   int i;
264
265   glGetIntegerv(GL_AUX_BUFFERS, &i);
266   printf("AUX BUFFERS: %d\n", i);
267
268   glLightfv(GL_LIGHT0, GL_POSITION, pos);
269   glEnable(GL_CULL_FACE);
270   glEnable(GL_LIGHTING);
271   glEnable(GL_LIGHT0);
272   glEnable(GL_DEPTH_TEST);
273
274   /* make the gears */
275   gear1 = glGenLists(1);
276   glNewList(gear1, GL_COMPILE);
277   glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
278   gear(1.0, 4.0, 1.0, 20, 0.7);
279   glEndList();
280
281   gear2 = glGenLists(1);
282   glNewList(gear2, GL_COMPILE);
283   glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
284   gear(0.5, 2.0, 2.0, 10, 0.7);
285   glEndList();
286
287   gear3 = glGenLists(1);
288   glNewList(gear3, GL_COMPILE);
289   glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
290   gear(1.3, 2.0, 0.5, 10, 0.7);
291   glEndList();
292
293   glEnable(GL_NORMALIZE);
294}
295
296
297/*
298 * Create an RGB, double-buffered window.
299 * Return the window and context handles.
300 */
301static void
302make_window( Display *dpy, const char *name,
303             int x, int y, int width, int height,
304             Window *winRet, GLXContext *ctxRet)
305{
306   int attrib[] = { GLX_RGBA,
307		    GLX_RED_SIZE, 1,
308		    GLX_GREEN_SIZE, 1,
309		    GLX_BLUE_SIZE, 1,
310		    GLX_DOUBLEBUFFER,
311		    GLX_DEPTH_SIZE, 1,
312                    GLX_AUX_BUFFERS, 1,
313		    None };
314   int scrnum;
315   XSetWindowAttributes attr;
316   unsigned long mask;
317   Window root;
318   Window win;
319   GLXContext ctx;
320   XVisualInfo *visinfo;
321
322   scrnum = DefaultScreen( dpy );
323   root = RootWindow( dpy, scrnum );
324
325   visinfo = glXChooseVisual( dpy, scrnum, attrib );
326   if (!visinfo) {
327      printf("Error: couldn't get an RGB, Double-buffered visual\n");
328      exit(1);
329   }
330
331   /* window attributes */
332   attr.background_pixel = 0;
333   attr.border_pixel = 0;
334   attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
335   attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
336   mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
337
338   win = XCreateWindow( dpy, root, 0, 0, width, height,
339		        0, visinfo->depth, InputOutput,
340		        visinfo->visual, mask, &attr );
341
342   /* set hints and properties */
343   {
344      XSizeHints sizehints;
345      sizehints.x = x;
346      sizehints.y = y;
347      sizehints.width  = width;
348      sizehints.height = height;
349      sizehints.flags = USSize | USPosition;
350      XSetNormalHints(dpy, win, &sizehints);
351      XSetStandardProperties(dpy, win, name, name,
352                              None, (char **)NULL, 0, &sizehints);
353   }
354
355   ctx = glXCreateContext( dpy, visinfo, NULL, True );
356   if (!ctx) {
357      printf("Error: glXCreateContext failed\n");
358      exit(1);
359   }
360
361   XFree(visinfo);
362
363   *winRet = win;
364   *ctxRet = ctx;
365}
366
367
368static void
369event_loop(Display *dpy, Window win)
370{
371   while (1) {
372      while (XPending(dpy) > 0) {
373         XEvent event;
374         XNextEvent(dpy, &event);
375         switch (event.type) {
376	 case Expose:
377            /* we'll redraw below */
378	    break;
379	 case ConfigureNotify:
380	    reshape(event.xconfigure.width, event.xconfigure.height);
381	    break;
382         case KeyPress:
383            {
384               char buffer[10];
385               int r, code;
386               code = XLookupKeysym(&event.xkey, 0);
387               if (code == XK_Left) {
388                  view_roty += 5.0;
389               }
390               else if (code == XK_Right) {
391                  view_roty -= 5.0;
392               }
393               else if (code == XK_Up) {
394                  view_rotx += 5.0;
395               }
396               else if (code == XK_Down) {
397                  view_rotx -= 5.0;
398               }
399               else {
400                  r = XLookupString(&event.xkey, buffer, sizeof(buffer),
401                                    NULL, NULL);
402                  if (buffer[0] == 27) {
403                     /* escape */
404                     return;
405                  }
406               }
407            }
408         }
409      }
410
411      /* next frame */
412      angle += 2.0;
413
414      /* draw to aux buffer */
415      glDrawBuffer(GL_AUX0);
416
417      draw();
418
419      /* Copy aux buffer image to back color buffer */
420      glReadBuffer(GL_AUX0);
421      glDrawBuffer(GL_BACK);
422      glWindowPos2iARB(0, 0);
423      glDisable(GL_DEPTH_TEST);
424      glCopyPixels(0, 0, WinWidth, WinHeight, GL_COLOR);
425      glEnable(GL_DEPTH_TEST);
426
427      glXSwapBuffers(dpy, win);
428
429      /* calc framerate */
430      {
431         static int t0 = -1;
432         static int frames = 0;
433         int t = current_time();
434
435         if (t0 < 0)
436            t0 = t;
437
438         frames++;
439
440         if (t - t0 >= 5.0) {
441            GLfloat seconds = t - t0;
442            GLfloat fps = frames / seconds;
443            printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds,
444                   fps);
445            t0 = t;
446            frames = 0;
447         }
448      }
449   }
450}
451
452
453int
454main(int argc, char *argv[])
455{
456   Display *dpy;
457   Window win;
458   GLXContext ctx;
459   char *dpyName = ":0";
460   GLboolean printInfo = GL_FALSE;
461   int i;
462
463   for (i = 1; i < argc; i++) {
464      if (strcmp(argv[i], "-display") == 0) {
465         dpyName = argv[i+1];
466         i++;
467      }
468      else if (strcmp(argv[i], "-info") == 0) {
469         printInfo = GL_TRUE;
470      }
471   }
472
473   dpy = XOpenDisplay(dpyName);
474   if (!dpy) {
475      printf("Error: couldn't open display %s\n", dpyName);
476      return -1;
477   }
478
479   make_window(dpy, "glxgears", 0, 0, WinWidth, WinHeight, &win, &ctx);
480   XMapWindow(dpy, win);
481   glXMakeCurrent(dpy, win, ctx);
482
483   glewInit();
484
485   if (printInfo) {
486      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
487      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
488      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
489      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
490   }
491
492   init();
493
494   event_loop(dpy, win);
495
496   glXDestroyContext(dpy, ctx);
497   XDestroyWindow(dpy, win);
498   XCloseDisplay(dpy);
499
500   return 0;
501}
502