1/*
2 * Test GL_ARB_vertex_buffer_object
3 * Also test GL_ARB_vertex_array_object if supported
4 *
5 * Brian Paul
6 * 16 Sep 2003
7 */
8
9
10#include <assert.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14#include <math.h>
15#include <GL/glew.h>
16#include "glut_wrap.h"
17
18#define NUM_OBJECTS 10
19
20struct object
21{
22   GLuint ArrayObjectID; /** GL_ARB_vertex_array_object */
23   GLuint VertexBufferID;
24   GLuint ColorBufferID;
25   GLuint ElementsBufferID;
26   GLuint NumVerts;
27   GLuint VertexOffset;
28   GLuint ColorOffset;
29   GLuint VertexStride;
30   GLuint ColorStride;
31   GLuint NumElements;
32   GLuint MaxElement;
33};
34
35static struct object Objects[NUM_OBJECTS];
36static GLuint NumObjects;
37
38static GLuint Win;
39
40static GLfloat Xrot = 0, Yrot = 0, Zrot = 0;
41static GLboolean Anim = GL_TRUE;
42static GLboolean Have_ARB_vertex_array_object = GL_FALSE;
43
44
45static void CheckError(int line)
46{
47   GLenum err = glGetError();
48   if (err) {
49      printf("GL Error 0x%x at line %d\n", (int) err, line);
50   }
51}
52
53
54static void DrawObject( const struct object *obj )
55{
56   if (Have_ARB_vertex_array_object && obj->ArrayObjectID) {
57      glBindVertexArray(obj->ArrayObjectID);
58
59      if (obj->NumElements > 0) {
60         /* indexed arrays */
61         glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID);
62         glDrawRangeElements(GL_LINE_LOOP, 0, obj->MaxElement,
63                             obj->NumElements, GL_UNSIGNED_INT, NULL);
64      }
65      else {
66         /* non-indexed arrays */
67         glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
68         glDrawArrays(GL_LINE_LOOP, 0, obj->NumVerts);
69      }
70
71      glBindVertexArray(0);
72   }
73   else {
74      /* no vertex array objects, must set vertex/color pointers per draw */
75
76      glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
77      glVertexPointer(3, GL_FLOAT, obj->VertexStride, (const void *) (size_t) obj->VertexOffset);
78      glEnableClientState(GL_VERTEX_ARRAY);
79
80      /* test push/pop attrib */
81      /* XXX this leads to a segfault with NVIDIA's 53.36 driver */
82#if 0
83      if (1)
84      {
85         glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT);
86         /*glVertexPointer(3, GL_FLOAT, 0, (const void *) (size_t) (obj->VertexOffset + 10000));*/
87         glBindBufferARB(GL_ARRAY_BUFFER_ARB, 999999);
88         glPopClientAttrib();
89      }
90#endif
91      glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->ColorBufferID);
92      glColorPointer(3, GL_FLOAT, obj->ColorStride, (const void *) (size_t) obj->ColorOffset);
93      glEnableClientState(GL_COLOR_ARRAY);
94
95      if (obj->NumElements > 0) {
96         /* indexed arrays */
97         glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID);
98         glDrawElements(GL_LINE_LOOP, obj->NumElements, GL_UNSIGNED_INT, NULL);
99      }
100      else {
101         /* non-indexed arrays */
102         glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
103         glDrawArrays(GL_LINE_LOOP, 0, obj->NumVerts);
104      }
105   }
106}
107
108
109static void Idle( void )
110{
111   Zrot = 0.05 * glutGet(GLUT_ELAPSED_TIME);
112   glutPostRedisplay();
113}
114
115
116static void Display( void )
117{
118   int i;
119
120   glClear( GL_COLOR_BUFFER_BIT );
121
122   for (i = 0; i < NumObjects; i++) {
123      float x = 7.0 * ((float) i / (NumObjects-1) - 0.5);
124      glPushMatrix();
125      glTranslatef(x, 0, 0);
126      glRotatef(Xrot, 1, 0, 0);
127      glRotatef(Yrot, 0, 1, 0);
128      glRotatef(Zrot, 0, 0, 1);
129
130      DrawObject(Objects + i);
131
132      glPopMatrix();
133   }
134
135   CheckError(__LINE__);
136   glutSwapBuffers();
137}
138
139
140static void Reshape( int width, int height )
141{
142   float ar = (float) width / (float) height;
143   glViewport( 0, 0, width, height );
144   glMatrixMode( GL_PROJECTION );
145   glLoadIdentity();
146   glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
147   glMatrixMode( GL_MODELVIEW );
148   glLoadIdentity();
149   glTranslatef( 0.0, 0.0, -15.0 );
150}
151
152
153static void FreeBuffers(void)
154{
155   int i;
156   for (i = 0; i < NUM_OBJECTS; i++) {
157      glDeleteBuffersARB(1, &Objects[i].VertexBufferID);
158      glDeleteBuffersARB(1, &Objects[i].ColorBufferID);
159      glDeleteBuffersARB(1, &Objects[i].ElementsBufferID);
160   }
161}
162
163
164static void Key( unsigned char key, int x, int y )
165{
166   const GLfloat step = 3.0;
167   (void) x;
168   (void) y;
169   switch (key) {
170      case 'a':
171         Anim = !Anim;
172         if (Anim)
173            glutIdleFunc(Idle);
174         else
175            glutIdleFunc(NULL);
176         break;
177      case 'z':
178         Zrot -= step;
179         break;
180      case 'Z':
181         Zrot += step;
182         break;
183      case 27:
184         FreeBuffers();
185         glutDestroyWindow(Win);
186         exit(0);
187         break;
188   }
189   glutPostRedisplay();
190}
191
192
193static void SpecialKey( int key, int x, int y )
194{
195   const GLfloat step = 3.0;
196   (void) x;
197   (void) y;
198   switch (key) {
199      case GLUT_KEY_UP:
200         Xrot -= step;
201         break;
202      case GLUT_KEY_DOWN:
203         Xrot += step;
204         break;
205      case GLUT_KEY_LEFT:
206         Yrot -= step;
207         break;
208      case GLUT_KEY_RIGHT:
209         Yrot += step;
210         break;
211   }
212   glutPostRedisplay();
213}
214
215
216/**
217 * If GL_ARB_vertex_array_object is supported, create an array object
218 * and set all the per-array state.
219 */
220static void
221CreateVertexArrayObject(struct object *obj)
222{
223   glGenVertexArrays(1, &obj->ArrayObjectID);
224   glBindVertexArray(obj->ArrayObjectID);
225
226   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
227   glVertexPointer(3, GL_FLOAT, obj->VertexStride, (const void *) (size_t) obj->VertexOffset);
228   glEnableClientState(GL_VERTEX_ARRAY);
229
230   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->ColorBufferID);
231   glColorPointer(3, GL_FLOAT, obj->ColorStride, (const void *) (size_t) obj->ColorOffset);
232   glEnableClientState(GL_COLOR_ARRAY);
233
234   glBindVertexArray(0);
235}
236
237
238/*
239 * Non-interleaved position/color data.
240 */
241static void MakeObject1(struct object *obj)
242{
243   GLfloat *v, *c;
244   void *p;
245   int i;
246   GLubyte buffer[500];
247
248   for (i = 0; i < 500; i++)
249      buffer[i] = i & 0xff;
250
251   obj->VertexBufferID = 0;
252   glGenBuffersARB(1, &obj->VertexBufferID);
253   obj->ColorBufferID = obj->VertexBufferID;
254   assert(obj->VertexBufferID != 0);
255   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
256   glBufferDataARB(GL_ARRAY_BUFFER_ARB, 500, buffer, GL_STATIC_DRAW_ARB);
257
258   for (i = 0; i < 500; i++)
259      buffer[i] = 0;
260
261   glGetBufferSubDataARB(GL_ARRAY_BUFFER_ARB, 0, 500, buffer);
262
263   for (i = 0; i < 500; i++)
264      assert(buffer[i] == (i & 0xff));
265
266   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_MAPPED_ARB, &i);
267   assert(!i);
268
269   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_USAGE_ARB, &i);
270
271   v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
272
273   /* do some sanity tests */
274   glGetBufferPointervARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_MAP_POINTER_ARB, &p);
275   assert(p == v);
276
277   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_SIZE_ARB, &i);
278   assert(i == 500);
279
280   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_USAGE_ARB, &i);
281   assert(i == GL_STATIC_DRAW_ARB);
282
283   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_ACCESS_ARB, &i);
284   assert(i == GL_WRITE_ONLY_ARB);
285
286   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_MAPPED_ARB, &i);
287   assert(i);
288
289   /* Make rectangle */
290   v[0] = -1;  v[1] = -1;  v[2] = 0;
291   v[3] =  1;  v[4] = -1;  v[5] = 0;
292   v[6] =  1;  v[7] =  1;  v[8] = 0;
293   v[9] = -1;  v[10] = 1;  v[11] = 0;
294   c = v + 12;
295   c[0] = 1;  c[1] = 0;  c[2] = 0;
296   c[3] = 1;  c[4] = 0;  c[5] = 0;
297   c[6] = 1;  c[7] = 0;  c[8] = 1;
298   c[9] = 1;  c[10] = 0;  c[11] = 1;
299   obj->NumVerts = 4;
300   obj->VertexOffset = 0;
301   obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
302   obj->VertexStride = 0;
303   obj->ColorStride = 0;
304   obj->NumElements = 0;
305   obj->MaxElement = 0;
306
307   glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
308
309   glGetBufferPointervARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_MAP_POINTER_ARB, &p);
310   assert(!p);
311
312   glGetBufferParameterivARB(GL_ARRAY_BUFFER_ARB, GL_BUFFER_MAPPED_ARB, &i);
313   assert(!i);
314
315   if (Have_ARB_vertex_array_object) {
316      CreateVertexArrayObject(obj);
317   }
318}
319
320
321/*
322 * Interleaved position/color data.
323 */
324static void MakeObject2(struct object *obj)
325{
326   GLfloat *v;
327   int start = 40; /* bytes, to test non-zero array offsets */
328
329   glGenBuffersARB(1, &obj->VertexBufferID);
330   obj->ColorBufferID = obj->VertexBufferID;
331
332   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
333   glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
334   v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
335
336   v += start / sizeof(GLfloat);
337
338   /* Make triangle: interleaved colors, then positions */
339   /*   R            G          B           X           Y            Z  */
340   v[0] = 0;   v[1] = 1;   v[2] = 0;   v[3] = -1;  v[4] = -1;   v[5] = 0;
341   v[6] = 0;   v[7] = 1;   v[8] = 0;   v[9] = 1;   v[10] = -1;  v[11] = 0;
342   v[12] = 1;  v[13] = 1;  v[14] = 0;  v[15] = 0;  v[16] =  1;  v[17] = 0;
343
344   obj->NumVerts = 3;
345   obj->VertexOffset = start + 3 * sizeof(GLfloat);
346   obj->ColorOffset = start;
347   obj->VertexStride = 6 * sizeof(GLfloat);
348   obj->ColorStride = 6 * sizeof(GLfloat);
349
350   obj->NumElements = 0;
351   obj->MaxElement = 0;
352
353   glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
354
355   if (Have_ARB_vertex_array_object) {
356      CreateVertexArrayObject(obj);
357   }
358}
359
360
361/*
362 * Use an index buffer and glDrawElements().
363 */
364static void MakeObject3(struct object *obj)
365{
366   GLfloat vertexData[1000];
367   GLfloat *v, *c;
368   GLuint *i;
369   int bytes;
370
371   /* Make rectangle */
372   v = vertexData;
373   v[0] = -1;  v[1] = -0.5;  v[2] = 0;
374   v[3] =  1;  v[4] = -0.5;  v[5] = 0;
375   v[6] =  1;  v[7] =  0.5;  v[8] = 0;
376   v[9] = -1;  v[10] = 0.5;  v[11] = 0;
377   c = vertexData + 12;
378   c[0] = 0;  c[1] = 0;  c[2] = 1;
379   c[3] = 0;  c[4] = 0;  c[5] = 1;
380   c[6] = 0;  c[7] = 1;  c[8] = 1;
381   c[9] = 0;  c[10] = 1;  c[11] = 1;
382   obj->NumVerts = 4;
383   obj->VertexOffset = 0;
384   obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
385   obj->VertexStride = 0;
386   obj->ColorStride = 0;
387
388   bytes = obj->NumVerts * (3 + 3) * sizeof(GLfloat);
389
390   /* Don't use glMap/UnmapBuffer for this object */
391   glGenBuffersARB(1, &obj->VertexBufferID);
392   obj->ColorBufferID = obj->VertexBufferID;
393
394   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
395   glBufferDataARB(GL_ARRAY_BUFFER_ARB, bytes, vertexData, GL_STATIC_DRAW_ARB);
396
397   /* Setup a buffer of indices to test the ELEMENTS path */
398   glGenBuffersARB(1, &obj->ElementsBufferID);
399   glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID);
400   glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 100, NULL, GL_STATIC_DRAW_ARB);
401   i = (GLuint *) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB);
402   i[0] = 0;
403   i[1] = 1;
404   i[2] = 2;
405   i[3] = 3;
406   glUnmapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB);
407   obj->NumElements = 4;
408   obj->MaxElement = 3;
409
410   if (Have_ARB_vertex_array_object) {
411      CreateVertexArrayObject(obj);
412   }
413}
414
415
416/*
417 * Vertex and color data in different buffers.
418 */
419static void MakeObject4(struct object *obj)
420{
421   static const GLfloat vertexData[] = {
422      0,   -1,  0,
423      0.5,  0,  0,
424      0,    1,  0,
425      -0.5, 0,  0
426   };
427   static const GLfloat colorData[] = {
428      1,    1,   1,
429      1,    1,   0,
430      .5,  .5,   0,
431      1,    1,   0
432   };
433
434   obj->VertexOffset = 0;
435   obj->VertexStride = 0;
436   obj->ColorOffset = 0;
437   obj->ColorStride = 0;
438   obj->NumVerts = 4;
439
440   glGenBuffersARB(1, &obj->VertexBufferID);
441   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->VertexBufferID);
442   glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(vertexData), vertexData,
443                   GL_STATIC_DRAW_ARB);
444
445   glGenBuffersARB(1, &obj->ColorBufferID);
446   glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->ColorBufferID);
447   glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(colorData), colorData,
448                   GL_STATIC_DRAW_ARB);
449
450   /* Setup a buffer of indices to test the ELEMENTS path */
451   obj->ElementsBufferID = 0;
452   obj->NumElements = 0;
453   obj->MaxElement = 0;
454
455   if (Have_ARB_vertex_array_object) {
456      CreateVertexArrayObject(obj);
457   }
458}
459
460
461
462static void Init( void )
463{
464   if (!glutExtensionSupported("GL_ARB_vertex_buffer_object")) {
465      printf("GL_ARB_vertex_buffer_object not found!\n");
466      exit(0);
467   }
468   printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
469
470   Have_ARB_vertex_array_object =
471      glutExtensionSupported("GL_ARB_vertex_array_object");
472
473   printf("Using GL_ARB_vertex_array_object: %s\n",
474          (Have_ARB_vertex_array_object ? "yes" : "no"));
475
476
477   /* Test buffer object deletion */
478   if (1) {
479      static GLubyte data[1000];
480      GLuint id = 999;
481      glBindBufferARB(GL_ARRAY_BUFFER_ARB, id);
482      glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, data, GL_STATIC_DRAW_ARB);
483      glVertexPointer(3, GL_FLOAT, 0, (void *) 0);
484      glDeleteBuffersARB(1, &id);
485      assert(!glIsBufferARB(id));
486      glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
487      glVertexPointer(3, GL_FLOAT, 0, (void *) 0);
488      assert(!glIsBufferARB(id));
489   }
490
491   memset(Objects, 0, sizeof(Objects));
492   MakeObject1(Objects + 0);
493   MakeObject2(Objects + 1);
494   MakeObject3(Objects + 2);
495   MakeObject4(Objects + 3);
496   NumObjects = 4;
497}
498
499
500int main( int argc, char *argv[] )
501{
502   glutInit( &argc, argv );
503   glutInitWindowPosition( 0, 0 );
504   glutInitWindowSize( 600, 300 );
505   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
506   Win = glutCreateWindow(argv[0]);
507   glewInit();
508   glutReshapeFunc( Reshape );
509   glutKeyboardFunc( Key );
510   glutSpecialFunc( SpecialKey );
511   glutDisplayFunc( Display );
512   if (Anim)
513      glutIdleFunc(Idle);
514   Init();
515   glutMainLoop();
516   return 0;
517}
518