progs/tests/bufferobj.c

   1 /*
   2  * Test GL_ARB_vertex_buffer_object
   3  *
   4  * Brian Paul
   5  * 16 Sep 2003
   6  */
   7
   8
   9 #define GL_GLEXT_PROTOTYPES
  10 #include <assert.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <math.h>
  14 #include <GL/glut.h>
  15
  16 #define NUM_OBJECTS 10
  17
  18 struct object
  19 {
  20    GLuint BufferID;
  21    GLuint NumVerts;
  22    GLuint VertexOffset;
  23    GLuint ColorOffset;
  24 };
  25
  26 static struct object Objects[NUM_OBJECTS];
  27 static GLuint NumObjects;
  28
  29 static GLfloat Xrot = 0, Yrot = 0, Zrot = 0;
  30 static GLboolean Anim = GL_TRUE;
  31
  32
  33 static void CheckError(int line)
  34 {
  35    GLenum err = glGetError();
  36    if (err) {
  37       printf("GL Error %d at line %d\n", (int) err, line);
  38    }
  39 }
  40
  41
  42 static void DrawObject( const struct object *obj )
  43 {
  44    glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
  45    glVertexPointer(3, GL_FLOAT, 0, (void *) obj->VertexOffset);
  46    glEnable(GL_VERTEX_ARRAY);
  47    glColorPointer(3, GL_FLOAT, 0, (void *) obj->ColorOffset);
  48    glEnable(GL_COLOR_ARRAY);
  49    glDrawArrays(GL_LINE_LOOP, 0, obj->NumVerts);
  50 }
  51
  52
  53 static void Idle( void )
  54 {
  55    Zrot = 0.05 * glutGet(GLUT_ELAPSED_TIME);
  56    glutPostRedisplay();
  57 }
  58
  59
  60 static void Display( void )
  61 {
  62    int i;
  63
  64    glClear( GL_COLOR_BUFFER_BIT );
  65
  66    for (i = 0; i < NumObjects; i++) {
  67       float x = 5.0 * ((float) i / (NumObjects-1) - 0.5);
  68       glPushMatrix();
  69       glTranslatef(x, 0, 0);
  70       glRotatef(Xrot, 1, 0, 0);
  71       glRotatef(Yrot, 0, 1, 0);
  72       glRotatef(Zrot, 0, 0, 1);
  73
  74       DrawObject(Objects + i);
  75
  76       glPopMatrix();
  77    }
  78
  79    CheckError(__LINE__);
  80    glutSwapBuffers();
  81 }
  82
  83
  84 static void Reshape( int width, int height )
  85 {
  86    float ar = (float) width / (float) height;
  87    glViewport( 0, 0, width, height );
  88    glMatrixMode( GL_PROJECTION );
  89    glLoadIdentity();
  90    glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
  91    glMatrixMode( GL_MODELVIEW );
  92    glLoadIdentity();
  93    glTranslatef( 0.0, 0.0, -15.0 );
  94 }
  95
  96
  97 static void Key( unsigned char key, int x, int y )
  98 {
  99    const GLfloat step = 3.0;
 100    (void) x;
 101    (void) y;
 102    switch (key) {
 103       case 'a':
 104          Anim = !Anim;
 105          if (Anim)
 106             glutIdleFunc(Idle);
 107          else
 108             glutIdleFunc(NULL);
 109          break;
 110       case 'z':
 111          Zrot -= step;
 112          break;
 113       case 'Z':
 114          Zrot += step;
 115          break;
 116       case 27:
 117          exit(0);
 118          break;
 119    }
 120    glutPostRedisplay();
 121 }
 122
 123
 124 static void SpecialKey( int key, int x, int y )
 125 {
 126    const GLfloat step = 3.0;
 127    (void) x;
 128    (void) y;
 129    switch (key) {
 130       case GLUT_KEY_UP:
 131          Xrot -= step;
 132          break;
 133       case GLUT_KEY_DOWN:
 134          Xrot += step;
 135          break;
 136       case GLUT_KEY_LEFT:
 137          Yrot -= step;
 138          break;
 139       case GLUT_KEY_RIGHT:
 140          Yrot += step;
 141          break;
 142    }
 143    glutPostRedisplay();
 144 }
 145
 146
 147
 148 static void MakeObject1(struct object *obj)
 149 {
 150    GLfloat *v, *c;
 151
 152    glGenBuffersARB(1, &obj->BufferID);
 153    glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
 154    glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
 155    v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB);
 156
 157    /* Make rectangle */
 158    v[0] = -1;  v[1] = -1;  v[2] = 0;
 159    v[3] =  1;  v[4] = -1;  v[5] = 0;
 160    v[6] =  1;  v[7] =  1;  v[8] = 0;
 161    v[9] = -1;  v[10] = 1;  v[11] = 0;
 162    c = v + 12;
 163    c[0] = 1;  c[1] = 0;  c[2] = 0;
 164    c[3] = 1;  c[4] = 0;  c[5] = 0;
 165    c[6] = 1;  c[7] = 0;  c[8] = 1;
 166    c[9] = 1;  c[10] = 0;  c[11] = 1;
 167    obj->NumVerts = 4;
 168    obj->VertexOffset = 0;
 169    obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
 170
 171    glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
 172 }
 173
 174
 175 static void MakeObject2(struct object *obj)
 176 {
 177    GLfloat *v, *c;
 178
 179    glGenBuffersARB(1, &obj->BufferID);
 180    glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
 181    glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
 182    v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB);
 183
 184    /* Make triangle */
 185    v[0] = -1;  v[1] = -1;  v[2] = 0;
 186    v[3] =  1;  v[4] = -1;  v[5] = 0;
 187    v[6] =  0;  v[7] =  1;  v[8] = 0;
 188    c = v + 9;
 189    c[0] = 0;  c[1] = 1;  c[2] = 0;
 190    c[3] = 0;  c[4] = 1;  c[5] = 0;
 191    c[6] = 1;  c[7] = 1;  c[8] = 0;
 192    obj->NumVerts = 3;
 193    obj->VertexOffset = 0;
 194    obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
 195
 196    glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
 197 }
 198
 199
 200 static void MakeObject3(struct object *obj)
 201 {
 202    GLfloat *v, *c;
 203
 204    glGenBuffersARB(1, &obj->BufferID);
 205    glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
 206    glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
 207    v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB);
 208
 209    /* Make rectangle */
 210    v[0] = -1;  v[1] = -0.5;  v[2] = 0;
 211    v[3] =  1;  v[4] = -0.5;  v[5] = 0;
 212    v[6] =  1;  v[7] =  0.5;  v[8] = 0;
 213    v[9] = -1;  v[10] = 0.5;  v[11] = 0;
 214    c = v + 12;
 215    c[0] = 0;  c[1] = 0;  c[2] = 1;
 216    c[3] = 0;  c[4] = 0;  c[5] = 1;
 217    c[6] = 0;  c[7] = 1;  c[8] = 1;
 218    c[9] = 0;  c[10] = 1;  c[11] = 1;
 219    obj->NumVerts = 4;
 220    obj->VertexOffset = 0;
 221    obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
 222
 223    glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
 224 }
 225
 226
 227
 228 static void Init( void )
 229 {
 230    if (!glutExtensionSupported("GL_ARB_vertex_buffer_object")) {
 231       printf("GL_ARB_vertex_buffer_object not found!\n");
 232       exit(0);
 233    }
 234    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 235
 236    MakeObject1(Objects + 0);
 237    MakeObject2(Objects + 1);
 238    MakeObject3(Objects + 2);
 239    NumObjects = 3;
 240 }
 241
 242
 243 int main( int argc, char *argv[] )
 244 {
 245    glutInit( &argc, argv );
 246    glutInitWindowPosition( 0, 0 );
 247    glutInitWindowSize( 600, 300 );
 248    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 249    glutCreateWindow(argv[0]);
 250    glutReshapeFunc( Reshape );
 251    glutKeyboardFunc( Key );
 252    glutSpecialFunc( SpecialKey );
 253    glutDisplayFunc( Display );
 254    if (Anim)
 255       glutIdleFunc(Idle);
 256    Init();
 257    glutMainLoop();
 258    return 0;
 259 }