/* * Test GL_ARB_vertex_buffer_object * * Brian Paul * 16 Sep 2003 */ #define GL_GLEXT_PROTOTYPES #include #include #include #include #include #define NUM_OBJECTS 10 struct object { GLuint BufferID; GLuint ElementsBufferID; GLuint NumVerts; GLuint VertexOffset; GLuint ColorOffset; GLuint NumElements; }; static struct object Objects[NUM_OBJECTS]; static GLuint NumObjects; static GLfloat Xrot = 0, Yrot = 0, Zrot = 0; static GLboolean Anim = GL_TRUE; static void CheckError(int line) { GLenum err = glGetError(); if (err) { printf("GL Error %d at line %d\n", (int) err, line); } } static void DrawObject( const struct object *obj ) { glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID); glVertexPointer(3, GL_FLOAT, 0, (void *) obj->VertexOffset); glEnable(GL_VERTEX_ARRAY); glColorPointer(3, GL_FLOAT, 0, (void *) obj->ColorOffset); glEnable(GL_COLOR_ARRAY); if (obj->NumElements > 0) { /* indexed arrays */ glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID); glDrawElements(GL_LINE_LOOP, obj->NumElements, GL_UNSIGNED_INT, NULL); } else { /* non-indexed arrays */ glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0); glDrawArrays(GL_LINE_LOOP, 0, obj->NumVerts); } } static void Idle( void ) { Zrot = 0.05 * glutGet(GLUT_ELAPSED_TIME); glutPostRedisplay(); } static void Display( void ) { int i; glClear( GL_COLOR_BUFFER_BIT ); for (i = 0; i < NumObjects; i++) { float x = 5.0 * ((float) i / (NumObjects-1) - 0.5); glPushMatrix(); glTranslatef(x, 0, 0); glRotatef(Xrot, 1, 0, 0); glRotatef(Yrot, 0, 1, 0); glRotatef(Zrot, 0, 0, 1); DrawObject(Objects + i); glPopMatrix(); } CheckError(__LINE__); glutSwapBuffers(); } static void Reshape( int width, int height ) { float ar = (float) width / (float) height; glViewport( 0, 0, width, height ); glMatrixMode( GL_PROJECTION ); glLoadIdentity(); glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glTranslatef( 0.0, 0.0, -15.0 ); } static void Key( unsigned char key, int x, int y ) { const GLfloat step = 3.0; (void) x; (void) y; switch (key) { case 'a': Anim = !Anim; if (Anim) glutIdleFunc(Idle); else glutIdleFunc(NULL); break; case 'z': Zrot -= step; break; case 'Z': Zrot += step; break; case 27: exit(0); break; } glutPostRedisplay(); } static void SpecialKey( int key, int x, int y ) { const GLfloat step = 3.0; (void) x; (void) y; switch (key) { case GLUT_KEY_UP: Xrot -= step; break; case GLUT_KEY_DOWN: Xrot += step; break; case GLUT_KEY_LEFT: Yrot -= step; break; case GLUT_KEY_RIGHT: Yrot += step; break; } glutPostRedisplay(); } static void MakeObject1(struct object *obj) { GLfloat *v, *c; glGenBuffersARB(1, &obj->BufferID); glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID); glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB); v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB); /* Make rectangle */ v[0] = -1; v[1] = -1; v[2] = 0; v[3] = 1; v[4] = -1; v[5] = 0; v[6] = 1; v[7] = 1; v[8] = 0; v[9] = -1; v[10] = 1; v[11] = 0; c = v + 12; c[0] = 1; c[1] = 0; c[2] = 0; c[3] = 1; c[4] = 0; c[5] = 0; c[6] = 1; c[7] = 0; c[8] = 1; c[9] = 1; c[10] = 0; c[11] = 1; obj->NumVerts = 4; obj->VertexOffset = 0; obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts; obj->NumElements = 0; glUnmapBufferARB(GL_ARRAY_BUFFER_ARB); } static void MakeObject2(struct object *obj) { GLfloat *v, *c; glGenBuffersARB(1, &obj->BufferID); glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID); glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB); v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB); /* Make triangle */ v[0] = -1; v[1] = -1; v[2] = 0; v[3] = 1; v[4] = -1; v[5] = 0; v[6] = 0; v[7] = 1; v[8] = 0; c = v + 9; c[0] = 0; c[1] = 1; c[2] = 0; c[3] = 0; c[4] = 1; c[5] = 0; c[6] = 1; c[7] = 1; c[8] = 0; obj->NumVerts = 3; obj->VertexOffset = 0; obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts; obj->NumElements = 0; glUnmapBufferARB(GL_ARRAY_BUFFER_ARB); } static void MakeObject3(struct object *obj) { GLfloat *v, *c; GLuint *i; glGenBuffersARB(1, &obj->BufferID); glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID); glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB); v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB); /* Make rectangle */ v[0] = -1; v[1] = -0.5; v[2] = 0; v[3] = 1; v[4] = -0.5; v[5] = 0; v[6] = 1; v[7] = 0.5; v[8] = 0; v[9] = -1; v[10] = 0.5; v[11] = 0; c = v + 12; c[0] = 0; c[1] = 0; c[2] = 1; c[3] = 0; c[4] = 0; c[5] = 1; c[6] = 0; c[7] = 1; c[8] = 1; c[9] = 0; c[10] = 1; c[11] = 1; obj->NumVerts = 4; obj->VertexOffset = 0; obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts; glUnmapBufferARB(GL_ARRAY_BUFFER_ARB); /* Setup a buffer of indices to test the ELEMENTS path */ glGenBuffersARB(1, &obj->ElementsBufferID); glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID); glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 100, NULL, GL_STATIC_DRAW_ARB); i = (GLuint *) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB); i[0] = 0; i[1] = 1; i[2] = 2; i[3] = 3; glUnmapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB); obj->NumElements = 4; } static void Init( void ) { if (!glutExtensionSupported("GL_ARB_vertex_buffer_object")) { printf("GL_ARB_vertex_buffer_object not found!\n"); exit(0); } printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); MakeObject1(Objects + 0); MakeObject2(Objects + 1); MakeObject3(Objects + 2); NumObjects = 3; } int main( int argc, char *argv[] ) { glutInit( &argc, argv ); glutInitWindowPosition( 0, 0 ); glutInitWindowSize( 600, 300 ); glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); glutCreateWindow(argv[0]); glutReshapeFunc( Reshape ); glutKeyboardFunc( Key ); glutSpecialFunc( SpecialKey ); glutDisplayFunc( Display ); if (Anim) glutIdleFunc(Idle); Init(); glutMainLoop(); return 0; }