/* * GL_ARB_occlusion_query demo * * Brian Paul * 12 June 2003 * * Copyright (C) 2003 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include #include #include #define NUM_OCC 10 static GLboolean Anim = GL_TRUE; static GLfloat Xpos[NUM_OCC], Ypos[NUM_OCC]; static GLfloat Sign[NUM_OCC]; static GLuint OccQuery[NUM_OCC]; static GLint Win = 0; static void PrintString(const char *s) { while (*s) { glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s); s++; } } static void Idle(void) { static int lastTime = 0; int time = glutGet(GLUT_ELAPSED_TIME); float step; int i; if (lastTime == 0) lastTime = time; else if (time - lastTime < 20) /* 50Hz update */ return; for (i = 0; i < NUM_OCC; i++) { step = (time - lastTime) / 1000.0 * Sign[i]; Xpos[i] += step; if (Xpos[i] > 2.5) { Xpos[i] = 2.5; Sign[i] = -1; } else if (Xpos[i] < -2.5) { Xpos[i] = -2.5; Sign[i] = +1; } } lastTime = time; glutPostRedisplay(); } static void Display( void ) { int i; glClearColor(0.25, 0.25, 0.25, 0.0); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); 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 ); /* draw the occluding polygons */ glColor3f(0, 0.4, 0.6); glBegin(GL_QUADS); glVertex2f(-1.6, -2.5); glVertex2f(-0.4, -2.5); glVertex2f(-0.4, 2.5); glVertex2f(-1.6, 2.5); glVertex2f( 0.4, -2.5); glVertex2f( 1.6, -2.5); glVertex2f( 1.6, 2.5); glVertex2f( 0.4, 2.5); glEnd(); glColorMask(0, 0, 0, 0); glDepthMask(GL_FALSE); /* draw the test polygons with occlusion testing */ for (i = 0; i < NUM_OCC; i++) { glPushMatrix(); glTranslatef(Xpos[i], Ypos[i], -0.5); glScalef(0.2, 0.2, 1.0); glRotatef(-90.0 * Xpos[i], 0, 0, 1); glBeginQueryARB(GL_SAMPLES_PASSED_ARB, OccQuery[i]); glBegin(GL_POLYGON); glVertex3f(-1, -1, 0); glVertex3f( 1, -1, 0); glVertex3f( 1, 1, 0); glVertex3f(-1, 1, 0); glEnd(); glEndQueryARB(GL_SAMPLES_PASSED_ARB); glPopMatrix(); } glColorMask(1, 1, 1, 1); glDepthMask(GL_TRUE); /* Draw the rectangles now. * Draw orange if result was ready * Draw red if result was not ready. */ for (i = 0; i < NUM_OCC; i++) { GLuint passed; GLint ready; glGetQueryObjectivARB(OccQuery[i], GL_QUERY_RESULT_AVAILABLE_ARB, &ready); glGetQueryObjectuivARB(OccQuery[i], GL_QUERY_RESULT_ARB, &passed); if (!ready) glColor3f(1, 0, 0); else glColor3f(0.8, 0.5, 0); if (!ready || passed) { glPushMatrix(); glTranslatef(Xpos[i], Ypos[i], -0.5); glScalef(0.2, 0.2, 1.0); glRotatef(-90.0 * Xpos[i], 0, 0, 1); glBegin(GL_POLYGON); glVertex3f(-1, -1, 0); glVertex3f( 1, -1, 0); glVertex3f( 1, 1, 0); glVertex3f(-1, 1, 0); glEnd(); glPopMatrix(); } { char s[10]; glRasterPos3f(0.45, Ypos[i], 1.0); sprintf(s, "%4d", passed); PrintString(s); } } glutSwapBuffers(); } static void Reshape( int width, int height ) { glViewport( 0, 0, width, height ); } static void Key( unsigned char key, int x, int y ) { (void) x; (void) y; switch (key) { case 27: glutDestroyWindow(Win); exit(0); break; case ' ': Anim = !Anim; if (Anim) glutIdleFunc(Idle); else glutIdleFunc(NULL); break; } glutPostRedisplay(); } static void SpecialKey( int key, int x, int y ) { const GLfloat step = 0.1; int i; (void) x; (void) y; switch (key) { case GLUT_KEY_LEFT: for (i = 0; i < NUM_OCC; i++) Xpos[i] -= step; break; case GLUT_KEY_RIGHT: for (i = 0; i < NUM_OCC; i++) Xpos[i] += step; break; } glutPostRedisplay(); } static void Init( void ) { const char *ext = (const char *) glGetString(GL_EXTENSIONS); GLint bits; int i; if (!strstr(ext, "GL_ARB_occlusion_query")) { printf("Sorry, this demo requires the GL_ARB_occlusion_query extension\n"); exit(-1); } glGetQueryivARB(GL_SAMPLES_PASSED_ARB, GL_QUERY_COUNTER_BITS_ARB, &bits); if (!bits) { printf("Hmmm, GL_QUERY_COUNTER_BITS_ARB is zero!\n"); exit(-1); } glGetIntegerv(GL_DEPTH_BITS, &bits); printf("Depthbits: %d\n", bits); glGenQueriesARB(NUM_OCC, OccQuery); glEnable(GL_DEPTH_TEST); for (i = 0; i < NUM_OCC; i++) { float t = (float) i / (NUM_OCC - 1); Xpos[i] = 2.5 * t; Ypos[i] = 4.0 * (t - 0.5); Sign[i] = 1.0; } } int main( int argc, char *argv[] ) { glutInitWindowSize( 400, 400 ); glutInit( &argc, argv ); glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH ); Win = glutCreateWindow(argv[0]); glewInit(); glutReshapeFunc( Reshape ); glutKeyboardFunc( Key ); glutSpecialFunc( SpecialKey ); if (Anim) glutIdleFunc(Idle); else glutIdleFunc(NULL); glutDisplayFunc( Display ); Init(); glutMainLoop(); return 0; }