/* * 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 <assert.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <GL/glew.h> #include <GL/glut.h> #define TEST_DISPLAY_LISTS 0 static GLboolean Anim = GL_TRUE; static GLfloat Xpos = 0; static GLuint OccQuery; 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; static int sign = +1; int time = glutGet(GLUT_ELAPSED_TIME); float step; if (lastTime == 0) lastTime = time; else if (time - lastTime < 20) /* 50Hz update */ return; step = (time - lastTime) / 1000.0 * sign; lastTime = time; Xpos += step; if (Xpos > 2.5) { Xpos = 2.5; sign = -1; } else if (Xpos < -2.5) { Xpos = -2.5; sign = +1; } glutPostRedisplay(); } static void Display( void ) { GLuint passed; GLint ready; char s[100]; 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, 0.6, 0.8); glBegin(GL_QUADS); glVertex2f(-1.6, -1.5); glVertex2f(-0.4, -1.5); glVertex2f(-0.4, 1.5); glVertex2f(-1.6, 1.5); glVertex2f( 0.4, -1.5); glVertex2f( 1.6, -1.5); glVertex2f( 1.6, 1.5); glVertex2f( 0.4, 1.5); glEnd(); /* draw the test polygon with occlusion testing */ glPushMatrix(); glTranslatef(Xpos, 0, -0.5); glScalef(0.3, 0.3, 1.0); glRotatef(-90.0 * Xpos, 0, 0, 1); #if defined(GL_ARB_occlusion_query) #if TEST_DISPLAY_LISTS glNewList(10, GL_COMPILE); glBeginQueryARB(GL_SAMPLES_PASSED_ARB, OccQuery); glEndList(); glCallList(10); #else glBeginQueryARB(GL_SAMPLES_PASSED_ARB, OccQuery); #endif glColorMask(0, 0, 0, 0); glDepthMask(GL_FALSE); glBegin(GL_POLYGON); glVertex3f(-1, -1, 0); glVertex3f( 1, -1, 0); glVertex3f( 1, 1, 0); glVertex3f(-1, 1, 0); glEnd(); #if TEST_DISPLAY_LISTS glNewList(11, GL_COMPILE); glEndQueryARB(GL_SAMPLES_PASSED_ARB); glEndList(); glCallList(11); #else glEndQueryARB(GL_SAMPLES_PASSED_ARB); #endif do { /* do useful work here, if any */ glGetQueryObjectivARB(OccQuery, GL_QUERY_RESULT_AVAILABLE_ARB, &ready); } while (!ready); glGetQueryObjectuivARB(OccQuery, GL_QUERY_RESULT_ARB, &passed); /* turn off occlusion testing */ glColorMask(1, 1, 1, 1); glDepthMask(GL_TRUE); #endif /* GL_ARB_occlusion_query */ /* draw the orange rect, so we can see what's going on */ glColor3f(0.8, 0.5, 0); glBegin(GL_POLYGON); glVertex3f(-1, -1, 0); glVertex3f( 1, -1, 0); glVertex3f( 1, 1, 0); glVertex3f(-1, 1, 0); glEnd(); glPopMatrix(); /* Print result message */ glMatrixMode( GL_PROJECTION ); glLoadIdentity(); glOrtho( -1.0, 1.0, -1.0, 1.0, -1.0, 1.0 ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glColor3f(1, 1, 1); #if defined(GL_ARB_occlusion_query) sprintf(s, " %4d Fragments Visible", passed); glRasterPos3f(-0.50, -0.7, 0); PrintString(s); if (!passed) { glRasterPos3f(-0.25, -0.8, 0); PrintString("Fully Occluded"); } #else glRasterPos3f(-0.25, -0.8, 0); PrintString("GL_ARB_occlusion_query not available at compile time"); #endif /* GL_ARB_occlusion_query */ 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; (void) x; (void) y; switch (key) { case GLUT_KEY_LEFT: Xpos -= step; break; case GLUT_KEY_RIGHT: Xpos += step; break; } glutPostRedisplay(); } static void Init( void ) { const char *ext = (const char *) glGetString(GL_EXTENSIONS); GLint bits; if (!strstr(ext, "GL_ARB_occlusion_query")) { printf("Sorry, this demo requires the GL_ARB_occlusion_query extension\n"); exit(-1); } #if defined(GL_ARB_occlusion_query) 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); } #endif /* GL_ARB_occlusion_query */ glGetIntegerv(GL_DEPTH_BITS, &bits); printf("Depthbits: %d\n", bits); #if defined(GL_ARB_occlusion_query) glGenQueriesARB(1, &OccQuery); assert(OccQuery > 0); #endif /* GL_ARB_occlusion_query */ glEnable(GL_DEPTH_TEST); } 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 ); glutIdleFunc( Idle ); glutDisplayFunc( Display ); Init(); glutMainLoop(); return 0; }