/* * (C) Copyright IBM Corporation 2004 * 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 * on the rights to use, copy, modify, merge, publish, distribute, sub * license, 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 (including the next * paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS 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. */ /** * \file stencil_wrap.c * * Simple test of GL_EXT_stencil_wrap functionality. Four squares are drawn * with different stencil modes, but all should be rendered with the same * final color. * * \author Ian Romanick */ #include #include #include static int Width = 550; static int Height = 200; static const GLfloat Near = 5.0, Far = 25.0; static void Display( void ) { GLint max_stencil; GLint stencil_bits; unsigned i; glGetIntegerv( GL_STENCIL_BITS, & stencil_bits ); max_stencil = (1U << stencil_bits) - 1; printf( "Stencil bits = %u, maximum stencil value = 0x%08x\n", stencil_bits, max_stencil ); glClearStencil( 0 ); glClearColor( 0.2, 0.2, 0.8, 0 ); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT ); glPushMatrix(); /* This is the "reference" square. */ glDisable(GL_STENCIL_TEST); glTranslatef(-6.0, 0, 0); glBegin(GL_QUADS); glColor3f( 0.5, 0.5, 0.5 ); glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); glEnd(); glEnable(GL_STENCIL_TEST); /* Draw the first two squares using the two non-wrap (i.e., saturate) * modes. */ glStencilFunc(GL_ALWAYS, 0, ~0); glStencilOp(GL_KEEP, GL_KEEP, GL_INCR); glTranslatef(3.0, 0, 0); glBegin(GL_QUADS); glColor3f( 0.9, 0.9, 0.9 ); for ( i = 0 ; i < (max_stencil + 5) ; i++ ) { glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); } glEnd(); glStencilFunc(GL_EQUAL, max_stencil, ~0); glBegin(GL_QUADS); glColor3f( 0.5, 0.5, 0.5 ); glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); glEnd(); glStencilFunc(GL_ALWAYS, 0, ~0); glStencilOp(GL_KEEP, GL_KEEP, GL_DECR); glTranslatef(3.0, 0, 0); glBegin(GL_QUADS); glColor3f( 0.9, 0.9, 0.9 ); for ( i = 0 ; i < (max_stencil + 5) ; i++ ) { glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); } glEnd(); glStencilFunc(GL_EQUAL, 0, ~0); glBegin(GL_QUADS); glColor3f( 0.5, 0.5, 0.5 ); glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); glEnd(); /* Draw the last two squares using the two wrap modes. */ glStencilFunc(GL_ALWAYS, 0, ~0); glStencilOp(GL_KEEP, GL_KEEP, GL_INCR_WRAP); glTranslatef(3.0, 0, 0); glBegin(GL_QUADS); glColor3f( 0.9, 0.9, 0.9 ); for ( i = 0 ; i < (max_stencil + 5) ; i++ ) { glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); } glEnd(); glStencilFunc(GL_EQUAL, 4, ~0); glBegin(GL_QUADS); glColor3f( 0.5, 0.5, 0.5 ); glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); glEnd(); glStencilFunc(GL_ALWAYS, 0, ~0); glStencilOp(GL_KEEP, GL_KEEP, GL_DECR_WRAP); glTranslatef(3.0, 0, 0); glBegin(GL_QUADS); glColor3f( 0.9, 0.9, 0.9 ); for ( i = 0 ; i < 5 ; i++ ) { glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); } glEnd(); glStencilFunc(GL_EQUAL, (max_stencil - 4), ~0); glBegin(GL_QUADS); glColor3f( 0.5, 0.5, 0.5 ); glVertex2f(-1, -1); glVertex2f( 1, -1); glVertex2f( 1, 1); glVertex2f(-1, 1); glEnd(); glPopMatrix(); glutSwapBuffers(); } static void Reshape( int width, int height ) { GLfloat ar = (float) width / (float) height; Width = width; Height = height; glViewport( 0, 0, width, height ); glMatrixMode( GL_PROJECTION ); glLoadIdentity(); glFrustum( -ar, ar, -1.0, 1.0, Near, Far ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glTranslatef( 0.0, 0.0, -15.0 ); } static void Key( unsigned char key, int x, int y ) { (void) x; (void) y; switch (key) { case 27: exit(0); break; } glutPostRedisplay(); } static void Init( void ) { const char * const ver_string = (const char * const) glGetString( GL_VERSION ); printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); printf("GL_VERSION = %s\n", ver_string); if ( !glutExtensionSupported("GL_EXT_stencil_wrap") && (atof( ver_string ) < 1.4) ) { printf("Sorry, this program requires either GL_EXT_stencil_wrap or OpenGL 1.4.\n"); exit(1); } printf("\nAll 5 squares should be the same color.\n"); glEnable( GL_BLEND ); } int main( int argc, char *argv[] ) { glutInit( &argc, argv ); glutInitWindowPosition( 0, 0 ); glutInitWindowSize( Width, Height ); glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL ); glutCreateWindow( "GL_EXT_stencil_wrap test" ); glutReshapeFunc( Reshape ); glutKeyboardFunc( Key ); glutDisplayFunc( Display ); Init(); glutMainLoop(); return 0; }