progs/tests/stencil_wrap.c

   1 /*
   2  * (C) Copyright IBM Corporation 2004
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file stencil_wrap.c
  27  *
  28  * Simple test of GL_EXT_stencil_wrap functionality.  Four squares are drawn
  29  * with different stencil modes, but all should be rendered with the same
  30  * final color.
  31  *
  32  * \author Ian Romanick <idr@us.ibm.com>
  33  */
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <GL/glut.h>
  38
  39 static int Width = 550;
  40 static int Height = 200;
  41 static const GLfloat Near = 5.0, Far = 25.0;
  42
  43
  44 static void Display( void )
  45 {
  46    GLint  max_stencil;
  47    GLint  stencil_bits;
  48    unsigned i;
  49
  50
  51    glGetIntegerv( GL_STENCIL_BITS, & stencil_bits );
  52    max_stencil = (1U << stencil_bits) - 1;
  53    printf( "Stencil bits = %u, maximum stencil value = 0x%08x\n",
  54            stencil_bits, max_stencil );
  55
  56    glClearStencil( 0 );
  57    glClearColor( 0.2, 0.2, 0.8, 0 );
  58    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT
  59             | GL_STENCIL_BUFFER_BIT );
  60
  61
  62    glPushMatrix();
  63
  64    /* This is the "reference" square.
  65     */
  66
  67    glDisable(GL_STENCIL_TEST);
  68    glTranslatef(-6.0, 0, 0);
  69    glBegin(GL_QUADS);
  70    glColor3f( 0.5, 0.5, 0.5 );
  71    glVertex2f(-1, -1);
  72    glVertex2f( 1, -1);
  73    glVertex2f( 1,  1);
  74    glVertex2f(-1,  1);
  75    glEnd();
  76
  77
  78    glEnable(GL_STENCIL_TEST);
  79
  80    /* Draw the first two squares using the two non-wrap (i.e., saturate)
  81     * modes.
  82     */
  83
  84    glStencilFunc(GL_ALWAYS, 0, ~0);
  85    glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
  86
  87    glTranslatef(3.0, 0, 0);
  88    glBegin(GL_QUADS);
  89    glColor3f( 0.9, 0.9, 0.9 );
  90
  91    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
  92       glVertex2f(-1, -1);
  93       glVertex2f( 1, -1);
  94       glVertex2f( 1,  1);
  95       glVertex2f(-1,  1);
  96    }
  97    glEnd();
  98
  99    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 100    glBegin(GL_QUADS);
 101    glColor3f( 0.5, 0.5, 0.5 );
 102    glVertex2f(-1, -1);
 103    glVertex2f( 1, -1);
 104    glVertex2f( 1,  1);
 105    glVertex2f(-1,  1);
 106    glEnd();
 107
 108
 109    glStencilFunc(GL_ALWAYS, 0, ~0);
 110    glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
 111
 112    glTranslatef(3.0, 0, 0);
 113    glBegin(GL_QUADS);
 114    glColor3f( 0.9, 0.9, 0.9 );
 115
 116    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 117       glVertex2f(-1, -1);
 118       glVertex2f( 1, -1);
 119       glVertex2f( 1,  1);
 120       glVertex2f(-1,  1);
 121    }
 122    glEnd();
 123
 124    glStencilFunc(GL_EQUAL, 0, ~0);
 125    glBegin(GL_QUADS);
 126    glColor3f( 0.5, 0.5, 0.5 );
 127    glVertex2f(-1, -1);
 128    glVertex2f( 1, -1);
 129    glVertex2f( 1,  1);
 130    glVertex2f(-1,  1);
 131    glEnd();
 132
 133
 134
 135
 136    /* Draw the last two squares using the two wrap modes.
 137     */
 138
 139    glStencilFunc(GL_ALWAYS, 0, ~0);
 140    glStencilOp(GL_KEEP, GL_KEEP, GL_INCR_WRAP);
 141
 142    glTranslatef(3.0, 0, 0);
 143    glBegin(GL_QUADS);
 144    glColor3f( 0.9, 0.9, 0.9 );
 145
 146    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 147       glVertex2f(-1, -1);
 148       glVertex2f( 1, -1);
 149       glVertex2f( 1,  1);
 150       glVertex2f(-1,  1);
 151    }
 152    glEnd();
 153
 154    glStencilFunc(GL_EQUAL, 4, ~0);
 155    glBegin(GL_QUADS);
 156    glColor3f( 0.5, 0.5, 0.5 );
 157    glVertex2f(-1, -1);
 158    glVertex2f( 1, -1);
 159    glVertex2f( 1,  1);
 160    glVertex2f(-1,  1);
 161    glEnd();
 162
 163
 164
 165    glStencilFunc(GL_ALWAYS, 0, ~0);
 166    glStencilOp(GL_KEEP, GL_KEEP, GL_DECR_WRAP);
 167
 168    glTranslatef(3.0, 0, 0);
 169    glBegin(GL_QUADS);
 170    glColor3f( 0.9, 0.9, 0.9 );
 171
 172    for ( i = 0 ; i < 5 ; i++ ) {
 173       glVertex2f(-1, -1);
 174       glVertex2f( 1, -1);
 175       glVertex2f( 1,  1);
 176       glVertex2f(-1,  1);
 177    }
 178    glEnd();
 179
 180    glStencilFunc(GL_EQUAL, (max_stencil - 4), ~0);
 181    glBegin(GL_QUADS);
 182    glColor3f( 0.5, 0.5, 0.5 );
 183    glVertex2f(-1, -1);
 184    glVertex2f( 1, -1);
 185    glVertex2f( 1,  1);
 186    glVertex2f(-1,  1);
 187    glEnd();
 188
 189
 190
 191    glPopMatrix();
 192
 193    glutSwapBuffers();
 194 }
 195
 196
 197 static void Reshape( int width, int height )
 198 {
 199    GLfloat ar = (float) width / (float) height;
 200    Width = width;
 201    Height = height;
 202    glViewport( 0, 0, width, height );
 203    glMatrixMode( GL_PROJECTION );
 204    glLoadIdentity();
 205    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 206    glMatrixMode( GL_MODELVIEW );
 207    glLoadIdentity();
 208    glTranslatef( 0.0, 0.0, -15.0 );
 209 }
 210
 211
 212 static void Key( unsigned char key, int x, int y )
 213 {
 214    (void) x;
 215    (void) y;
 216    switch (key) {
 217       case 27:
 218          exit(0);
 219          break;
 220    }
 221    glutPostRedisplay();
 222 }
 223
 224
 225 static void Init( void )
 226 {
 227    const char * const ver_string = (const char * const)
 228        glGetString( GL_VERSION );
 229
 230    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 231    printf("GL_VERSION = %s\n", ver_string);
 232
 233    if ( !glutExtensionSupported("GL_EXT_stencil_wrap")
 234         && (atof( ver_string ) < 1.4) ) {
 235       printf("Sorry, this program requires either GL_EXT_stencil_wrap or OpenGL 1.4.\n");
 236       exit(1);
 237    }
 238
 239    printf("\nAll 5 squares should be the same color.\n");
 240    glEnable( GL_BLEND );
 241 }
 242
 243
 244 int main( int argc, char *argv[] )
 245 {
 246    glutInit( &argc, argv );
 247    glutInitWindowPosition( 0, 0 );
 248    glutInitWindowSize( Width, Height );
 249    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL );
 250    glutCreateWindow( "GL_EXT_stencil_wrap test" );
 251    glutReshapeFunc( Reshape );
 252    glutKeyboardFunc( Key );
 253    glutDisplayFunc( Display );
 254    Init();
 255    glutMainLoop();
 256    return 0;
 257 }