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/glew.h>
  38 #include <GL/glut.h>
  39
  40 static int Width = 550;
  41 static int Height = 200;
  42 static const GLfloat Near = 5.0, Far = 25.0;
  43
  44
  45 static void Display( void )
  46 {
  47    GLint  max_stencil;
  48    GLint  stencil_bits;
  49    unsigned i;
  50
  51
  52    glGetIntegerv( GL_STENCIL_BITS, & stencil_bits );
  53    max_stencil = (1U << stencil_bits) - 1;
  54    printf( "Stencil bits = %u, maximum stencil value = 0x%08x\n",
  55            stencil_bits, max_stencil );
  56
  57    glClearStencil( 0 );
  58    glClearColor( 0.2, 0.2, 0.8, 0 );
  59    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT
  60             | GL_STENCIL_BUFFER_BIT );
  61
  62
  63    glPushMatrix();
  64
  65    /* This is the "reference" square.
  66     */
  67
  68    glDisable(GL_STENCIL_TEST);
  69    glTranslatef(-6.0, 0, 0);
  70    glBegin(GL_QUADS);
  71    glColor3f( 0.5, 0.5, 0.5 );
  72    glVertex2f(-1, -1);
  73    glVertex2f( 1, -1);
  74    glVertex2f( 1,  1);
  75    glVertex2f(-1,  1);
  76    glEnd();
  77
  78
  79    glEnable(GL_STENCIL_TEST);
  80
  81    /* Draw the first two squares using the two non-wrap (i.e., saturate)
  82     * modes.
  83     */
  84
  85    glStencilFunc(GL_ALWAYS, 0, ~0);
  86    glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
  87
  88    glTranslatef(3.0, 0, 0);
  89    glBegin(GL_QUADS);
  90    glColor3f( 0.9, 0.9, 0.9 );
  91
  92    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
  93       glVertex2f(-1, -1);
  94       glVertex2f( 1, -1);
  95       glVertex2f( 1,  1);
  96       glVertex2f(-1,  1);
  97    }
  98    glEnd();
  99
 100    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 101    glBegin(GL_QUADS);
 102    glColor3f( 0.5, 0.5, 0.5 );
 103    glVertex2f(-1, -1);
 104    glVertex2f( 1, -1);
 105    glVertex2f( 1,  1);
 106    glVertex2f(-1,  1);
 107    glEnd();
 108
 109
 110    glStencilFunc(GL_ALWAYS, 0, ~0);
 111    glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
 112
 113    glTranslatef(3.0, 0, 0);
 114    glBegin(GL_QUADS);
 115    glColor3f( 0.9, 0.9, 0.9 );
 116
 117    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 118       glVertex2f(-1, -1);
 119       glVertex2f( 1, -1);
 120       glVertex2f( 1,  1);
 121       glVertex2f(-1,  1);
 122    }
 123    glEnd();
 124
 125    glStencilFunc(GL_EQUAL, 0, ~0);
 126    glBegin(GL_QUADS);
 127    glColor3f( 0.5, 0.5, 0.5 );
 128    glVertex2f(-1, -1);
 129    glVertex2f( 1, -1);
 130    glVertex2f( 1,  1);
 131    glVertex2f(-1,  1);
 132    glEnd();
 133
 134
 135
 136
 137    /* Draw the last two squares using the two wrap modes.
 138     */
 139
 140    glStencilFunc(GL_ALWAYS, 0, ~0);
 141    glStencilOp(GL_KEEP, GL_KEEP, GL_INCR_WRAP);
 142
 143    glTranslatef(3.0, 0, 0);
 144    glBegin(GL_QUADS);
 145    glColor3f( 0.9, 0.9, 0.9 );
 146
 147    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 148       glVertex2f(-1, -1);
 149       glVertex2f( 1, -1);
 150       glVertex2f( 1,  1);
 151       glVertex2f(-1,  1);
 152    }
 153    glEnd();
 154
 155    glStencilFunc(GL_EQUAL, 4, ~0);
 156    glBegin(GL_QUADS);
 157    glColor3f( 0.5, 0.5, 0.5 );
 158    glVertex2f(-1, -1);
 159    glVertex2f( 1, -1);
 160    glVertex2f( 1,  1);
 161    glVertex2f(-1,  1);
 162    glEnd();
 163
 164
 165
 166    glStencilFunc(GL_ALWAYS, 0, ~0);
 167    glStencilOp(GL_KEEP, GL_KEEP, GL_DECR_WRAP);
 168
 169    glTranslatef(3.0, 0, 0);
 170    glBegin(GL_QUADS);
 171    glColor3f( 0.9, 0.9, 0.9 );
 172
 173    for ( i = 0 ; i < 5 ; i++ ) {
 174       glVertex2f(-1, -1);
 175       glVertex2f( 1, -1);
 176       glVertex2f( 1,  1);
 177       glVertex2f(-1,  1);
 178    }
 179    glEnd();
 180
 181    glStencilFunc(GL_EQUAL, (max_stencil - 4), ~0);
 182    glBegin(GL_QUADS);
 183    glColor3f( 0.5, 0.5, 0.5 );
 184    glVertex2f(-1, -1);
 185    glVertex2f( 1, -1);
 186    glVertex2f( 1,  1);
 187    glVertex2f(-1,  1);
 188    glEnd();
 189
 190
 191
 192    glPopMatrix();
 193
 194    glutSwapBuffers();
 195 }
 196
 197
 198 static void Reshape( int width, int height )
 199 {
 200    GLfloat ar = (float) width / (float) height;
 201    Width = width;
 202    Height = height;
 203    glViewport( 0, 0, width, height );
 204    glMatrixMode( GL_PROJECTION );
 205    glLoadIdentity();
 206    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 207    glMatrixMode( GL_MODELVIEW );
 208    glLoadIdentity();
 209    glTranslatef( 0.0, 0.0, -15.0 );
 210 }
 211
 212
 213 static void Key( unsigned char key, int x, int y )
 214 {
 215    (void) x;
 216    (void) y;
 217    switch (key) {
 218       case 27:
 219          exit(0);
 220          break;
 221    }
 222    glutPostRedisplay();
 223 }
 224
 225
 226 static void Init( void )
 227 {
 228    const char * const ver_string = (const char * const)
 229        glGetString( GL_VERSION );
 230
 231    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 232    printf("GL_VERSION = %s\n", ver_string);
 233
 234    if ( !glutExtensionSupported("GL_EXT_stencil_wrap")
 235         && (atof( ver_string ) < 1.4) ) {
 236       printf("Sorry, this program requires either GL_EXT_stencil_wrap or OpenGL 1.4.\n");
 237       exit(1);
 238    }
 239
 240    printf("\nAll 5 squares should be the same color.\n");
 241    glEnable( GL_BLEND );
 242 }
 243
 244
 245 int main( int argc, char *argv[] )
 246 {
 247    glutInit( &argc, argv );
 248    glutInitWindowPosition( 0, 0 );
 249    glutInitWindowSize( Width, Height );
 250    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL );
 251    glutCreateWindow( "GL_EXT_stencil_wrap test" );
 252    glewInit();
 253    glutReshapeFunc( Reshape );
 254    glutKeyboardFunc( Key );
 255    glutDisplayFunc( Display );
 256    Init();
 257    glutMainLoop();
 258    return 0;
 259 }