progs/tests/stencil_twoside.c

   1 /*
   2  * (C) Copyright IBM Corporation 2004
   3  * All Rights Reserved.
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   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
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   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
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  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_twoside.c
  27  *
  28  * Simple test of GL_ATI_separate_stencil (or the OGL 2.0 equivalent) functionality.
  29  * Four squares are drawn
  30  * with different stencil modes, but all should be rendered with the same
  31  * final color.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <GL/glut.h>
  37
  38 static int use20syntax = 1;
  39 static int Width = 550;
  40 static int Height = 200;
  41 static const GLfloat Near = 5.0, Far = 25.0;
  42
  43
  44 static PFNGLSTENCILFUNCSEPARATEPROC stencil_func_separate = NULL;
  45 static PFNGLSTENCILFUNCSEPARATEATIPROC stencil_func_separate_ati = NULL;
  46 static PFNGLSTENCILOPSEPARATEPROC stencil_op_separate = NULL;
  47
  48 static void Display( void )
  49 {
  50    GLint  max_stencil;
  51    GLint  stencil_bits;
  52    unsigned i;
  53
  54
  55    glGetIntegerv( GL_STENCIL_BITS, & stencil_bits );
  56    max_stencil = (1U << stencil_bits) - 1;
  57    printf( "Stencil bits = %u, maximum stencil value = 0x%08x\n",
  58            stencil_bits, max_stencil );
  59
  60    glClearStencil( 1 );
  61    glClearColor( 0.2, 0.2, 0.8, 0 );
  62    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT
  63             | GL_STENCIL_BUFFER_BIT );
  64
  65
  66    glPushMatrix();
  67
  68    /* This is the "reference" square.
  69     */
  70
  71    glDisable(GL_STENCIL_TEST);
  72    glTranslatef(-6.0, 0, 0);
  73    glBegin(GL_QUADS);
  74    glColor3f( 0.5, 0.5, 0.5 );
  75    glVertex2f(-1, -1);
  76    glVertex2f( 1, -1);
  77    glVertex2f( 1,  1);
  78    glVertex2f(-1,  1);
  79    glEnd();
  80
  81
  82    glEnable(GL_STENCIL_TEST);
  83
  84    /* Draw the first two squares using incr for the affected face
  85     */
  86
  87    if (use20syntax) {
  88       stencil_func_separate(GL_FRONT, GL_ALWAYS, 0, ~0);
  89       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
  90    }
  91    else {
  92       stencil_func_separate_ati(GL_ALWAYS, GL_ALWAYS, 0, ~0);
  93    }
  94    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_INCR);
  95    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_DECR);
  96
  97    glTranslatef(3.0, 0, 0);
  98    glBegin(GL_QUADS);
  99    glColor3f( 0.9, 0.9, 0.9 );
 100    /* this should be front facing */
 101    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 102       glVertex2f(-1, -1);
 103       glVertex2f( 1, -1);
 104       glVertex2f( 1,  1);
 105       glVertex2f(-1,  1);
 106    }
 107    glEnd();
 108
 109    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 110    glBegin(GL_QUADS);
 111    glColor3f( 0.5, 0.5, 0.5 );
 112    glVertex2f(-1, -1);
 113    glVertex2f( 1, -1);
 114    glVertex2f( 1,  1);
 115    glVertex2f(-1,  1);
 116    glEnd();
 117
 118    if (use20syntax) {
 119       stencil_func_separate(GL_FRONT, GL_ALWAYS, 0, ~0);
 120       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 121    }
 122    else {
 123       stencil_func_separate_ati(GL_ALWAYS, GL_ALWAYS, 0, ~0);
 124    }
 125    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 126    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 127
 128    glTranslatef(3.0, 0, 0);
 129    glBegin(GL_QUADS);
 130    glColor3f( 0.9, 0.9, 0.9 );
 131
 132    /* this should be back facing */
 133    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 134       glVertex2f(-1, -1);
 135       glVertex2f(-1,  1);
 136       glVertex2f( 1,  1);
 137       glVertex2f( 1, -1);
 138    }
 139    glEnd();
 140
 141    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 142    glBegin(GL_QUADS);
 143    glColor3f( 0.5, 0.5, 0.5 );
 144    glVertex2f(-1, -1);
 145    glVertex2f( 1, -1);
 146    glVertex2f( 1,  1);
 147    glVertex2f(-1,  1);
 148    glEnd();
 149
 150    if (use20syntax) {
 151       stencil_func_separate(GL_FRONT, GL_NEVER, 0, ~0);
 152       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 153    }
 154    else {
 155       stencil_func_separate_ati(GL_NEVER, GL_ALWAYS, 0, ~0);
 156    }
 157    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 158    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 159
 160    glTranslatef(3.0, 0, 0);
 161    glBegin(GL_QUADS);
 162    glColor3f( 0.9, 0.9, 0.9 );
 163
 164    /* this should be back facing */
 165    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 166    /* this should be back facing */
 167       glVertex2f(-1, -1);
 168       glVertex2f(-1,  1);
 169       glVertex2f( 1,  1);
 170       glVertex2f( 1, -1);
 171    /* this should be front facing */
 172       glVertex2f(-1, -1);
 173       glVertex2f( 1, -1);
 174       glVertex2f( 1,  1);
 175       glVertex2f(-1,  1);
 176    }
 177    glEnd();
 178
 179    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 180    glBegin(GL_QUADS);
 181    glColor3f( 0.5, 0.5, 0.5 );
 182    glVertex2f(-1, -1);
 183    glVertex2f( 1, -1);
 184    glVertex2f( 1,  1);
 185    glVertex2f(-1,  1);
 186    glEnd();
 187
 188    if (use20syntax) {
 189       stencil_func_separate(GL_FRONT, GL_ALWAYS, 0, ~0);
 190       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 191    }
 192    else {
 193       stencil_func_separate_ati(GL_ALWAYS, GL_ALWAYS, 0, ~0);
 194    }
 195    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 196    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 197
 198    glTranslatef(3.0, 0, 0);
 199    glBegin(GL_QUADS);
 200    glColor3f( 0.9, 0.9, 0.9 );
 201
 202    /* this should be back facing */
 203    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 204    /* this should be back facing */
 205       glVertex2f(-1, -1);
 206       glVertex2f(-1,  1);
 207       glVertex2f( 1,  1);
 208       glVertex2f( 1, -1);
 209    /* this should be front facing */
 210       glVertex2f(-1, -1);
 211       glVertex2f( 1, -1);
 212       glVertex2f( 1,  1);
 213       glVertex2f(-1,  1);
 214    }
 215    glEnd();
 216
 217    glStencilFunc(GL_EQUAL, 1, ~0);
 218    glBegin(GL_QUADS);
 219    glColor3f( 0.5, 0.5, 0.5 );
 220    glVertex2f(-1, -1);
 221    glVertex2f( 1, -1);
 222    glVertex2f( 1,  1);
 223    glVertex2f(-1,  1);
 224    glEnd();
 225
 226    glPopMatrix();
 227
 228    glutSwapBuffers();
 229 }
 230
 231
 232 static void Reshape( int width, int height )
 233 {
 234    GLfloat ar = (float) width / (float) height;
 235    Width = width;
 236    Height = height;
 237    glViewport( 0, 0, width, height );
 238    glMatrixMode( GL_PROJECTION );
 239    glLoadIdentity();
 240    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 241    glMatrixMode( GL_MODELVIEW );
 242    glLoadIdentity();
 243    glTranslatef( 0.0, 0.0, -15.0 );
 244 }
 245
 246
 247 static void Key( unsigned char key, int x, int y )
 248 {
 249    (void) x;
 250    (void) y;
 251    switch (key) {
 252       case 27:
 253          exit(0);
 254          break;
 255    }
 256    glutPostRedisplay();
 257 }
 258
 259
 260 static void Init( void )
 261 {
 262    const char * const ver_string = (const char * const)
 263        glGetString( GL_VERSION );
 264
 265    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 266    printf("GL_VERSION = %s\n", ver_string);
 267
 268    if ( !glutExtensionSupported("GL_ATI_separate_stencil")
 269         && (atof( ver_string ) < 2.0) ) {
 270       printf("Sorry, this program requires either GL_ATI_separate_stencil or OpenGL 2.0.\n");
 271       exit(1);
 272    }
 273    if (atof( ver_string ) < 2.0) {
 274       use20syntax = 0;
 275    }
 276    stencil_func_separate = glutGetProcAddress( "glStencilFuncSeparate" );
 277    stencil_func_separate_ati = glutGetProcAddress( "glStencilFuncSeparateATI" );
 278    stencil_op_separate = glutGetProcAddress( "glStencilOpSeparate" );
 279
 280    printf("\nAll 5 squares should be the same color.\n");
 281 }
 282
 283
 284 int main( int argc, char *argv[] )
 285 {
 286    glutInit( &argc, argv );
 287    glutInitWindowPosition( 0, 0 );
 288    glutInitWindowSize( Width, Height );
 289    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL );
 290    glutCreateWindow( "GL_ATI_separate_stencil test" );
 291    glutReshapeFunc( Reshape );
 292    glutKeyboardFunc( Key );
 293    glutDisplayFunc( Display );
 294    Init();
 295    glutMainLoop();
 296    return 0;
 297 }