progs/tests/stencil_twoside.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"),
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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
 119    if (use20syntax) {
 120       stencil_func_separate(GL_FRONT, GL_ALWAYS, 0, ~0);
 121       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 122    }
 123    else {
 124       stencil_func_separate_ati(GL_ALWAYS, GL_ALWAYS, 0, ~0);
 125    }
 126    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 127    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 128
 129    glTranslatef(3.0, 0, 0);
 130    glBegin(GL_QUADS);
 131    glColor3f( 0.9, 0.9, 0.9 );
 132
 133    /* this should be back facing */
 134    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 135       glVertex2f(-1, -1);
 136       glVertex2f(-1,  1);
 137       glVertex2f( 1,  1);
 138       glVertex2f( 1, -1);
 139    }
 140    glEnd();
 141
 142    glStencilFunc(GL_EQUAL, max_stencil, ~0);
 143    glBegin(GL_QUADS);
 144    glColor3f( 0.5, 0.5, 0.5 );
 145    glVertex2f(-1, -1);
 146    glVertex2f( 1, -1);
 147    glVertex2f( 1,  1);
 148    glVertex2f(-1,  1);
 149    glEnd();
 150
 151    if (use20syntax) {
 152       stencil_func_separate(GL_FRONT, GL_NEVER, 0, ~0);
 153       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 154    }
 155    else {
 156       stencil_func_separate_ati(GL_NEVER, GL_ALWAYS, 0, ~0);
 157    }
 158    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 159    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 160
 161    glTranslatef(3.0, 0, 0);
 162    glBegin(GL_QUADS);
 163    glColor3f( 0.9, 0.9, 0.9 );
 164
 165    /* this should be back facing */
 166    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 167    /* this should be back facing */
 168       glVertex2f(-1, -1);
 169       glVertex2f(-1,  1);
 170       glVertex2f( 1,  1);
 171       glVertex2f( 1, -1);
 172    /* this should be front facing */
 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, ~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    if (use20syntax) {
 190       stencil_func_separate(GL_FRONT, GL_ALWAYS, 0, ~0);
 191       stencil_func_separate(GL_BACK, GL_ALWAYS, 0, ~0);
 192    }
 193    else {
 194       stencil_func_separate_ati(GL_ALWAYS, GL_ALWAYS, 0, ~0);
 195    }
 196    stencil_op_separate(GL_FRONT, GL_KEEP, GL_KEEP, GL_DECR);
 197    stencil_op_separate(GL_BACK, GL_KEEP, GL_KEEP, GL_INCR);
 198
 199    glTranslatef(3.0, 0, 0);
 200    glBegin(GL_QUADS);
 201    glColor3f( 0.9, 0.9, 0.9 );
 202
 203    /* this should be back facing */
 204    for ( i = 0 ; i < (max_stencil + 5) ; i++ ) {
 205    /* this should be back facing */
 206       glVertex2f(-1, -1);
 207       glVertex2f(-1,  1);
 208       glVertex2f( 1,  1);
 209       glVertex2f( 1, -1);
 210    /* this should be front facing */
 211       glVertex2f(-1, -1);
 212       glVertex2f( 1, -1);
 213       glVertex2f( 1,  1);
 214       glVertex2f(-1,  1);
 215    }
 216    glEnd();
 217
 218    glStencilFunc(GL_EQUAL, 1, ~0);
 219    glBegin(GL_QUADS);
 220    glColor3f( 0.5, 0.5, 0.5 );
 221    glVertex2f(-1, -1);
 222    glVertex2f( 1, -1);
 223    glVertex2f( 1,  1);
 224    glVertex2f(-1,  1);
 225    glEnd();
 226
 227    glPopMatrix();
 228
 229    glutSwapBuffers();
 230 }
 231
 232
 233 static void Reshape( int width, int height )
 234 {
 235    GLfloat ar = (float) width / (float) height;
 236    Width = width;
 237    Height = height;
 238    glViewport( 0, 0, width, height );
 239    glMatrixMode( GL_PROJECTION );
 240    glLoadIdentity();
 241    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 242    glMatrixMode( GL_MODELVIEW );
 243    glLoadIdentity();
 244    glTranslatef( 0.0, 0.0, -15.0 );
 245 }
 246
 247
 248 static void Key( unsigned char key, int x, int y )
 249 {
 250    (void) x;
 251    (void) y;
 252    switch (key) {
 253       case 27:
 254          exit(0);
 255          break;
 256    }
 257    glutPostRedisplay();
 258 }
 259
 260
 261 static void Init( void )
 262 {
 263    const char * const ver_string = (const char * const)
 264        glGetString( GL_VERSION );
 265
 266    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 267    printf("GL_VERSION = %s\n", ver_string);
 268
 269    if ( !glutExtensionSupported("GL_ATI_separate_stencil")
 270         && (atof( ver_string ) < 2.0) ) {
 271       printf("Sorry, this program requires either GL_ATI_separate_stencil or OpenGL 2.0.\n");
 272       exit(1);
 273    }
 274    if (atof( ver_string ) < 2.0) {
 275       use20syntax = 0;
 276    }
 277    stencil_func_separate = glutGetProcAddress( "glStencilFuncSeparate" );
 278    stencil_func_separate_ati = glutGetProcAddress( "glStencilFuncSeparateATI" );
 279    stencil_op_separate = glutGetProcAddress( "glStencilOpSeparate" );
 280
 281    printf("\nAll 5 squares should be the same color.\n");
 282    glEnable( GL_BLEND );
 283 }
 284
 285
 286 int main( int argc, char *argv[] )
 287 {
 288    glutInit( &argc, argv );
 289    glutInitWindowPosition( 0, 0 );
 290    glutInitWindowSize( Width, Height );
 291    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL );
 292    glutCreateWindow( "GL_ATI_separate_stencil test" );
 293    glutReshapeFunc( Reshape );
 294    glutKeyboardFunc( Key );
 295    glutDisplayFunc( Display );
 296    Init();
 297    glutMainLoop();
 298    return 0;
 299 }