src/tests/blendsquare.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 blendsquare.c
  27  *
  28  * Simple test of GL_NV_blend_square functionality.  Four squares are drawn
  29  * with different blending 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 = 400;
  40 static int Height = 200;
  41 static const GLfloat Near = 5.0, Far = 25.0;
  42
  43
  44 static void Display( void )
  45 {
  46    glClearColor(0.2, 0.2, 0.8, 0);
  47    glClear( GL_COLOR_BUFFER_BIT );
  48
  49    glPushMatrix();
  50
  51    glTranslatef(-4.5, 0, 0);
  52    glBlendFunc( GL_ONE, GL_ZERO );
  53    glBegin(GL_QUADS);
  54    glColor3f( 0.5 * 0.5, 0.5 * 0.5, 0.5 * 0.5 );
  55    glVertex2f(-1, -1);
  56    glVertex2f( 1, -1);
  57    glVertex2f( 1,  1);
  58    glVertex2f(-1,  1);
  59    glEnd();
  60
  61
  62    glTranslatef(3.0, 0, 0);
  63    glBlendFunc( GL_ONE, GL_ZERO );
  64    glBegin(GL_QUADS);
  65    glColor3f( 0.5, 0.5, 0.5 );
  66    glVertex2f(-1, -1);
  67    glVertex2f( 1, -1);
  68    glVertex2f( 1,  1);
  69    glVertex2f(-1,  1);
  70    glEnd();
  71
  72    glBlendFunc( GL_DST_COLOR, GL_ZERO );
  73    glBegin(GL_QUADS);
  74    glVertex2f(-1, -1);
  75    glVertex2f( 1, -1);
  76    glVertex2f( 1,  1);
  77    glVertex2f(-1,  1);
  78    glEnd();
  79
  80
  81    glTranslatef(3.0, 0, 0);
  82    glBlendFunc( GL_SRC_COLOR, GL_ZERO );
  83    glBegin(GL_QUADS);
  84    glVertex2f(-1, -1);
  85    glVertex2f( 1, -1);
  86    glVertex2f( 1,  1);
  87    glVertex2f(-1,  1);
  88    glEnd();
  89
  90
  91    glTranslatef(3.0, 0, 0);
  92    glBlendFunc( GL_ONE, GL_ZERO );
  93    glBegin(GL_QUADS);
  94    glVertex2f(-1, -1);
  95    glVertex2f( 1, -1);
  96    glVertex2f( 1,  1);
  97    glVertex2f(-1,  1);
  98    glEnd();
  99
 100    glBlendFunc( GL_ZERO, GL_DST_COLOR );
 101    glBegin(GL_QUADS);
 102    glVertex2f(-1, -1);
 103    glVertex2f( 1, -1);
 104    glVertex2f( 1,  1);
 105    glVertex2f(-1,  1);
 106    glEnd();
 107
 108    glPopMatrix();
 109
 110    glutSwapBuffers();
 111 }
 112
 113
 114 static void Reshape( int width, int height )
 115 {
 116    GLfloat ar = (float) width / (float) height;
 117    Width = width;
 118    Height = height;
 119    glViewport( 0, 0, width, height );
 120    glMatrixMode( GL_PROJECTION );
 121    glLoadIdentity();
 122    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 123    glMatrixMode( GL_MODELVIEW );
 124    glLoadIdentity();
 125    glTranslatef( 0.0, 0.0, -15.0 );
 126 }
 127
 128
 129 static void Key( unsigned char key, int x, int y )
 130 {
 131    (void) x;
 132    (void) y;
 133    switch (key) {
 134       case 27:
 135          exit(0);
 136          break;
 137    }
 138    glutPostRedisplay();
 139 }
 140
 141
 142 static void Init( void )
 143 {
 144    const char * const ver_string = (const char * const)
 145        glGetString( GL_VERSION );
 146    const double version = strtod( ver_string, NULL );
 147
 148    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 149    printf("GL_VERSION = %s\n", ver_string);
 150
 151    if ( (version < 1.4) && !glutExtensionSupported("GL_NV_blend_square")) {
 152       printf("Sorry, this program requires either OpenGL 1.4 or GL_NV_blend_square\n");
 153       exit(1);
 154    }
 155
 156    printf("\nAll 4 squares should be the same color.  The two on the left are drawn\n"
 157           "without NV_blend_square functionality, and the two on the right are drawn\n"
 158           "with NV_blend_square functionality.  If the two on the left are dark, but\n"
 159           "the two on the right are not, then NV_blend_square is broken.\n");
 160    glEnable( GL_BLEND );
 161    glBlendEquation( GL_FUNC_ADD );
 162 }
 163
 164
 165 int main( int argc, char *argv[] )
 166 {
 167    glutInit( &argc, argv );
 168    glutInitWindowPosition( 0, 0 );
 169    glutInitWindowSize( Width, Height );
 170    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 171    glutCreateWindow( "GL_NV_blend_square test" );
 172    glutReshapeFunc( Reshape );
 173    glutKeyboardFunc( Key );
 174    glutDisplayFunc( Display );
 175    Init();
 176    glutMainLoop();
 177    return 0;
 178 }