blendsquare.c 4.65 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
/*
 * (C) Copyright IBM Corporation 2004
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * \file blendsquare.c
 * 
 * Simple test of GL_NV_blend_square functionality.  Four squares are drawn
 * with different blending modes, but all should be rendered with the same
 * final color.
 *
 * \author Ian Romanick <idr@us.ibm.com>
 */

#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GL/glut.h>

static int Width = 400;
static int Height = 200;
static const GLfloat Near = 5.0, Far = 25.0;


static void Display( void )
{
   glClearColor(0.2, 0.2, 0.8, 0);
   glClear( GL_COLOR_BUFFER_BIT );

   glPushMatrix();

   glTranslatef(-4.5, 0, 0);
   glBlendFunc( GL_ONE, GL_ZERO );
   glBegin(GL_QUADS);
   glColor3f( 0.5 * 0.5, 0.5 * 0.5, 0.5 * 0.5 );
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();


   glTranslatef(3.0, 0, 0);
   glBlendFunc( GL_ONE, GL_ZERO );
   glBegin(GL_QUADS);
   glColor3f( 0.5, 0.5, 0.5 );
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();

   glBlendFunc( GL_DST_COLOR, GL_ZERO );
   glBegin(GL_QUADS);
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();


   glTranslatef(3.0, 0, 0);
   glBlendFunc( GL_SRC_COLOR, GL_ZERO );
   glBegin(GL_QUADS);
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();


   glTranslatef(3.0, 0, 0);
   glBlendFunc( GL_ONE, GL_ZERO );
   glBegin(GL_QUADS);
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();

   glBlendFunc( GL_ZERO, GL_DST_COLOR );
   glBegin(GL_QUADS);
   glVertex2f(-1, -1);
   glVertex2f( 1, -1);
   glVertex2f( 1,  1);
   glVertex2f(-1,  1);
   glEnd();

   glPopMatrix();

   glutSwapBuffers();
}


static void Reshape( int width, int height )
{
   GLfloat ar = (float) width / (float) height;
   Width = width;
   Height = height;
   glViewport( 0, 0, width, height );
   glMatrixMode( GL_PROJECTION );
   glLoadIdentity();
   glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
   glMatrixMode( GL_MODELVIEW );
   glLoadIdentity();
   glTranslatef( 0.0, 0.0, -15.0 );
}


static void Key( unsigned char key, int x, int y )
{
   (void) x;
   (void) y;
   switch (key) {
      case 27:
         exit(0);
         break;
   }
   glutPostRedisplay();
}


static void Init( void )
{
   const char * const ver_string = (const char *)
       glGetString( GL_VERSION );
   const double version = strtod( ver_string, NULL );

   printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
   printf("GL_VERSION = %s\n", ver_string);

   if ( (version < 1.4) && !glutExtensionSupported("GL_NV_blend_square")) {
      printf("Sorry, this program requires either OpenGL 1.4 or GL_NV_blend_square\n");
      exit(1);
   }

   printf("\nAll 4 squares should be the same color.  The two on the left are drawn\n"
	  "without NV_blend_square functionality, and the two on the right are drawn\n"
	  "with NV_blend_square functionality.  If the two on the left are dark, but\n"
	  "the two on the right are not, then NV_blend_square is broken.\n");
   glEnable( GL_BLEND );
   glBlendEquation( GL_FUNC_ADD );
}


int main( int argc, char *argv[] )
{
   glutInit( &argc, argv );
   glutInitWindowPosition( 0, 0 );
   glutInitWindowSize( Width, Height );
   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
   glutCreateWindow( "GL_NV_blend_square test" );
   glewInit();
   glutReshapeFunc( Reshape );
   glutKeyboardFunc( Key );
   glutDisplayFunc( Display );
   Init();
   glutMainLoop();
   return 0;
}