progs/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/glew.h>
  38 #include <GL/glut.h>
  39
  40 static int Width = 400;
  41 static int Height = 200;
  42 static const GLfloat Near = 5.0, Far = 25.0;
  43
  44
  45 static void Display( void )
  46 {
  47    glClearColor(0.2, 0.2, 0.8, 0);
  48    glClear( GL_COLOR_BUFFER_BIT );
  49
  50    glPushMatrix();
  51
  52    glTranslatef(-4.5, 0, 0);
  53    glBlendFunc( GL_ONE, GL_ZERO );
  54    glBegin(GL_QUADS);
  55    glColor3f( 0.5 * 0.5, 0.5 * 0.5, 0.5 * 0.5 );
  56    glVertex2f(-1, -1);
  57    glVertex2f( 1, -1);
  58    glVertex2f( 1,  1);
  59    glVertex2f(-1,  1);
  60    glEnd();
  61
  62
  63    glTranslatef(3.0, 0, 0);
  64    glBlendFunc( GL_ONE, GL_ZERO );
  65    glBegin(GL_QUADS);
  66    glColor3f( 0.5, 0.5, 0.5 );
  67    glVertex2f(-1, -1);
  68    glVertex2f( 1, -1);
  69    glVertex2f( 1,  1);
  70    glVertex2f(-1,  1);
  71    glEnd();
  72
  73    glBlendFunc( GL_DST_COLOR, GL_ZERO );
  74    glBegin(GL_QUADS);
  75    glVertex2f(-1, -1);
  76    glVertex2f( 1, -1);
  77    glVertex2f( 1,  1);
  78    glVertex2f(-1,  1);
  79    glEnd();
  80
  81
  82    glTranslatef(3.0, 0, 0);
  83    glBlendFunc( GL_SRC_COLOR, GL_ZERO );
  84    glBegin(GL_QUADS);
  85    glVertex2f(-1, -1);
  86    glVertex2f( 1, -1);
  87    glVertex2f( 1,  1);
  88    glVertex2f(-1,  1);
  89    glEnd();
  90
  91
  92    glTranslatef(3.0, 0, 0);
  93    glBlendFunc( GL_ONE, GL_ZERO );
  94    glBegin(GL_QUADS);
  95    glVertex2f(-1, -1);
  96    glVertex2f( 1, -1);
  97    glVertex2f( 1,  1);
  98    glVertex2f(-1,  1);
  99    glEnd();
 100
 101    glBlendFunc( GL_ZERO, GL_DST_COLOR );
 102    glBegin(GL_QUADS);
 103    glVertex2f(-1, -1);
 104    glVertex2f( 1, -1);
 105    glVertex2f( 1,  1);
 106    glVertex2f(-1,  1);
 107    glEnd();
 108
 109    glPopMatrix();
 110
 111    glutSwapBuffers();
 112 }
 113
 114
 115 static void Reshape( int width, int height )
 116 {
 117    GLfloat ar = (float) width / (float) height;
 118    Width = width;
 119    Height = height;
 120    glViewport( 0, 0, width, height );
 121    glMatrixMode( GL_PROJECTION );
 122    glLoadIdentity();
 123    glFrustum( -ar, ar, -1.0, 1.0, Near, Far );
 124    glMatrixMode( GL_MODELVIEW );
 125    glLoadIdentity();
 126    glTranslatef( 0.0, 0.0, -15.0 );
 127 }
 128
 129
 130 static void Key( unsigned char key, int x, int y )
 131 {
 132    (void) x;
 133    (void) y;
 134    switch (key) {
 135       case 27:
 136          exit(0);
 137          break;
 138    }
 139    glutPostRedisplay();
 140 }
 141
 142
 143 static void Init( void )
 144 {
 145    const char * const ver_string = (const char * const)
 146        glGetString( GL_VERSION );
 147    const double version = strtod( ver_string, NULL );
 148
 149    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 150    printf("GL_VERSION = %s\n", ver_string);
 151
 152    if ( (version < 1.4) && !glutExtensionSupported("GL_NV_blend_square")) {
 153       printf("Sorry, this program requires either OpenGL 1.4 or GL_NV_blend_square\n");
 154       exit(1);
 155    }
 156
 157    printf("\nAll 4 squares should be the same color.  The two on the left are drawn\n"
 158           "without NV_blend_square functionality, and the two on the right are drawn\n"
 159           "with NV_blend_square functionality.  If the two on the left are dark, but\n"
 160           "the two on the right are not, then NV_blend_square is broken.\n");
 161    glEnable( GL_BLEND );
 162    glBlendEquation( GL_FUNC_ADD );
 163 }
 164
 165
 166 int main( int argc, char *argv[] )
 167 {
 168    glutInit( &argc, argv );
 169    glutInitWindowPosition( 0, 0 );
 170    glutInitWindowSize( Width, Height );
 171    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 172    glutCreateWindow( "GL_NV_blend_square test" );
 173    glewInit();
 174    glutReshapeFunc( Reshape );
 175    glutKeyboardFunc( Key );
 176    glutDisplayFunc( Display );
 177    Init();
 178    glutMainLoop();
 179    return 0;
 180 }