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/*
* (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;
}
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