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/*
* Copyright 2005 Eric Anholt
* 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
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* 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 NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS 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.
*
* Authors:
* Eric Anholt <anholt@FreeBSD.org>
* Brian Paul (fogcoord.c used as a skeleton)
*/
/*
* Test to exercise fog modes and for comparison with GL_EXT_fog_coord.
*/
#define GL_GLEXT_PROTOTYPES
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
static int Width = 600;
static int Height = 600;
static GLfloat Near = 0.0, Far = 1.0;
GLboolean has_fogcoord;
static void drawString( const char *string )
{
glRasterPos2f(0, .5);
while ( *string ) {
glutBitmapCharacter( GLUT_BITMAP_TIMES_ROMAN_10, *string );
string++;
}
}
static void Display( void )
{
GLint i, depthi;
GLfloat fogcolor[4] = {1, 1, 1, 1};
glEnable(GL_FOG);
glFogfv(GL_FOG_COLOR, fogcolor);
glClearColor(0.2, 0.2, 0.8, 0);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glPushMatrix();
for (i = 0; i < 6; i++) {
if (i >= 3 && !has_fogcoord)
break;
glPushMatrix();
for (depthi = 0; depthi < 5; depthi++) {
GLfloat depth = Near + (Far - Near) * depthi / 4;
switch (i % 3) {
case 0:
glFogi(GL_FOG_MODE, GL_LINEAR);
glFogf(GL_FOG_START, Near);
glFogf(GL_FOG_END, Far);
break;
case 1:
glFogi(GL_FOG_MODE, GL_EXP);
glFogf(GL_FOG_DENSITY, 2);
break;
case 2:
glFogi(GL_FOG_MODE, GL_EXP2);
glFogf(GL_FOG_DENSITY, 2);
break;
}
glColor4f(0, 0, 0, 0);
if (i < 3) {
if (has_fogcoord)
glFogi(GL_FOG_COORDINATE_SOURCE_EXT, GL_FRAGMENT_DEPTH_EXT);
glBegin(GL_POLYGON);
glVertex3f(0, 0, depth);
glVertex3f(1, 0, depth);
glVertex3f(1, 1, depth);
glVertex3f(0, 1, depth);
glEnd();
} else {
glFogi(GL_FOG_COORDINATE_SOURCE_EXT, GL_FOG_COORDINATE_EXT);
glFogCoordfEXT(depth);
glBegin(GL_POLYGON);
glVertex3f(0, 0, (Near + Far) / 2);
glVertex3f(1, 0, (Near + Far) / 2);
glVertex3f(1, 1, (Near + Far) / 2);
glVertex3f(0, 1, (Near + Far) / 2);
glEnd();
}
glTranslatef(1.5, 0, 0);
}
glTranslatef(.1, 0, 0);
switch (i) {
case 0:
drawString("GL_LINEAR");
break;
case 1:
drawString("GL_EXP");
break;
case 2:
drawString("GL_EXP2");
break;
case 3:
drawString("GL_FOGCOORD GL_LINEAR");
break;
case 4:
drawString("GL_FOGCOORD GL_EXP");
break;
case 5:
drawString("GL_FOGCOORD GL_EXP2");
break;
}
glPopMatrix();
glTranslatef(0, 1.5, 0);
}
glPopMatrix();
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
Width = width;
Height = height;
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glOrtho( 0, 11, 9, 0, -Near, -Far );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef(.25, .25, 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 )
{
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
/* setup lighting, etc */
has_fogcoord = glutExtensionSupported("GL_EXT_fog_coord");
if (!has_fogcoord) {
printf("Some output of this program requires GL_EXT_fog_coord\n");
}
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition( 0, 0 );
glutInitWindowSize( Width, Height );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow(argv[0]);
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutDisplayFunc( Display );
Init();
glutMainLoop();
return 0;
}
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