| /* |
| * 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; |
| } |