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Diffstat (limited to 'progs/redbook/shadowmap.c')
| -rw-r--r-- | progs/redbook/shadowmap.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/progs/redbook/shadowmap.c b/progs/redbook/shadowmap.c new file mode 100644 index 0000000000..3fe1d1e8df --- /dev/null +++ b/progs/redbook/shadowmap.c @@ -0,0 +1,352 @@ +/* + * Copyright (c) 1993-2003, Silicon Graphics, Inc. + * All Rights Reserved + * + * Permission to use, copy, modify, and distribute this software for any + * purpose and without fee is hereby granted, provided that the above + * copyright notice appear in all copies and that both the copyright + * notice and this permission notice appear in supporting documentation, + * and that the name of Silicon Graphics, Inc. not be used in + * advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. + * + * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND + * WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE, + * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR + * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON + * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT, + * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, + * OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, LOSS OF + * PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD + * PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN ADVISED OF + * THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE + * OR PERFORMANCE OF THIS SOFTWARE. + * + * US Government Users Restricted Rights + * Use, duplication, or disclosure by the Government is subject to + * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph + * (c)(1)(ii) of the Rights in Technical Data and Computer Software + * clause at DFARS 252.227-7013 and/or in similar or successor clauses + * in the FAR or the DOD or NASA FAR Supplement. Unpublished - rights + * reserved under the copyright laws of the United States. + * + * Contractor/manufacturer is: + * Silicon Graphics, Inc. + * 1500 Crittenden Lane + * Mountain View, CA 94043 + * United State of America + * + * OpenGL(R) is a registered trademark of Silicon Graphics, Inc. + */ + +#define GL_GLEXT_PROTOTYPES + +#include <math.h> +#include <stdio.h> +#include <stdlib.h> +#include <GL/glut.h> +/*#include "helpers.h"*/ + +#define SHADOW_MAP_WIDTH 256 +#define SHADOW_MAP_HEIGHT 256 + +#define PI 3.14159265359 + +GLdouble fovy = 60.0; +GLdouble nearPlane = 10.0; +GLdouble farPlane = 100.0; + +GLfloat angle = 0.0; +GLfloat torusAngle = 0.0; + +GLfloat lightPos[] = { 25.0, 25.0, 25.0, 1.0 }; +GLfloat lookat[] = { 0.0, 0.0, 0.0 }; +GLfloat up[] = { 0.0, 0.0, 1.0 }; + +GLboolean showShadow = GL_FALSE; + +static void +init( void ) +{ + GLfloat white[] = { 1.0, 1.0, 1.0, 1.0 }; + + glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, + SHADOW_MAP_WIDTH, SHADOW_MAP_HEIGHT, 0, + GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL ); + + glLightfv( GL_LIGHT0, GL_POSITION, lightPos ); + glLightfv( GL_LIGHT0, GL_SPECULAR, white ); + glLightfv( GL_LIGHT0, GL_DIFFUSE, white ); + + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL ); + glTexParameteri( GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE, GL_LUMINANCE ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, + GL_COMPARE_R_TO_TEXTURE ); + + glTexGeni( GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR ); + glTexGeni( GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR ); + glTexGeni( GL_R, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR ); + glTexGeni( GL_Q, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR ); + + glColorMaterial( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE ); + + glCullFace( GL_BACK ); + + glEnable( GL_DEPTH_TEST ); + glEnable( GL_LIGHT0 ); + glEnable( GL_LIGHTING ); + glEnable( GL_TEXTURE_2D ); + glEnable( GL_TEXTURE_GEN_S ); + glEnable( GL_TEXTURE_GEN_T ); + glEnable( GL_TEXTURE_GEN_R ); + glEnable( GL_TEXTURE_GEN_Q ); + glEnable( GL_COLOR_MATERIAL ); + glEnable( GL_CULL_FACE ); +} + +static void +reshape( int width, int height ) +{ + glViewport( 0, 0, width, height ); + + glMatrixMode( GL_PROJECTION ); + glLoadIdentity(); + gluPerspective( fovy, (GLdouble) width/height, nearPlane, farPlane ); + glMatrixMode( GL_MODELVIEW ); +} + +static void +idle( void ) +{ + angle += PI / 10000; + torusAngle += .1; + glutPostRedisplay(); +} + +static void +keyboard( unsigned char key, int x, int y ) +{ + switch( key ) { + case 27: /* Escape */ + exit( 0 ); + break; + + case 't': { + static GLboolean textureOn = GL_TRUE; + textureOn = !textureOn; + if ( textureOn ) + glEnable( GL_TEXTURE_2D ); + else + glDisable( GL_TEXTURE_2D ); + } + break; + + case 'm': { + static GLboolean compareMode = GL_TRUE; + compareMode = !compareMode; + printf( "Compare mode %s\n", compareMode ? "On" : "Off" ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, + compareMode ? GL_COMPARE_R_TO_TEXTURE : GL_NONE ); + } + break; + + case 'f': { + static GLboolean funcMode = GL_TRUE; + funcMode = !funcMode; + printf( "Operator %s\n", funcMode ? "GL_LEQUAL" : "GL_GEQUAL" ); + glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, + funcMode ? GL_LEQUAL : GL_GEQUAL ); + } + break; + + case 's': + showShadow = !showShadow; + break; + + case 'p': { + static GLboolean animate = GL_TRUE; + animate = !animate; + glutIdleFunc( animate ? idle : NULL ); + } + break; + } + + glutPostRedisplay(); +} + +static void +transposeMatrix( GLfloat m[16] ) +{ + GLfloat tmp; +#define Swap( a, b ) tmp = a; a = b; b = tmp + Swap( m[1], m[4] ); + Swap( m[2], m[8] ); + Swap( m[3], m[12] ); + Swap( m[6], m[9] ); + Swap( m[7], m[13] ); + Swap( m[11], m[14] ); +#undef Swap +} + +static void +drawObjects( GLboolean shadowRender ) +{ + GLboolean textureOn = glIsEnabled( GL_TEXTURE_2D ); + + if ( shadowRender ) + glDisable( GL_TEXTURE_2D ); + + if ( !shadowRender ) { + glNormal3f( 0, 0, 1 ); + glColor3f( 1, 1, 1 ); + glRectf( -20.0, -20.0, 20.0, 20.0 ); + } + + glPushMatrix(); + glTranslatef( 11, 11, 11 ); + glRotatef( 54.73, -5, 5, 0 ); + glRotatef( torusAngle, 1, 0, 0 ); + glColor3f( 1, 0, 0 ); + glutSolidTorus( 1, 4, 8, 36 ); + glPopMatrix(); + + glPushMatrix(); + glTranslatef( 2, 2, 2 ); + glColor3f( 0, 0, 1 ); + glutSolidCube( 4 ); + glPopMatrix(); + + glPushMatrix(); + glTranslatef( lightPos[0], lightPos[1], lightPos[2] ); + glColor3f( 1, 1, 1 ); + glutWireSphere( 0.5, 6, 6 ); + glPopMatrix(); + + if ( shadowRender && textureOn ) + glEnable( GL_TEXTURE_2D ); +} + +static void +generateShadowMap( void ) +{ + GLint viewport[4]; + GLfloat lightPos[4]; + + glGetLightfv( GL_LIGHT0, GL_POSITION, lightPos ); + glGetIntegerv( GL_VIEWPORT, viewport ); + + glViewport( 0, 0, SHADOW_MAP_WIDTH, SHADOW_MAP_HEIGHT ); + + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); + + glMatrixMode( GL_PROJECTION ); + glPushMatrix(); + glLoadIdentity(); + gluPerspective( 80.0, 1.0, 10.0, 1000.0 ); + glMatrixMode( GL_MODELVIEW ); + + glPushMatrix(); + glLoadIdentity(); + gluLookAt( lightPos[0], lightPos[1], lightPos[2], + lookat[0], lookat[1], lookat[2], + up[0], up[1], up[2] ); + + drawObjects( GL_TRUE ); + + glPopMatrix(); + glMatrixMode( GL_PROJECTION ); + glPopMatrix(); + glMatrixMode( GL_MODELVIEW ); + + glCopyTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 0, 0, + SHADOW_MAP_WIDTH, SHADOW_MAP_HEIGHT, 0 ); + + glViewport( viewport[0], viewport[1], viewport[2], viewport[3] ); + + if ( showShadow ) { + GLfloat depthImage[SHADOW_MAP_WIDTH][SHADOW_MAP_HEIGHT]; + glReadPixels( 0, 0, SHADOW_MAP_WIDTH, SHADOW_MAP_HEIGHT, + GL_DEPTH_COMPONENT, GL_FLOAT, depthImage ); + glWindowPos2f( viewport[2]/2, 0 ); + glDrawPixels( SHADOW_MAP_WIDTH, SHADOW_MAP_HEIGHT, GL_LUMINANCE, + GL_FLOAT, depthImage ); + glutSwapBuffers(); + } +} + +static void +generateTextureMatrix( void ) +{ + GLfloat tmpMatrix[16]; + + /* + * Set up projective texture matrix. We use the GL_MODELVIEW matrix + * stack and OpenGL matrix commands to make the matrix. + */ + glPushMatrix(); + glLoadIdentity(); + glTranslatef( 0.5, 0.5, 0.0 ); + glScalef( 0.5, 0.5, 1.0 ); + gluPerspective( 60.0, 1.0, 1.0, 1000.0 ); + gluLookAt( lightPos[0], lightPos[1], lightPos[2], + lookat[0], lookat[1], lookat[2], + up[0], up[1], up[2] ); + glGetFloatv( GL_MODELVIEW_MATRIX, tmpMatrix ); + glPopMatrix(); + + transposeMatrix( tmpMatrix ); + + glTexGenfv( GL_S, GL_OBJECT_PLANE, &tmpMatrix[0] ); + glTexGenfv( GL_T, GL_OBJECT_PLANE, &tmpMatrix[4] ); + glTexGenfv( GL_R, GL_OBJECT_PLANE, &tmpMatrix[8] ); + glTexGenfv( GL_Q, GL_OBJECT_PLANE, &tmpMatrix[12] ); +} + +static void +display( void ) +{ + GLfloat radius = 30; + + generateShadowMap(); + generateTextureMatrix(); + + if ( showShadow ) + return; + + glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); + + glPushMatrix(); + gluLookAt( radius*cos(angle), radius*sin(angle), 30, + lookat[0], lookat[1], lookat[2], + up[0], up[1], up[2] ); + drawObjects( GL_FALSE ); + glPopMatrix(); + + glutSwapBuffers(); +} + +int +main( int argc, char** argv ) +{ + glutInit( &argc, argv ); + glutInitDisplayMode( GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE ); + glutInitWindowSize( 512, 512 ); + glutInitWindowPosition( 100, 100 ); + glutCreateWindow( argv[0] ); + + init(); + + glutDisplayFunc( display ); + glutReshapeFunc( reshape ); + glutKeyboardFunc( keyboard ); + glutIdleFunc( idle ); + + glutMainLoop(); + + return 0; +} |