DOF.C
/*
* (c) Copyright 1993, Silicon Graphics, Inc.
* 1993-1995 Microsoft Corporation
*
* ALL RIGHTS RESERVED
*
* Please refer to OpenGL/readme.txt for additional information
*
*/
/*
* dof.c
* This program demonstrates use of the accumulation buffer to
* create an out-of-focus depth-of-field effect. The teapots
* are drawn several times into the accumulation buffer. The
* viewing volume is jittered, except at the focal point, where
* the viewing volume is at the same position, each time. In
* this case, the gold teapot remains in focus.
*/
#include "glos.h"
#include <GL/gl.h>
#include <GL/glu.h>
#include <math.h>
#include <GL/glaux.h>
#include "jitter.h"
void myinit(void);
void accFrustum(GLdouble left, GLdouble right, GLdouble bottom,
GLdouble top, GLdouble znear, GLdouble zfar, GLdouble pixdx,
GLdouble pixdy, GLdouble eyedx, GLdouble eyedy, GLdouble focus);
void accPerspective(GLdouble fovy, GLdouble aspect,
GLdouble znear, GLdouble zfar, GLdouble pixdx, GLdouble pixdy,
GLdouble eyedx, GLdouble eyedy, GLdouble focus);
void renderTeapot (GLfloat x, GLfloat y, GLfloat z,
GLfloat ambr, GLfloat ambg, GLfloat ambb,
GLfloat difr, GLfloat difg, GLfloat difb,
GLfloat specr, GLfloat specg, GLfloat specb, GLfloat shine);
void CALLBACK myReshape(GLsizei w, GLsizei h);
void CALLBACK display(void);
#define PI_ 3.14159265358979323846
/* accFrustum()
* The first 6 arguments are identical to the glFrustum() call.
*
* pixdx and pixdy are anti-alias jitter in pixels.
* Set both equal to 0.0 for no anti-alias jitter.
* eyedx and eyedy are depth-of field jitter in pixels.
* Set both equal to 0.0 for no depth of field effects.
*
* focus is distance from eye to plane in focus.
* focus must be greater than, but not equal to 0.0.
*
* Note that accFrustum() calls glTranslatef(). You will
* probably want to insure that your ModelView matrix has been
* initialized to identity before calling accFrustum().
*/
void accFrustum(GLdouble left, GLdouble right, GLdouble bottom,
GLdouble top, GLdouble znear, GLdouble zfar, GLdouble pixdx,
GLdouble pixdy, GLdouble eyedx, GLdouble eyedy, GLdouble focus)
{
GLdouble xwsize, ywsize;
GLdouble dx, dy;
GLint viewport[4];
glGetIntegerv (GL_VIEWPORT, viewport);
xwsize = right - left;
ywsize = top - bottom;
dx = -(pixdx*xwsize/(GLdouble) viewport[2] + eyedx*znear/focus);
dy = -(pixdy*ywsize/(GLdouble) viewport[3] + eyedy*znear/focus);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum (left + dx, right + dx, bottom + dy, top + dy, znear, zfar);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef (-eyedx, -eyedy, 0.0);
}
/* accPerspective()
*
* The first 4 arguments are identical to the gluPerspective() call.
* pixdx and pixdy are anti-alias jitter in pixels.
* Set both equal to 0.0 for no anti-alias jitter.
* eyedx and eyedy are depth-of field jitter in pixels.
* Set both equal to 0.0 for no depth of field effects.
*
* focus is distance from eye to plane in focus.
* focus must be greater than, but not equal to 0.0.
*
* Note that accPerspective() calls accFrustum().
*/
void accPerspective(GLdouble fovy, GLdouble aspect,
GLdouble znear, GLdouble zfar, GLdouble pixdx, GLdouble pixdy,
GLdouble eyedx, GLdouble eyedy, GLdouble focus)
{
GLdouble fov2,left,right,bottom,top;
fov2 = ((fovy*PI_) / 180.0) / 2.0;
top = znear / (cos(fov2) / sin(fov2));
bottom = -top;
right = top * aspect;
left = -right;
accFrustum (left, right, bottom, top, znear, zfar,
pixdx, pixdy, eyedx, eyedy, focus);
}
void myinit(void)
{
GLfloat ambient[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat position[] = { 0.0, 3.0, 3.0, 0.0 };
GLfloat lmodel_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
GLfloat local_view[] = { 0.0 };
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, local_view);
glFrontFace (GL_CW);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_AUTO_NORMAL);
glEnable(GL_NORMALIZE);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
glClearColor(0.0, 0.0, 0.0, 0.0);
glClearAccum(0.0, 0.0, 0.0, 0.0);
}
void renderTeapot (GLfloat x, GLfloat y, GLfloat z,
GLfloat ambr, GLfloat ambg, GLfloat ambb,
GLfloat difr, GLfloat difg, GLfloat difb,
GLfloat specr, GLfloat specg, GLfloat specb, GLfloat shine)
{
float mat[3];
glPushMatrix();
glTranslatef (x, y, z);
mat[0] = ambr; mat[1] = ambg; mat[2] = ambb;
glMaterialfv (GL_FRONT, GL_AMBIENT, mat);
mat[0] = difr; mat[1] = difg; mat[2] = difb;
glMaterialfv (GL_FRONT, GL_DIFFUSE, mat);
mat[0] = specr; mat[1] = specg; mat[2] = specb;
glMaterialfv (GL_FRONT, GL_SPECULAR, mat);
glMaterialf (GL_FRONT, GL_SHININESS, shine*128.0);
auxSolidTeapot(0.5);
glPopMatrix();
}
/* display() draws 5 teapots into the accumulation buffer
* several times; each time with a jittered perspective.
* The focal point is at z = 5.0, so the gold teapot will
* stay in focus. The amount of jitter is adjusted by the
* magnitude of the accPerspective() jitter; in this example, 0.33.
* In this example, the teapots are drawn 8 times. See jitter.h
*/
void CALLBACK display(void)
{
int jitter;
GLint viewport[4];
glGetIntegerv (GL_VIEWPORT, viewport);
if (!viewport[3]) return;
glClear(GL_ACCUM_BUFFER_BIT);
for (jitter = 0; jitter < 8; jitter++) {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
accPerspective (45.0,
(GLdouble) viewport[2]/(GLdouble) viewport[3],
1.0, 15.0, 0.0, 0.0,
0.33*j8[jitter].x, 0.33*j8[jitter].y, 5.0);
/* ruby, gold, silver, emerald, and cyan teapots */
renderTeapot (-1.1, -0.5, -4.5, 0.1745, 0.01175, 0.01175,
0.61424, 0.04136, 0.04136, 0.727811, 0.626959, 0.626959, 0.6);
renderTeapot (-0.5, -0.5, -5.0, 0.24725, 0.1995, 0.0745,
0.75164, 0.60648, 0.22648, 0.628281, 0.555802, 0.366065, 0.4);
renderTeapot (0.2, -0.5, -5.5, 0.19225, 0.19225, 0.19225,
0.50754, 0.50754, 0.50754, 0.508273, 0.508273, 0.508273, 0.4);
renderTeapot (1.0, -0.5, -6.0, 0.0215, 0.1745, 0.0215,
0.07568, 0.61424, 0.07568, 0.633, 0.727811, 0.633, 0.6);
renderTeapot (1.8, -0.5, -6.5, 0.0, 0.1, 0.06, 0.0, 0.50980392,
0.50980392, 0.50196078, 0.50196078, 0.50196078, .25);
glAccum (GL_ACCUM, 0.125);
glFlush();
auxSwapBuffers();
}
glAccum (GL_RETURN, 1.0);
glFlush();
auxSwapBuffers();
}
void CALLBACK myReshape(GLsizei w, GLsizei h)
{
glViewport(0, 0, w, h);
}
/* Main Loop
* Open window with initial window size, title bar,
* RGBA display mode, depth buffer, and handle input events.
*/
int main(int argc, char** argv)
{
auxInitDisplayMode (AUX_DOUBLE | AUX_RGB
| AUX_ACCUM | AUX_DEPTH16);
auxInitPosition (0, 0, 400, 400);
auxInitWindow ("Depth-of-Field");
myinit();
auxReshapeFunc (myReshape);
auxMainLoop(display);
return(0);
}