// opengl_explosion.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
/*
* explosion.cpp - Simple particle system based explosion demonstration.
*
*
* This program is in the Public Domain. You may freely use, modify
* and distribute this program.
*
*
* Description:
* This program shows an easy way to make simple explosions using
* OpenGL. Press SPACE to blow the rotating cube to pieces! Use
* the menu to toggle between normalized speed vectors and non-
* normalized speed vectors.
*
* Theory:
* This program uses an extremely simple particle system to create
* an explosion effect. Each particle is moved from the origin
* towards a random direction and, if activated, a random speed.
* The color of the particles are changed from white to orange to
* red to create a glowing effect. The GL_POINTS primitive is used
* to render the particles.
* The debris is similar to the particles, with the addition of
* orientation and orientation speed.
* A point light source is placed in the center of the explosion.
*
*/
#include <GL/glut.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <stdio.h>
#define NUM_PARTICLES 1000 /* Number of particles */
#define NUM_DEBRIS 70 /* Number of debris */
/* GLUT menu entries */
#define PAUSE 0
#define NORMALIZE_SPEED 1
#define QUIT 2
/* A particle */
struct particleData
{
float position[3];
float speed[3];
float color[3];
};
typedef struct particleData particleData;
/* A piece of debris */
struct debrisData
{
float position[3];
float speed[3];
float orientation[3]; /* Rotation angles around x, y, and z axes */
float orientationSpeed[3];
float color[3];
float scale[3];
};
typedef struct debrisData debrisData;
/* Globals */
particleData particles[NUM_PARTICLES];
debrisData debris[NUM_DEBRIS];
int fuel = 0; /* "fuel" of the explosion */
float angle = 0.0; /* camera rotation angle */
//material * /
GLfloat light0Amb[4] = { 1.0, 0.6, 0.2, 1.0 };
GLfloat light0Dif[4] = { 1.0, 0.6, 0.2, 1.0 };
GLfloat light0Spec[4] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light0Pos[4] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light1Amb[4] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light1Dif[4] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light1Spec[4] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light1Pos[4] = { 0.0, 5.0, 5.0, 0.0 };
GLfloat materialAmb[4] = { 0.25, 0.22, 0.26, 1.0 };
GLfloat materialDif[4] = { 0.63, 0.57, 0.60, 1.0 };
GLfloat materialSpec[4] = { 0.99, 0.91, 0.81, 1.0 };
GLfloat materialShininess = 27.8;
int wantNormalize = 0; /* Speed vector normalization flag */
int wantPause = 0; /* Pause flag */
void
newSpeed(float dest[3])
{
float x;
float y;
float z;
float len;
x = (2.0 * ((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
y = (2.0 * ((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
z = (2.0 * ((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
/*
* Normalizing the speed vectors gives a "fireball" effect
*
*/
if (wantNormalize)
{
len = sqrt(x * x + y * y + z * z);
if (len)
{
x = x / len;
y = y / len;
z = z / len;
}
}
dest[0] = x;
dest[1] = y;
dest[2] = z;
}
/*
* newExplosion
*
* Create a new explosion.
*
*/
void newExplosion(void)
{
int i;
for (i = 0; i < NUM_PARTICLES; i++)
{
particles[i].position[0] = 0.0;
particles[i].position[1] = 0.0;
particles[i].position[2] = 0.0;
particles[i].color[0] = 1.0;
particles[i].color[1] = 1.0;
particles[i].color[2] = 0.5;
newSpeed(particles[i].speed);
}
for (i = 0; i < NUM_DEBRIS; i++)
{
debris[i].position[0] = 0.0;
debris[i].position[1] = 0.0;
debris[i].position[2] = 0.0;
debris[i].orientation[0] = 0.0;
debris[i].orientation[1] = 0.0;
debris[i].orientation[2] = 0.0;
debris[i].color[0] = 0.7;
debris[i].color[1] = 0.7;
debris[i].color[2] = 0.7;
debris[i].scale[0] = (2.0 *
((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
debris[i].scale[1] = (2.0 *
((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
debris[i].scale[2] = (2.0 *
((GLfloat)rand()) / ((GLfloat)RAND_MAX)) - 1.0;
newSpeed(debris[i].speed);
newSpeed(debris[i].orientationSpeed);
}
fuel = 100;
}
/*
* display
*
* Draw the scene.
*
*/
void display(void)
{
int i;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
/* Place the camera */
glTranslatef(0.0, 0.0, -10.0);
glRotatef(angle, 0.0, 1.0, 0.0);
/* If no explosion, draw cube */
if (fuel == 0)
{
glEnable(GL_LIGHTING);
glDisable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
glutSolidCube(1.0);
//glutSolidCone(2.0, 2.0, 5, 5);
}
if (fuel > 0)
{
glPushMatrix();
glDisable(GL_LIGHTING);
glDisable(GL_DEPTH_TEST);
glBegin(GL_POINTS);
for (i = 0; i < NUM_PARTICLES; i++)
{
glColor3fv(particles[i].color);
glVertex3fv(particles[i].position);
}
glEnd();
glPopMatrix();
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
glNormal3f(0.0, 0.0, 1.0);
for (i = 0; i < NUM_DEBRIS; i++)
{
glColor3fv(debris[i].color);
glPushMatrix();
glTranslatef(debris[i].position[0],
debris[i].position[1],
debris[i].position[2]);
glRotatef(debris[i].orientation[0], 1.0, 0.0, 0.0);
glRotatef(debris[i].orientation[1], 0.0, 1.0, 0.0);
glRotatef(debris[i].orientation[2], 0.0, 0.0, 1.0);
glScalef(debris[i].scale[0],
debris[i].scale[1],
debris[i].scale[2]);
glBegin(GL_TRIANGLES);
glVertex3f(0.0, 0.5, 0.0);
glVertex3f(-0.25, 0.0, 0.0);
glVertex3f(0.25, 0.0, 0.0);
glEnd();
glPopMatrix();
}
}
glutSwapBuffers();
}
/*
* keyboard
*
* Keyboard callback.
*
*/
void keyboard(unsigned char key,
int x,
int y)
{
switch (key)
{
case ' ':
case 27:
newExplosion();
break;
exit(0);
break;
wantPause = 1 - wantPause;
break;
case 'p':
break;
}
}
/*
* idle
*
* Update animation variables.
*
*/
void idle(void)
{
int i;
if (!wantPause)
{
if (fuel > 0)
{
for (i = 0; i < NUM_PARTICLES; i++)
{
particles[i].position[0] += particles[i].speed[0] * 0.2;
particles[i].position[1] += particles[i].speed[1] * 0.2;
particles[i].position[2] += particles[i].speed[2] * 0.2;
particles[i].color[0] -= 1.0 / 500.0;
if (particles[i].color[0] < 0.0)
{
}
particles[i].color[1] -= 1.0 / 100.0;
if (particles[i].color[1] < 0.0)
{
}
particles[i].color[2] -= 1.0 / 50.0;
if (particles[i].color[2] < 0.0)
{
}
}
for (i = 0; i < NUM_DEBRIS; i++)
{
debris[i].position[0] += debris[i].speed[0] * 0.1;
debris[i].position[1] += debris[i].speed[1] * 0.1;
debris[i].position[2] += debris[i].speed[2] * 0.1;
debris[i].orientation[0] += debris[i].orientationSpeed[0] * 10;
debris[i].orientation[1] += debris[i].orientationSpeed[1] * 10;
debris[i].orientation[2] += debris[i].orientationSpeed[2] * 10;
}
--fuel;
}
angle += 0.3; /* Always continue to rotate the camera */
}
glutPostRedisplay();
}
/*
* reshape
*
* Window reshape callback.
*
*/
void reshape(int w,
int h)
{
glViewport(0.0, 0.0, (GLfloat)w, (GLfloat)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (GLfloat)w / (GLfloat)h, 0.1, 100.0);
glMatrixMode(GL_MODELVIEW);
}
/*
* menuSelect
*
* Menu selection callback.
*
*/
void menuSelect(int value)
{
switch (value)
{
case PAUSE:
wantPause = 1 - wantPause;
break;
case NORMALIZE_SPEED:
wantNormalize = 1 - wantNormalize;
break;
exit(0);
break;
case QUIT:
break;
}
}
/*
* main
*
* Setup OpenGL and hand over to GLUT.
*
*/
int main(int argc,
char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH | GLUT_RGB);
glutCreateWindow("Explosion demo");
glutKeyboardFunc(keyboard);
glutIdleFunc(idle);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
srand(time(NULL));
glEnable(GL_LIGHT0);
glEnable(GL_LIGHT1);
glLightfv(GL_LIGHT0, GL_AMBIENT, light0Amb);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light0Dif);
glLightfv(GL_LIGHT0, GL_SPECULAR, light0Spec);
glLightfv(GL_LIGHT0, GL_POSITION, light0Pos);
glLightfv(GL_LIGHT1, GL_AMBIENT, light1Amb);
glLightfv(GL_LIGHT1, GL_DIFFUSE, light1Dif);
glLightfv(GL_LIGHT1, GL_SPECULAR, light1Spec);
glLightfv(GL_LIGHT1, GL_POSITION, light1Pos);
glLightModelf(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, materialAmb);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, materialDif);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, materialSpec);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, materialShininess);
glEnable(GL_NORMALIZE);
glutCreateMenu(menuSelect);
glutAddMenuEntry("Pause", PAUSE);
glutAddMenuEntry("Toggle normalized speed vectors", NORMALIZE_SPEED);
glutAddMenuEntry("Quit", QUIT);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
