我开始使用 glut 在 OpenGL 中编写一个小粒子喷泉。我已经让粒子出现并在屏幕上反弹，就像我打算的那样。所以当我第一次运行程序时，我得到了这个
并在大约 2 秒内更改为
我尝试弄乱代码以查看导致此问题的原因，但我无法解决它。
到目前为止，这就是我在程序中所拥有的
- 诠释主（）
- init_particles() //初始化一切，在main中调用一次
- 无效激活_粒子（）；//激活粒子
- void Adjust_particle() //设置粒子的速度和弹跳
void Render_particle() //渲染粒子，这个函数在DrawGLScene()函数中调用。
void idle()// 调用 Adjust_particles 和 Activate_particles 的空闲函数，后跟 glutPostRedisplay()
这是完整的代码：
// particle_fountain.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<stdlib.h>
#include <stdio.h>
#include<Windows.h>
#include <time.h>
#include <GL\glut.h>
#include<GL\GLU.h>
#define MAX_PARTICLES 100
#define MAX_BOUNCE_COUNT 10
#define MAX_PARTICLE_AGE 50
//Colours
float R = 0.8f;
float G = 0.2f;
float B = 0.0f;
float cR = 0.001f;
float cG = 0.002f;
float cB = 0.003f;
float Size = 0.01f; //size for points
GLuint txParticle;
GLuint txPlane;
struct PARTICLE {
float X,Y,Z; // Current position
float sX,sY,sZ; // Current Speed/Movement
float tX,tY,tZ; // Target Speed/Movement
float R,B,G; // Particle Colour
bool Active; // Is particle Active
int Age; // Age of the particle
int MaxAge; // Maximum Age before particle dies
int BounceCount;
} Particles[MAX_PARTICLES];
void Init_Particles();
void Activate_Particles();
void Adjust_Particles();
void Render_Particles();
bool LoadBitmapTexture(char * FileName, GLuint &texid);
void idle();
void DrawGLscene();
void Reshape(GLsizei w, GLsizei h);
int main(int argc, char** argv){
glutInit(&argc,argv);
glutCreateWindow("Particle fountain");
Init_Particles();
glTranslatef(0.0f, -0.7f, 0.0f);
glutDisplayFunc(Render_Particles);
glutIdleFunc(idle);
glutMainLoop();
}
void idle(){
Activate_Particles();
Adjust_Particles();
glutPostRedisplay();
}
void Init_Particles(){
int p;
srand((int)time(NULL));
for(p=0; p<MAX_PARTICLES; p++){
Particles[p].Active = FALSE;
Particles[p].tX = 0.0f;
Particles[p].tY = -0.1f;
Particles[p].tZ = 0.0f;
}
}
void Activate_Particles(){
int p;
for(p=0; p<MAX_PARTICLES; p++){
if(!Particles[p].Active){
// Start the particle at 0,0,0 origin
Particles[p].X = 0.0f;
Particles[p].Y = 0.0f;
Particles[p].Z = 0.0f;
// The following lines set a random speed value
Particles[p].sX = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
Particles[p].sY = (((float)((rand() % 100) + 50)) /
500.0f);
Particles[p].sZ = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
// We also activate the particle
Particles[p].Active = true;
// Set it's Age to zero
Particles[p].Age = 0;
// We also assign a max age to the particles
Particles[p].MaxAge = MAX_PARTICLE_AGE;
// We Also reset the bouncecount to zero
Particles[p].BounceCount = 0;
return;
}
}
}
void Adjust_Particles(){
int p;
for(p=0; p<MAX_PARTICLES; p++){
// We move the speed towards the target speed by 1/20 (5%)
Particles[p].sX+= (Particles[p].tX - Particles[p].sX) / 20.0f;
Particles[p].sY+= (Particles[p].tY - Particles[p].sY) / 20.0f;
Particles[p].sZ+= (Particles[p].tZ - Particles[p].sZ) / 20.0f;
// Then we adjust the position of
// the particle by the new speed
Particles[p].X+= Particles[p].sX;
Particles[p].Y+= Particles[p].sY;
Particles[p].Z+= Particles[p].sZ;
// Now for the bounce code.
if(Particles[p].Y < 0.0f){
Particles[p].Y = 0.0f;
Particles[p].sY = -Particles[p].sY;
Particles[p].BounceCount++;
if(Particles[p].BounceCount > MAX_BOUNCE_COUNT){
Particles[p].Active = FALSE;
}
}
// And finally the age check
Particles[p].Age++;
if(Particles[p].Age > Particles[p].MaxAge){
Particles[p].Active = FALSE;
}
}
}
void Render_Particles(){
int p;
glBegin(GL_POINTS);
for(p=0; p<MAX_PARTICLES; p++){
if(Particles[p].Active){
glColor4f(1.0f, 1.0f, 1.0f, 0.5f);
glVertex3f(Particles[p].X,
Particles[p].Y,
Particles[p].Z);
}
}
glEnd();
glFlush();
}