我正在处理一个采用模块化设计的代码。其中,我的一个类名为Splash
,需要创建另一个称为Emitter
的类的对象。通常情况下,您只需创建对象并完成操作即可,但是这里不起作用,因为Emitter
类具有自定义构造函数。但是当我尝试创建对象时,它却无法工作。
以一个例子来说明;
Emitter
具有以下构造函数:Emitter::Emitter(int x, int y, int amount);
,需要被创建以便在Splash
类中进行访问。
我尝试了以下方法,但它没有起作用:
class Splash{
private:
Emitter ps(100, 200, 400, "firstimage.png", "secondimage.png"); // Try to create object, doesn't work.
public:
// Other splash class functions.
}
我也尝试了这个方法,但它也不起作用:
class Splash{
private:
Emitter ps; // Try to create object, doesn't work.
public:
Splash() : ps(100, 200, 400, "firstimage.png", "secondimage.png")
{};
}
编辑:我知道第二种方法应该可以工作,但实际上并没有。如果我删除Emitter
部分,代码就能正常运行。但是当我采用第二种方式时,没有窗口打开,也没有执行任何应用程序。
那么我该如何创建我的Emitter
对象以供在Splash
中使用?
编辑:
这是我的发射器类和头文件的代码:Header
// Particle engine for the project
#ifndef _PARTICLE_H_
#define _PARTICLE_H_
#include <vector>
#include <string>
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "image.h"
extern SDL_Surface* gameScreen;
class Particle{
private: // Particle settings
int x, y;
int lifetime;
private: // Particle surface that shall be applied
SDL_Surface* particleScreen;
public: // Constructor and destructor
Particle(int xA, int yA, string particleSprite);
~Particle(){};
public: // Various functions
void show();
bool isDead();
};
class Emitter{
private: // Emitter settings
int x, y;
int xVel, yVel;
private: // The particles for a dot
vector<Particle> particles;
SDL_Surface* emitterScreen;
string particleImg;
public: // Constructor and destructor
Emitter(int amount, int x, int y, string particleImage, string emitterImage);
~Emitter();
public: // Helper functions
void move();
void show();
void showParticles();
};
#endif
这里是发射器函数:
#include "particle.h"
// The particle class stuff
Particle::Particle(int xA, int yA, string particleSprite){
// Draw the particle in a random location about the emitter within 25 pixels
x = xA - 5 + (rand() % 25);
y = yA - 5 + (rand() % 25);
lifetime = rand() % 6;
particleScreen = Image::loadImage(particleSprite);
}
void Particle::show(){
// Apply surface and age particle
Image::applySurface(x, y, particleScreen, gameScreen);
++lifetime;
}
bool Particle::isDead(){
if(lifetime > 11)
return true;
return false;
}
// The emitter class stuff
Emitter::Emitter(int amount, int x, int y, string particleImage, string emitterImage){
// Seed the time for random emitter
srand(SDL_GetTicks());
// Set up the variables and create the particles
x = y = xVel = yVel = 0;
particles.resize(amount, Particle(x, y, particleImage));
emitterScreen = Image::loadImage(emitterImage);
particleImg = particleImage;
}
Emitter::~Emitter(){
particles.clear();
}
void Emitter::move(){
}
void Emitter::show(){
// Show the dot image.
Image::applySurface(x, y, emitterScreen, gameScreen);
}
void Emitter::showParticles(){
// Go through all the particles
for(vector<Particle>::size_type i = 0; i != particles.size(); i++){
if(particles[i].isDead() == true){
particles.erase(particles.begin() + i);
particles.insert(particles.begin() + i, Particle(x, y, particleImg));
}
}
// And show all the particles
for(vector<Particle>::size_type i = 0; i != particles.size(); i++){
particles[i].show();
}
}