如何解决引发奇怪的异常：在SFML中获取子画面图像的高度
|| 嗨，所以我已经找到了异常的根，它位于以下代码行：>= obj2->GetPosition().y + (obj2->GetCenter().y - obj2->GetImage()->GetHeight()))
#include<SFML/Graphics.hpp>
#include<SFML/System.hpp>
#include<cmath>
#include<vector>
# define M_PI 3.14159265358979323846
enum{xXx= 0,yYy= 1};
enum{ScreenWidth=800,ScreenHeight=600};
sf::RenderWindow Window;
template<typename T/*,typename T2*/>
bool CheckCollision(T* obj1,T* obj2){
bool xColl=false,yColl=false;
// check if any part of object 1 is between object 2\'s top and bottom
if(obj1->GetPosition().y + (obj1->GetCenter().y - obj1->GetImage()->GetHeight())
<= obj2->GetPosition().y + (obj2->GetImage()->GetHeight() - obj2->GetCenter().y)
&& obj1->GetPosition().y + (obj1->GetImage()->GetHeight() - obj1->GetCenter().y)
>= obj2->GetPosition().y + (obj2->GetCenter().y - obj2->GetImage()->GetHeight()))
yColl= true;
// check if any part of object 1 is between object 2\'s left and right
if(obj1->GetPosition().x + (obj1->GetCenter().x - obj1->GetImage()->GetWidth())
<= obj2->GetPosition().x + (obj2->GetImage()->GetWidth() - obj2->GetCenter().x)
&& obj1->GetPosition().x + (obj1->GetImage()->GetWidth() - obj1->GetCenter().x)
>= obj2->GetPosition().x + (obj2->GetCenter().x - obj2->GetImage()->GetWidth()))
xColl= true;
if(xColl==true && yColl==true) return true;
else return false;
};
template<typename T>
void CalculateMove(T Time,T Speed,T Angle,T& buffX,T& buffY)
{ //Make the degrees positive
if(Angle<0) Angle= 360+Angle;
//determine what quadrant of circle we\'re in
unsigned int Quadrant= 1;
if(Angle>=90) Quadrant= 2;
if(Angle>=180) Quadrant= 3;
if(Angle>=270) Quadrant= 4;
//anything above 90 would be impossible triangle
Angle= (float)(Angle-(int)Angle)+(float)((int)Angle%90);
// calculates x and y based on angle and Hypotenuse
if((int)Angle!=0){
if(Quadrant==2 || Quadrant==4) Angle=90-Angle; //The unit circle triangle is flipped otherwise,causing x and y to be switched
buffY= sin(Angle / 180 * M_PI)/ (1.f/(Speed*Time));
buffX= sin((180-Angle-90)/ 180 * M_PI)/ (1.f/(Speed*Time));}
else{// Movement is a straight line on X or Y axis
if(Quadrant==1 || Quadrant==3) buffX= Speed*Time;
if(Quadrant==2 || Quadrant==4) buffY= Speed*Time;}
//Quadrant Factor (positive or negative movement on the axis)
switch(Quadrant){
case 1: break;
case 2: buffX=-buffX; break;
case 3: buffX=-buffX; buffY=-buffY; break;
case 4: buffY=-buffY; break;}
};
template<typename T>
struct MoveData{
float X,Y;
T* Object;
MoveData(float x,float y,T* object):X(x),Y(y),Object(object){};
};
///////////////////////////////////////// Mysprite ////////////////////////////////
class mySprite : public sf::Sprite
{
private:
float velocity;
float angle;
public:
// all the values needed by the base class sprite();
mySprite(
const sf::Image& Img,const sf::Vector2f& Position = sf::Vector2f(0,0),const sf::Vector2f& Scale = sf::Vector2f(1,1),float Rotation = 0.f,const float Angle= 0.f,const float Velocity= 0.f,const sf::Color& Col = sf::Color(255,255,255)):
Sprite(Img,Position,Scale,Rotation,Col){
angle= Angle;
velocity= Velocity;};
float Velocity(){return velocity;};
void SetVelocity(float newVelocity){velocity=newVelocity;};
float Angle(){return angle;};
void SetAngle(float newAngle){angle=(float)(newAngle-(int)newAngle)+(float)((int)newAngle%360);};
void Update(){
float frameTime= Window.GetFrameTime();
float X=0,Y=0;
//SetRotation(angle);
CalculateMove(frameTime,velocity,angle,X,Y);
Move(X,-Y);
};
void Accelerate(float PPS){velocity+=PPS;};
void Turn(float degrees){
angle=(float)((angle+degrees)-(int)(angle+degrees))+(float)((int)(angle+degrees)%360);};
void Reflect(float CollAngle){
SetRotation(-GetRotation());
angle=360-angle;
//TODO: factor in the collision angle
};
};
class MoveBuff
{
private:
std::vector<MoveData<mySprite>> buff;
public:
void AddMove(mySprite obj,float X,float Y){
MoveData<mySprite> data(X,Y,&obj);
buff.push_back(data);};
void TestColl(){
for(unsigned int Object= 0; Object< buff.size(); Object++){
for(unsigned int CollCheck=Object+1; CollCheck<=buff.size()-1; CollCheck++){
if(CheckCollision(buff[Object].Object,buff[CollCheck].Object)){
buff[Object].Object->Reflect(0);
buff[Object].Object->Reflect(0);}}}
};
void Move(){
for(unsigned int I= 0; I<buff.size(); I++)
buff[I].Object->Move(buff[I].X,buff[I].Y);
};
};
int main()
{
Window.Create(sf::VideoMode(ScreenWidth,ScreenHeight),\"Pong! by Griffin Howlett\",sf::Style::Resize | sf::Style::Close);
sf::Image img;
img.Create(30,50,sf::Color(255,0));
mySprite box(img,sf::Vector2f(400,sf::Vector2f(1,270,100); //TODO: test collision with different speeds
box.SetCenter(15,25);
sf::Image img2;
img2.Create(56.5,80,0));
mySprite box2(img2,400),90,100);
box2.SetCenter(25,40);
Window.Display();
for(;;){
Window.Clear();
MoveBuff MoveBuff;
float frameTime= Window.GetFrameTime();
float X=0,Y=0;
CalculateMove(frameTime,box.Velocity(),box.Angle(),Y);
MoveBuff.AddMove(box,Y);
CalculateMove(frameTime,box2.Velocity(),box2.Angle(),Y);
MoveBuff.AddMove(box2,Y);
MoveBuff.TestColl();
MoveBuff.Move();
Window.Draw(box);
Window.Draw(box2);
Window.Display();
}
}
解决方法
MoveData(float x,float y,T* object):X(x),Y(y),Object(object){}; // Constructor
// ^^^^^^^^^^^^
// Just making a reference to the argument. Shallow copy.
void AddMove(mySprite obj,float X,float Y){
MoveData<mySprite> data(X,Y,&obj);
buff.push_back(data);
}// => lifetime of the obj ends at this point.
obj
MoveData::Object
void TestColl()
{
for(unsigned int Object= 0; Object< buff.size(); Object++){
for(unsigned int CollCheck=Object+1; CollCheck<=buff.size()-1; CollCheck++){
if(CheckCollision(buff[Object].Object,buff[CollCheck].Object)){
// ^^^^^^^^^ This the problem. buff[Object].Object is dangling.
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