C++ 使用复制构造函数后未渲染SDL纹理
我正在用SDL制作一个基本程序来渲染图形。我有两个类处理渲染: 纹理类(加载和渲染SDL_纹理) 还有一个Button类(该类可以更容易地在与按钮状态相关联的不同纹理之间切换。每个对象在按钮中应该有3个纹理对象) 声明:C++ 使用复制构造函数后未渲染SDL纹理,c++,class,rendering,sdl,copy-constructor,C++,Class,Rendering,Sdl,Copy Constructor,我正在用SDL制作一个基本程序来渲染图形。我有两个类处理渲染: 纹理类(加载和渲染SDL_纹理) 还有一个Button类(该类可以更容易地在与按钮状态相关联的不同纹理之间切换。每个对象在按钮中应该有3个纹理对象) 声明: //Class for buttons and chips class Button { public: //Initializes internal variables Button();
//Class for buttons and chips
class Button
{
public:
//Initializes internal variables
Button();
//Handles mouse events
void handleEvent(SDL_Event* e);
//Render buttons
void render();
//Sets top left position
void setPosition(int x, int y);
//Gets image dimensions
void setWidth(int w);
void setHeight(int h);
//Set button status
void setButtonAction(buttonAction action);
//Get button status
buttonStatus getButtonStatus();
//Perform button action !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!FIXME::HAVEN'T DEFINED!!!!!!!!!!!!!!!!!!!!!!!!!!!!1!!
void activateButton(buttonAction action);
void setTextures(LTexture out, LTexture over, LTexture down);
private:
//Top left position
SDL_Point mPosition;
//Currently used global image
buttonStatus mButtonStatus;
//What happens if button is pressed
buttonAction mButtonAction;
//Width and height
int mWidth;
int mHeight;
//Textures
LTexture mOut;
LTexture mOver;
LTexture mDown;
};
Button::Button()
{
mPosition.x = 0;
mPosition.y = 0;
mWidth = 0;
mHeight = 0;
mButtonStatus = MOUSE_OUT;
}
void Button::setPosition(int x, int y)
{
mPosition.x = x;
mPosition.y = y;
}
void Button::handleEvent(SDL_Event* e)
{
bool mInside = true;
//If mouse event happened
if (e->type == SDL_MOUSEBUTTONDOWN || e->type == SDL_MOUSEMOTION)
{
//Get mouse position
int x, y;
SDL_GetMouseState(&x, &y);
//Mouse is left of the button
if (x < mPosition.x)
{
mInside = false;
}
//Mouse is right of button
else if (x > mPosition.x + mWidth)
{
mInside = false;
}
//Mouse is above button
else if (y < mPosition.y)
{
mInside = false;
}
//Mouse is below button
else if (y > mPosition.y + mHeight)
{
mInside = false;
}
//Logic\\
//Mouse is outside of button
if (!mInside)
{
mButtonStatus = MOUSE_OUT;
}
//Mouse is inside of button
else
{
switch (e->type)
{
case SDL_MOUSEMOTION:
mButtonStatus = MOUSE_OVER;
break;
case SDL_MOUSEBUTTONDOWN:
mButtonStatus = MOUSE_BUTTON_DOWN;
break;
}
}
}
}
void Button::render()
{
switch (mButtonStatus)
{
case MOUSE_OUT:
mOut.render(mPosition.x, mPosition.y);
printf("Out rendered\n");
break;
case MOUSE_OVER:
mOver.render(mPosition.x, mPosition.y);
printf("Over rendered\n");
break;
case MOUSE_BUTTON_DOWN:
mDown.render(mPosition.x, mPosition.y);
printf("Down rendered\n");
break;
}
}
void Button::setWidth(int w)
{
mWidth = w;
}
void Button::setHeight(int h)
{
mHeight = h;
}
void Button::setButtonAction(buttonAction action)
{
mButtonAction = action;
}
buttonStatus Button::getButtonStatus()
{
return mButtonStatus;
}
void Button::setTextures(LTexture out, LTexture over, LTexture down)
{
mOut = out;
mOver = over;
mDown = down;
}
//按钮和芯片类
类按钮
{
公众:
//初始化内部变量
按钮();
//处理鼠标事件
无效handleEvent(SDL_事件*e);
//渲染按钮
void render();
//设置左上角位置
无效设置位置(整数x,整数y);
//获取图像维度
空隙宽度(int w);
空隙高度(inth);
//设置按钮状态
无效设置按钮动作(按钮动作);
//获取按钮状态
buttonStatus getButtonStatus();
//执行按钮操作!!
无效激活按钮(按钮动作);
空洞设置(LTEXTRE out、LTEXTRE over、LTEXTRE down);
私人:
//左上角位置
SDL_点组合;
//当前使用的全局映像
按钮状态mButtonStatus;
//如果按下按钮会发生什么
按钮式按钮式按钮;
//宽度和高度
国际宽度;
整数mHeight;
//质地
土壤结构移动;
混合移动器;
LTexture mDown;
};
按钮::按钮()
{
mPosition.x=0;
mPosition.y=0;
mWidth=0;
mHeight=0;
mButtonStatus=鼠标离开;
}
无效按钮::设置位置(整数x,整数y)
{
mPosition.x=x;
mPosition.y=y;
}
无效按钮::handleEvent(SDL_事件*e)
{
bool mInside=true;
//如果鼠标事件发生
如果(e->type==SDL|U鼠标按钮下| e->type==SDL|U鼠标按钮下)
{
//获取鼠标位置
int x,y;
SDL_GetMouseState(x&y);
//鼠标在按钮的左边
if(xmPosition.x+mWidth)
{
mInside=false;
}
//鼠标在按钮上方
else if(ymPosition.y+mHeight)
{
mInside=false;
}
//逻辑\\
//鼠标在按钮外面
如果(!mInside)
{
mButtonStatus=鼠标离开;
}
//鼠标在按钮的内部
其他的
{
开关(e->类型)
{
案例SDL_:
mButtonStatus=鼠标悬停;
打破
外壳SDL_鼠标按钮向下:
mButtonStatus=鼠标按下按钮;
打破
}
}
}
}
void按钮::render()
{
开关(mButtonStatus)
{
大小写鼠标_OUT:
移动渲染(mPosition.x,mPosition.y);
printf(“输出渲染\n”);
打破
鼠标右键置于上方:
渲染器(mPosition.x,mPosition.y);
printf(“过度渲染”\n);
打破
大小写鼠标按钮按下:
mDown.render(mPosition.x,mPosition.y);
printf(“向下渲染\n”);
打破
}
}
无效按钮::设置宽度(整数w)
{
mWidth=w;
}
无效按钮::设置高度(inth)
{
mHeight=h;
}
void按钮::setButtonAction(按钮操作)
{
mbutonaction=动作;
}
buttonStatus Button::getButtonStatus()
{
返回mButtonStatus;
}
void按钮::setTextures(LTextureout、LTextureover、LTexturedown)
{
mOut=out;
移动=结束;
mDown=向下;
}
不幸的是,当我尝试使用复制构造函数将SDL_纹理值从原始纹理传递到buttons Private纹理时,它没有传递任何值,但仍然认为它不是“NULL”这段代码有两个问题。 第一个是在
LTexture
copy构造函数中,只复制指向SDL\u纹理的指针。这称为浅拷贝。然后,在LTexture
的析构函数中,调用free()
,删除SDL\u纹理。这是不好的,因为这意味着LTexture
的任何副本现在都有指向已删除纹理的指针,因此它们将不再工作。这里最好的两种解决方案是使用名为shared_ptr
的c++11类来存储纹理,这将防止纹理被删除,或者实际复制纹理并指向新的纹理(深度副本)。对于测试,您可以尝试在free()
中注释掉对SDL\u DestroyTexture
的调用
此外,您忘记实现赋值运算符。目前,它的行为与复制构造函数类似(因为您所做的只是一个浅层复制),但是如果您将其设置为深度复制,那么您也必须实现它
//Class for buttons and chips
class Button
{
public:
//Initializes internal variables
Button();
//Handles mouse events
void handleEvent(SDL_Event* e);
//Render buttons
void render();
//Sets top left position
void setPosition(int x, int y);
//Gets image dimensions
void setWidth(int w);
void setHeight(int h);
//Set button status
void setButtonAction(buttonAction action);
//Get button status
buttonStatus getButtonStatus();
//Perform button action !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!FIXME::HAVEN'T DEFINED!!!!!!!!!!!!!!!!!!!!!!!!!!!!1!!
void activateButton(buttonAction action);
void setTextures(LTexture out, LTexture over, LTexture down);
private:
//Top left position
SDL_Point mPosition;
//Currently used global image
buttonStatus mButtonStatus;
//What happens if button is pressed
buttonAction mButtonAction;
//Width and height
int mWidth;
int mHeight;
//Textures
LTexture mOut;
LTexture mOver;
LTexture mDown;
};
Button::Button()
{
mPosition.x = 0;
mPosition.y = 0;
mWidth = 0;
mHeight = 0;
mButtonStatus = MOUSE_OUT;
}
void Button::setPosition(int x, int y)
{
mPosition.x = x;
mPosition.y = y;
}
void Button::handleEvent(SDL_Event* e)
{
bool mInside = true;
//If mouse event happened
if (e->type == SDL_MOUSEBUTTONDOWN || e->type == SDL_MOUSEMOTION)
{
//Get mouse position
int x, y;
SDL_GetMouseState(&x, &y);
//Mouse is left of the button
if (x < mPosition.x)
{
mInside = false;
}
//Mouse is right of button
else if (x > mPosition.x + mWidth)
{
mInside = false;
}
//Mouse is above button
else if (y < mPosition.y)
{
mInside = false;
}
//Mouse is below button
else if (y > mPosition.y + mHeight)
{
mInside = false;
}
//Logic\\
//Mouse is outside of button
if (!mInside)
{
mButtonStatus = MOUSE_OUT;
}
//Mouse is inside of button
else
{
switch (e->type)
{
case SDL_MOUSEMOTION:
mButtonStatus = MOUSE_OVER;
break;
case SDL_MOUSEBUTTONDOWN:
mButtonStatus = MOUSE_BUTTON_DOWN;
break;
}
}
}
}
void Button::render()
{
switch (mButtonStatus)
{
case MOUSE_OUT:
mOut.render(mPosition.x, mPosition.y);
printf("Out rendered\n");
break;
case MOUSE_OVER:
mOver.render(mPosition.x, mPosition.y);
printf("Over rendered\n");
break;
case MOUSE_BUTTON_DOWN:
mDown.render(mPosition.x, mPosition.y);
printf("Down rendered\n");
break;
}
}
void Button::setWidth(int w)
{
mWidth = w;
}
void Button::setHeight(int h)
{
mHeight = h;
}
void Button::setButtonAction(buttonAction action)
{
mButtonAction = action;
}
buttonStatus Button::getButtonStatus()
{
return mButtonStatus;
}
void Button::setTextures(LTexture out, LTexture over, LTexture down)
{
mOut = out;
mOver = over;
mDown = down;
}