lesson 7: Window class gist

1.h

#ifndef WINDOW_H
#define WINDOW_H

//What we think our window class should look like
class Window {
public:
    //Start SDL and TTF, create the window and renderer
    static void Init();
    //Quit SDL and TTF
    static void Quit();
    //Draw an SDL_Texture
    static void Draw(SDL_Texture*, ...);
    //Load an image
    static SDL_Texture* LoadImage(std::string file);
    //Render some text
    static SDL_Texture* RenderText(std::string, std::string, SDL_Color, int);
    //Clear window
    static void Clear();
    //Present renderer
    static void Present();
    //Get the window's box
    static SDL_Rect Box();

private:
    static SDL_Window* mWindow;
    static SDL_Renderer* mRenderer;
    static SDL_Rect mBox;
};

#endif

2.h

private:
    static std::unique_ptr<SDL_Window, void (*)(SDL_Window*)> mWindow;
    static std::unique_ptr<SDL_Renderer, void (*)(SDL_Renderer*)> mRenderer;
    static SDL_Rect mBox;
};

3.cpp

//Initialize the unique_ptr's deleters here
std::unique_ptr<SDL_Window, void (*)(SDL_Window*)> Window::mWindow 
	= std::unique_ptr<SDL_Window, void (*)(SDL_Window*)>(nullptr, SDL_DestroyWindow);
std::unique_ptr<SDL_Renderer, void (*)(SDL_Renderer*)> Window::mRenderer
	= std::unique_ptr<SDL_Renderer, void (*)(SDL_Renderer*)>(nullptr, SDL_DestroyRenderer);
//Other static members
SDL_Rect Window::mBox;

4.cpp

//In window.cpp
void Window::Init(std::string title){
    //initialize all SDL subsystems
    if (SDL_Init(SDL_INIT_EVERYTHING) == -1)
        throw std::runtime_error("SDL Init Failed");
    if (TTF_Init() == -1)
	throw std::runtime_error("TTF Init Failed");

    //Setup our window size
    mBox.x = 0;
    mBox.y = 0;
    mBox.w = 640;
    mBox.h = 480;
    //Create our window
    mWindow.reset(SDL_CreateWindow(title.c_str(), SDL_WINDOWPOS_CENTERED, 
        SDL_WINDOWPOS_CENTERED, mBox.w, mBox.h, SDL_WINDOW_SHOWN));
    //Make sure it created ok
    if (mWindow == nullptr)
        throw std::runtime_error("Failed to create window");

    //Create the renderer
    mRenderer.reset(SDL_CreateRenderer(mWindow.get(), -1, 
        SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC));
    //Make sure it created ok
    if (mRenderer == nullptr)
        throw std::runtime_error("Failed to create renderer");
}

4.h

//In window.h
/**
*  Initialize SDL, setup the window and renderer
*  @param title The window title
*/
static void Init(std::string title = "Window");

5.cpp

//In window.cpp
void Window::Quit(){
    TTF_Quit();
    SDL_Quit();
}

5.h

//In window.h
///Quit SDL and destroy the window and renderer
static void Quit();

6.cpp

void Window::Draw(SDL_Texture *tex, SDL_Rect &dstRect, SDL_Rect *clip, float angle, 
                  int xPivot, int yPivot, SDL_RendererFlip flip)
{
    //Convert pivot pos from relative to object's center to screen space
    xPivot += dstRect.w / 2;
    yPivot += dstRect.h / 2;
    //SDL expects an SDL_Point as the pivot location
    SDL_Point pivot = { xPivot, yPivot };
    //Draw the texture
    SDL_RenderCopyEx(mRenderer.get(), tex, clip, &dstRect, angle, &pivot, flip);
}

6.h

//In window.h
/**
*  Draw a SDL_Texture to the screen at dstRect with various other options
*  @param tex The SDL_Texture to draw
*  @param dstRect The destination position and width/height to draw the texture with
*  @param clip The clip to apply to the image, if desired
*  @param angle The rotation angle to apply to the texture, default is 0
*  @param xPivot The x coordinate of the pivot, relative to (0, 0) being center of dstRect
*  @param yPivot The y coordinate of the pivot, relative to (0, 0) being center of dstRect
*  @param flip The flip to apply to the image, default is none
*/
static void Draw(SDL_Texture *tex, SDL_Rect &dstRect, SDL_Rect *clip = NULL,
                 float angle = 0.0, int xPivot = 0, int yPivot = 0,
                 SDL_RendererFlip flip = SDL_FLIP_NONE);

7.h

//In window.h
/**
*  Loads an image directly to texture using SDL_image's
*  built in function IMG_LoadTexture
*  @param file The image file to load
*  @return SDL_Texture* to the loaded texture
*/
static SDL_Texture* LoadImage(const std::string &file);
/**
*  Generate a texture containing the message we want to display
*  @param message The message we want to display
*  @param fontFile The font we want to use to render the text
*  @param color The color we want the text to be
*  @param fontSize The size we want the font to be
*  @return An SDL_Texture* to the rendered message
*/
static SDL_Texture* RenderText(const std::string &message, const std::string &fontFile, 
                               SDL_Color color, int fontSize);