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如果這篇文章太長，請道歉。我只是試圖讓SDL以面向對象的方式工作 - 在我越過這一點之前，我沒有任何意義。花了相當長的時間編譯並獲取錯誤。我將發佈我的頭文件和源代碼，以及我的makefile和輸出以查看發生了什麼。SDL - 面向對象的方式
這裏的render.h：
#ifndef RENDER_H
#define RENDER_H
#include <string>
#include <SDL/SDL.h>
using std::string;
class Render
{
public:
Render(string filename, int x, int y, SDL_Surface * destination);
~Render();
private:
SDL_Surface * m_optimizedImage;
void load_image(string filename);
void apply_surface(int x, int y, SDL_Surface * source, SDL_Surface * destination);
};
#endif
...和render.cpp：
#include <SDL/SDL.h>
#include <SDL/SDL_image.h>
#include <string>
#include "render.h"
using std::string;
Render::Render(string filename, int x, int y, SDL_Surface * destination)
{
this->m_optimizedImage = NULL;
load_image(filename);
apply_surface(x, y, m_optimizedImage, destination);
}
Render::~Render()
{
delete m_optimizedImage;
}
void Render::load_image(string filename)
{
SDL_Surface * loadedImage = IMG_Load(filename.c_str());
if (loadedImage != NULL)
{
m_optimizedImage = SDL_DisplayFormat(loadedImage);
SDL_FreeSurface(loadedImage);
}
}
void Render::apply_surface(int x, int y, SDL_Surface * source, SDL_Surface * destination)
{
SDL_Rect offset;
offset.x = x;
offset.y = y;
SDL_BlitSurface(source, NULL, destination, &offset);
}
...和screenwriter.h：
#include <iostream>
#include <SDL/SDL.h>
#ifndef SCREENWRITER_H
#define SCREENWRITER_H
class ScreenWriter
{
public:
~ScreenWriter();
bool flip_screen();
void delay_screen(int milliseconds);
bool get_screen_state() const;
static ScreenWriter& get_instance();
SDL_Surface * get_screen() const;
private:
ScreenWriter();
void initialize();
bool m_screenFailure;
SDL_Surface * m_screen;
};
#endif
...和screenwriter.cpp：
#include <SDL/SDL.h>
#include "screenwriter.h"
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define SCREEN_BPP 32
ScreenWriter::ScreenWriter()
{
this->m_screenFailure = false;
initialize();
}
ScreenWriter::~ScreenWriter()
{
SDL_Quit();
}
ScreenWriter& ScreenWriter::get_instance()
{
static ScreenWriter instance;
return instance;
}
SDL_Surface * ScreenWriter::get_screen() const
{
return m_screen;
}
bool ScreenWriter::get_screen_state() const
{
return this->m_screenFailure;
}
void ScreenWriter::delay_screen(int milliseconds)
{
SDL_Delay(milliseconds);
}
int ScreenWriter::flip_screen()
{
if (SDL_Flip(m_screen) == -1)
{
return 1;
}
else
{
SDL_Flip(m_screen);
return 0;
}
}
void ScreenWriter::initialize()
{
if (SDL_Init(SDL_INIT_EVERYTHING == -1))
{
std::cout << "SDL_Init has failed";
}
else
{
SDL_Init(SDL_INIT_EVERYTHING);
//initialize screen
this->m_screen = SDL_SetVideoMode(SCREEN_WIDTH,
SCREEN_HEIGHT,
SCREEN_BPP,
SDL_SWSURFACE);
if (m_screen == NULL)
{
this->m_screenFailure = true;
}
else
{
this->m_screenFailure = false;
}
//set caption header
SDL_WM_SetCaption("Hello WOrld", NULL);
}
}
...當然main.cpp中的：
...我輸出：
g++ -c main.cpp render.h screenwriter.h -lSDL -lSDL_image
main.cpp: In function ‘int main(int, char**)’:
main.cpp:10:55: error: cannot convert ‘ScreenWriter’ to ‘ScreenWriter*’ in initialization
main.cpp:12:69: error: conversion from ‘Render*’ to non-scalar type ‘Render’ requested
make: *** [main.o] Error 1
... my makefile
program : main.o render.o screenwriter.o
g++ -o program main.o render.o screenwriter.o -lSDL -lSDL_image
main.o : main.cpp render.h screenwriter.h
g++ -c main.cpp render.h screenwriter.h -lSDL -lSDL_image
render.o : render.h render.cpp
g++ -c render.h render.cpp -lSDL
screenwriter.o : screenwriter.h screenwriter.cpp
g++ -c screenwriter.h screenwriter.cpp -lSDL -lSDL_image
clean:
rm program main.o render.o screenwriter.o
的細節問題：
我與這個目標是有編劇實現爲一個單獨設置快板和標誌的一切，通過初始化需要。第二個目標依賴於渲染通過指定x和y座標以及要渲染以在地圖上加載的文件的路徑來渲染。這很容易在程序上做，但我已經準備好在這方面嘗試OO設計。
那麼，有什麼想法？
等一下，你正在使SDL面向對象？ [有沒有人已經這樣做？]（http://www.sfml-dev.org/） –
這很好，如果這已經完成。我決定以面向對象的方式做到這一點，所以我可以學習。另外，SDL是一個很好的圖形庫。 – zeboidlund
是的，我只是指出，SDL是用C編寫的，但SFML是用C++編寫的。另外許多人認爲它的設計更好，速度也比SDL快。 –