目录
- 预备知识
- SDL基础应用示例
- SDL常用函数、结构体、枚举、宏定义
- 函数
- SDL_Init
- SDL_Quit
- SDL_CreateWindow
- SDL_DestroyWindow
- SDL_Delay
- SDL_Log
- SDL_GetError
- SDL_GetWindowSurface
- SDL_FreeSurface
- SDL_FillRect
- SDL_UpdateWindowSurface
- SDL_MapRGB
- SDL_MapRGBA
- SDL_LoadBMP
- SDL_BlitSurface
- SDL_BlitScaled
- SDL_CreateRGBSurface
- SDL_CreateRGBSurfaceWithFormat
- SDL_CreateRGBSurfaceFrom
- SDL_CreateRGBSurfaceWithFormatFrom
- SDL_LockSurface
- SDL_UnlockSurface
- SDL_CreateRenderer
- SDL_DestroyRenderer
- SDL_SetRenderDrawColor
- SDL_RenderClear
- SDL_RenderPresent
- SDL_SetRenderDrawBlendMode
- SDL_RenderDrawPoint
- SDL_RenderDrawPoints
- SDL_RenderDrawLine
- SDL_RenderDrawLines
- SDL_RenderDrawRect
- SDL_RenderDrawRects
- SDL_RenderFillRect
- SDL_RenderFillRects
- SDL_RenderSetScale
- SDL_CreateTextureFromSurface
- SDL_DestroyTexture
- SDL_RenderCopy
- SDL_RenderCopyEx
- SDL_SetTextureAlphaMod
- SDL_SetTextureBlendMode
- SDL_UpdateTexture
- SDL_UpdateYUVTexture
- SDL_UpdateNVTexture
- SDL_LockTexture
- SDL_LockTextureToSurface
- SDL_UnlockTexture
- SDL_PointInRect
- SDL_RectEmpty
- SDL_RectEquals
- SDL_HasIntersection
- SDL_IntersectRect
- SDL_UnionRect
- SDL_LoadWAV
- SDL_FreeWAV
- SDL_OpenAudioDevice
- SDL_PauseAudioDevice
- SDL_GetAudioDeviceName
- 结构体、枚举、宏定义
- 函数
- Unknown
- CPP多线程
预备知识
+SDL是什么
+一个C语言媒体库，可用于音视频播放、游戏制作等媒体层。
+环境准备
+Ubuntu
+前置条件
+已安装gcc/g++/make，如果没安装可用下列命令安装
+sudo apt install gcc g++ make+
再通过以下命令安装SDL开发环境
+sudo apt install libsdl2-devMakefile
LDLIBS += -lSDL2
+
+main: main.o # 源文件为main.cpp
+ $(CXX) $^ -o $@ $(LDFLAGS) $(LDLIBS)
+
+.PHONY: run clean
+
+run: main
+ ./$<
+
+clean:
+ $(RM) main *.oWindows
+SDL官网地址：http://www.libsdl.org/
+SDL GitHub地址：https://github.com/libsdl-org
+MinGW
+编译器 ：MinGW（用的w64devkit包gcc/g++/make）
+ +https://github.com/skeeto/w64devkit/releases
+代码编辑器： VSCode
+构建方式：手动写Makefile编译构建
+所以下载的库为这个版本
+解压到指定位置之后准备C语言文件main.c（测试用，先不用理解是啥）
+#include <stdlib.h>
+#include <time.h>
+#include <SDL2/SDL.h>
+
+#undef main
+
+#define WIDTH 1000
+#define HEIGHT 600
+
+
+
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO) < 0)
+ {
+ SDL_Log("Init Failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow(
+ "TestWindow",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ WIDTH, HEIGHT,
+ SDL_WINDOW_SHOWN);
+
+ SDL_Renderer *renderer = SDL_CreateRenderer(win, -1, 0);
+ SDL_Rect rect = {100, 100, 100, 100};
+
+ srand(time(0));
+ Uint8 r = 255;
+ Uint8 g = 255;
+ Uint8 b = 255;
+ int8_t dx = 8;
+ int8_t dy = 10;
+
+
+ int x = rect.x + rect.w / 2;
+ int y = rect.y + rect.h / 2;
+
+ SDL_Event event;
+ while (1)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+
+ }
+
+ SDL_RenderClear(renderer);
+
+ rect.x += dx;
+ x = rect.x + rect.w / 2;
+ if (rect.x + rect.w >= WIDTH || rect.x <= 0)
+ {
+ dx = -dx;
+ rect.y += dy;
+ y = rect.y + rect.h / 2;
+ if (rect.y + rect.h >= HEIGHT || rect.y <= 0)
+ {
+ dy = -dy;
+ }
+
+ r = rand() % 256;
+ g = rand() % 256;
+ b = rand() % 256;
+ }
+
+ SDL_SetRenderDrawColor(renderer, r, g, b, 255);
+ SDL_RenderFillRect(renderer, &rect);
+
+ SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+ for (int i = rect.x; i < rect.x + rect.w; i++)
+ {
+ for (int j = rect.y; j < rect.y + rect.h; j++)
+ {
+ if ((i - x) * (i - x) + (j - y) * (j - y) > rect.w * rect.h / 4)
+ {
+ SDL_RenderDrawPoint(renderer, i, j);
+ }
+
+ }
+
+ }
+ SDL_RenderPresent(renderer);
+
+ SDL_Delay(10);
+ }
+
+ SDL_DestroyRenderer(renderer);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}写如下Makefile
+Windows版本Makefile
CXXFLAGS += -ID:/CPP/Libs/SDL2-2.26.5/include #改成你电脑上的include路径
+# CXXFLAGS += -fexec-charset=GBK -finput-charset=UTF-8
+LDFLAGS += -LD:/CPP/Libs/SDL2-2.26.5/lib # 改成你电脑上的lib路径
+
+CXXFLAGS += -std=c++23
+# 如果不用特别新的C++特性，上面这行不用写
+LDLIBS += -lSDL2
+
+LDLIBS += -mwindows # 用于去除运行时命令行窗口
+
+
+main.exe: main.o
+ $(CXX) $^ -o $(basename $@) $(LDFLAGS) $(LDLIBS)
+
+.PHONY: run clean
+
+run: main.exe
+ $<
+
+clean:
+ $(RM) *.exe *.o完成之后用下列命令编译运行，正常即可
+make run+
+
+
Visual Studio
+如果是用其他IDE，则需要自行配置SDL的头文件和库文件引用位置。例如Visual Studio，则需要下载SDL2-devel-2.28.2-VC.zip这个版本的库文件，解压到指定位置后再进行配置。
新建一个Visual Studio的项目，添加main.c文件，内容如下：
+#include <stdlib.h>
+#include <time.h>
+#include <SDL.h>
+
+#undef main
+
+#define WIDTH 1000
+#define HEIGHT 600
+
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO) < 0)
+ {
+ SDL_Log("Init Failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow(
+ "TestWindow",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ WIDTH, HEIGHT,
+ SDL_WINDOW_SHOWN);
+
+ SDL_Renderer *renderer = SDL_CreateRenderer(win, -1, 0);
+ SDL_Rect rect = {100, 100, 100, 100};
+
+ srand(time(0));
+ Uint8 r = 255;
+ Uint8 g = 255;
+ Uint8 b = 255;
+ int8_t dx = 8;
+ int8_t dy = 10;
+
+
+ int x = rect.x + rect.w / 2;
+ int y = rect.y + rect.h / 2;
+
+ SDL_Event event;
+ while (1)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+
+ }
+
+ SDL_RenderClear(renderer);
+
+ rect.x += dx;
+ x = rect.x + rect.w / 2;
+ if (rect.x + rect.w >= WIDTH || rect.x <= 0)
+ {
+ dx = -dx;
+ rect.y += dy;
+ y = rect.y + rect.h / 2;
+ if (rect.y + rect.h >= HEIGHT || rect.y <= 0)
+ {
+ dy = -dy;
+ }
+
+ r = rand() % 256;
+ g = rand() % 256;
+ b = rand() % 256;
+ }
+
+ SDL_SetRenderDrawColor(renderer, r, g, b, 255);
+ SDL_RenderFillRect(renderer, &rect);
+
+ SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+ for (int i = rect.x; i < rect.x + rect.w; i++)
+ {
+ for (int j = rect.y; j < rect.y + rect.h; j++)
+ {
+ if ((i - x) * (i - x) + (j - y) * (j - y) > rect.w * rect.h / 4)
+ {
+ SDL_RenderDrawPoint(renderer, i, j);
+ }
+
+ }
+
+ }
+ SDL_RenderPresent(renderer);
+
+ SDL_Delay(10);
+ }
+
+ SDL_DestroyRenderer(renderer);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}再配置静态库引用位置，头文件引用位置。最后编译运行测试，如果正常输出信息，则配置正确。其他IDE也是类似，配置好库文件、头文件即可。
+Visual Studio 2022配置SDL2开发环境
+-
+
鼠标右键项目-->属性(Properties)打开属性配置面板)
+
+
+路径配置：
+配置(Configuration)选择所有配置(All Configuration)，平台(Platform)选择x64(也可以选择Win32，需要与后续配置的库对应上)。点击VC++目录(VC++ Directories)分别配置包含目录(Include Directories)和库目录(Library Directories)
+
+
包含目录配置：将解压后的SDL中的include目录添加进来，点击确定(OK)。
+
+
库目录配置：将解压后的SDL中的lib\x64(如果选的平台是Win32则选x86)目录添加进来，点击确定(OK)。
+
+
+链接库配置：点击链接器(Linker)，编辑添加依赖项(Additional Dependencies)
+
+
输入SDL2.lib点击确定。
+
+
+
Windows上动态链接库找不到的解决办法
+-
+
将SDL2.dll文件复制到C:\Windows\System32目录下
+
+将SDL2.dll所在的目录添加到环境变量
+
+将SDL2.dll复制到当前项目生成的.exe文件同级目录
+
+
SDL基础应用示例
+SDL环境初始化与退出
+每次使用SDL都需要进行初始化，使用结束之后需要退出。用到的函数为
+初始化与退出
// 初始化
+int SDL_Init(Uint32 flags);
+// 退出
+void SDL_Quit(void);初始化成功则返回0，失败则返回一个负数。
+flags的取值见下表宏定义
例如
+使用SDL的C语言文件结构一般如下：
+#include <SDL2/SDL.h>
+
+#undef main // 加上这句防止一些奇怪的报错
+
+
+int main()
+{
+ SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO);
+
+ // 一些操作
+ // ....
+
+ SDL_Quit();
+ return 0;
+}窗口显示
+窗口创建与销毁函数
// 创建函数，成功则返回窗口指针，失败则返回NULL
+SDL_Window * SDL_CreateWindow(const char *title, int x, int y, int w, int h, Uint32 flags);
+
+// 销毁
+void SDL_DestroyWindow(SDL_Window * window);| 参数 | +含义 | +
|---|---|
| title | +窗口标题，UTF-8编码 | +
| x | +窗口起始位置x坐标 通常为居中SDL_WINDOWPOS_CENTERED或未定义SDL_WINDOWPOS_UNDEFINED | +
| y | +窗口起始位置y坐标 通常为居中SDL_WINDOWPOS_CENTERED或未定义SDL_WINDOWPOS_UNDEFINED | +
| w | +窗口宽度 | +
| h | +窗口高度 | +
| flags | +窗口显示标志，可以是0，或者是多个其他标志组合 | +
| window | +由SDL_CreateWindow创建返回的窗口指针 | +
flags常用可取值（定义在SDL_video.h中），多个值时用|连接
延迟（阻塞）函数
void SDL_Delay(Uint32 ms);让程序暂停指定的时间，单位为毫秒
+完整窗口显示示例
+#include <SDL2/SDL.h>
+
+#undef main
+
+int main()
+{
+ SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO);
+
+ SDL_Window *win = SDL_CreateWindow(
+ "Hello SDL",
+ SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+ 600, 400,
+ SDL_WINDOW_SHOWN);
+
+ SDL_Delay(5000);
+
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}事件循环
+直接用SDL_Delay阻塞程序的话无法响应事件，所以需要加入事件循环进行事件监听。通常做法是把事件循环单独写到一个函数当中，此时SDL程序结构如下：
+#include <SDL2/SDL.h>
+
+#define WIDTH 640
+#define HEIGHT 480
+
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (1)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ default:
+ break;
+ }
+ }
+ }
+}
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_VIDEO) < 0)
+ {
+ SDL_Log("SDL_Init failed: %s", SDL_GetError());
+ return -1;
+ }
+ SDL_Window *window = SDL_CreateWindow(
+ "SDLWindow",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ WIDTH, HEIGHT,
+ SDL_WINDOW_SHOWN);
+ if (NULL == window)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ event_loop();
+
+ SDL_DestroyWindow(window);
+ SDL_Quit();
+ return 0;
+}结构体SDL_Event
定义于文件 SDL_Events.h中，以下为一些常用成员，如需了解更多请到SDL_Events.h文件中查看
+typedef union SDL_Event
+{
+ Uint32 type; // 事件类型，见下
+ SDL_CommonEvent common; /**< Common event data */
+ SDL_DisplayEvent display; /**< Display event data */
+ SDL_WindowEvent window; /**< Window event data */
+ SDL_KeyboardEvent key; /**< Keyboard event data */
+ SDL_TextEditingEvent edit; /**< Text editing event data */
+ SDL_TextEditingExtEvent editExt; /**< Extended text editing event data */
+ SDL_TextInputEvent text; /**< Text input event data */
+ SDL_MouseMotionEvent motion; /**< Mouse motion event data */
+ SDL_MouseButtonEvent button; /**< Mouse button event data */
+ SDL_MouseWheelEvent wheel; /**< Mouse wheel event data */
+
+ SDL_AudioDeviceEvent adevice; /**< Audio device event data */
+ SDL_SensorEvent sensor; /**< Sensor event data */
+ SDL_QuitEvent quit; /**< Quit request event data */
+ SDL_UserEvent user; /**< Custom event data */
+ SDL_SysWMEvent syswm; /**< System dependent window event data */
+ SDL_TouchFingerEvent tfinger; /**< Touch finger event data */
+ SDL_MultiGestureEvent mgesture; /**< Gesture event data */
+ SDL_DollarGestureEvent dgesture; /**< Gesture event data */
+ SDL_DropEvent drop; /**< Drag and drop event data */
+
+ // ....更多内容请查阅SDL_Events.h文件
+
+} SDL_Event;枚举类型SDL_EventType
事件类型，定义于文件 SDL_Events.h中，以下为一些常用成员，如需了解更多请查阅 SDL_Events.h文件
+typedef enum
+{
+ SDL_QUIT = 0x100, // 用户请求 退出
+
+ /* 键盘事件 */
+ SDL_KEYDOWN = 0x300, // 键盘按下
+ SDL_KEYUP, // 键盘弹起
+ SDL_TEXTEDITING, //
+ SDL_TEXTINPUT, // 文字输入
+
+
+ /* 鼠标事件 */
+ SDL_MOUSEMOTION = 0x400, // 鼠标运动
+ SDL_MOUSEBUTTONDOWN, // 鼠标键按下
+ SDL_MOUSEBUTTONUP, // 鼠标键松开
+ SDL_MOUSEWHEEL, // 鼠标滚轮滚动
+
+ // .... 更多事件类型请到SDL_Events.h文件查看
+
+} SDL_EventType;事件检测函数
int SDL_PollEvent(SDL_Event * event)检测是否有等待处理的事件。如果队列中有事件，则把里面的第一个事件从事件队列中移除，保存到event这个指针中，并返回1。如果已经没有事件，则返回0。
+event用于接收事件队列中下一事件的指针，如果没有等待的事件则用NULL填充。
图形绘制
+在屏幕上绘制一个矩形需要用到如下三个函数
+// 获取与对应window关联的SDL surface，失败则返回NULL
+SDL_Surface * SDL_GetWindowSurface(SDL_Window * window);
+
+// 在SDL surface上画一个矩形区域，成功返回0， 失败返回负数
+int SDL_FillRect(SDL_Surface * dst, const SDL_Rect * rect, Uint32 color);
+
+// 将surface的内容更新到屏幕上，成功返回0， 失败返回负数
+int SDL_UpdateWindowSurface(SDL_Window * window)color为4个字节无符号整数，为4通道颜色值ARGB，其中第一个字节为Alpha通道，即透明度通道；R为红色分量通道；G为绿色分量通道；B为蓝色分量通道。通常用十六进制表示，例如0xff00aa8c。用这种方式绘制图形时，透明通道是不生效的，所以颜色值可以只写三个字节RGB分量，例如0xff00bb。
+如果不习惯将颜色值写成一整个十六进制数值，可以将各个通道值分开写，则需要用到如下函数进行转换：
+// 将R，G， B三个通道分量转换为一个整数值。三个分量取值范围均为0~255
+Uint32 SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b);
+// 将R, G， B, A四个通道分量转为一个整数值。四个分量取值范围均为0~255
+Uint32 SDLCALL SDL_MapRGBA(const SDL_PixelFormat * format,
+ Uint8 r, Uint8 g, Uint8 b,
+ Uint8 a);SDL_PixelFormat由以下方式获得与释放
+SDL_PixelFormat * format = SDL_AllocFormat(SDL_PIXELFORMAT_BGRA32);
+
+SDL_FreeFormat(format);SDL_AllocFormat的参数为枚举类型SDL_PixelFormatEnum，定义在SDL_pixels.h里，常用的有：
+-
+
- 三通道：SDL_PIXELFORMAT_RGB24，SDL_PIXELFORMAT_BGR24 +
- 四通道：SDL_PIXELFORMAT_ARGB32，SDL_PIXELFORMAT_BGRA32 +
小端存储的用BGR这个顺序的，大端存储的用RGB这个顺序的，如果无法判断用哪个，可每个顺序试一下看是否能达到想要的效果即可。
+完整颜色转换示例：
+SDL_PixelFormat * format = SDL_AllocFormat(SDL_PIXELFORMAT_BGR24);
+
+Uint32 color = SDL_MapRGB(format, 255, 0, 111));
+SDL_FreeFormat(format);SDL_Rect
在屏幕上绘制矩形
+#include <SDL2/SDL.h>
+
+#define W 1200
+#define H 800
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ // 在窗口上绘制一个矩形
+ // 1. 获取与窗口关联的Surface
+ SDL_Surface *surf = SDL_GetWindowSurface(win);
+ if (NULL == surf)
+ {
+ SDL_Log("SDL_GetWindowSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ // 2. 定义一个区域
+ SDL_Rect rect = {200, 200, 50, 50};
+
+ // 3. 在Surface上进行绘制
+ // SDL_FillRect(surf, &rect, SDL_MapRGB(surf->format, 0, 255, 0));
+ SDL_FillRect(surf, &rect, 0x00ff00);
+
+ // 4. 将绘制的内容更新到屏幕上
+ SDL_UpdateWindowSurface(win);
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ SDL_FillRect(surf, &rect, 0x000000);
+ rect.x += 2;
+ SDL_FillRect(surf, &rect, 0x00ff00);
+ SDL_UpdateWindowSurface(win);
+ SDL_Delay(10);
+ }
+
+
+ // 4. 释放Surface
+ SDL_FreeSurface(surf);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}图片显示
+SDL核心库只支持BMP图片的操作。如需操作更多格式的图片，需要SDL2_image库，添加与使用方式与SDL核心库一样。头文件为#include <SDL2/SDL_image.h>，库文件为SDL2_image。这里为了简便不再引入SDL2_image库，直接使用BMP图片进行操作。
+#include <SDL2/SDL.h>
+
+#define W 1200
+#define H 800
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ // 显示BMP图片
+ // 1. 获取与窗口关联的Surface
+ SDL_Surface *surf = SDL_GetWindowSurface(win);
+ if (NULL == surf)
+ {
+ SDL_Log("SDL_GetWindowSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 2. 导入BMP图片
+ SDL_Surface *img_surf = SDL_LoadBMP("8.bmp");
+ if (NULL == img_surf)
+ {
+ SDL_Log("SDL_LoadBMP failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+
+ // 3. 将图片Surface复制到窗口Surface上
+ SDL_BlitSurface(img_surf, NULL, surf, NULL);
+
+
+ // 4. 将绘制的内容更新到屏幕上
+ SDL_UpdateWindowSurface(win);
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ }
+
+
+ // 4. 释放Surface
+ SDL_FreeSurface(img_surf);
+ SDL_FreeSurface(surf);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}像素点操作
+修改像素点的颜色值
+#include <SDL2/SDL.h>
+
+#define W 600
+#define H 400
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ // 操作像素点
+ // 1. 获取与窗口关联的Surface
+ SDL_Surface *surf = SDL_GetWindowSurface(win);
+ if (NULL == surf)
+ {
+ SDL_Log("SDL_GetWindowSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 2. 修改像素点颜色值
+ Uint32 *px = (Uint32 *)surf->pixels;
+ px[20000] = 0xffffff;
+
+ // 3. 将绘制的内容更新到屏幕上
+ SDL_UpdateWindowSurface(win);
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ }
+
+
+ // 4. 释放Surface
+ SDL_FreeSurface(surf);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}随机像素点显示照片
+#include <SDL2/SDL.h>
+#include <random>
+
+
+#undef main
+
+void event_loop()
+{
+ SDL_Event event;
+ while (1)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ default:
+ break;
+ }
+ }
+
+ }
+
+}
+
+
+typedef struct tagARGB {
+ Uint8 b;
+ Uint8 g;
+ Uint8 r;
+ Uint8 a;
+} ARGB;
+typedef struct tagRGB {
+ Uint8 b;
+ Uint8 g;
+ Uint8 r;
+} RGB;
+
+void swap_value(Uint32 *ptr1, Uint32 *ptr2)
+{
+ Uint32 tmp = *ptr1;
+ *ptr1 = *ptr2;
+ *ptr2 = tmp;
+}
+
+void shuffle_array(Uint32 arr[], Uint32 count)
+{
+ std::random_device rdv;
+ std::default_random_engine rdn(rdv());
+ std::uniform_int_distribution<> distrib(0, count);
+
+ Uint32 j = 0;
+ for (Uint32 i = 0; i < count; i++)
+ {
+ j = distrib(rdn);
+ if (i != j)
+ {
+ swap_value(&arr[i], &arr[j]);
+ }
+
+ }
+
+}
+
+
+int main()
+{
+ SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO);
+
+ SDL_Surface *bmpimg = SDL_LoadBMP("1684826393041.bmp");
+
+ SDL_Window *win = SDL_CreateWindow(
+ "像素显示图片",
+ SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+ bmpimg->w, bmpimg->h,
+ SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
+
+ SDL_Surface *surf = SDL_GetWindowSurface(win);
+
+ ARGB *px = (ARGB *)surf->pixels;
+
+ Uint32 index = 0;
+ Uint32 max_num = surf->w * surf->h;
+ Uint32 *index_arr = (Uint32 *)malloc(max_num * sizeof(Uint32));
+ for (Uint32 i = 0; i < max_num; i++)
+ {
+ index_arr[i] = i;
+ }
+
+ shuffle_array(index_arr, max_num);
+
+ for (int i = max_num - 1; i >= 0; i--)
+ {
+ px[index_arr[i]].a = 255;
+ px[index_arr[i]].r = ((RGB *)bmpimg->pixels)[index_arr[i]].r;
+ px[index_arr[i]].g = ((RGB *)bmpimg->pixels)[index_arr[i]].g;
+ px[index_arr[i]].b = ((RGB *)bmpimg->pixels)[index_arr[i]].b;
+
+ if (i % 200 == 0)
+ {
+ SDL_UpdateWindowSurface(win);
+ SDL_Delay(1);
+ }
+
+
+ }
+
+
+
+
+ SDL_UpdateWindowSurface(win);
+
+
+ event_loop();
+ free(index_arr);
+ SDL_FreeSurface(surf);
+ SDL_DestroyWindow(win);
+ SDL_FreeSurface(bmpimg);
+ SDL_Quit();
+ return 0;
+}绘制玫瑰
+#include <math.h>
+#include <SDL2/SDL.h>
+
+#undef main
+
+// 定义全局变量
+int rosesize = 500;
+int h = -250;
+
+// 定义结构体
+struct DOT
+{
+ double x;
+ double y;
+ double z;
+ double r; // 红色
+ double g; // 绿色
+ // b(蓝色) 通过 r 计算
+};
+
+
+
+// 计算点
+bool calc(double a, double b, double c, DOT &d)
+{
+ double j, n, o, w, z;
+
+ if(c > 60) // 花柄
+ {
+ d.x = sin(a * 7) * (13 + 5 / (0.2 + pow(b * 4, 4))) - sin(b) * 50;
+ d.y = b * rosesize + 50;
+ d.z = 625 + cos(a * 7) * (13 + 5 / (0.2 + pow(b * 4, 4))) + b * 400;
+ d.r = a * 1 - b / 2;
+ d.g = a;
+ return true;
+ }
+
+ double A = a * 2 - 1;
+ double B = b * 2 - 1;
+ if(A * A + B * B < 1)
+ {
+ if(c > 37) // 叶
+ {
+ j = (int(c) & 1);
+ n = j ? 6 : 4;
+ o = 0.5 / (a + 0.01) + cos(b * 125) * 3 - a * 300;
+ w = b * h;
+
+ d.x = o * cos(n) + w * sin(n) + j * 610 - 390;
+ d.y = o * sin(n) - w * cos(n) + 550 - j * 350;
+ d.z = 1180 + cos(B + A) * 99 - j * 300;
+ d.r = 0.4 - a * 0.1 + pow(1 - B * B, -h * 6) * 0.15 - a * b * 0.4 + cos(a + b) / 5 + pow(cos((o * (a + 1) + (B > 0 ? w : -w)) / 25), 30) * 0.1 * (1 - B * B);
+ d.g = o / 1000 + 0.7 - o * w * 0.000003;
+ return true;
+ }
+ if(c > 32) // 花萼
+ {
+ c = c * 1.16 - 0.15;
+ o = a * 45 - 20;
+ w = b * b * h;
+ z = o * sin(c) + w * cos(c) + 620;
+
+ d.x = o * cos(c) - w * sin(c);
+ d.y = 28 + cos(B * 0.5) * 99 - b * b * b * 60 - z / 2 - h;
+ d.z = z;
+ d.r = (b * b * 0.3 + pow((1 - (A * A)), 7) * 0.15 + 0.3) * b;
+ d.g = b * 0.7;
+ return true;
+ }
+
+ // 花
+ o = A * (2 - b) * (80 - c * 2);
+ w = 99 - cos(A) * 120 - cos(b) * (-h - c * 4.9) + cos(pow(1 - b, 7)) * 50 + c * 2;
+ z = o * sin(c) + w * cos(c) + 700;
+
+ d.x = o * cos(c) - w * sin(c);
+ d.y = B * 99 - cos(pow(b, 7)) * 50 - c / 3 - z / 1.35 + 450;
+ d.z = z;
+ d.r = (1 - b / 1.2) * 0.9 + a * 0.1;
+ d.g = pow((1 - b), 20) / 4 + 0.05;
+ return true;
+ }
+
+ return false;
+}
+
+
+
+
+int main()
+{
+ short *zBuffer;
+ int x, y, z, zBufferIndex;
+ DOT dot;
+
+ if (SDL_Init(SDL_INIT_VIDEO) < 0)
+ {
+ SDL_Log("Init Failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow(
+ "花花",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ 640, 480,
+ SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("Window create failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Surface *win_surface = SDL_GetWindowSurface(win);
+
+ SDL_Rect rect = {0, 0, win_surface->w, win_surface->h};
+ SDL_FillRect(win_surface, &rect, 0xffffffff);
+ SDL_UpdateWindowSurface(win);
+
+
+ // 初始化 z-buffer
+ zBuffer = new short[rosesize * rosesize];
+ memset(zBuffer, 0, sizeof(short) * rosesize * rosesize);
+
+
+ SDL_Event event;
+ while (1)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ for(int i = 0; i < 1000; i++)
+ {
+ if(calc(double(rand()) / RAND_MAX, double(rand()) / RAND_MAX, rand() % 46 / 0.74, dot))
+ {
+ z = int(dot.z + 0.5);
+ x = int(dot.x * rosesize / z - h + 0.5);
+ y = int(dot.y * rosesize / z - h + 0.5);
+ if (y >= rosesize) continue;
+
+ zBufferIndex = y * rosesize + x;
+
+ if(!zBuffer[zBufferIndex] || zBuffer[zBufferIndex] > z)
+ {
+ zBuffer[zBufferIndex] = z;
+
+ // 画点
+ int r = ~int((dot.r * h)); if (r < 0) r = 0; if (r > 255) r = 255;
+ int g = ~int((dot.g * h)); if (g < 0) g = 0; if (g > 255) g = 255;
+ int b = ~int((dot.r * dot.r * -80)); if (b < 0) b = 0; if (b > 255) b = 255;
+ int index = (x + 50) + (y - 20) * win_surface->w;
+ ((Uint32 *)win_surface->pixels)[index] = SDL_MapRGB(win_surface->format, r, g, b);
+
+ }
+ }
+ }
+ SDL_UpdateWindowSurface(win);
+ SDL_Delay(1);
+ }
+
+ delete []zBuffer;
+ SDL_FreeSurface(win_surface);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}+
+
渲染
+渲染器创建与清屏
+#include <SDL2/SDL.h>
+
+#define W 800
+#define H 600
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器与清屏
+ // 1. 创建渲染器
+ SDL_Renderer *rdr = SDL_CreateRenderer(win, -1, 0);
+ // 2. 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+
+ // 3. 清除屏幕
+ SDL_RenderClear(rdr);
+
+ // 4. 渲染呈现
+ SDL_RenderPresent(rdr);
+
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ }
+
+
+ // 5. 销毁渲染器
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}绘制点、线
+#include <deque>
+#include <SDL2/SDL.h>
+
+#define W 800
+#define H 600
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器与清屏
+ SDL_Renderer *rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ // 渲染点、线
+ SDL_SetRenderDrawColor(rdr, 0, 0, 0, 255);
+ SDL_RenderDrawPoint(rdr, 200, 200);
+ for (int i = 200; i < 300; i+=5)
+ {
+ SDL_RenderDrawPoint(rdr, i, 200);
+ }
+
+ SDL_RenderDrawLine(rdr, 0, 0, 200, 250);
+
+ SDL_Point pt[5] = {{0, 0}, {100, 100}, {100, 300}, {200, 100}, {250, 190}};
+ SDL_RenderDrawLines(rdr, pt, 5);
+
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ // 练习：绘制一个19*19的围棋棋盘
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ }
+
+
+ // 销毁渲染器
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}绘制、填充矩形区域
+#include <SDL2/SDL.h>
+
+#define W 800
+#define H 600
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器与清屏
+ SDL_Renderer *rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+ SDL_SetRenderDrawBlendMode(rdr, SDL_BLENDMODE_BLEND);
+
+ // 渲染矩形
+ SDL_SetRenderDrawColor(rdr, 0, 0, 0, 255);
+ SDL_Rect rect = {200, 200, 100, 100};
+ // SDL_RenderDrawRect(rdr, &rect);
+ SDL_RenderFillRect(rdr, &rect);
+
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ // 练习：思考一下如何实现贪吃蛇一条蛇移动的效果
+ // 可以借助一下vector/deque等容器
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ // 清除屏幕
+ // SDL_RenderClear(rdr);
+ SDL_RenderFillRect(rdr, &rect);
+ SDL_SetRenderDrawColor(rdr, 0, 0, 0, 255);
+ rect.x ++;
+ // SDL_RenderDrawRect(rdr, &rect);
+ SDL_RenderFillRect(rdr, &rect);
+
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ SDL_Delay(10);
+ }
+
+
+ // 销毁渲染器
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}图片渲染
+#include <SDL2/SDL.h>
+
+#define W 1369
+#define H 768
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器与清屏
+ SDL_Renderer *rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ // 渲染图片
+ // 1. 导入图片
+ SDL_Surface *img_surf = SDL_LoadBMP("../SDL/img/2.bmp"); // 1296*864
+
+ if (NULL == img_surf)
+ {
+ SDL_Log("SDL_LoadBMP failed: %s", SDL_GetError());
+ return -1;
+ }
+ SDL_SetWindowSize(win, img_surf->w, img_surf->h);
+
+
+ // 2. 创建Texture
+ SDL_Texture *texture = SDL_CreateTextureFromSurface(rdr, img_surf);
+ if (NULL == texture)
+ {
+ SDL_Log("SDL_CreateTextureFromSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Rect rect = {200, 200, 648, 432};
+ // 3. 复制Texture
+ SDL_RenderCopy(rdr, texture, NULL, &rect);
+
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+ }
+
+
+ // 5. 销毁Texture
+ SDL_DestroyTexture(texture);
+ SDL_FreeSurface(img_surf);
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}图片缩放、旋转
+#include <SDL2/SDL.h>
+
+#define W 1369
+#define H 768
+
+#undef main
+int main()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Window *win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器与清屏
+ SDL_Renderer *rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ // 渲染图片
+ // 1. 导入图片
+ SDL_Surface *img_surf = SDL_LoadBMP("../SDL/img/2.bmp"); // 1296*864
+
+ if (NULL == img_surf)
+ {
+ SDL_Log("SDL_LoadBMP failed: %s", SDL_GetError());
+ return -1;
+ }
+ SDL_SetWindowSize(win, img_surf->w, img_surf->h);
+
+
+ // 2. 创建Texture
+ SDL_Texture *texture = SDL_CreateTextureFromSurface(rdr, img_surf);
+ if (NULL == texture)
+ {
+ SDL_Log("SDL_CreateTextureFromSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ SDL_Rect rect = {200, 200, 648, 432};
+ SDL_Point pt = {0, 0};
+ // 3. 复制Texture
+ SDL_RenderCopyEx(rdr, texture, NULL, &rect, 90, NULL, SDL_FLIP_NONE);
+
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+
+
+
+ SDL_Event event;
+ while (true)
+ {
+ if (SDL_PollEvent(&event))
+ {
+ if (event.type == SDL_QUIT)
+ {
+ break;
+ }
+ }
+ }
+
+
+ // 5. 销毁Texture
+ SDL_DestroyTexture(texture);
+ SDL_FreeSurface(img_surf);
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+ return 0;
+}代码结构整理
+#include <SDL2/SDL.h>
+
+#define W 720
+#define H 640
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 200, 100};
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+
+void deinit()
+{
+ // 销毁
+
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ return 0;
+}
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+
+ default:
+ break;
+ }
+ }
+ }
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}窗口事件
+#include <SDL2/SDL.h>
+
+#define W 720
+#define H 640
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 200, 100};
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+
+void deinit()
+{
+ // 销毁
+
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ return 0;
+}
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}鼠标事件
+移动
+#include <SDL2/SDL.h>
+
+#define W 720
+#define H 640
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 200, 100};
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+
+void deinit()
+{
+ // 销毁
+
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ return 0;
+}
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+ case SDL_MOUSEMOTION:
+ SDL_Log("x = %d, y = %d", event.motion.x, event.motion.y);
+ rect.x = event.motion.x - 100;
+ rect.y = event.motion.y - 50;
+ draw();
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}按键
+#include <SDL2/SDL.h>
+
+#define W 720
+#define H 640
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 200, 100};
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+
+void deinit()
+{
+ // 销毁
+
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ return 0;
+}
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ SDL_Point pt;
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+ case SDL_MOUSEMOTION:
+ // SDL_Log("x = %d, y = %d", event.motion.x, event.motion.y);
+ // rect.x = event.motion.x - 100;
+ // rect.y = event.motion.y - 50;
+ // draw();
+ break;
+ case SDL_MOUSEBUTTONDOWN:
+ SDL_Log("SDL_MOUSEBUTTONDOWN x = %d, y = %d, button = %d, clicks = %d",
+ event.button.x, event.button.y, event.button.button, event.button.clicks);
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 200, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+
+
+ break;
+ case SDL_MOUSEBUTTONUP:
+ SDL_Log("SDL_MOUSEBUTTONUP x = %d, y = %d, button = %d, clicks = %d",
+ event.button.x, event.button.y, event.button.button, event.button.clicks);
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}键盘事件
+#include <SDL2/SDL.h>
+
+#define W 720
+#define H 640
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 50, 50};
+int dx = 1;
+int dy = 0;
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+
+void deinit()
+{
+ // 销毁
+
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ return 0;
+}
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ SDL_Point pt;
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+ case SDL_MOUSEMOTION:
+ // SDL_Log("x = %d, y = %d", event.motion.x, event.motion.y);
+ // rect.x = event.motion.x - 100;
+ // rect.y = event.motion.y - 50;
+ // draw();
+ break;
+ case SDL_MOUSEBUTTONDOWN:
+ SDL_Log("SDL_MOUSEBUTTONDOWN x = %d, y = %d, button = %d, clicks = %d",
+ event.button.x, event.button.y, event.button.button, event.button.clicks);
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 200, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+
+
+ break;
+ case SDL_MOUSEBUTTONUP:
+ SDL_Log("SDL_MOUSEBUTTONUP x = %d, y = %d, button = %d, clicks = %d",
+ event.button.x, event.button.y, event.button.button, event.button.clicks);
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+ break;
+ case SDL_KEYDOWN:
+ if (event.key.keysym.sym == SDLK_UP)
+ {
+ SDL_Log("UP");
+ dy = -1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_DOWN)
+ {
+ SDL_Log("DOWN");
+ dy = 1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_LEFT)
+ {
+ SDL_Log("LEFT");
+ dx = -1;
+ dy = 0;
+ }
+ if (event.key.keysym.sym == SDLK_RIGHT)
+ {
+ SDL_Log("RIGHT");
+ dx = 1;
+ dy = 0;
+ }
+
+ break;
+ case SDL_KEYUP:
+ break;
+ case SDL_TEXTEDITING:
+ SDL_Log("Edit %s", event.edit.text);
+ break;
+
+ case SDL_TEXTINPUT:
+ SDL_Log("Input %s", event.text.text);
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ rect.x += dx;
+ rect.y += dy;
+ draw();
+ SDL_Delay(10);
+ }
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}碰撞以及范围检测
+播放声音
+#include <SDL2/SDL.h>
+
+#define W 1027
+#define H 761
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 50, 50};
+int dx = 1;
+int dy = 0;
+
+Uint8 *audio_buf;
+Uint32 audio_len;
+Uint32 audio_pos = 0;
+SDL_AudioDeviceID device_id;
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+void deinit()
+{
+ // 销毁
+ SDL_CloseAudioDevice(device_id);
+ SDL_FreeWAV(audio_buf);
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ SDL_Surface *surf = SDL_LoadBMP("10.bmp");
+ SDL_Texture *texture = SDL_CreateTextureFromSurface(rdr, surf);
+ SDL_RenderCopy(rdr, texture, NULL, NULL);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ SDL_DestroyTexture(texture);
+ SDL_FreeSurface(surf);
+ return 0;
+}
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ SDL_Point pt;
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+ case SDL_MOUSEMOTION:
+ // SDL_Log("x = %d, y = %d", event.motion.x, event.motion.y);
+ // rect.x = event.motion.x - 100;
+ // rect.y = event.motion.y - 50;
+ // draw();
+ break;
+ case SDL_MOUSEBUTTONDOWN:
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 200, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+
+
+ break;
+ case SDL_MOUSEBUTTONUP:
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+ break;
+ case SDL_KEYDOWN:
+ if (event.key.keysym.sym == SDLK_UP)
+ {
+ dy = -1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_DOWN)
+ {
+ dy = 1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_LEFT)
+ {
+ dx = -1;
+ dy = 0;
+ }
+ if (event.key.keysym.sym == SDLK_RIGHT)
+ {
+ dx = 1;
+ dy = 0;
+ }
+
+ break;
+ case SDL_KEYUP:
+ break;
+ case SDL_TEXTEDITING:
+ break;
+
+ case SDL_TEXTINPUT:
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ // draw();
+ SDL_Delay(10);
+ }
+}
+
+
+
+void callback(void *userdata, Uint8 * stream, int len)
+{
+ int remain = audio_len - audio_pos;
+ if (remain > len)
+ {
+ SDL_memcpy(stream, audio_buf + audio_pos, len);
+ audio_pos += len;
+ }
+ else
+ {
+ SDL_memcpy(stream, audio_buf + audio_pos, remain);
+ audio_pos = 0;
+ }
+
+}
+
+
+void play_wav()
+{
+ SDL_AudioSpec audio_spec;
+
+
+ // 1. 导入WAV文件
+ SDL_LoadWAV("1.wav", &audio_spec, &audio_buf, &audio_len);
+
+ // 2. 定义播放回调函数
+ audio_spec.userdata = (void *)"这是外部传进来的数据";
+ audio_spec.callback = callback;
+
+ // 3. 打开音频设备
+ device_id = SDL_OpenAudioDevice(NULL, 0, &audio_spec, NULL, 0);
+
+ // 4. 开始播放
+ SDL_PauseAudioDevice(device_id, 0);
+
+ // 5. 释放资源 关闭设备
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+ play_wav();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}动画帧率
+#include <SDL2/SDL.h>
+
+#define W 1280
+#define H 720
+#define FR 25
+#define FT 1000 / FR
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+SDL_Rect rect = {100, 100, 50, 50};
+int dx = 1;
+int dy = 0;
+
+int index = 0;
+
+Uint8 *audio_buf;
+Uint32 audio_len;
+Uint32 audio_pos = 0;
+SDL_AudioDeviceID device_id;
+
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+void deinit()
+{
+ // 销毁
+ SDL_FreeWAV(audio_buf);
+ SDL_CloseAudioDevice(device_id);
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+int draw()
+{
+ // 设置渲染颜色
+ SDL_SetRenderDrawColor(rdr, 100, 100, 100, 100);
+ // 清除屏幕
+ SDL_RenderClear(rdr);
+
+ char file[20] = {0};
+ if (index > 1736)
+ {
+ return -1;
+ }
+
+ SDL_snprintf(file, 20, "img/%d.bmp", index++);
+
+ SDL_Surface *surf = SDL_LoadBMP(file);
+ SDL_Texture *texture = SDL_CreateTextureFromSurface(rdr, surf);
+ SDL_RenderCopy(rdr, texture, NULL, NULL);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ SDL_DestroyTexture(texture);
+ SDL_FreeSurface(surf);
+ return 0;
+}
+
+void event_loop()
+{
+ SDL_Event event;
+ Uint64 start, end;
+ int delay;
+ while (true)
+ {
+ start = SDL_GetTicks64();
+ while (SDL_PollEvent(&event))
+ {
+ SDL_Point pt;
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ draw();
+ }
+ break;
+ case SDL_MOUSEMOTION:
+ // SDL_Log("x = %d, y = %d", event.motion.x, event.motion.y);
+ // rect.x = event.motion.x - 100;
+ // rect.y = event.motion.y - 50;
+ // draw();
+ break;
+ case SDL_MOUSEBUTTONDOWN:
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 200, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+
+
+ break;
+ case SDL_MOUSEBUTTONUP:
+ pt = {event.button.x, event.button.y};
+ if (SDL_PointInRect(&pt, &rect))
+ {
+ SDL_SetRenderDrawColor(rdr, 0, 255, 0, 255);
+ SDL_RenderFillRect(rdr, &rect);
+
+ // 渲染呈现
+ SDL_RenderPresent(rdr);
+ }
+ break;
+ case SDL_KEYDOWN:
+ if (event.key.keysym.sym == SDLK_UP)
+ {
+ dy = -1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_DOWN)
+ {
+ dy = 1;
+ dx = 0;
+ }
+ if (event.key.keysym.sym == SDLK_LEFT)
+ {
+ dx = -1;
+ dy = 0;
+ }
+ if (event.key.keysym.sym == SDLK_RIGHT)
+ {
+ dx = 1;
+ dy = 0;
+ }
+
+ break;
+ case SDL_KEYUP:
+ break;
+ case SDL_TEXTEDITING:
+ break;
+
+ case SDL_TEXTINPUT:
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ draw();
+ end = SDL_GetTicks64();
+
+ delay = FT - (end -start);
+ if (delay > 0)
+ {
+ SDL_Delay(delay);
+ }
+
+
+ }
+}
+
+
+void callback(void *userdata, Uint8 * stream, int len)
+{
+ int remain = audio_len - audio_pos;
+ if (remain > len)
+ {
+ SDL_memcpy(stream, audio_buf + audio_pos, len);
+ audio_pos += len;
+ }
+ else
+ {
+ SDL_memcpy(stream, audio_buf + audio_pos, remain);
+ audio_pos = 0;
+ }
+
+}
+
+void play_wav()
+{
+ SDL_AudioSpec audio_spec;
+ // 1. 导入WAV文件
+ if (SDL_LoadWAV("2.wav", &audio_spec, &audio_buf, &audio_len) == NULL)
+ {
+ SDL_Log("SDL_LoadWAV failed: %s", SDL_GetError());
+ return;
+ }
+
+ // 2. 定义播放回调函数
+ audio_spec.callback = callback;
+
+ audio_spec.userdata = (void *)"这是外部传进来的数据";
+
+ // 3. 打开音频设备
+ device_id = SDL_OpenAudioDevice(NULL, 0, &audio_spec, NULL, 0);
+
+ // 4. 开始播放
+ SDL_PauseAudioDevice(device_id, 0);
+
+ // 5. 释放资源 关闭设备
+}
+
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw();
+ play_wav();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}其他模块使用
+其他模块的使用方式同核心模块一样，下载对应的库文件，将头文件、库文件合并到核心库的安装目录，在配置中添加对应的库即可。
+CXXFLAGS += -IC:/Users/YAN/Desktop/SDL/lib/SDL2-devel-2.28.2-mingw/SDL2-2.28.2/x86_64-w64-mingw32/include #改成你电脑上的include路径
+# CXXFLAGS += -fexec-charset=GBK -finput-charset=UTF-8
+LDFLAGS += -LC:/Users/YAN/Desktop/SDL/lib/SDL2-devel-2.28.2-mingw/SDL2-2.28.2/x86_64-w64-mingw32/lib
+
+CXXFLAGS += -std=c++23
+
+LDLIBS += -lSDL2 -lSDL2_ttf # 链接库时加上对应的模块
+
+LDLIBS += -mwindows
+
+
+main.exe: main.o
+ $(CXX) $^ -o $(basename $@) $(LDFLAGS) $(LDLIBS)
+
+.PHONY: run clean
+
+run: main.exe
+ $<
+
+clean:
+ $(RM) *.exe *.o文字模块示例
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_ttf.h>
+
+#define W 1280
+#define H 720
+
+SDL_Window *win = NULL;
+SDL_Renderer *rdr = NULL;
+
+
+int init()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ win = SDL_CreateWindow("Hello", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ W, H, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
+ if (NULL == win)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+
+
+ // 创建渲染器
+ rdr = SDL_CreateRenderer(win, -1, 0);
+ if (NULL == rdr)
+ {
+ SDL_Log("SDL_CreateRenderer failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ return 0;
+}
+
+void deinit()
+{
+ // 销毁
+ SDL_FreeWAV(audio_buf);
+ SDL_CloseAudioDevice(device_id);
+ SDL_DestroyRenderer(rdr);
+ SDL_DestroyWindow(win);
+ SDL_Quit();
+}
+
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (true)
+ {
+ while (SDL_PollEvent(&event))
+ {
+ SDL_Point pt;
+ switch (event.type)
+ {
+ case SDL_QUIT:
+ return;
+
+ default:
+ break;
+ }
+ }
+
+ }
+}
+
+void draw_text()
+{
+ // 1. 初始化TTF
+ if (TTF_Init() < 0)
+ {
+ SDL_Log("TTF_Init failed: %s", TTF_GetError());
+ return ;
+ }
+
+ // 2. 打开字体
+ TTF_Font *font = TTF_OpenFont("C:\\Windows\\Fonts\\simfang.ttf", 48);
+ if (!font)
+ {
+ SDL_Log("TTF_OpenFont failed: %s", TTF_GetError());
+ return ;
+ }
+
+ // 3. 渲染字体
+ SDL_Surface *txt_surf = TTF_RenderUTF8_LCD(font, "你好Hello", {255, 255, 255, 50}, {0, 0, 255, 0});
+ if (!txt_surf)
+ {
+ SDL_Log("TTF_RenderText_Solid failed: %s", TTF_GetError());
+ return ;
+ }
+
+ // 4. 获取与窗口关联的Surface
+ SDL_Surface *surf = SDL_GetWindowSurface(win);
+ if (!surf)
+ {
+ SDL_Log("SDL_GetWindowSurface failed: %s", SDL_GetError());
+ return ;
+ }
+
+ // 5. 将字体Surface复制到窗口Surface上
+ SDL_Rect rect = {500, 300, txt_surf->w, txt_surf->h};
+ SDL_BlitSurface(txt_surf, NULL, surf, &rect);
+
+ // 6. 更新窗口
+ SDL_UpdateWindowSurface(win);
+
+ // 7. 释放与销毁资源
+ SDL_FreeSurface(surf);
+ SDL_FreeSurface(txt_surf);
+ TTF_CloseFont(font);
+ TTF_Quit();
+}
+
+#undef main
+int main()
+{
+ if (init() < 0)
+ {
+ return -1;
+ }
+
+ draw_text();
+
+ event_loop();
+
+ deinit();
+ return 0;
+}关于文字渲染的几种类型：
+*_Solid: 使用纯色填充，速度快，文字渲染质量不佳
+*_Shaded: 使用纯色填充，添加一定阴影效果
+*_Blended: 使用抗锯齿算法高质量渲染
+*_LCD: 针对LCD显示器优化渲染
多线程操作
+SDL常用函数、结构体、枚举、宏定义
+函数
+SDL_Init
+声明
+// SDL.h
+int SDL_Init(Uint32 flags);功能
+初始化SDL库（子系统）。
+参数
+接收参数为宏定义，见下表
+| flags取值 | +初始化系统 | +
|---|---|
| SDL_INIT_VIDEO | +视频子系统，会自动初始化事件子系统 | +
| SDL_INIT_AUDIO | +音频子系统 | +
| SDL_INIT_TIMER | +定时器子系统 | +
| SDL_INIT_EVENTS | +事件子系统 | +
| SDL_INIT_JOYSTICK | +操纵杆子系统，自动初始化事件子系统 | +
| SDL_INIT_HAPTIC | +触觉子系统 | +
| SDL_INIT_GAMECONTROLLER | +控制子系统，自动初始化操纵杆子系统 | +
| SDL_INIT_EVERYTHING | +初始化所有子系统 | +
上述定义可以只初始化其中一个子系统，也可以多个一起初始化，多个时用|连接。
+返回值
+初始化成功返回0，失败返回一个负数错误代码
+用法示例
+SDL_Init(SDL_INIT_VIDEO); // 只初始化视频子系统
+SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO); // 初始化视频与音频子系统
+
+// 在初始化的同时进行是否成功判断
+if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_VIDEO) < 0)
+{
+ SDL_Log("SDL_Init failed: %s", SDL_GetError());
+ return -1;
+}+
+
SDL_Quit
+声明
+// SDL.h
+void SDL_Quit(void);功能
+清除（退出）所有已初始化的子系统。
++
+
SDL_CreateWindow
+声明
+// SDL_video.h
+SDL_Window * SDL_CreateWindow(const char *title, int x, int y, int w,int h, Uint32 flags);功能
+参数
+| 参数 | +含义 | +
|---|---|
| title | +窗口标题，UTF-8编码 | +
| x | +窗口起始位置x坐标 通常为居中SDL_WINDOWPOS_CENTERED或未定义SDL_WINDOWPOS_UNDEFINED | +
| y | +窗口起始位置y坐标 通常为居中SDL_WINDOWPOS_CENTERED或未定义SDL_WINDOWPOS_UNDEFINED | +
| w | +窗口宽度 | +
| h | +窗口高度 | +
| flags | +窗口显示标志，可以是0，或者是枚举类型SDL_WindowFlags中多个标志组合 | +
flags可取值为枚举类型SDL_WindowFlags（定义在SDL_video.h中），多个值时用|连接，一些常用值如下
typedef enum
+{
+ SDL_WINDOW_FULLSCREEN = 0x00000001, // 全屏显示
+ SDL_WINDOW_OPENGL = 0x00000002, // 使用OpenGL
+ SDL_WINDOW_SHOWN = 0x00000004, // 显示窗口
+ SDL_WINDOW_HIDDEN = 0x00000008, // 隐藏窗口
+ SDL_WINDOW_BORDERLESS = 0x00000010, // 窗口无边框
+ SDL_WINDOW_RESIZABLE = 0x00000020, // 窗口大小可变
+ SDL_WINDOW_MINIMIZED = 0x00000040, // 窗口最大化
+ SDL_WINDOW_MAXIMIZED = 0x00000080, // 窗口最小化
+ SDL_WINDOW_MOUSE_GRABBED = 0x00000100,
+ SDL_WINDOW_INPUT_FOCUS = 0x00000200,
+ SDL_WINDOW_MOUSE_FOCUS = 0x00000400,
+ SDL_WINDOW_FULLSCREEN_DESKTOP = ( SDL_WINDOW_FULLSCREEN | 0x00001000 ),
+ SDL_WINDOW_FOREIGN = 0x00000800,
+ SDL_WINDOW_ALLOW_HIGHDPI = 0x00002000,
+ SDL_WINDOW_MOUSE_CAPTURE = 0x00004000,
+ SDL_WINDOW_ALWAYS_ON_TOP = 0x00008000, // 窗口保持在最顶层
+ SDL_WINDOW_SKIP_TASKBAR = 0x00010000,
+ SDL_WINDOW_UTILITY = 0x00020000,
+ SDL_WINDOW_TOOLTIP = 0x00040000,
+ SDL_WINDOW_POPUP_MENU = 0x00080000,
+ SDL_WINDOW_KEYBOARD_GRABBED = 0x00100000, //
+ SDL_WINDOW_VULKAN = 0x10000000,
+ SDL_WINDOW_METAL = 0x20000000,
+
+ SDL_WINDOW_INPUT_GRABBED = SDL_WINDOW_MOUSE_GRABBED
+} SDL_WindowFlags;返回值
+窗口创建成功则返回对应窗口指针，失败则返回NULL。
++
+
SDL_DestroyWindow
+声明
+// SDL_video.h
+void SDL_DestroyWindow(SDL_Window * window);功能
+销毁由SDL_CreateWindow创建的窗口。
+用法示例
+SDL_Window *window = SDL_CreateWindow(
+ "SDLWindow",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ WIDTH, HEIGHT,
+ SDL_WINDOW_SHOWN);
+if (NULL == window)
+{
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+}
+
+SDL_Delay(5000);
+
+SDL_DestroyWindow(window);+
+
SDL_Delay
+声明
+// SDL_timer.h
+void SDL_Delay(Uint32 ms);功能
+让程序暂停（阻塞）指定时间，单位为毫秒。
++
+
SDL_Log
+声明
+// SDL_log.h
+void SDL_Log(const char *fmt, ...)功能
+向控制台输出信息，用法与C语言中printf一样。
++
+
SDL_GetError
+声明
+// SDL_error.h
+const char * SDL_GetError(void);功能
+获取最后一次发生错误对应的错误信息。
++
+
SDL_GetWindowSurface
+声明
+// SDL_video.h
+SDL_Surface * SDL_GetWindowSurface(SDL_Window * window);功能
+获取与window关联的SDL_Surface指针。
+返回值
+成功则返回SDL_Surface指针，失败则返回NULL。
++
+
SDL_FreeSurface
+声明
+// SDL_surface.h
+void SDL_FreeSurface(SDL_Surface * surface);功能
+释放SDL_Surface指针。
++
+
SDL_FillRect
+声明
+// SDL_surface.h
+int SDL_FillRect(SDL_Surface * dst, const SDL_Rect * rect, Uint32 color);功能
+在指定的surface上绘制（填充）一个指定区域的矩形。
+参数
+| 参数 | +含义 | +
|---|---|
| dst | +需要在上面进行绘制的surface指针 | +
| rect | +需要绘制的区域 | +
| color | +4字节无符号整型，表示颜色，通常用十六进制表示，例如0xFF32BACD。每两个字符表示一个通道，分别人ARGB通道。但在本函数中透明通道A不会生效，所以可以只写RGB三个字节，即0x32BACD | +
区域结构体见SDL_Rect
+返回值
+填充成功返回0，失败返回负数错误代码。
++
+
SDL_UpdateWindowSurface
+声明
+// SDL_video.h
+int SDL_UpdateWindowSurface(SDL_Window * window);功能
+将Surface的数据更新到屏幕上
+返回值
+更新成功返回0，失败返回负数错误代码
++
+
SDL_MapRGB
+声明
+// SDL_pixels.h
+Uint32 SDL_MapRGB(const SDL_PixelFormat * format,Uint8 r, Uint8 g, Uint8 b);功能
+使用指定的像素格式将r, g, b三个通道的颜色分量转为一个颜色值。
+参数
+| 参数 | +含义 | +
|---|---|
| format | +描述像素格式的结构体 | +
| r | +红色通道分量值，0~255 | +
| g | +绿色通道分量值， 0~255 | +
| b | +蓝色通道分量值， 0~255 | +
返回值
+由三个分量合并成的像素颜色值。
++
+
SDL_MapRGBA
+声明
+// SDL_pixels.h
+Uint32 SDL_MapRGBA(const SDL_PixelFormat * format,Uint8 r, Uint8 g, Uint8 b, Uint8 a);功能
+使用指定的像素格式将r, g, b, a 四个通道的颜色分量转为一个颜色值。
+参数
+| 参数 | +含义 | +
|---|---|
| format | +描述像素格式的结构体 | +
| r | +红色通道分量值，0~255 | +
| g | +绿色通道分量值， 0~255 | +
| b | +蓝色通道分量值， 0~255 | +
| a | +透明通道分量值， 0~255 | +
返回值
+由三个分量合并成的像素颜色值。
++
+
SDL_LoadBMP
+声明
+// SDL_surface.h
+#define SDL_LoadBMP(file) SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)
+// SDL_LoadBMP的声明是一个宏定义，其效果等同于下面的写法
+SDL_Surface * SDL_LoadBMP_RW(const char * file);功能
+导入BMP图片数据。
+参数
+file: 文件名
+返回值
+导入成功返回一个指向SDL_Surface的指针，导入失败则返回NULL。
++
+
SDL_BlitSurface
+声明
+// SDL_surface.h
+#define SDL_BlitSurface SDL_UpperBlit
+
+int SDL_UpperBlit(SDL_Surface * src, const SDL_Rect * srcrect,SDL_Surface * dst, SDL_Rect * dstrect);功能
+将一个surface的内容复制到另一个surface当中。
+参数
+| 参数 | +含义 | +
|---|---|
| src | +源surface | +
| srcrect | +源surface需要复制的区域 | +
| dst | +目标surface | +
| dstrect | +目标surface的区域（不生效） | +
返回值
+复制成功返回0，失败返回负数错误码。
++
+
SDL_BlitScaled
+声明
+// SDL_surface.h
+#define SDL_BlitScaled SDL_UpperBlitScaled
+int SDL_UpperBlitScaled(SDL_Surface * src, const SDL_Rect * srcrect,SDL_Surface * dst, SDL_Rect * dstrect);功能
+将一个surface的内容复制到另一个surface当中。两个区域大小不一致时，进行缩放。
+参数
+| 参数 | +含义 | +
|---|---|
| src | +源surface | +
| srcrect | +源surface需要复制的区域 | +
| dst | +目标surface | +
| dstrect | +目标surface的区域 | +
返回值
+复制成功返回0，失败返回负数错误码。
++
+
SDL_CreateRGBSurface
+SDL_CreateRGBSurfaceWithFormat
+SDL_CreateRGBSurfaceFrom
+SDL_CreateRGBSurfaceWithFormatFrom
+SDL_LockSurface
+SDL_UnlockSurface
+SDL_CreateRenderer
+声明
+// SDL_render.h
+SDL_Renderer * SDL_CreateRenderer(SDL_Window * window,int index, Uint32 flags);功能
+给指定窗口创建一个2D渲染环境。
+参数
+| 参数 | +含义 | +
|---|---|
| window | +需要创建渲染环境的窗口指针 | +
| index | +初始化渲染驱动索引。通常为-1，表示自动初始化第一个支持的驱动 | +
| flags | +0或者SDL_RendererFlags一个或多个值的组合 | +
SDL_RendererFlags为枚举类型，多个值时用|连接。如下
// SDL_render.h
+typedef enum
+{
+ SDL_RENDERER_SOFTWARE = 0x00000001, // 软件(CPU)渲染
+ SDL_RENDERER_ACCELERATED = 0x00000002, // 硬件加速
+ SDL_RENDERER_PRESENTVSYNC = 0x00000004,
+ SDL_RENDERER_TARGETTEXTURE = 0x00000008
+} SDL_RendererFlags;返回值
+成功返回渲染器指针，失败返回NULL。
++
+
SDL_DestroyRenderer
+声明
+// SDL_render.h
+void SDL_DestroyRenderer(SDL_Renderer * renderer);功能
+销毁渲染环境并释放关联的texture
++
+
SDL_SetRenderDrawColor
+声明
+// SDL_render.h
+int SDL_SetRenderDrawColor(SDL_Renderer * renderer,Uint8 r, Uint8 g, Uint8 b,Uint8 a);功能
+设置绘制操作（绘制/填充矩形、线条、点以及清除屏幕）的颜色。
+参数
+| 参数 | +含义 | +
|---|---|
| render | +渲染器 | +
| r | +红色通道值 | +
| g | +绿色通道值 | +
| b | +蓝色通道值 | +
| a | +透明通道值 | +
返回值
+设置成功返回0，失败返回负数错误代码。
++
+
SDL_RenderClear
+声明
+// SDL_render.h
+int SDL_RenderClear(SDL_Renderer * renderer);功能
+利用SDL_SetRenderDrawColor设置的颜色清除当前渲染目标。
+返回值
+清除成功返回0，失败返回负数错误码。
++
+
SDL_RenderPresent
+声明
+// SDL_render.h
+void SDL_RenderPresent(SDL_Renderer * renderer);功能
+将渲染操作的数据更新到屏幕上。
++
+
SDL_SetRenderDrawBlendMode
+声明
+// SDL_render.h
+int SDL_SetRenderDrawBlendMode(SDL_Renderer * renderer,SDL_BlendMode blendMode);功能
+为绘制操作设置颜色混合模式。
+参数
+混合模式为枚举类型SDL_BlendMode，定义及常用值如下：
+// SDL_blendmode.h
+
+typedef enum
+{
+ SDL_BLENDMODE_NONE = 0x00000000, // 默认模式。无混合，透明通道不生效
+ SDL_BLENDMODE_BLEND = 0x00000001, // Alpha通道混合，透明通道生效
+
+ // 下面这些混合模式暂时不用管， 有兴趣可以自行研究一下
+ SDL_BLENDMODE_ADD = 0x00000002,
+ SDL_BLENDMODE_MOD = 0x00000004,
+ SDL_BLENDMODE_MUL = 0x00000008,
+ SDL_BLENDMODE_INVALID = 0x7FFFFFFF
+} SDL_BlendMode;+
+
SDL_RenderDrawPoint
+声明
+// SDL_render.h
+int SDL_RenderDrawPoint(SDL_Renderer * renderer,int x, int y);功能
+根据提供的坐标在当前渲染目标上绘制一个点。
+返回值
+绘制成功返回0，失败返回负值错误码。
++
+
SDL_RenderDrawPoints
+声明
+// SDL_render.h
+int SDL_RenderDrawPoints(SDL_Renderer * renderer,const SDL_Point * points,int count);功能
+在当前渲染环境上绘制多个点。
+参数
+| 参数 | +含义 | +
|---|---|
| renderer | +当前渲染器指针 | +
| points | +指向一个SDL_Point数组的指针 | +
| count | +点的数量 | +
返回值
+绘制成功则返回0，失败返回负数错误码。
++
+
SDL_RenderDrawLine
+声明
+// SDL_render.h
+int SDL_RenderDrawLine(SDL_Renderer * renderer,int x1, int y1, int x2, int y2);功能
+根据提供的两个点的坐标在当前渲染环境上绘制一条线。
+返回值
+绘制成功返回0，失败返回负数错误码。
++
+
SDL_RenderDrawLines
+声明
+// SDL_render.h
+int SDLCALL SDL_RenderDrawLines(SDL_Renderer * renderer,const SDL_Point * points,int count);功能
+沿着提供的多个点绘制线段。
+参数
+ +返回值
+绘制成功返回0，失败返回负数错误码。
++
+
SDL_RenderDrawRect
+声明
+// SDL_render.h
+int SDL_RenderDrawRect(SDL_Renderer * renderer, const SDL_Rect * rect);功能
+在当前渲染目标上指定区域绘制一个矩形。
+返回值
+绘制成功返回0，失败返回负数错误码。
++
+
SDL_RenderDrawRects
+声明
+// SDL_render.h
+int SDL_RenderDrawRects(SDL_Renderer * renderer, const SDL_Rect * rects, int count);功能
+根据提供的区域数组在当前渲染目标上绘制多个矩形。
+参数
+| 参数 | +含义 | +
|---|---|
| renderer | +渲染器指针 | +
| rects | +指向SDL_Rect数组的指针 | +
| count | +区域数量 | +
返回值
+绘制成功返回0，失败返回负数错误码。
++
+
SDL_RenderFillRect
+声明
+// SDL_render.h
+int SDL_RenderFillRect(SDL_Renderer * renderer, const SDL_Rect * rect);功能
+在当前渲染目标上指定区域填充一个矩形。
+返回值
+填充成功返回0，失败返回负数错误码。
++
+
SDL_RenderFillRects
+声明
+// SDL_render.h
+int SDL_RenderFillRects(SDL_Renderer * renderer, const SDL_Rect * rects, int count);功能
+根据提供的区域数组在当前渲染目标上填充多个矩形。
+参数
+| 参数 | +含义 | +
|---|---|
| renderer | +渲染器指针 | +
| rects | +指向SDL_Rect数组的指针 | +
| count | +区域数量 | +
返回值
+填充成功返回0，失败返回负数错误码。
++
+
SDL_RenderSetScale
+SDL_CreateTextureFromSurface
+声明
+// SDL_render.h
+DL_Texture * SDL_CreateTextureFromSurface(SDL_Renderer * renderer, SDL_Surface * surface);功能
+由已存在的Surface创建Texture。
+返回值
+创建成功返回对应SDL_Texture指针，失败返回NULL。
++
+
SDL_DestroyTexture
+声明
+// SDL_render.h
+void SDL_DestroyTexture(SDL_Texture * texture);功能
+销毁指定的Texture。
++
+
SDL_RenderCopy
+声明
+// SDL_render.h
+int SDL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture, const SDL_Rect * srcrect, const SDL_Rect * dstrect);功能
+从Texture中复制指定部分到渲染目标中。当源区域与指定区域大小不一致时，会进行相应缩放。
+参数
+| 参数 | +含义 | +
|---|---|
| renderer | +渲染器指针 | +
| texture | +需要进行复制的texture | +
| srcrect | +需要进行复制的源区域，NULL表示整个区域 | +
| dstrect | +需要进行复制的目标区域，NULL表示整个区域 | +
+
+
SDL_RenderCopyEx
+声明
+// SDL_render.h
+int SDLCALL SDL_RenderCopyEx(SDL_Renderer * renderer, SDL_Texture * texture, const SDL_Rect * srcrect, const SDL_Rect * dstrect, const double angle, const SDL_Point *center, const SDL_RendererFlip flip);功能
+从Texture中复制指定部分到渲染目标中， 同时可进行旋转和镜像翻转操作。
+参数
+| 参数 | +含义 | +
|---|---|
| render | +渲染器指针 | +
| texture | +需要进行复制的Texture | +
| srcrect | +需要进行复制的源区域，NULL表示整个区域 | +
| dstrect | +复制去的目标区域，NULL表示整个渲染目标区域 | +
| angle | +旋转角度，顺时针方向旋转 | +
| center | +旋转中心点，为相对dstrect左上角的坐标。NULL表示围绕dstrect中心旋转 | +
| flip | +镜像翻转。为枚举类型SDL_RendererFlip，见下 | +
// SDL_render.h
+typedef enum
+{
+ SDL_FLIP_NONE = 0x00000000, // 不进行翻转
+ SDL_FLIP_HORIZONTAL = 0x00000001, // 进行水平镜像翻转
+ SDL_FLIP_VERTICAL = 0x00000002 // 进行垂直镜像翻转
+} SDL_RendererFlip;+
+
SDL_SetTextureAlphaMod
+声明
+// SDL_render.h
+int SDL_SetTextureAlphaMod(SDL_Texture * texture, Uint8 alpha);功能
+为render copy设置透明度，需要配合SDL_SetTextureBlendMode使用。
+返回值
+设置成功返回0，失败返回负数错误码。
++
+
SDL_SetTextureBlendMode
+声明
+// SDL_render.h
+int SDL_SetTextureBlendMode(SDL_Texture * texture, SDL_BlendMode blendMode);功能
+为SDL_RenderCopy设置颜色混合模式。
+参数
+SDL_BlendMode见SDL_SetRenderDrawBlendMode参数。
+返回值
+成功返回0，失败返回负数错误码。
++
+
SDL_UpdateTexture
+SDL_UpdateYUVTexture
+SDL_UpdateNVTexture
+SDL_LockTexture
+SDL_LockTextureToSurface
+SDL_UnlockTexture
+SDL_PointInRect
+声明
+// SDL_rect.h
+SDL_bool SDL_PointInRect(const SDL_Point *p, const SDL_Rect *r);功能
+判断一个点是否在一个区域中。
+参数
+ + +返回值
+ +点在区域内返回SDL_TRUE， 点不在区域内返回SDL_FALSE。
++
+
SDL_RectEmpty
+声明
+// SDL_rect.h
+SDL_bool SDL_RectEmpty(const SDL_Rect *r);功能
+判断一个区域是否面积。
+参数
+ +返回值
+如果r为NULL或者对应区域面积（计算值）小于或等于0则返回SDL_TRUE，否则返回SDL_FALSE。
++
+
SDL_RectEquals
+声明
+// SDL_rect.h
+SDL_bool SDL_RectEquals(const SDL_Rect *a, const SDL_Rect *b);功能
+判断两个区域是否相同。
+参数
+ +返回值
+如果两个SDL_Rect指针都不为NULL，且左上角坐标相同、宽高也相同则返回SDL_TRUE，否则返回SDL_FALSE。
++
+
SDL_HasIntersection
+声明
+// SDL_rect.h
+SDL_bool SDL_HasIntersection(const SDL_Rect * A,const SDL_Rect * B);功能
+判断两个矩形区域是否有相交部分。
+参数
+ +返回值
+如果两个SDL_Rect指针都不为NULL且有相交部分则返回SDL_TRUE，否则返回SDL_FALSE。
++
+
SDL_IntersectRect
+声明
+// SDL_rect.h
+SDL_bool SDLCALL SDL_IntersectRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result);功能
+计算两个矩形区域相交部分。
+参数
+A，B： 需要计算的两个区域
+result： A与B相交的部分。
+ +返回值
+如果A、B有相交部分则返回SDL_TRUE，否则返回SDL_FALSE。
++
+
SDL_UnionRect
+声明
+// SDL_rect.h
+void SDLCALL SDL_UnionRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result);功能
+计算两个矩形区域的并集。如果A、B是两个分离开的区域，则并为能将A、B两个区域包含在内的最小矩形区域。
+参数
+A，B： 需要计算的两个区域
+result： A与B并集。
+ ++
+
SDL_LoadWAV
+声明
+// SDL_audio.h
+
+#define SDL_LoadWAV(file, spec, audio_buf, audio_len) \
+ SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len)
+
+SDL_AudioSpec * SDL_LoadWAV_RW(SDL_RWops * src, int freesrc, SDL_AudioSpec * spec, Uint8 ** audio_buf, Uint32 * audio_len);功能
+导入WAV格式音频文件。
+参数
+| 参数 | +含义 | +
|---|---|
| file | +WAV文件名 | +
| spec | +SDL_AudioSpec，音频文件信息 | +
| audio_buf | +音频文件数据指针 | +
| audio_len | +音频文件长度（字节）指针 | +
返回值
+成功返回SDL_AudioSpec指针，失败返回NULL。
++
+
SDL_FreeWAV
+声明
+// SDL_audio.h
+void SDL_FreeWAV(Uint8 * audio_buf);功能
+释放SDL_LoadWAV导入的音频数据。
++
+
SDL_OpenAudioDevice
+声明
+// SDL_audio.h
+SDL_AudioDeviceID SDL_OpenAudioDevice(const char *device, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes);功能
+打开指定的音频设备。
+参数
+| 参数 | +含义 | +
|---|---|
| device | +设备名称，由SDL_GetAudioDeviceName获得，为NULL则请求能使用的默认设备 | +
| iscapture | +是否是录音设备，0表示播放设备，非0表示录音设备 | +
| desired | +期望输出格式。SDL_AudioSpec | +
| obtained | +实际输出格式。SDL_AudioSpec | +
| allowed_changes | +当硬件不支持时是否允许改变。通常为0 | +
返回值
+成功则返回一个有效设备ID。失败返回0
++
+
SDL_PauseAudioDevice
+声明
+// SDL_audio.h
+void SDL_PauseAudioDevice(SDL_AudioDeviceID dev, int pause_on);功能
+设置指定播放设备的暂停和播放。
+参数
+dev： 由SDL_OpenAudioDevice打开的设备ID。
+pause_on： 暂停/播放，0为播放，非0为暂停。
++
+
SDL_GetAudioDeviceName
+声明
+// SDL_audio.h
+
+const char * SDL_GetAudioDeviceName(int index, int iscapture);功能
+根据索引查询音频设备名称。
+参数
+index： 设备索引
+iscapture： 是否为录音设备。0查询非录音设备，非0查询录音设备。
+返回值
+查询到设备返回设备名称，否则返回NULL。
++
+
结构体、枚举、宏定义
+SDL_bool
+定义
+// SDL_stdinc.h
+
+typedef enum
+{
+ SDL_FALSE = 0,
+ SDL_TRUE = 1
+} SDL_bool;描述
+定义布尔值。虽然也是1为真0为假，但是这样定义之后在代码中使用这个定义可以增加可读性。
++
+
SDL_Point
+定义
+// SDL_rect.h
+typedef struct SDL_Point
+{
+ int x; // 点的横坐标
+ int y; // 点的纵坐标
+} SDL_Point;描述
+定义了一个点。
++
+
SDL_Rect
+定义
+// SDL_rect.h
+typedef struct SDL_Rect
+{
+ int x, y; //矩形区域左上角坐标
+ int w, h; // 矩形区域宽和高 单位为像素
+} SDL_Rect;描述
+一个由左上角坐标和宽高决定的矩形区域。
++
+
SDL_Surface
+定义
+// SDL_surface.h
+typedef struct SDL_Surface
+{
+ Uint32 flags; //
+ SDL_PixelFormat *format; // 像素格式信息
+ int w, h; // 宽、高
+ int pitch; // 每一行像素字节数
+ void *pixels; // 界面上像素对应的数据内存指针
+
+
+ /** 以下这些成员可以暂时先不用了解 */
+ void *userdata;
+ int locked;
+ void *list_blitmap;
+ SDL_Rect clip_rect;
+ SDL_BlitMap *map;
+ int refcount;
+} SDL_Surface;描述
+进行位图操作的像素集。可以理解为一张画布，可以在上面进行绘图和其他像素操作。
++
+
SDL_AudioSpec
+定义
+// SDL_audio.h
+
+typedef struct SDL_AudioSpec
+{
+ int freq; // 采样率
+ SDL_AudioFormat format; // 音频数据格式
+ Uint8 channels; // 声道数： 1为单声道 2为立体声
+ Uint8 silence; //
+ Uint16 samples; //
+ Uint16 padding; //
+ Uint32 size; // 音频数据大小（字节）
+ SDL_AudioCallback callback; // 为音频设备提供数据的回调函数
+ void *userdata; // 向回调函数中传递的数据
+} SDL_AudioSpec;描述
+保存音频文件一些格式信息。
+userdata最主要用于传递SDL_LoadWAV加载进来的audio_buf数据，也可以自定义一些其他数据。
+SDL_AudioCallback为回调函数类型，定义如下：
+typedef void (SDLCALL * SDL_AudioCallback) (void *userdata, Uint8 * stream,int len);userdata为通过SDL_AudioSpec传入的userdata,
+stream为每次向音频设备传递的声音数据，
+len为传递的stream长度。
+一个SDL_AudioCallback例子如下：
+typedef struct {
+ Uint8 *audio_buf;
+ Uint32 audio_len;
+ Uint32 pos;
+} AudioInfo;
+
+
+void callback(void *userdata, Uint8 * stream, int len)
+{
+ AudioInfo *audio_info = (AudioInfo *)userdata;
+
+ Uint32 remain_len = audio_info->audio_len - audio_info->pos;
+ if (remain_len > len)
+ {
+ SDL_memcpy(stream, audio_info->audio_buf + audio_info->pos, len);
+ audio_info->pos += len;
+ }
+ else
+ {
+ SDL_memcpy(stream, audio_info->audio_buf + audio_info->pos, remain_len);
+ audio_info->pos = 0;
+ }
+
+}
+
+void play_audio()
+{
+ SDL_AudioSpec spec;
+ Uint8 *audio_buf;
+ Uint32 audio_len;
+ if (SDL_LoadWAV("sound.wav", &spec, &audio_buf, &audio_len) == NULL)
+ {
+ SDL_Log("wav load failed: %s", SDL_GetError());
+ return -1;
+ }
+ spec.callback = callback;
+ AudioInfo audio_info = {audio_buf, audio_len, 0};
+ spec.userdata = &audio_info;
+
+ SDL_AudioDeviceID dvice_id = SDL_OpenAudioDevice(NULL, 0, &spec, &spec, 0);
+
+ SDL_PauseAudioDevice(dvice_id, SDL_FALSE);
+}Unknown
+#include <SDL2/SDL.h>
+
+#define WIDTH 720
+#define HEIGHT 720
+
+#define FR 30
+#define FT 1000 / FR
+
+
+SDL_Window *window;
+SDL_Renderer *render;
+SDL_Surface *image_surface;
+SDL_Texture *image_texture;
+SDL_Rect render_rect;
+
+
+void calc_redner_rect()
+{
+ int window_width, window_height, texture_width, texture_height;
+ SDL_GetWindowSize(window, &window_width, &window_height);
+ SDL_QueryTexture(image_texture, NULL, NULL, &texture_width, &texture_height);
+ double scale = 1.0;
+ if ((texture_width > window_width) && (texture_height > window_height))
+ {
+ double xscale = (double)window_width / texture_width;
+ double yscale = (double)window_height / texture_height;
+ scale = xscale < yscale ? xscale : yscale;
+ }
+ else if (texture_width > window_width)
+ {
+ scale = (double)window_width / texture_width;
+ }
+ else if (texture_height > window_height)
+ {
+ scale = (double)window_height / texture_height;
+ }
+
+ texture_height *= scale;
+ texture_width *= scale;
+
+ render_rect.x = (window_width - texture_width) / 2;
+ render_rect.y = (window_height - texture_height) / 2;
+ render_rect.w = texture_width;
+ render_rect.h = texture_height;
+
+
+ SDL_Log("calc_redner_rect");
+}
+
+
+int initialize()
+{
+ if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0)
+ {
+ SDL_Log("SDL_Init failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ window = SDL_CreateWindow("SDL",
+ SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+ WIDTH, HEIGHT,
+ SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE
+ );
+ if (NULL == window)
+ {
+ SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
+ return -1;
+ }
+ render = SDL_CreateRenderer(window, -1, 0);
+ if (NULL == render)
+ {
+ SDL_Log("SDL_CreateRenderer error: %s", SDL_GetError());
+ return -1;
+ }
+
+ image_surface = SDL_LoadBMP("1685074549643.bmp");
+ if (NULL == image_surface)
+ {
+ SDL_Log("Image load failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ image_texture = SDL_CreateTextureFromSurface(render, image_surface);
+ if (NULL == image_texture)
+ {
+ SDL_Log("SDL_CreateTextureFromSurface failed: %s", SDL_GetError());
+ return -1;
+ }
+
+ calc_redner_rect();
+
+ return 0;
+}
+
+void release()
+{
+ if (NULL != image_texture)
+ {
+ SDL_DestroyTexture(image_texture);
+ }
+
+ if (NULL != image_surface)
+ {
+ SDL_FreeSurface(image_surface);
+ }
+
+ if (NULL != render)
+ {
+ SDL_DestroyRenderer(render);
+ }
+
+ if (NULL != window)
+ {
+ SDL_DestroyWindow(window);
+ }
+
+ SDL_Quit();
+}
+
+
+void draw()
+{
+ SDL_SetRenderDrawColor(render, 255, 255, 255, 255);
+ SDL_RenderClear(render);
+
+ SDL_RenderCopy(render, image_texture, NULL, &render_rect);
+ SDL_RenderPresent(render);
+}
+
+
+
+
+void event_loop()
+{
+ SDL_Event event;
+ while (1)
+ {
+ Uint64 start = SDL_GetTicks64();
+ while (SDL_PollEvent(&event))
+ {
+ switch (event.type)
+ {
+ case SDL_MOUSEMOTION:
+ break;
+ case SDL_MOUSEBUTTONDOWN:
+ break;
+ case SDL_MOUSEBUTTONUP:
+ break;
+ case SDL_MOUSEWHEEL:
+ break;
+ case SDL_QUIT:
+ return;
+ case SDL_WINDOWEVENT:
+ if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+ {
+ calc_redner_rect();
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ draw();
+ Uint64 end = SDL_GetTicks64();
+ int time = end - start;
+ // SDL_Log("time = %d, FT = %d", time, FT);
+ if (time < FT)
+ {
+ SDL_Delay(FT - time);
+ }
+ }
+
+}
+
+
+typedef struct {
+ Uint8 *audio_buf;
+ Uint32 audio_len;
+ Uint32 pos;
+} AudioInfo;
+
+void callback(void *userdata, Uint8 * stream, int len)
+{
+ AudioInfo *audio_info = (AudioInfo *)userdata;
+ // SDL_Log("len = %d, len = %d, pos = %u", audio_info->audio_len, len, audio_info->pos);
+ Uint32 remain_len = audio_info->audio_len - audio_info->pos;
+ if (remain_len > len)
+ {
+ SDL_memcpy(stream, audio_info->audio_buf + audio_info->pos, len);
+ audio_info->pos += len;
+ }
+ else
+ {
+ SDL_memcpy(stream, audio_info->audio_buf + audio_info->pos, remain_len);
+ audio_info->pos = 0;
+ }
+
+}
+
+
+void play_wav()
+{
+
+}
+
+#undef main
+int main(int argc, char *argv[])
+{
+ if (initialize() < 0)
+ {
+ release();
+ return -1;
+ }
+ SDL_AudioSpec spec;
+ Uint8 *audio_buf;
+ Uint32 audio_len;
+ if (SDL_LoadWAV("sound.wav", &spec, &audio_buf, &audio_len) == NULL)
+ {
+ SDL_Log("wav load failed: %s", SDL_GetError());
+ return -1;
+ }
+ spec.callback = callback;
+ AudioInfo audio_info = {audio_buf, audio_len, 0};
+ spec.userdata = &audio_info;
+ SDL_Log("%u", audio_len);
+ SDL_AudioDeviceID dvice_id = SDL_OpenAudioDevice(NULL, 0, &spec, &spec, 0);
+
+ SDL_PauseAudioDevice(dvice_id, SDL_FALSE);
+ SDL_Log("Here !");
+ event_loop();
+ SDL_CloseAudioDevice(dvice_id);
+ SDL_FreeWAV(audio_buf);
+ release();
+ return 0;
+}CPP多线程
+