SDL显示图像和文字-白红宇

SDL显示图像和文字

阅读量：4109 次

发布时间：2019-05-25

本文共 4161 字，大约阅读时间需要 13 分钟。

这两天在做一个视频分析软件需要用到SDL显示图像及文字，将阶段成果做一下总结：

SDL本身并没有实际文字的功能，需要用到其扩展库SDL_ttf，下载地址：

http://www.libsdl.org/projects/SDL_ttf/docs/SDL_ttf.html

闲话少说，请看代码（工程环境：VS2005）：

#include "stdafx.h"#pragma comment(lib,"SDL.lib")#pragma comment(lib,"SDL2_image.lib")#pragma comment(lib,"SDL_ttf.lib")#include 
   
    #include 
    
     #include 
     
      #include 
      
       #include "SDL.h"#include "SDL_ttf.h"/* 屏幕分辩率 */#define  SCREEN_WIDTH   720#define  SCREEN_HEIGHT  480#define  SCREEN_BPP     32const SDL_Color RGB_Black   = { 0, 0, 0 };const SDL_Color RGB_Red     = { 255, 0, 0 };const SDL_Color RGB_White   = { 255, 255, 255 };const SDL_Color RGB_Yellow  = { 255, 255, 0 };void ApplySurface(int x, int y, SDL_Surface* pSrc, SDL_Surface* pDest){    SDL_Rect rect;    rect.x = x;    rect.y = y;    rect.w = pSrc->w;    rect.h = pSrc->h;    SDL_BlitSurface(pSrc, NULL, pDest, &rect);}char *localeToUTF8(char *src){    static char *buf = NULL;    wchar_t *unicode_buf;    int nRetLen;    if(buf){        free(buf);        buf = NULL;    }    nRetLen = MultiByteToWideChar(CP_ACP,0,src,-1,NULL,0);    unicode_buf = (wchar_t*)malloc((nRetLen+1)*sizeof(wchar_t));    MultiByteToWideChar(CP_ACP,0,src,-1,unicode_buf,nRetLen);    nRetLen = WideCharToMultiByte(CP_UTF8,0,unicode_buf,-1,NULL,0,NULL,NULL);    buf = (char*)malloc(nRetLen+1);    WideCharToMultiByte(CP_UTF8,0,unicode_buf,-1,buf,nRetLen,NULL,NULL);    free(unicode_buf);    return buf;}int main(int argc,char * argv[]){    SDL_Surface     *pScreen;    SDL_Surface     *pBackground;    SDL_Surface     *pText;    SDL_Event       myEvent;    TTF_Font *font;    char szEnglish[]        = "Hello World!";    wchar_t wszChinese[]    = L"世界，你好！";    /* 初始化 SDL */    if (SDL_Init(SDL_INIT_VIDEO) == -1)        return 0;    /* 初始化窗口 */    pScreen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE | SDL_HWSURFACE);    if (NULL == pScreen)//检测是否初始化成功        return 0;    /* 初始化字体库 */    if (TTF_Init() == -1 )        return 0;    /* 设置窗口名字和图标 */    SDL_WM_SetCaption(localeToUTF8("测试SDL显示文字"), NULL);    /* 打开simfang.ttf 字库，设字体为20号 */    font  = TTF_OpenFont("C:\\Windows\\Fonts\\simhei.ttf", 20);    if (font == NULL)    {        return 0;    }      /* 显示背景 */    pBackground =  SDL_LoadBMP(".\\22.bmp");    if (NULL != pBackground)    {        ApplySurface(0, 0, pBackground, pScreen);        SDL_FreeSurface(pBackground);    }    /* 设置字体样式（加粗｜斜体）*/    TTF_SetFontStyle(font, TTF_STYLE_BOLD |  TTF_STYLE_ITALIC);    /* 显示英文 */    pText = TTF_RenderText_Solid(font, szEnglish, RGB_Red);    if (NULL != pText)    {        ApplySurface(80, 120, pText, pScreen);        SDL_FreeSurface(pText);    }    pText = TTF_RenderText_Shaded(font,szEnglish,RGB_Red, RGB_White);    if (NULL != pText)    {        ApplySurface(80, 150, pText, pScreen);        SDL_FreeSurface(pText);    }    pText = TTF_RenderText_Blended(font,szEnglish,RGB_Red);    if (NULL != pText)    {        ApplySurface(80, 180, pText, pScreen);        SDL_FreeSurface(pText);    }    /* 显示中文 */    pText = TTF_RenderUNICODE_Solid(font, (const Uint16 *)wszChinese, RGB_Red);    if (NULL != pText)    {        ApplySurface(280, 120, pText, pScreen);        SDL_FreeSurface(pText);    }    pText = TTF_RenderUNICODE_Shaded(font, (const Uint16 *)wszChinese, RGB_Red, RGB_White);    if (NULL != pText)    {        ApplySurface(280, 150, pText, pScreen);        SDL_FreeSurface(pText);    }    pText = TTF_RenderUNICODE_Blended(font, (const Uint16 *)wszChinese, RGB_Red);    if (NULL != pText)    {        ApplySurface(280, 180, pText, pScreen);        SDL_FreeSurface(pText);    }        /* 将缓冲在界面显示出来 */    SDL_Flip(pScreen);    /* 事件处理 */    int quit = 0;    while (!quit)    {        if (SDL_PollEvent(&myEvent))        {            if (SDL_QUIT == myEvent.type)            {                quit = 1;            }        }           }       return 0;}