SDL2.0でPNG画像と文字列を表示

ubuntu 12.04環境ではSDL1.2のパッケージしか入っていない為、SDL2.0をソー スコードからインストールする必要があります。

PNG画像と文字列を表示するサンプルを以下に記載します。別途PNG画像のファ イルとフォントのファイルが必要となります。

#include <iostream>
#include <SDL.h>
#include <SDL_ttf.h>
#include <SDL_image.h>

#define SAMPLE_SPRITE "sample.png"
#define SAMPLE_FONT "sazanami-gothic.ttf"
#define SAMPLE_FONT_SIZE (32)
#define SAMPLE_STRING "Sample string"

static SDL_Window *gWindow;
static int gWindowWidth;
static int gWindowHeight;

static SDL_Renderer *gRenderer;

static SDL_RWops *gFontRWops;
static TTF_Font *gFont;
static int gFontWidth;
static int gFontHeight;
static SDL_Color gFontColor = { 255, 255, 0 };

static bool initializeFont()
{
  gFontRWops = SDL_RWFromFile(SAMPLE_FONT, "rb");
  if (gFontRWops == nullptr)
    return false;

  gFont = TTF_OpenFontRW(gFontRWops, 0, SAMPLE_FONT_SIZE);
  if (gFont == nullptr)
    goto err1;

  if (TTF_SizeUTF8(gFont, "a", &gFontWidth, &gFontHeight) < 0)
    goto err2;

  return true;

 err2:
  TTF_CloseFont(gFont);
 err1:
  SDL_RWclose(gFontRWops);
  return false;
}

static void finalizeFont()
{
  TTF_CloseFont(gFont);
  SDL_RWclose(gFontRWops);
}

static bool initialize(int width, int height)
{
  if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
    return false;

  if (TTF_Init() < 0)
    goto err1;

  if (SDL_CreateWindowAndRenderer(width, height, 0,
                                  &gWindow, &gRenderer) < 0)
    goto err2;

  if (!initializeFont())
    goto err3;

  SDL_GetWindowSize(gWindow, &gWindowWidth, &gWindowHeight);
  return true;

 err3:
  SDL_DestroyRenderer(gRenderer);
  SDL_DestroyWindow(gWindow);
 err2:
  TTF_Quit();
 err1:
  SDL_Quit();
  return false;
}

static void finalize()
{
  finalizeFont();
  SDL_DestroyRenderer(gRenderer);
  SDL_DestroyWindow(gWindow);
  TTF_Quit();
  SDL_Quit();
}

SDL_Texture *createSprite(const char *spriteName)
{
  SDL_RWops *rwops;
  SDL_Surface *surface;
  SDL_Texture *texture;

  rwops = SDL_RWFromFile(spriteName, "rb");
  if (rwops == nullptr)
    return nullptr;

  surface = IMG_LoadPNG_RW(rwops);
  if (surface == nullptr)
    goto err;

  texture = SDL_CreateTextureFromSurface(gRenderer, surface);
  SDL_FreeSurface(surface);
 err:
  SDL_RWclose(rwops);
  return texture;
}

SDL_Texture *createString(const char *string)
{
  SDL_Surface *surface;
  SDL_Texture *texture;

  surface = TTF_RenderUTF8_Solid(gFont, string, gFontColor);
  if (surface == nullptr) {
    std::cerr << "utf8" << std::endl;
    return nullptr;
  }

  texture = SDL_CreateTextureFromSurface(gRenderer, surface);
  SDL_FreeSurface(surface);
  return texture;
}

int main()
{
  SDL_Texture *sprite, *string;
  int ret = 1;

  if (!initialize(400, 400)) {
    std::cerr << "Initialize error" << std::endl;
    return 1;
  }

  sprite = createSprite(SAMPLE_SPRITE);
  if (sprite == nullptr) {
    std::cerr << "Sprite error" << std::endl;
    goto err1;
  }

  string = createString(SAMPLE_STRING);
  if (string == nullptr) {
    std::cerr << "String error" << std::endl;
    goto err2;
  }

  SDL_RenderClear(gRenderer);
  SDL_RenderCopy(gRenderer, sprite, nullptr, nullptr);
  SDL_RenderCopy(gRenderer, string, nullptr, nullptr);
  SDL_RenderPresent(gRenderer);
  SDL_Delay(10000);
  ret = 0;

  SDL_DestroyTexture(string);
 err2:
  SDL_DestroyTexture(sprite);
 err1:
  finalize();
  return ret;
}