SDL2.0_06_text

使用了SDL_ttf扩展库，字体文件*.ttf可以在Sourceforge上下载。

#include <iostream>
#include <windows.h>
#include <string>
using namespace std;

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

const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

void renderTexture(SDL_Texture *tex, SDL_Renderer *ren, SDL_Rect dst, SDL_Rect *clip = nullptr) {
	SDL_RenderCopy(ren, tex, clip, &dst);
}

void renderTexture(SDL_Texture *tex, SDL_Renderer *ren, int x, int y, SDL_Rect *clip = nullptr) {
	SDL_Rect dst;
	dst.x = x;
	dst.y = y;
	if (clip != nullptr) {
		dst.w = clip->w;
		dst.h = clip->h;
	}
	else 
		SDL_QueryTexture(tex, NULL, NULL, &dst.w, &dst.h);
	renderTexture(tex, ren, dst, clip);
}

SDL_Texture *renderText(const string &message, const string &fontFile, SDL_Color color, int fontSize, SDL_Renderer *ren) {
	TTF_Font *font = TTF_OpenFont(fontFile.c_str(), fontSize);
	if (font == nullptr) {
		cout << "Failed to open font..." << endl;
		exit(0);
	}
	SDL_Surface *surf = TTF_RenderText_Blended(font, message.c_str(), color);
	SDL_Texture *tex = SDL_CreateTextureFromSurface(ren, surf);

	SDL_FreeSurface(surf);
	TTF_CloseFont(font);

	return tex;
}

int main(int argc, char** argv)
{
	if (SDL_Init(SDL_INIT_EVERYTHING) == -1) {
		cout << SDL_GetError() << endl;
		return 0;
	}

	if (TTF_Init() == -1) {
		cout << TTF_GetError() << endl;
		return 0;
	}

	SDL_Window *win = nullptr;
	win = SDL_CreateWindow("05:", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_RESIZABLE);

	if (win == nullptr) {
		cout << SDL_GetError() << endl;
		return 0;
	}
	
	SDL_Renderer *ren = nullptr;
	ren = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
	if (ren == nullptr) {
		cout << SDL_GetError() << endl;
		return 0;
	}

	SDL_Color color = { 128, 128, 128 };
	SDL_Texture *bg = renderText("Why I have to learn SDL?", "chivo-black-webfont.ttf", color, 64, ren);

	if (bg == nullptr) {
		cout << "Could not load font correctly!" << endl;
		return 0;
	}

	SDL_RenderClear(ren);

	int bw, bh;
	SDL_QueryTexture(bg, NULL, NULL, &bw, &bh);

	SDL_Event e;
	bool quit = false;
	while (!quit) {
		while (SDL_PollEvent(&e))
		{
			if (e.type == SDL_QUIT) {
				cout << "quit..." << endl;
				quit = true;
			}
			if (e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_ESCAPE) {
				quit = true;
			}
		}
		SDL_RenderClear(ren);
		renderTexture(bg, ren, SCREEN_WIDTH/2 - bw/2, SCREEN_HEIGHT/2 - bh/2);
		SDL_RenderPresent(ren);
	}

	SDL_DestroyTexture(bg);
	SDL_DestroyRenderer(ren);
	SDL_DestroyWindow(win);
	SDL_Quit();
	IMG_Quit();

	cout << "Success!" << endl;
	return 0;
}