SDL2.0_04_event

也是在前一课的基础上稍作修改的。

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

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

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

SDL_Window *win = nullptr;
SDL_Renderer *ren = nullptr;

SDL_Texture * LoadImage(string file) {
	SDL_Texture *tex = nullptr;
	tex = IMG_LoadTexture(ren, file.c_str());
	if (tex == nullptr) {
		cout << "Fail to load image in function LoadImage()!" << endl;
	}

	return tex;
}

void renderTexture(SDL_Texture *tex, SDL_Renderer *ren, int x, int y, int w, int h) {
	SDL_Rect dst;
	dst.x = x;
	dst.y = y;
	dst.w = w;
	dst.h = h;
	SDL_RenderCopy(ren, tex, NULL, &dst);
}

void renderTexture(SDL_Texture *tex, SDL_Renderer *ren, int x, int y) {
	int w, h;
	SDL_QueryTexture(tex, NULL, NULL, &w, &h);
	renderTexture(tex, ren, x, y, w, h);
}

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

	win = SDL_CreateWindow("04:", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_RESIZABLE);

	if (win == nullptr) {
		cout << SDL_GetError() << endl;
		return 0;
	}
	
	ren = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
	if (ren == nullptr) {
		cout << SDL_GetError() << endl;
		return 0;
	}
	SDL_Texture *bg = LoadImage("f:/material/giantShadowFlash.jpg");

	if (bg == nullptr) {
		cout << "Could not load one of the images!" << 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 type..." << endl;
				quit = true;
			}
			if (e.type == SDL_KEYDOWN) {
				cout << "keydown type..." << endl;
				quit = true;
			}
			if (e.type == SDL_MOUSEBUTTONDOWN) {
				cout << "mousebuttondown type..." << endl;
				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;
}