bunnymark.cpp

#include "SDL.h"

#include "windows.h"
#include <ctime>
#include <cstdarg>
#include <vector>

SDL_DisplayMode  mode;
SDL_Window      *window;
SDL_Renderer	*renderer;
SDL_Surface		*image;
SDL_Texture		*texture;

float minX = 0;
float maxX = 0;
float minY = 0;
float maxY = 0;

float fpsTime  = 0;
int   fpsCount = 0;

WCHAR debug[1024];

typedef struct {
	float x, xv, y, yv, r, rv;
} Bunny;

std::vector<Bunny> bunnies;

void initBunny(Bunny *bunny);

int
randomInt(int min, int max) {
	return min + rand() % (max - min + 1);
}

void
moreBunnies(int more) {
	Bunny bunny;

	for (int i = 0; i < more; i++) {
		initBunny(&bunny);
		bunnies.push_back(bunny);
	}
}

void
initBunny(Bunny *bunny) {
	bunny->x = minX + randomInt((int)minX, (int)maxX);
	bunny->y = minY + randomInt((int)minY, (int)maxY);

	do {
		bunny->xv = 100 - randomInt(0, 200);
	} while (bunny->xv < 10 && bunny->xv > -10);

	do {
		bunny->yv = 100 - randomInt(0, 200);
	} while (bunny->yv < 10 && bunny->yv > -10);

	bunny->r = randomInt(0, 360);

	do {
		bunny->rv = 50 - randomInt(0, 100);
	} while (bunny->rv < 10 && bunny->rv > -10);
}

void
renderBunnies(float dt) {
	SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
	SDL_RenderClear(renderer);

	SDL_Rect  src = { 0,0,image->w,image->h };
	SDL_Rect  dst = { 0,0,image->w,image->h };

	for (auto bunny = bunnies.begin(); bunny != bunnies.end(); bunny++) {
		bunny->x += dt * bunny->xv;
		if (bunny->x < minX) { bunny->x = minX; bunny->xv = -bunny->xv; }
		if (bunny->x > maxX) { bunny->x = maxX; bunny->xv = -bunny->xv; }

		bunny->y += dt * bunny->yv;
		if (bunny->y < minY) { bunny->y = minY; bunny->yv = -bunny->yv; }
		if (bunny->y > maxY) { bunny->y = maxY; bunny->yv = -bunny->yv; }

		bunny->r = ((int)round(bunny->r + dt * bunny->rv)) % 360;

		dst.x = (int)round(bunny->x);
		dst.y = (int)round(bunny->y);
		SDL_RenderCopy(renderer, texture, &src, &dst);
	}

	SDL_RenderPresent(renderer);
}

int
main(int argc, char *argv[]) {
	// seed random number generator
	srand(time(NULL));

	// initialize SDL
	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
		return 1;
	}

	// create window and renderer
	if (SDL_GetCurrentDisplayMode(0, &mode) != 0) {
		return 1;
	}
	if (SDL_CreateWindowAndRenderer(mode.w, mode.h, 0, &window, &renderer) != 0) {
		return 1;
	}

	// load test image and create texture
	image = SDL_LoadBMP("wabbit_alpha.bmp");
	if (!image) {
		return 1;
	}

	texture = SDL_CreateTextureFromSurface(renderer, image);
	if (!texture) {
		return 1;
	}

	// initialise bunnies
	minX = 0;
	maxX = mode.w - image->w;
	minY = 0;
	maxY = mode.h - image->h;

	moreBunnies(100);

	// main loop
	float prevTime = SDL_GetTicks() - (1000.0f / 60.0f);

	int done = 0;
	while (!done) {
		float currTime = SDL_GetTicks();
		float deltaTime = (currTime - prevTime) / 1000.0f;
		prevTime = currTime;

		SDL_Event event;
		while (SDL_PollEvent(&event)) {
			switch (event.type) {
			case SDL_QUIT:
				done = 1;
				break;

			case SDL_FINGERUP:
				moreBunnies(100);
				break;
			}
		}

		renderBunnies(deltaTime);

		fpsTime += deltaTime;
		fpsCount++;
		if (fpsTime > 1.0) {
			swprintf(debug, 1024, L"%d bunnies %.2f FPS\n", bunnies.size(), (((float)fpsCount) / fpsTime));
			OutputDebugString(debug);

			fpsTime = 0;
			fpsCount = 0;
		}
	}

	// shutdown
	SDL_FreeSurface(image);
	SDL_DestroyWindow(window);
	SDL_Quit();

	return 0;
}