initial commit

2 files changed, 169 insertions, 0 deletions

diff --git a/life.c b/life.c
new file mode 100755
index 0000000..de8e1b8
--- /dev/null
+++ b/life.c
@@ -0,0 +1,142 @@
+#define SDL_DISABLE_IMMINTRIN_H
+#include <stdlib.h>
+#include <time.h>
+#include "SDL2/SDL.h"
+
+#define HEIGHT 80
+#define WIDTH 130
+#define SPF 1000 / 30
+
+void wrap(int *a, int w) {
+	if (*a < 0) *a = w - 1;
+	else if (*a > w - 1) *a = 0;
+}
+
+int place(int x, int y) {
+	wrap(&x, WIDTH);
+	wrap(&y, HEIGHT);
+	return x + y * WIDTH;
+}
+
+int neighbors(char *cells, int x, int y) {
+	int count = 0;
+	for (int i = -1; i <= 1; i++)
+		for (int j = -1; j <= 1; j++) {
+			if (i == 0 && j == 0) continue;
+			if (cells[place(i + x, j + y)] & 2) count++;
+		}
+	return count;
+}
+
+int resize(SDL_Renderer *r) {
+	int w, h;
+	SDL_GetRendererOutputSize(r, &w, &h);
+	return w / WIDTH < h / HEIGHT ? w / WIDTH : h / HEIGHT;
+}
+
+char inside(int n, char *v) {
+	char result = 0;
+	if (n >= 0 && n <= 8)
+		for (int i = 0; i < strlen(v); i++) {
+			result |= (n == v[i] - 48);
+		}
+	return result;
+}
+
+void init(char *cells, char random) {
+	for (int x = 0; x < WIDTH; x++) {
+		for (int y = 0; y < HEIGHT; y++) {
+			if (random) cells[place(x, y)] ^= 3 * (rand() % 2);
+			else cells[place(x, y)] = 0;
+		}
+	}
+}
+
+int main(int argc, char **argv) {
+	if (argc != 3) exit(1);
+	srand(time(0));
+	SDL_Init(SDL_INIT_VIDEO);
+	SDL_Window *w = SDL_CreateWindow(argv[0], 0, 0, 800, 600, SDL_WINDOW_RESIZABLE);
+	SDL_Renderer *r = SDL_CreateRenderer(w, -1, SDL_RENDERER_ACCELERATED);
+	int cellsize = resize(r);
+	int oldtime = 0;
+	int newtime = 0;
+	char paused = 0;
+	char grid = 1;
+	int symtime = 0;
+	int rendertime = 0;
+	char cells[WIDTH * HEIGHT];
+	init(cells, 1);
+	SDL_Event e;
+	while (e.type != SDL_QUIT) {
+		SDL_Delay(SPF);
+		while (SDL_PollEvent(&e)) {
+			if (e.window.event == SDL_WINDOWEVENT_RESIZED)
+				cellsize = resize(r);
+			if (e.key.state == SDL_PRESSED) {
+				if (e.key.keysym.sym == SDLK_BACKSPACE)
+					init(cells, 0);
+				if (e.key.keysym.sym == SDLK_RETURN)
+					init(cells, 1);
+				if (e.key.keysym.sym == SDLK_SPACE)
+					paused ^= 1;
+				if (e.key.keysym.sym == SDLK_PERIOD) {
+					paused = 1;
+					symtime = SPF + 1;
+				}
+				if (e.key.keysym.sym == SDLK_g) {
+					grid ^= 1;
+				}
+			}
+			int mx, my;
+			int mstate = SDL_GetMouseState(&mx, &my);
+			if (mstate & SDL_BUTTON(SDL_BUTTON_RIGHT)) {
+				cells[place(mx / cellsize, my / cellsize)] = 0;
+				paused = 1;
+			} else if (mstate & SDL_BUTTON(SDL_BUTTON_LEFT)) {
+				cells[place(mx / cellsize, my / cellsize)] = 3;
+				paused = 1;
+			}
+		};
+		oldtime = newtime;
+		newtime = SDL_GetTicks();
+		if (!paused) symtime += newtime - oldtime;
+		if (symtime > SPF) {
+			symtime = 0;
+			for (int x = 0; x < WIDTH; x++)
+				for (int y = 0; y < HEIGHT; y++) {
+					int n = neighbors(cells, x, y);
+					if (inside(n, argv[1]) && ~cells[place(x, y)] & 2)
+						cells[place(x, y)] |= 1; // Birth
+					if (!inside(n, argv[2]) && cells[place(x, y)] & 2)
+						cells[place(x, y)] &= 2; // Death
+				}
+			for (int i = 0; i < WIDTH * HEIGHT; i++)
+			       	cells[i] = cells[i] & 1 ? 3 : 0;
+		}
+		rendertime += newtime - oldtime;
+		if (rendertime > SPF) {
+			rendertime = 0;
+			SDL_SetRenderDrawColor(r, 160, 160, 160, 255);
+			SDL_RenderClear(r);
+			for (int x = 0; x < WIDTH; x++)
+				for (int y = 0; y < HEIGHT; y++) {
+					SDL_Rect rect = { x * cellsize, y * cellsize, cellsize, cellsize };
+					if (grid && cellsize > 1) {
+						rect.x += 1;
+						rect.y += 1;
+						rect.w -= 1;
+						rect.h -= 1;
+					}
+					if (cells[place(x, y)]) SDL_SetRenderDrawColor(r, 0, 0, 0, 255);
+					else SDL_SetRenderDrawColor(r, 255, 255, 255, 255);
+					SDL_RenderFillRect(r, &rect);
+				}
+			SDL_RenderPresent(r);
+		}
+	}
+	SDL_DestroyRenderer(r);
+	SDL_DestroyWindow(w);
+	SDL_Quit();
+	return 0;
+}
diff --git a/readme.md b/readme.md
new file mode 100755
index 0000000..f251d95
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,27 @@
+Compilation: gcc -o life -lSDL2 life.c
+
+Usage: life B S
+
+	B                   neighbors needed to be born
+
+	S                   neighbors needed to stay alive
+
+Example: life 3 23
+
+	Each cell becomes alive if it has 3 neighbors and stays alive if it has 2 or 3 neighbors.
+
+Keybindings:
+
+	enter               restart with random seed
+
+	backspace           clear screen
+
+	space               pause
+
+	period              step
+
+	g                   toggle grid
+
+	left mouse button   draw
+
+	right mouse button  erase