gol.c

   1 #include <SDL2/SDL.h>
   2 #include <stdio.h>
   3 #include "array.h"
   4 #include "tick.h"
   5
   6 const int ZOOM_LEVELS[10] = {1, 2, 3, 5, 8, 12, 20, 30};
   7 const unsigned int MAX_ZOOM_LEVEL = 7;
   8
   9 struct viewport {
  10         int origin_x;
  11         int origin_y;
  12         int zoom_level;
  13 };
  14
  15 void quit(int e_st)
  16 {
  17         SDL_Quit();
  18         exit(e_st);
  19 }
  20
  21 int redraw_screen(struct gol_board *state, SDL_Surface *screen, struct viewport viewport);
  22
  23 int handle_mousedown(struct gol_board *state, struct viewport viewport, SDL_Event e);
  24
  25 int main(int argc, char* args[])
  26 {
  27         struct gol_board state = {
  28                 .live_cells = NULL,
  29                 .n = 0,
  30                 .size = 10,
  31                 .max_x = 0,
  32                 .min_x = 0,
  33                 .max_y = 0,
  34                 .min_y = 0
  35         };
  36         SDL_Window *window = NULL;
  37         SDL_Surface *screen = NULL;
  38
  39         char finished = 0;
  40         char tick = 0;
  41         char redraw = 1;
  42
  43         // The coordinates of the cell to draw in the bottom left corner of the
  44         // canvas
  45         struct viewport viewport = {0, 0, 4};
  46
  47         SDL_Event e;
  48
  49         state.live_cells = malloc(10 * sizeof(int_least32_t));
  50         if (!state.live_cells) {
  51                 return 1;
  52         }
  53
  54         gol_vivify(&state, 10, 10);
  55
  56         if (SDL_Init(SDL_INIT_EVERYTHING) < 0) {
  57                 quit(1);
  58         }
  59
  60         window = SDL_CreateWindow("SDL Tutorial",
  61                                   SDL_WINDOWPOS_UNDEFINED,
  62                                   SDL_WINDOWPOS_UNDEFINED,
  63                                   640,
  64                                   480,
  65                                   SDL_WINDOW_SHOWN);
  66         if (!window) {
  67                 quit(1);
  68         }
  69
  70         screen = SDL_GetWindowSurface(window);
  71         if (!screen) {
  72                 quit(1);
  73         }
  74         SDL_UpdateWindowSurface(window);
  75
  76         while (!finished) {
  77                 while (SDL_PollEvent(&e) != 0) {
  78                         if (e.type == SDL_QUIT) {
  79                                 finished = 1;
  80                         } else if (e.type == SDL_KEYDOWN) {
  81                                 switch (e.key.keysym.sym) {
  82                                 case SDLK_q:
  83                                 case SDLK_x:
  84                                         finished = 1;
  85                                         break;
  86                                 case SDLK_PLUS:
  87                                 case SDLK_EQUALS:
  88                                         if (viewport.zoom_level != MAX_ZOOM_LEVEL)
  89                                                 viewport.zoom_level++;
  90                                         redraw = 1;
  91                                         break;
  92                                 case SDLK_MINUS:
  93                                 case SDLK_UNDERSCORE:
  94                                         if (viewport.zoom_level != 0)
  95                                                 viewport.zoom_level--;
  96                                         redraw = 1;
  97                                         break;
  98                                 case SDLK_SPACE:
  99                                         tick = 1;
 100                                 default:
 101                                         break;
 102                                 }
 103                         } else if (e.type == SDL_MOUSEBUTTONDOWN) {
 104                                 handle_mousedown(&state, viewport, e);
 105                                 redraw = 1;
 106                         }
 107                 }
 108                 if (tick) {
 109                         tick = 0;
 110                         gol_tick(&state);
 111                         redraw = 1;
 112                 }
 113                 if (redraw) {
 114                         redraw = 0;
 115                         redraw_screen(&state, screen, viewport);
 116                         SDL_UpdateWindowSurface(window);
 117                 }
 118         }
 119
 120         SDL_DestroyWindow(window);
 121         quit(0);
 122 }
 123
 124
 125 int redraw_screen(struct gol_board *state, SDL_Surface *screen,
 126         struct viewport viewport)
 127 {
 128         SDL_Rect rect;
 129         int i, j, ppc;
 130         char is_live;
 131
 132         ppc = ZOOM_LEVELS[viewport.zoom_level];
 133
 134         SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 255, 255, 255));
 135
 136         for (i = viewport.origin_x;
 137              i < (screen->w/ppc) + viewport.origin_x;
 138              ++i) {
 139                 for (j = viewport.origin_y;
 140                      j < (screen->h/ppc) + viewport.origin_y;
 141                      ++j) {
 142                         if (gol_is_live(state, i, j, &is_live) && is_live) {
 143                                 rect = (SDL_Rect) {
 144                                         ((i - viewport.origin_x) * ppc),
 145                                         ((j - viewport.origin_y) * ppc),
 146                                         ppc,
 147                                         ppc
 148                                 };
 149                                 SDL_FillRect(screen, &rect,
 150                                         SDL_MapRGB(screen->format, 0, 0, 0));
 151                         }
 152                 }
 153         }
 154         return 0;
 155 }
 156
 157 int handle_mousedown(struct gol_board *state, struct viewport viewport, SDL_Event e)
 158 {
 159         int x, y;
 160         char is_live;
 161         x = e.button.x/ZOOM_LEVELS[viewport.zoom_level] - viewport.origin_x;
 162         y = e.button.y/ZOOM_LEVELS[viewport.zoom_level] - viewport.origin_y;
 163
 164         gol_is_live(state, x, y, &is_live);
 165         if (!is_live)
 166                 gol_vivify(state, x, y);
 167
 168         return 1;
 169 }