RosettaCodeData/Task/Langtons-ant/JavaScript/langtons-ant-4.js

69 lines
1.6 KiB
JavaScript

///////////////////
// LODASH IMPORT //
///////////////////
// import all lodash functions to the main namespace, but isNaN not to cause conflicts
_.each(_.keys(_), k => window[k === 'isNaN' ? '_isNaN' : k] = _[k]);
const
WORLD_WIDTH = 100,
WORLD_HEIGHT = 100,
PIXEL_SIZE = 4,
DIRTY_COLOR = '#000',
VIRGIN_COLOR = '#fff',
RUNS = 10000,
SPEED = 50,
// up right down left
DIRECTIONS = [0, 1, 2, 3],
displayWorld = (world) => each(world, (row, rowidx) => {
each(row, (cell, cellidx) => {
canvas.fillStyle = cell === 1 ? DIRTY_COLOR : VIRGIN_COLOR;
canvas.fillRect(rowidx * PIXEL_SIZE, cellidx * PIXEL_SIZE, PIXEL_SIZE, PIXEL_SIZE);
});
}),
moveAnt = (world, ant) => {
world[ant.x][ant.y] = world[ant.x][ant.y] === 1 ? 0 : 1;
ant.dir = DIRECTIONS[(4 + ant.dir + (world[ant.x][ant.y] === 0 ? 1 : -1)) % 4];
switch (ant.dir) {
case DIRECTIONS[0]:
ant.y -= 1;
break;
case DIRECTIONS[1]:
ant.x -= 1;
break;
case DIRECTIONS[2]:
ant.y += 1;
break;
case DIRECTIONS[3]:
ant.x += 1;
break;
}
return [world, ant];
},
updateWorld = (world, ant, runs) => {
[world, ant] = moveAnt(world, ant);
displayWorld(world);
if (runs > 0) setTimeout(partial(updateWorld, world, ant, --runs), SPEED);
},
canvas = document.getElementById('c').getContext('2d');
let
world = map(range(WORLD_HEIGHT), i => map(range(WORLD_WIDTH), partial(identity, 0))),
ant = {
x: WORLD_WIDTH / 2,
y: WORLD_HEIGHT / 2,
dir: DIRECTIONS[0]
};
canvas.canvas.width = WORLD_WIDTH * PIXEL_SIZE;
canvas.canvas.height = WORLD_HEIGHT * PIXEL_SIZE;
updateWorld(world, ant, RUNS);