SandGame/smoke.js

import { grid, cols, rows } from './state.js';
import { config } from './config.js';
import { move, swap } from './actions.js';

export function updateSmoke(x, y, cell) {
    // Check lifespan / dissipation
    if (cell.lifespan !== undefined) {
        cell.lifespan--;
        if (cell.lifespan <= 0) {
            grid[x][y] = null;
            return;
        }
    } else if (Math.random() < config.smoke.dissipateChance) {
        grid[x][y] = null;
        return;
    }

    const above = y - 1;
    if (above < 0) {
        // Escapes into sky
        grid[x][y] = null;
        return;
    }

    // Try rising
    const cellAbove = grid[x][above];
    if (!cellAbove) {
        move(x, y, x, above);
        // Slight drift while rising
        if (Math.random() < 0.4) {
            const dir = Math.random() < 0.5 ? -1 : 1;
            const nx = x + dir;
            if (nx >= 0 && nx < cols && !grid[nx][above]) {
                move(x, above, nx, above);
            }
        }
        return;
    }

    // Bubble through liquids
    if (cellAbove.type === 'water' || cellAbove.type === 'acid' || cellAbove.type === 'oil') {
        swap(x, y, x, above);
        return;
    }

    // Drifting sideways if blocked above
    const leftIdx = x - 1;
    const rightIdx = x + 1;
    const leftFree = leftIdx >= 0 && !grid[leftIdx][y];
    const rightFree = rightIdx < cols && !grid[rightIdx][y];

    if (leftFree && rightFree) {
        const dir = Math.random() < 0.5 ? -1 : 1;
        move(x, y, x + dir, y);
    } else if (leftFree) {
        move(x, y, leftIdx, y);
    } else if (rightFree) {
        move(x, y, rightIdx, y);
    }
}