init

js/gravity.js

@@ -0,0 +1,99 @@
+/*
+    Code for gravity.
+
+    mass: Density (in kg/cm^3)
+    fluid: Spread of substance
+    saturation: Maximum mass for gravity reactions to occur
+*/
+
+function gravity(event, mass, fluid, saturation) {
+    if (event.type != 'tick') return;
+    
+    let cx = event.data[0];
+    let cy = event.data[1];
+    let chunks = event.canvas;
+
+    let dir = [0, 0];
+    let force = [0,0];
+    let density = 0;
+
+    let currBlock = chunks.getBlock(cx, cy);
+
+
+    for (let x = -1; x < 2; x ++) {
+        for (let y = -1; y < 2; y++) {
+            let blok = chunks.getBlock(cx + x, cy + y);
+            
+            if (blok == -1) continue;
+
+            let mass2 = mainTiles.tiles[blok].attributes.mass;
+
+            density += mass2;
+            if (density > saturation) break;
+
+            if (blok == currBlock) continue;
+
+            let massDiff = (mass / mass2) - (mass2 / mass);
+            let x2 = x / fluid;
+            let dirDiff = (y - 1 + fluid) / (1/8 * (x2 * x2 - y * y + 8) * (x2 * x2 + y * y));
+
+
+            if (y == 0 && x == 0) dirDiff = 0;
+            if (isNaN(dirDiff)) dirDiff = 0;
+
+            force[0] += massDiff * x2;
+            force[1] += massDiff * dirDiff * y;
+        }
+        if (density > saturation) break;
+    }
+
+    dir[0] = (Math.abs(force[0]) < .5) ? 0 : Math.sign(force[0]);
+    dir[1] = (Math.abs(force[1]) < .5) ? 0 : Math.sign(force[1]);
+
+    if (density > saturation ) {
+        return;
+    }
+
+    let offBlock = chunks.getBlock(cx + dir[0], cy + dir[1]);
+
+    if (currBlock == offBlock && density <= saturation) {
+        dir[0] = Math.sign(force[0]);
+        offBlock = chunks.getBlock(cx + dir[0], cy + dir[1]);
+    }
+
+    if (currBlock == -1 || offBlock == -1 || currBlock == offBlock ||offBlock == undefined || mainTiles.tiles[offBlock].attributes.saturation / 9 < mass || chunks.noTick[(cx+dir[0])*chunks.height + (cy+dir[1])]) return;
+
+
+    
+    if (!canGravity[offBlock]) return;
+
+    chunks.noTick[cx*chunks.height + cy] = true;
+    chunks.noTick[(cx+dir[0])*chunks.height + (cy+dir[1])] = true;
+
+    chunks.setBlock(cx, cy, offBlock);
+    chunks.setBlock(cx + dir[0], cy + dir[1], currBlock);
+
+    let t = chunks.getBlock(cx, cy,true);
+    let t2 = chunks.getBlock(cx + dir[0], cy + dir[1],true);
+    
+    if (t != undefined && t2 != undefined) {
+        chunks.setBlock(cx, cy,t2, true);
+        chunks.setBlock(cx + dir[0], cy + dir[1], t, true);
+    }
+
+    return true;
+}
+
+Tile.prototype.gravity = function (mass, fluid, saturation) {
+    this.interactions.push(function (event) {
+        gravity(event, mass, fluid, saturation)
+    });
+    this.attributes.mass = mass;
+    this.attributes.saturation = saturation;
+    return this;
+}
+
+Tile.prototype.unGravity = function () {
+    this.attributes.noGravity = true;
+    return this;
+}