fix: Improve detection/placement when slices are falling and landing

In high CPU utilization situations (like level 4), slices would fall too
far or "clump" together while falling. By reducing floor precision,
floors are detected even in higher CPU utilization situations.

We also optimize slice-bumps-slice detection by only have one slice bit
(the first one) check for bumping into other slice bits, instead of all
four of them, which just causes multiple collisions.

Then, to counter the reduced precision, we snap the slices to the exact
position of the floor so that placement is pixel-perfect.

src/objects/Slice.ts

@@ -67,7 +67,7 @@ export function addSlice(options: Partial<SliceCompOpt> = {}): Slice {
    return add([
       anchor('center'),
       pos(opt.pos),
-      canDetect({ floorPrecision: 0.5 }),
+      canDetect({ floorPrecision: 1.25 }),
       slice(opt),
    ]);
 }
@@ -120,7 +120,7 @@ export function slice(options: Partial<SliceCompOpt> = {}): SliceComp {
       },
       fall(newFallCount=0) {
          if (this.isFalling || this.isOnPlate) return;
-         this.pos = this.pos.add(0, 1);
+         this.pos = this.pos.add(0, 1.3);
          dir.y = FALL_SPEED;
          fallCount = newFallCount<0 ? 0 : newFallCount;
          play('burger_drop', { volume: getVol(DATA_SFX_VOL) });
@@ -129,6 +129,12 @@ export function slice(options: Partial<SliceCompOpt> = {}): SliceComp {
       land() {
          if (dir.isZero()) return;
          dir.y = 0;
+         // Snap to the closest floor for exact placement
+         const closestFloor = this.getClosestObject(this.isOnPlate ? 'plates' : 'floors');
+         if (closestFloor && Math.abs(closestFloor.pos.y-this.pos.y)<1.3) {
+            this.moveTo(closestFloor.pos);
+         }
+         // Reset slice bits to non-trampled position
          this.children.forEach(child=>child.pos.y = Y_NORMAL);
          play('burger_floor', { volume: getVol(DATA_SFX_VOL) });
          enemies.forEach(enemy=>{
@@ -155,7 +161,7 @@ export function slice(options: Partial<SliceCompOpt> = {}): SliceComp {
                "slice-bit"
             ]);
          }
-         this.children.forEach(child=>{
+         this.children.forEach((child, idx)=>{
             // Player can trample slices
             child.onCollide('player', ()=>{
                if (child.pos.y !== Y_TRAMPLED) play('burger_step', { volume: getVol(DATA_SFX_VOL) });
@@ -169,18 +175,18 @@ export function slice(options: Partial<SliceCompOpt> = {}): SliceComp {
                enemy.squash();
             });
             // Slices will bump other slices while falling
-            child.onCollide('slice-bit', (sliceBit)=>{
+            if (idx===0) child.onCollide('slice-bit', (sliceBit)=>{
                if (!sliceBit.isOverlapping(child)) return;
                const otherSlice = sliceBit.parent as Slice;
                if (otherSlice.isOnPlate) {
                   this.isOnPlate = true;
+                  this.pos = this.pos.add(0, -4);
                   this.land();
-                  this.pos = this.pos.add(0, -1);
                   return;
                }
                sliceBit.parent.fall(fallCount);
-               this.pos.y-=1.5
-               enemies.forEach(enemy=>enemy.pos.y-=1.5);
+               this.pos.y-=3;
+               enemies.forEach(enemy=>enemy.pos.y-=3);
             });
          });
       },