diff --git a/main.js b/main.js
index 49837d5..71a9a33 100644
--- a/main.js
+++ b/main.js
@@ -79,7 +79,7 @@ function update() {
       let ai = AI_TYPES[player.ai];
       const plan = ai.decide();
       const a = player.a = wrap(0, plan.a, 180);
-      const p = player.p = wrap(0, plan.p, maxPower);
+      const p = player.p = clamp(0, plan.p, maxPower);
       shoot = {a, p};
     }
 
@@ -366,7 +366,7 @@ function drawTrajectories() {
 
 function drawProjectile() {
   if (!projectile) return;
-  plot(foreground, clamp(0, projectile.x, W), clamp(0, projectile.y, H), 'white');
+  plot(foreground, clamp(0, projectile.x, W-1), clamp(0, projectile.y, H-1), 'white');
 }
 
 function fadeTrajectories(amount) {
diff --git a/terrain.js b/terrain.js
index f51c0b7..f75c2bf 100644
--- a/terrain.js
+++ b/terrain.js
@@ -29,8 +29,8 @@ const TERRAIN_TYPES = {
     for (let x=0; x<width; x++) {
       if (x % stepSize === 0) dy = ((random(.3, .7) * height) - cy) / stepSize;
       if (x % (stepSize/16) === 0) dy = dy - random(-1, 1);
-      const ty = clamp(0, cy + dy, height);
-      const wy = clamp(70, ty, height-70);
+      const ty = clamp(0, cy+dy, height-1);
+      const wy = clamp(70, ty, height-70-1);
       cy = wy + (ty-wy) * 0.5;
       drawRect(ctx, x, cy, 1, height-cy, ctx.color);
     }