Shared/Geometry.cs

@@ -29,12 +29,12 @@ namespace SemiColinGames {
       return degToRad[degrees];
     }
 
-    public static float Sin(double radians) {
-      return (float) Math.Sin(radians);
+    public static float Sin(double degrees) {
+      return (float) Math.Sin(degrees);
     }
 
-    public static float Cos(double radians) {
-      return (float) Math.Cos(radians);
+    public static float Cos(double degrees) {
+      return (float) Math.Cos(degrees);
     }
 
     public static T Clamp<T>(T value, T min, T max) where T : IComparable {
@@ -139,6 +139,7 @@ namespace SemiColinGames {
         return null;
       }
 
+      // TODO: which of delta/normal/hitPos do we actually care about?
       if (px < py) {
         int sign = Math.Sign(dx);
         Vector2 delta = new Vector2(px * sign, 0);
@@ -184,13 +185,14 @@ namespace SemiColinGames {
       Vector2 normal = nearTimeX > nearTimeY ?
           new Vector2(-signX, 0) :
           new Vector2(0, -signY);
-      Vector2 hitDelta = Vector2.Multiply(delta, -(1.0f - hitTime));
-      Vector2 hitPos = Vector2.Add(pos, Vector2.Multiply(delta, hitTime));
+      // TODO: replace these with Vector2.Multiply (etc)
+      Vector2 hitDelta = new Vector2((1.0f - hitTime) * -delta.X, (1.0f - hitTime) * -delta.Y);
+      Vector2 hitPos = new Vector2(pos.X + delta.X * hitTime, pos.Y + delta.Y * hitTime);
       return new Hit(this, hitPos, hitDelta, normal, hitTime);
     }
 
     public Sweep Sweep(AABB box, Vector2 delta) {
-      // Fast-path case if the other box is static.
+      // fast-path case if the other box is static
       if (delta.X == 0 && delta.Y == 0) {
         Hit? staticHit = Intersect(box);
         // TODO: I don't understand the original source here, but I think this is correct.
@@ -201,16 +203,18 @@ namespace SemiColinGames {
         return new Sweep(null, Vector2.Add(box.Position, delta), 1);
       }
       Hit hit = (Hit) maybeHit;
-      Vector2 hitPos = Vector2.Add(box.Position, Vector2.Multiply(delta, hit.Time));
+      Vector2 hitPos = new Vector2(
+        box.Position.X + delta.X * hit.Time,
+        box.Position.Y + delta.Y * hit.Time);
+      Vector2 direction = Vector2.Normalize(delta);
       // TODO: why is this calculation made, and then thrown away?
-      // Vector2 direction = Vector2.Normalize(delta);
-      // Vector2 sweepHitPos = new Vector2(
-      //   FMath.Clamp(hit.Position.X + direction.X * box.HalfSize.X,
-      //       Position.X - HalfSize.X,
-      //       Position.X + HalfSize.X),
-      //   FMath.Clamp(hit.Position.Y + direction.Y * box.HalfSize.Y,
-      //       Position.Y - HalfSize.Y,
-      //       Position.Y + HalfSize.Y));
+      Vector2 sweepHitPos = new Vector2(
+        FMath.Clamp(hit.Position.X + direction.X * box.HalfSize.X,
+            Position.X - HalfSize.X,
+            Position.X + HalfSize.X),
+        FMath.Clamp(hit.Position.Y + direction.Y * box.HalfSize.Y,
+            Position.Y - HalfSize.Y,
+            Position.Y + HalfSize.Y));
       return new Sweep(hit, hitPos, hit.Time);
     }
   }