make NPCs stop at the edge of platforms

Shared/LinesOfSight.cs

@@ -19,7 +19,7 @@ namespace SemiColinGames {
     // The number of total triangles drawn is one less than the number of edge points.
     readonly int[] indices = new int[(NUM_EDGE_VERTICES - 1) * 3];
 
-    Color color = Color.FromNonPremultiplied(new Vector4(1, 0, 0, 0.5f));
+    Color color = Color.FromNonPremultiplied(new Vector4(1, 0, 0, 0.25f));
 
     public LinesOfSight(GraphicsDevice graphics) {
       for (int i = 0; i < MAX_NPCS; i++) {
@@ -88,11 +88,13 @@ namespace SemiColinGames {
           }
         }
 
-        coneVertices[index][i + 1] = new VertexPositionColor(new Vector3(closestHit, 0), color);
+        coneVertices[index][i + 1] = new VertexPositionColor(
+            new Vector3((int) closestHit.X, (int) closestHit.Y, 0), color);
       }
     }
 
     public void Draw(GraphicsDevice graphics, BasicEffect lightingEffect) {
+      // Draw the cones themselves.
       for (int i = 0; i < NUM_EDGE_VERTICES - 1; i++) {
         indices[i * 3] = 0;
         indices[i * 3 + 1] = i + 1;
@@ -113,6 +115,31 @@ namespace SemiColinGames {
           graphics.DrawIndexedPrimitives(PrimitiveType.TriangleList, 0, 0, indices.Length / 3);
         }
       }
+
+      // Draw the outlines of the cones.
+      for (int i = 0; i <= NUM_EDGE_VERTICES; i++) {
+        indices[i] = i;
+      }
+      indices[NUM_EDGE_VERTICES + 1] = 0;
+
+      for (int npcIndex = 0; npcIndex < MAX_NPCS; npcIndex++) {
+        if (!coneEnabled[npcIndex]) {
+          continue;
+        }
+        vertexBuffer.SetData(coneVertices[npcIndex]);
+        indexBuffer.SetData(indices);
+        graphics.SetVertexBuffer(vertexBuffer);
+        graphics.Indices = indexBuffer;
+
+        foreach (EffectPass pass in lightingEffect.CurrentTechnique.Passes) {
+          pass.Apply();
+          // TODO: just draw a single opaque outline.
+          for (int i = 0; i < 4; i++) {
+            graphics.DrawIndexedPrimitives(
+                PrimitiveType.LineStrip, 0, 0, NUM_EDGE_VERTICES + 1);
+          }
+        }
+      }
     }
   }
 }

Shared/NPC.cs

@@ -26,8 +26,9 @@ namespace SemiColinGames {
     public string Update(NPC npc, float modelTime, World world) {
       int moveSpeed = 120;
       int desiredX = npc.Position.X + (int) (moveSpeed * npc.Facing * modelTime);
+      int testPoint = desiredX + 12 * npc.Facing;
       // TODO: define the box modularly & correctly.
-      AABB npcBox = new AABB(new Vector2(desiredX, npc.Position.Y), new Vector2(1, 33));
+      AABB npcBox = new AABB(new Vector2(testPoint, npc.Position.Y), new Vector2(1, 33));
       Debug.AddRect(npcBox, Color.Cyan);
       bool foundBox = false;
       foreach (AABB box in world.CollisionTargets) {