LinesOfSight: draw outline separately, with a different color

Shared/LinesOfSight.cs

@@ -14,16 +14,19 @@ namespace SemiColinGames {
     readonly VertexBuffer vertexBuffer;
     readonly IndexBuffer indexBuffer;
     readonly bool[] coneEnabled = new bool[MAX_NPCS];
-    // coneVertices[i][0] is the eye position; the rest are the edge vertices.
-    readonly VertexPositionColor[][] coneVertices = new VertexPositionColor[MAX_NPCS][];
+    // coneFillVertices[i][0] is the eye position; the rest are the edge vertices.
+    readonly VertexPositionColor[][] coneFillVertices = new VertexPositionColor[MAX_NPCS][];
+    readonly VertexPositionColor[][] coneOutlineVertices = new VertexPositionColor[MAX_NPCS][];
     // 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, 0.25f));
+    Color fill = Color.FromNonPremultiplied(new Vector4(1, 1, 1, 0.1f));
+    Color outline = Color.FromNonPremultiplied(new Vector4(1, 0, 0, 0.5f));
 
     public LinesOfSight(GraphicsDevice graphics) {
       for (int i = 0; i < MAX_NPCS; i++) {
-        coneVertices[i] = new VertexPositionColor[NUM_EDGE_VERTICES + 1];
+        coneFillVertices[i] = new VertexPositionColor[NUM_EDGE_VERTICES + 1];
+        coneOutlineVertices[i] = new VertexPositionColor[NUM_EDGE_VERTICES + 1];
       }
 
       vertexBuffer = new VertexBuffer(
@@ -61,7 +64,10 @@ namespace SemiColinGames {
       float visionRangeSq = visionRange * visionRange;
       float fovStep = fov / (NUM_EDGE_VERTICES - 1);
 
-      coneVertices[index][0] = new VertexPositionColor(new Vector3(npc.EyePosition, 0), color);
+      coneFillVertices[index][0] =
+          new VertexPositionColor(new Vector3(npc.EyePosition, 0), fill);
+      coneOutlineVertices[index][0] =
+          new VertexPositionColor(new Vector3(npc.EyePosition, 0), outline);
       for (int i = 0; i < NUM_EDGE_VERTICES; i++) {
         float angle = -fov / 2 + fovStep * i;
         Vector2 rotated = ray.Rotate(angle);
@@ -87,8 +93,10 @@ namespace SemiColinGames {
           }
         }
 
-        coneVertices[index][i + 1] = new VertexPositionColor(
-            new Vector3((int) closestHit.X, (int) closestHit.Y, 0), color);
+        coneFillVertices[index][i + 1] = new VertexPositionColor(
+            new Vector3((int) closestHit.X, (int) closestHit.Y, 0), fill);
+        coneOutlineVertices[index][i + 1] = new VertexPositionColor(
+            new Vector3((int) closestHit.X, (int) closestHit.Y, 0), outline);
       }
     }
 
@@ -104,7 +112,7 @@ namespace SemiColinGames {
         if (!coneEnabled[npcIndex]) {
           continue;
         }
-        vertexBuffer.SetData(coneVertices[npcIndex]);
+        vertexBuffer.SetData(coneFillVertices[npcIndex]);
         indexBuffer.SetData(indices);
         graphics.SetVertexBuffer(vertexBuffer);
         graphics.Indices = indexBuffer;
@@ -125,18 +133,15 @@ namespace SemiColinGames {
         if (!coneEnabled[npcIndex]) {
           continue;
         }
-        vertexBuffer.SetData(coneVertices[npcIndex]);
+        vertexBuffer.SetData(coneOutlineVertices[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);
-          }
+          graphics.DrawIndexedPrimitives(
+              PrimitiveType.LineStrip, 0, 0, NUM_EDGE_VERTICES + 1);
         }
       }
     }