Split LinesOfSight into separate Draw() and Update() functions.

Don't make new arrays every frame.

Partial solution to bug #41, just need to DrawIndexedPrimitives() now.

GitOrigin-RevId: 0e769d3288dce17fe174b2a1d82a99b1d9994213

Shared/LinesOfSight.cs

@@ -4,14 +4,22 @@ using System;
 
 namespace SemiColinGames {
   class LinesOfSight {
-    public static void Draw(Player player, AABB[] collisionTargets, GraphicsDevice graphics,
+
-        BasicEffect lightingEffect) {
+    const int numConePoints = 60;
-      // TODO: DrawIndexedPrimitives
-      Color color = Color.FromNonPremultiplied(new Vector4(0, 0, 1, 0.6f));
-      Vector2 eyePos = player.EyePosition;
-      int numConePoints = 60;
-      // TODO: don't new[] every frame.
     VertexPositionColor[] conePoints = new VertexPositionColor[numConePoints];
+    Color color = Color.FromNonPremultiplied(new Vector4(0, 0, 1, 0.6f));
+    VertexPositionColor[] vertices = new VertexPositionColor[numConePoints * 3];
+    VertexBuffer vertexBuffer;
+
+    public LinesOfSight(GraphicsDevice graphics) {
+      vertexBuffer = new VertexBuffer(
+           graphics, typeof(VertexPositionColor), numConePoints * 3, BufferUsage.WriteOnly);
+    }
+
+    public void Update(Player player, AABB[] collisionTargets) {
+      // TODO: DrawIndexedPrimitives
+      Vector2 eyePos = player.EyePosition;
+
       float visionRange = 150;
       float visionRangeSq = visionRange * visionRange;
       float fov = FMath.DegToRad(120);
@@ -55,18 +63,19 @@ namespace SemiColinGames {
         Color tinted = Color.FromNonPremultiplied(new Vector4(0, 0, 1, tint));
         conePoints[i] = new VertexPositionColor(new Vector3(closestHit, 0), tinted);
       }
+    }
 
-      // TODO: don't new[] every frame.
+    public void Draw(Player player, AABB[] collisionTargets, GraphicsDevice graphics,
-      VertexPositionColor[] vertices = new VertexPositionColor[numConePoints * 3];
+        BasicEffect lightingEffect) {
-      VertexPositionColor eyeVertex = new VertexPositionColor(new Vector3(eyePos, 0), color);
+
+      VertexPositionColor eyeVertex = new VertexPositionColor(
+          new Vector3(player.EyePosition, 0), color);
       for (int i = 0; i < numConePoints - 1; i++) {
         vertices[i * 3] = eyeVertex;
         vertices[i * 3 + 1] = conePoints[i];
         vertices[i * 3 + 2] = conePoints[i + 1];
       }
 
-      VertexBuffer vertexBuffer = new VertexBuffer(
-          graphics, typeof(VertexPositionColor), vertices.Length, BufferUsage.WriteOnly);
       vertexBuffer.SetData<VertexPositionColor>(vertices);
 
       graphics.SetVertexBuffer(vertexBuffer);

Shared/Shared.projitems

@@ -19,6 +19,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)IDisplay.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Levels.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Line.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)LinesOfSight.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Player.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SneakGame.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Timer.cs" />

Shared/SneakGame.cs

@@ -36,6 +36,7 @@ namespace SemiColinGames {
 
     Player player;
     World world;
+    LinesOfSight linesOfSight;
     readonly Camera camera = new Camera();
 
     public SneakGame() {
@@ -84,6 +85,7 @@ namespace SemiColinGames {
 
       player = new Player(Content.Load<Texture2D>("Ninja_Female"));
       world = new World(Content.Load<Texture2D>("grassland"), Levels.ONE_ONE);
+      linesOfSight = new LinesOfSight(GraphicsDevice);
       grasslandBg1 = Content.Load<Texture2D>("grassland_bg1");
       grasslandBg2 = Content.Load<Texture2D>("grassland_bg2");
     }
@@ -121,6 +123,7 @@ namespace SemiColinGames {
         float modelTime = (float) gameTime.ElapsedGameTime.TotalSeconds;
         Clock.AddModelTime(modelTime);
         player.Update(modelTime, input, world.CollisionTargets);
+        linesOfSight.Update(player, world.CollisionTargets);
         camera.Update(player.Position, world.Width);
       }
 
@@ -183,7 +186,7 @@ namespace SemiColinGames {
       GraphicsDevice.SetRenderTarget(lightingTarget);
       GraphicsDevice.Clear(new Color(0, 0, 0, 0f));
       lightingEffect.Projection = camera.Projection;
-      DrawFov();
+      linesOfSight.Draw(player, world.CollisionTargets, GraphicsDevice, lightingEffect);
 
       // Draw sceneTarget to screen.
       GraphicsDevice.SetRenderTarget(null);
@@ -206,77 +209,5 @@ namespace SemiColinGames {
       base.Draw(gameTime);
       drawTimer.Stop();
     }
-
-    private void DrawFov() {
-      // TODO: DrawIndexedPrimitives
-      Color color = Color.FromNonPremultiplied(new Vector4(0, 0, 1, 0.6f));
-      Vector2 eyePos = player.EyePosition;
-      int numConePoints = 60;
-      // TODO: don't new[] every frame.
-      VertexPositionColor[] conePoints = new VertexPositionColor[numConePoints];
-      float visionRange = 150;
-      float visionRangeSq = visionRange * visionRange;
-      float fov = FMath.DegToRad(120);
-      float fovStep = fov / (numConePoints - 1);
-
-      Vector2 ray = new Vector2(visionRange * player.GetFacing, 0);
-      if (player.GetPose == Player.Pose.Stretching) {
-        ray = ray.Rotate(player.GetFacing * FMath.DegToRad(-30));
-      }
-      if (player.GetPose == Player.Pose.Crouching) {
-        ray = ray.Rotate(player.GetFacing * FMath.DegToRad(30));
-      }
-
-      for (int i = 0; i < conePoints.Length; i++) {
-        float angle = -fov / 2 + fovStep * i;
-        Vector2 rotated = ray.Rotate(angle);
-        Vector2 closestHit = Vector2.Add(eyePos, rotated);
-        float hitTime = 1f;
-
-        Vector2 halfTileSize = new Vector2(World.TileSize / 2.0f, World.TileSize / 2.0f);
-        for (int j = 0; j < world.CollisionTargets.Length; j++) {
-          AABB box = world.CollisionTargets[j];
-          if (Math.Abs(box.Position.X - player.Position.X) > visionRange + halfTileSize.X) {
-            continue;
-          }
-          Vector2 delta = Vector2.Add(halfTileSize, Vector2.Subtract(box.Position, eyePos));
-          if (delta.LengthSquared() > visionRangeSq) {
-            continue;
-          }
-          Hit? maybeHit = box.IntersectSegment(eyePos, rotated);
-          if (maybeHit != null) {
-            Hit hit = maybeHit.Value;
-            if (hit.Time < hitTime) {
-              hitTime = hit.Time;
-              closestHit = hit.Position;
-            }
-          }
-        }
-
-        float tint = 0.6f - hitTime / 2;
-        Color tinted = Color.FromNonPremultiplied(new Vector4(0, 0, 1, tint));
-        conePoints[i] = new VertexPositionColor(new Vector3(closestHit, 0), tinted);
-      }
-
-      // TODO: don't new[] every frame.
-      VertexPositionColor[] vertices = new VertexPositionColor[numConePoints * 3];
-      VertexPositionColor eyeVertex = new VertexPositionColor(new Vector3(eyePos, 0), color);
-      for (int i = 0; i < numConePoints - 1; i++) {
-        vertices[i * 3] = eyeVertex;
-        vertices[i * 3 + 1] = conePoints[i];
-        vertices[i * 3 + 2] = conePoints[i + 1];
-      }
-
-      VertexBuffer vertexBuffer = new VertexBuffer(
-          GraphicsDevice, typeof(VertexPositionColor), vertices.Length, BufferUsage.WriteOnly);
-      vertexBuffer.SetData<VertexPositionColor>(vertices);
-
-      GraphicsDevice.SetVertexBuffer(vertexBuffer);
-
-      foreach (EffectPass pass in lightingEffect.CurrentTechnique.Passes) {
-        pass.Apply();
-        GraphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, vertices.Length / 3);
-      }
-    }
   }
 }