Make lighting use all cores

KeepersCompound.LGS/Database/Chunks/WorldRep.cs

@@ -243,6 +243,32 @@ public class WorldRep : IChunk
                 Pixels[idx + 3] = 255;
             }
 
+            public void AddLight(int layer, int x, int y, Vector3 color, float strength, bool hdr)
+            {
+                if (hdr)
+                {
+                    strength /= 2.0f;
+                }
+
+                // We need to make sure we don't go over (255, 255, 255).
+                // If we just do Max(color, (255, 255, 255)) then we change
+                // the hue/saturation of coloured lights. Got to make sure we
+                // maintain the colour ratios.
+                var c = color * strength;
+                var ratio = 0.0f;
+                foreach (var e in new float[] { c.X, c.Y, c.Z })
+                {
+                    ratio = Math.Max(ratio, e / 255.0f);
+                }
+
+                if (ratio > 1.0f)
+                {
+                    c /= ratio;
+                }
+
+                AddLight(layer, x, y, (byte)c.X, (byte)c.Y, (byte)c.Z);
+            }
+
             public readonly void Write(BinaryWriter writer)
             {
                 writer.Write(Pixels);

KeepersCompound.Lightmapper/Program.cs

@@ -52,7 +52,7 @@ class Program
         if (!mis.Chunks.TryGetValue("RENDPARAMS", out var rendParamsRaw))
             return;
         var ambient = ((RendParams)rendParamsRaw).ambientLight * 255;
-        Timing.TimeStage("Light", () => CastScene(scene, worldRep, [.. lights], ambient));
+        Timing.TimeStage("Light", () => CastSceneParallel(scene, worldRep, [.. lights], ambient));
 
         var dir = Path.GetDirectoryName(misPath);
         var filename = Path.GetFileNameWithoutExtension(misPath);
@@ -214,16 +214,12 @@ class Program
         return new TriangleMesh([.. vertices], [.. indices]);
     }
 
-    private static void CastScene(Raytracer scene, WorldRep wr, Light[] lights, Vector3 ambientLight)
+    private static void CastSceneParallel(Raytracer scene, WorldRep wr, Light[] lights, Vector3 ambientLight)
     {
         var hdr = wr.DataHeader.LightmapFormat == 2;
 
-        var cells = wr.Cells;
+        Parallel.ForEach(wr.Cells, cell =>
-        for (var cellIdx = 0; cellIdx < cells.Length; cellIdx++)
         {
-            Console.Write($"\rLighting cell... {cellIdx + 1}/{cells.Length}");
-
-            var cell = cells[cellIdx];
             var numPolys = cell.PolyCount;
             var numRenderPolys = cell.RenderPolyCount;
             var numPortalPolys = cell.PortalPolyCount;
@@ -232,7 +228,7 @@ class Program
             // Portal polys can be render polys (e.g. water) but we're ignoring them for now
             if (numRenderPolys == 0 || numPortalPolys >= numPolys)
             {
-                continue;
+                return;
             }
 
             var maxPolyIdx = Math.Min(numRenderPolys, numPolys - numPortalPolys);
@@ -339,36 +335,8 @@ class Program
                             var hit = hitResult && Math.Abs(hitResult.Distance - direction.Length()) < MathUtils.Epsilon;
                             if (hit)
                             {
-                                // Calculate light strength at a given point. As far as I can tell
+                                var strength = CalculateLightStrengthAtPoint(light, pos, plane);
-                                // this is exact to Dark (I'm a genius??). It's just an inverse distance
+                                lightmap.AddLight(0, x, y, light.color, strength, hdr);
-                                // falloff with diffuse angle, except we have to scale the length.
-                                var dir = light.position - pos;
-                                var angle = Vector3.Dot(Vector3.Normalize(dir), plane.Normal);
-                                var len = dir.Length();
-                                var slen = len / 4.0f;
-                                var strength = (angle + 1.0f) / slen;
-                                if (hdr)
-                                {
-                                    strength /= 2;
-                                }
-
-                                // We need to make sure we don't go over (255, 255, 255).
-                                // If we just do Max(color, (255, 255, 255)) then we change
-                                // the hue/saturation of coloured lights. Got to make sure we
-                                // maintain the colour ratios.
-                                var c = light.color * strength;
-                                var ratio = 0.0f;
-                                foreach (var e in new float[] { c.X, c.Y, c.Z })
-                                {
-                                    ratio = Math.Max(ratio, e / 255.0f);
-                                }
-
-                                if (ratio > 1.0f)
-                                {
-                                    c /= ratio;
-                                }
-
-                                lightmap.AddLight(0, x, y, (byte)c.X, (byte)c.Y, (byte)c.Z);
                             }
                         }
                     }
@@ -376,9 +344,21 @@ class Program
 
                 cellIdxOffset += poly.VertexCount;
             }
-        }
+        });
+    }
 
-        Console.Write("\n");
+    private static float CalculateLightStrengthAtPoint(Light light, Vector3 point, Plane plane)
+    {
+        // Calculate light strength at a given point. As far as I can tell
+        // this is exact to Dark (I'm a genius??). It's just an inverse distance
+        // falloff with diffuse angle, except we have to scale the length.
+        var dir = light.position - point;
+        var angle = Vector3.Dot(Vector3.Normalize(dir), plane.Normal);
+        var len = dir.Length();
+        var slen = len / 4.0f;
+        var strength = (angle + 1.0f) / slen;
+
+        return strength;
     }
 
     private static void ResetLightmap(Vector3 ambientLight, WorldRep.Cell.Lightmap lightmap, bool hdr)
@@ -388,17 +368,11 @@ class Program
             lightmap.Pixels[i] = 0;
         }
 
-        var c = ambientLight;
-        if (hdr)
-        {
-            c /= 2.0f;
-        }
-
         for (var y = 0; y < lightmap.Height; y++)
         {
             for (var x = 0; x < lightmap.Width; x++)
             {
-                lightmap.AddLight(0, x, y, (byte)c.X, (byte)c.Y, (byte)c.Z);
+                lightmap.AddLight(0, x, y, ambientLight, 1.0f, hdr);
             }
         }
     }