Merge pull request #247 from UnityTech/allocator2

GC optimization on renderer

Author: Yuncong Zhang

Runtime/editor/rasterizer.cs

@@ -76,7 +76,6 @@ bool _drawToSurface(LayerTree layerTree) {
                     this._fireNextFrameCallbackIfPresent();
                     return true;
                 }
-
                 return false;
             }
         }

Runtime/flow.meta

@@ -116,8 +116,7 @@ public override void applyPaintTransform(RenderObject child, Matrix3 transform)
 
         public void compositeFrame() {
             var builder = new SceneBuilder();
-            this.layer.buildScene(builder);
-            using (var scene = builder.build()) {
+            using (var scene = this.layer.buildScene(builder)) {
                 Window.instance.render(scene);
             }
 

Runtime/flow/compositor_context.cs.meta

@@ -1438,8 +1438,22 @@ public static bool ScalarsAreFinite(float[] array, int count) {
             return prod == 0; // if prod is NaN, this check will return false
         }
 
+        static byte[] _scalar_as_2s_compliment_vars = new byte[4];
+
+
+        static unsafe int GetBytesToInt32(float value) {
+            var intVal = *(int*) &value;
+            fixed (byte* b = _scalar_as_2s_compliment_vars) {
+                *((int*) b) = intVal;
+            }
+
+            fixed (byte* pbyte = &_scalar_as_2s_compliment_vars[0]) {
+                return *((int*) pbyte);
+            }
+        }
+
         public static int ScalarAs2sCompliment(float x) {
-            var result = BitConverter.ToInt32(BitConverter.GetBytes(x), 0);
+            var result = GetBytesToInt32(x);
             if (result < 0) {
                 result &= 0x7FFFFFFF;
                 result = -result;