Made shadows blurry (thru implementing variance mapping)

src/utils/SkShadowPaintFilterCanvas.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPathEffect.h"
 #include "SkShadowPaintFilterCanvas.h"
 
 #ifdef SK_EXPERIMENTAL_SHADOWING
 

[robertphillips, 2016/08/10 14:23:18]

Add parameter

[vjiaoblack, 2016/08/11 18:28:51]

Done.

 SkShadowPaintFilterCanvas::SkShadowPaintFilterCanvas(SkCanvas *canvas)
         : SkPaintFilterCanvas(canvas) { }
 
 // TODO use a shader instead
 bool SkShadowPaintFilterCanvas::onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type type) const {
     if (*paint) {
         int z = this->getZ();
         SkASSERT(z <= 0xFF && z >= 0x00);
 
         SkPaint newPaint;
         newPaint.setPathEffect(sk_ref_sp<SkPathEffect>((*paint)->getPathEffect()));
 
         SkColor color = 0xFF000000; // init color to opaque black
         color |= z; // Put the index into the blue component
+

[robertphillips, 2016/08/10 14:23:18]

parameterize & comment

[vjiaoblack, 2016/08/11 18:28:51]

Done.

+        int z2 = z * z;
+        if (z2 > 255 * 256) {
+            color |= (255) << 8;
+        } else {
+            color |= (z2 / 256) << 8;
+        }
+//        color |= (z * z / 256) << 8;
         newPaint.setColor(color);
 
         *paint->writable() = newPaint;
     }
 
     return true;
 }
 
 SkISize SkShadowPaintFilterCanvas::ComputeDepthMapSize(const SkLights::Light& light, int maxDepth,
                                                        int width, int height) {
@@ skipping 175 matching lines @@
 }
 
 void SkShadowPaintFilterCanvas::onDrawTextBlob(const SkTextBlob *blob, SkScalar x, SkScalar y,
                                                const SkPaint &paint) {
     this->updateMatrix();
     this->INHERITED::onDrawTextBlob(blob, x, y, paint);
     this->restore();
 }
 
 #endif