Made shadows blurry (thru implementing variance mapping)

gm/shadowmaps.cpp

Index: gm/shadowmaps.cpp
diff --git a/gm/shadowmaps.cpp b/gm/shadowmaps.cpp
index b343d9b142221b60379c52901808e317462838d2..b024bac9cde4ce05985dbaf971183c2d04c21647 100644
--- a/gm/shadowmaps.cpp
+++ b/gm/shadowmaps.cpp
@@ -76,6 +76,11 @@ public:
                                     SkVector3::Make(0.1f, 0.2f, 1.0f)));
         builder.add(SkLights::Light(SkColor3f::Make(0.4f, 0.4f, 0.4f)));
         fLights = builder.finish();
+
+        fShadowType.fShadowRadius = 4.0f;
+        fShadowType.fBiasingConstant = 0.3f;
+        fShadowType.fMinVariance = 1024;
+        fShadowType.fBlurAlgorithm = SkShadowType::kVariance_BlurAlgorithm;
     }
 
 protected:
@@ -95,11 +100,12 @@ protected:
         // It's used to generate the depth maps.
         sk_sp<SkPicture> pic(make_test_picture(kWidth, kHeight));
         canvas->setLights(fLights);
-        canvas->drawShadowedPicture(pic, nullptr, nullptr);
+        canvas->drawShadowedPicture(pic, nullptr, nullptr, fShadowType);
     }
 
 private:
     sk_sp<SkLights> fLights;
+    SkShadowType fShadowType;
     typedef GM INHERITED;
 };