Added distance attenuation and diffuse shading to PointLights

samplecode/SampleShadowing.cpp

Index: samplecode/SampleShadowing.cpp
diff --git a/samplecode/SampleShadowing.cpp b/samplecode/SampleShadowing.cpp
index d0b37fb15ab7921f259a93f2ed2c236f3fb124cf..59f954109432a7b6c31d0fec123c2377f6ff6f65 100644
--- a/samplecode/SampleShadowing.cpp
+++ b/samplecode/SampleShadowing.cpp
@@ -19,11 +19,10 @@ public:
 
         this->setBGColor(0xFFCCCCCC);
         SkLights::Builder builder;
-        builder.add(SkLights::Light::MakeDirectional(SkColor3f::Make(0.2f, 0.3f, 0.4f),
-                                                     SkVector3::Make(0.2f, 0.05f, 1.0f)));
-        builder.add(SkLights::Light::MakeDirectional(SkColor3f::Make(0.4f, 0.3f, 0.2f),
-                                                     SkVector3::Make(0.05f, 0.2f, 1.0f)));
-        builder.add(SkLights::Light::MakeAmbient(SkColor3f::Make(0.4f, 0.4f, 0.4f)));
+        builder.add(SkLights::Light::MakePoint(SkColor3f::Make(0.3f, 0.5f, 0.7f),
+                                               SkVector3::Make(150.0f, 150.0f, 300.0f)));
+        builder.add(SkLights::Light::MakePoint(SkColor3f::Make(0.7f, 0.5f, 0.3f),
+                                               SkVector3::Make(250.0f, 250.0f, 300.0f)));
         fLights = builder.finish();
 
         fTestRects[0].fColor = 0xFFEE8888;
@@ -44,6 +43,7 @@ public:
         fSelectedRect = -1;
         fMoveLight = false;
 
+        fLightDepth = 300.0f;
         fClearShadowMaps = false;
     }
 
@@ -67,6 +67,14 @@ protected:
                     // the shadow maps will be re-generated according to the new backend.
                     fClearShadowMaps = true;
                     break;
+                case 'q':
+                    fLightDepth += 5.0f;
+                    fMoveLight = true;
+                    break;
+                case 'w':
+                    fLightDepth -= 5.0f;
+                    fMoveLight = true;
+                    break;
                 default:
                     break;
             }
@@ -117,9 +125,9 @@ protected:
             fLightsChanged = false;
             fClearShadowMaps = false;
 
-            canvas->setLights(fLights);
-            canvas->drawShadowedPicture(fPicture, nullptr, nullptr);
         }
+        canvas->setLights(fLights);
+        canvas->drawShadowedPicture(fPicture, nullptr, nullptr);
     }
 
     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
@@ -135,22 +143,16 @@ protected:
 
         if (fMoveLight) {
             if (dx != 0 || dy != 0) {
-                float recipX = 1.0f / kWidth;
-                float recipY = 1.0f / kHeight;
-
                 SkLights::Builder builder;
-                builder.add(SkLights::Light::MakeDirectional(
-                        SkColor3f::Make(0.2f, 0.3f, 0.4f),
-                        SkVector3::Make(0.2f + (200.0f - x) * recipX,
-                                        0.05f + (200.0f - y) * recipY,
-                                        1.0f)));
-                builder.add(SkLights::Light::MakeDirectional(
-                        SkColor3f::Make(0.4f, 0.3f, 0.2f),
-                        SkVector3::Make(0.05f + (200.0f - x) * recipX,
-                                        0.2f + (200.0f - y) * recipY,
-                                        1.0f)));
-                builder.add(SkLights::Light::MakeAmbient(
-                        SkColor3f::Make(0.4f, 0.4f, 0.4f)));
+                builder.add(SkLights::Light::MakePoint(SkColor3f::Make(0.3f, 0.5f, 0.7f),
+                                                       SkVector3::Make(x - 50,
+                                                                       350 - y,
+                                                                       fLightDepth)));
+
+                builder.add(SkLights::Light::MakePoint(SkColor3f::Make(0.7f, 0.5f, 0.3f),
+                                                       SkVector3::Make(x + 50,
+                                                                       450 - y,
+                                                                       fLightDepth)));
                 fLights = builder.finish();
 
                 fLightsChanged = true;
@@ -208,6 +210,8 @@ private:
     bool fSceneChanged;
     bool fLightsChanged;
 
+    SkScalar fLightDepth;
+
     sk_sp<SkLights> fLights;
 
     typedef SampleView INHERITED;