Update SkLightingShader to support rotation

samplecode/SampleLighting.cpp

 
 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SampleCode.h"
 #include "Resources.h"
 
 #include "SkCanvas.h"
 #include "SkImageDecoder.h"
 #include "SkLightingShader.h"
+#include "SkPoint3.h"
+
+static const SkLightingShader::Lights* create_lights(SkScalar angle, SkScalar blue) {
+
+    const SkVector3 dir = SkVector3::Make(SkScalarSin(angle)*SkScalarSin(SK_ScalarPI*0.25f),
+                                          SkScalarCos(angle)*SkScalarSin(SK_ScalarPI*0.25f),
+                                          SkScalarCos(SK_ScalarPI*0.25f));
+
+    SkLightingShader::Lights::Builder builder;
+
+    builder.add(SkLight(SkColor3f::Make(1.0f, 1.0f, blue), dir));
+    builder.add(SkLight(SkColor3f::Make(0.1f, 0.1f, 0.1f)));
+
+    return builder.finish();
+}
 
 ////////////////////////////////////////////////////////////////////////////
 
 class LightingView : public SampleView {
 public:
     SkAutoTUnref<SkShader> fShader;
     SkBitmap               fDiffuseBitmap;
     SkBitmap               fNormalBitmap;
     SkScalar               fLightAngle;
     SkScalar               fColorFactor;
-    SkColor3f              fAmbientColor;
 
     LightingView() {
         SkString diffusePath = GetResourcePath("brickwork-texture.jpg");
         SkImageDecoder::DecodeFile(diffusePath.c_str(), &fDiffuseBitmap);
         SkString normalPath = GetResourcePath("brickwork_normal-map.jpg");
         SkImageDecoder::DecodeFile(normalPath.c_str(), &fNormalBitmap);
 
         fLightAngle = 0.0f;
         fColorFactor = 0.0f;
 
-        SkLightingShader::Light light;
-        light.fColor = SkColor3f::Make(1.0f, 1.0f, 1.0f);
-        light.fDirection.fX = SkScalarSin(fLightAngle)*SkScalarSin(SK_ScalarPI*0.25f);
-        light.fDirection.fY = SkScalarCos(fLightAngle)*SkScalarSin(SK_ScalarPI*0.25f);
-        light.fDirection.fZ = SkScalarCos(SK_ScalarPI*0.25f);
-
-        fAmbientColor = SkColor3f::Make(0.1f, 0.1f, 0.1f);
+        SkAutoTUnref<const SkLightingShader::Lights> lights(create_lights(fLightAngle, 1.0f));
 
         fShader.reset(SkLightingShader::Create(fDiffuseBitmap, fNormalBitmap,
-                                               light, fAmbientColor, nullptr));
+                                               lights, SkVector::Make(1.0f, 0.0f),
+                                               nullptr, nullptr));
     }
 
     virtual ~LightingView() {}
 
 protected:
     // overrides from SkEventSink
     bool onQuery(SkEvent* evt) override {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "Lighting");
             return true;
         }
         return this->INHERITED::onQuery(evt);
     }
 
     void onDrawContent(SkCanvas* canvas) override {
         fLightAngle += 0.015f;
         fColorFactor += 0.01f;
         if (fColorFactor > 1.0f) {
             fColorFactor = 0.0f;
         }
 
-        SkLightingShader::Light light;
-        light.fColor = SkColor3f::Make(1.0f, 1.0f, fColorFactor);
-        light.fDirection.fX = SkScalarSin(fLightAngle)*SkScalarSin(SK_ScalarPI*0.25f);
-        light.fDirection.fY = SkScalarCos(fLightAngle)*SkScalarSin(SK_ScalarPI*0.25f);
-        light.fDirection.fZ = SkScalarCos(SK_ScalarPI*0.25f);
+        SkAutoTUnref<const SkLightingShader::Lights> lights(create_lights(fLightAngle,
+                                                                          fColorFactor));
 
         fShader.reset(SkLightingShader::Create(fDiffuseBitmap, fNormalBitmap,
-                                               light, fAmbientColor, nullptr));
+                                               lights, SkVector::Make(1.0f, 0.0f),
+                                               nullptr, nullptr));
 
         SkPaint paint;
         paint.setShader(fShader);
         paint.setColor(SK_ColorBLACK);
 
         SkRect r = SkRect::MakeWH((SkScalar)fDiffuseBitmap.width(), 
                                   (SkScalar)fDiffuseBitmap.height());
         canvas->drawRect(r, paint);
 
         // so we're constantly updating
         this->inval(NULL);
     }
 
     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
         this->inval(NULL);
         return this->INHERITED::onFindClickHandler(x, y, modi);
     }
 
 private:
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new LightingView; }
 static SkViewRegister reg(MyFactory);