Update SkLightingShader to support rotation

src/core/SkLightingShader.h

 
 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkLightingShader_DEFINED
 #define SkLightingShader_DEFINED
 
-#include "SkPoint3.h"
+#include "SkFlattenable.h"
+#include "SkLight.h"
 #include "SkShader.h"
+#include "SkTDArray.h"
+
+class SkBitmap;
+class SkMatrix;
 
 class SK_API SkLightingShader {
 public:
-    struct Light {
-        SkVector3   fDirection;       // direction towards the light (+Z is out of the screen).
-                                      // If degenerate, it will be replaced with (0, 0, 1).
-        SkColor3f   fColor;           // linear (unpremul) color. Range is 0..1 in each channel.
+    class Lights  : public SkRefCnt {
+    public:
+        class Builder {

[jvanverth1, 2015/08/19 13:57:48]

This class is new -- can you mention it in the change description?

[robertphillips, 2015/08/19 16:17:57]

Done.

+        public:
+            Builder(const SkLight lights[], int numLights)
+                : fLights(SkNEW_ARGS(Lights, (lights, numLights))) {
+            }
+
+            Builder() : fLights(SkNEW(Lights)) { }
+    
+            void add(const SkLight& light) {

[jvanverth1, 2015/08/19 13:57:48]

I think we'll need a way to limit the number of directional lights you can add.

[robertphillips, 2015/08/19 16:17:57]

I've added a TODO.

+                if (fLights) {
+                    *fLights->fLights.push() = light;
+                }
+            }
+
+            const Lights* finish() {
+                return fLights.detach();
+            }
+
+        private:
+            SkAutoTUnref<Lights> fLights;
+        };
+
+        int numLights() const {
+            return fLights.count();
+        }
+
+        const SkLight& light(int index) const {
+            return fLights[index];
+        }
+
+    private:
+        Lights() {}
+        Lights(const SkLight lights[], int numLights) : fLights(lights, numLights) {}
+
+        SkTDArray<SkLight> fLights;
+
+        typedef SkRefCnt INHERITED;
     };
 
     /** Returns a shader that lights the diffuse and normal maps with a single light.
 
         It returns a shader with a reference count of 1.
         The caller should decrement the shader's reference count when done with the shader.
         It is an error for count to be < 2.
         @param  diffuse     the diffuse bitmap
         @param  normal      the normal map
         @param  light       the light applied to the normal map
@@ skipping 11 matching lines @@
         The normal map is currently assumed to be an 8888 image where the normal at a texel
         is retrieved by:
             N.x = R-127;
             N.y = G-127;
             N.z = B-127;
             N.normalize();
         The +Z axis is thus encoded in RGB as (127, 127, 255) while the -Z axis is
         (127, 127, 0).
     */
     static SkShader* Create(const SkBitmap& diffuse, const SkBitmap& normal,
-                            const SkLightingShader::Light& light, const SkColor3f& ambient,
-                            const SkMatrix* localMatrix);
+                            const Lights* lights, const SkVector& invNormRotation,
+                            const SkMatrix* diffLocalMatrix, const SkMatrix* normLocalMatrix);
 
     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
 };
 
 #endif