[Reland] Relocate shaders to own dir

Consolidate all shader impls under src/shaders/.

(reland of https://skia-review.googlesource.com/c/17927/)

Change-Id: I7918bdc1aafe842ed194412ba95b9ae53a2ec1d7
Reviewed-on: https://skia-review.googlesource.com/18146
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/src/shaders/SkLightingShader.h b/src/shaders/SkLightingShader.h
new file mode 100644
index 0000000000..aa90710aa4
--- /dev/null
+++ b/src/shaders/SkLightingShader.h
@@ -0,0 +1,39 @@
+/*
+ * 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 "SkLights.h"
+#include "SkShader.h"
+
+class SkBitmap;
+class SkMatrix;
+class SkNormalSource;
+
+class SK_API SkLightingShader {
+public:
+    /** Returns a shader that lights the shape, colored by the diffuseShader, using the
+        normals from normalSource, with the set of lights provided.
+
+        @param  diffuseShader     the shader that provides the colors. If nullptr, uses the paint's
+                                  color.
+        @param  normalSource      the source for the shape's normals. If nullptr, assumes straight
+                                  up normals (<0,0,1>).
+        @param  lights            the lights applied to the normals
+
+        The lighting equation is currently:
+            result = (LightColor * dot(Normal, LightDir) + AmbientColor) * DiffuseColor
+
+    */
+    static sk_sp<SkShader> Make(sk_sp<SkShader> diffuseShader, sk_sp<SkNormalSource> normalSource,
+                                sk_sp<SkLights> lights);
+
+    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
+};
+
+#endif