| |
| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #ifndef SkShadowUtils_DEFINED |
| #define SkShadowUtils_DEFINED |
| |
| #include "SkColor.h" |
| #include "SkScalar.h" |
| #include "../private/SkShadowFlags.h" |
| #include <functional> |
| |
| class SkCanvas; |
| class SkPath; |
| class SkResourceCache; |
| |
| class SkShadowUtils { |
| public: |
| /** |
| * Draw an offset spot shadow and outlining ambient shadow for the given path using a disc |
| * light. |
| * |
| * @param canvas The canvas on which to draw the shadows. |
| * @param path The occluder used to generate the shadows. |
| * @param occluderHeight The vertical offset of the occluder from the canvas. This is |
| * independent of the canvas's current matrix. |
| * @param lightPos The 3D position of the light relative to the canvas plane. This is |
| * independent of the canvas's current matrix. |
| * @param lightRadius The radius of the disc light. |
| * @param ambientAlpha The maximum alpha of the ambient shadow. |
| * @param spotAlpha The maxium alpha of the spot shadow. |
| * @param color The shadow color. |
| * @param flags Options controlling opaque occluder optimizations and shadow appearance. See |
| * SkShadowFlags. |
| * @param cache Used for testing purposes. Clients should pass nullptr (default). |
| */ |
| static void DrawShadow(SkCanvas* canvas, const SkPath& path, SkScalar occluderHeight, |
| const SkPoint3& lightPos, SkScalar lightRadius, SkScalar ambientAlpha, |
| SkScalar spotAlpha, SkColor color, |
| uint32_t flags = SkShadowFlags::kNone_ShadowFlag, |
| SkResourceCache* cache = nullptr); |
| |
| /** |
| * Draw an offset spot shadow and outlining ambient shadow for the given path using a disc |
| * light. Takes a function to vary the z value based on the transformed x and y position. |
| * This shadow will not be cached, as the assumption is that this will be used for animation. |
| * |
| * @param canvas The canvas on which to draw the shadows. |
| * @param path The occluder used to generate the shadows. |
| * @param heightFunc A function which returns the vertical offset of the occluder from the |
| * canvas based on local x and y values (the current matrix is not applied). |
| * @param lightPos The 3D position of the light relative to the canvas plane. This is |
| * independent of the canvas's current matrix. |
| * @param lightRadius The radius of the disc light. |
| * @param ambientAlpha The maximum alpha of the ambient shadow. |
| * @param spotAlpha The maxium alpha of the spot shadow. |
| * @param color The shadow color. |
| * @param flags Options controlling opaque occluder optimizations and shadow appearance. See |
| * SkShadowFlags. |
| */ |
| static void DrawUncachedShadow(SkCanvas* canvas, const SkPath& path, |
| std::function<SkScalar(SkScalar, SkScalar)> heightFunc, |
| const SkPoint3& lightPos, SkScalar lightRadius, |
| SkScalar ambientAlpha, SkScalar spotAlpha, SkColor color, |
| uint32_t flags = SkShadowFlags::kNone_ShadowFlag); |
| }; |
| |
| #endif |