| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef FLUTTER_FLOW_RASTER_CACHE_UTIL_H_ |
| #define FLUTTER_FLOW_RASTER_CACHE_UTIL_H_ |
| |
| #include "flutter/fml/logging.h" |
| #include "include/core/SkMatrix.h" |
| #include "include/core/SkRect.h" |
| |
| namespace flutter { |
| |
| struct RasterCacheUtil { |
| // The default max number of picture and display list raster caches to be |
| // generated per frame. Generating too many caches in one frame may cause jank |
| // on that frame. This limit allows us to throttle the cache and distribute |
| // the work across multiple frames. |
| static constexpr int kDefaultPictureAndDispLayListCacheLimitPerFrame = 3; |
| |
| // The ImageFilterLayer might cache the filtered output of this layer |
| // if the layer remains stable (if it is not animating for instance). |
| // If the ImageFilterLayer is not the same between rendered frames, |
| // though, it will cache its children instead and filter their cached |
| // output on the fly. |
| // Caching just the children saves the time to render them and also |
| // avoids a rendering surface switch to draw them. |
| // Caching the layer itself avoids all of that and additionally avoids |
| // the cost of applying the filter, but can be worse than caching the |
| // children if the filter itself is not stable from frame to frame. |
| // This constant controls how many times we will Preroll and Paint this |
| // same ImageFilterLayer before we consider the layer and filter to be |
| // stable enough to switch from caching the children to caching the |
| // filtered output of this layer. |
| static constexpr int kMinimumRendersBeforeCachingFilterLayer = 3; |
| |
| static bool CanRasterizeRect(const SkRect& cull_rect) { |
| if (cull_rect.isEmpty()) { |
| // No point in ever rasterizing an empty display list. |
| return false; |
| } |
| |
| if (!cull_rect.isFinite()) { |
| // Cannot attempt to rasterize into an infinitely large surface. |
| FML_LOG(INFO) << "Attempted to raster cache non-finite display list"; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static SkRect GetDeviceBounds(const SkRect& rect, const SkMatrix& ctm) { |
| SkRect device_rect; |
| ctm.mapRect(&device_rect, rect); |
| return device_rect; |
| } |
| }; |
| |
| } // namespace flutter |
| |
| #endif // FLUTTER_FLOW_RASTER_CACHE_UTIL_H_ |