| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "flutter/flow/raster_cache.h" |
| |
| #include <vector> |
| |
| #include "flutter/flow/paint_utils.h" |
| #include "flutter/fml/logging.h" |
| #include "flutter/fml/trace_event.h" |
| #include "third_party/skia/include/core/SkCanvas.h" |
| #include "third_party/skia/include/core/SkColorSpaceXformCanvas.h" |
| #include "third_party/skia/include/core/SkImage.h" |
| #include "third_party/skia/include/core/SkPicture.h" |
| #include "third_party/skia/include/core/SkSurface.h" |
| |
| namespace flow { |
| |
| void RasterCacheResult::draw(SkCanvas& canvas) const { |
| SkAutoCanvasRestore auto_restore(&canvas, true); |
| SkIRect bounds = |
| RasterCache::GetDeviceBounds(logical_rect_, canvas.getTotalMatrix()); |
| FML_DCHECK(bounds.size() == image_->dimensions()); |
| canvas.resetMatrix(); |
| canvas.drawImage(image_, bounds.fLeft, bounds.fTop); |
| } |
| |
| RasterCache::RasterCache(size_t threshold) |
| : threshold_(threshold), checkerboard_images_(false), weak_factory_(this) {} |
| |
| RasterCache::~RasterCache() = default; |
| |
| static bool CanRasterizePicture(SkPicture* picture) { |
| if (picture == nullptr) { |
| return false; |
| } |
| |
| const SkRect cull_rect = picture->cullRect(); |
| |
| if (cull_rect.isEmpty()) { |
| // No point in ever rasterizing an empty picture. |
| return false; |
| } |
| |
| if (!cull_rect.isFinite()) { |
| // Cannot attempt to rasterize into an infinitely large surface. |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool IsPictureWorthRasterizing(SkPicture* picture, |
| bool will_change, |
| bool is_complex) { |
| if (will_change) { |
| // If the picture is going to change in the future, there is no point in |
| // doing to extra work to rasterize. |
| return false; |
| } |
| |
| if (!CanRasterizePicture(picture)) { |
| // No point in deciding whether the picture is worth rasterizing if it |
| // cannot be rasterized at all. |
| return false; |
| } |
| |
| if (is_complex) { |
| // The caller seems to have extra information about the picture and thinks |
| // the picture is always worth rasterizing. |
| return true; |
| } |
| |
| // TODO(abarth): We should find a better heuristic here that lets us avoid |
| // wasting memory on trivial layers that are easy to re-rasterize every frame. |
| return picture->approximateOpCount() > 10; |
| } |
| |
| RasterCacheResult RasterizePicture(SkPicture* picture, |
| GrContext* context, |
| const SkMatrix& ctm, |
| SkColorSpace* dst_color_space, |
| bool checkerboard) { |
| TRACE_EVENT0("flutter", "RasterCachePopulate"); |
| |
| const SkRect logical_rect = picture->cullRect(); |
| SkIRect cache_rect = RasterCache::GetDeviceBounds(logical_rect, ctm); |
| |
| const SkImageInfo image_info = |
| SkImageInfo::MakeN32Premul(cache_rect.width(), cache_rect.height()); |
| |
| sk_sp<SkSurface> surface = |
| context |
| ? SkSurface::MakeRenderTarget(context, SkBudgeted::kYes, image_info) |
| : SkSurface::MakeRaster(image_info); |
| |
| if (!surface) { |
| return {}; |
| } |
| |
| SkCanvas* canvas = surface->getCanvas(); |
| std::unique_ptr<SkCanvas> xformCanvas; |
| if (dst_color_space) { |
| xformCanvas = SkCreateColorSpaceXformCanvas(surface->getCanvas(), |
| sk_ref_sp(dst_color_space)); |
| if (xformCanvas) { |
| canvas = xformCanvas.get(); |
| } |
| } |
| |
| canvas->clear(SK_ColorTRANSPARENT); |
| canvas->translate(-cache_rect.left(), -cache_rect.top()); |
| canvas->concat(ctm); |
| canvas->drawPicture(picture); |
| |
| if (checkerboard) { |
| DrawCheckerboard(canvas, logical_rect); |
| } |
| |
| return {surface->makeImageSnapshot(), logical_rect}; |
| } |
| |
| static inline size_t ClampSize(size_t value, size_t min, size_t max) { |
| if (value > max) { |
| return max; |
| } |
| |
| if (value < min) { |
| return min; |
| } |
| |
| return value; |
| } |
| |
| RasterCacheResult RasterCache::GetPrerolledImage( |
| GrContext* context, |
| SkPicture* picture, |
| const SkMatrix& transformation_matrix, |
| SkColorSpace* dst_color_space, |
| bool is_complex, |
| bool will_change) { |
| if (!IsPictureWorthRasterizing(picture, will_change, is_complex)) { |
| // We only deal with pictures that are worthy of rasterization. |
| return {}; |
| } |
| |
| // Decompose the matrix (once) for all subsequent operations. We want to make |
| // sure to avoid volumetric distortions while accounting for scaling. |
| const MatrixDecomposition matrix(transformation_matrix); |
| |
| if (!matrix.IsValid()) { |
| // The matrix was singular. No point in going further. |
| return {}; |
| } |
| |
| RasterCacheKey cache_key(*picture, transformation_matrix); |
| |
| Entry& entry = cache_[cache_key]; |
| entry.access_count = ClampSize(entry.access_count + 1, 0, threshold_); |
| entry.used_this_frame = true; |
| |
| if (entry.access_count < threshold_ || threshold_ == 0) { |
| // Frame threshold has not yet been reached. |
| return {}; |
| } |
| |
| if (!entry.image.is_valid()) { |
| entry.image = RasterizePicture(picture, context, transformation_matrix, |
| dst_color_space, checkerboard_images_); |
| } |
| |
| return entry.image; |
| } |
| |
| void RasterCache::SweepAfterFrame() { |
| std::vector<RasterCacheKey::Map<Entry>::iterator> dead; |
| |
| for (auto it = cache_.begin(); it != cache_.end(); ++it) { |
| Entry& entry = it->second; |
| if (!entry.used_this_frame) { |
| dead.push_back(it); |
| } |
| entry.used_this_frame = false; |
| } |
| |
| for (auto it : dead) { |
| cache_.erase(it); |
| } |
| } |
| |
| void RasterCache::Clear() { |
| cache_.clear(); |
| } |
| |
| void RasterCache::SetCheckboardCacheImages(bool checkerboard) { |
| if (checkerboard_images_ == checkerboard) { |
| return; |
| } |
| |
| checkerboard_images_ = checkerboard; |
| |
| // Clear all existing entries so previously rasterized items (with or without |
| // a checkerboard) will be refreshed in subsequent passes. |
| Clear(); |
| } |
| |
| } // namespace flow |