DEV/flutter_flutter
1
0
Fork 0
mirror of https://github.com/flutter/flutter.git synced 2026-02-20 02:29:02 +08:00
Code Issues Packages Projects Releases Wiki Activity

[Impeller] write glyphs to malloc buffer. (flutter/engine#52937)

Browse Source 
Writing to a malloc buffer and then copying is faster on a variety of Pixel devices. Since this change was supposed to be a performance optimization, just back it out.
This commit is contained in:
Jonah Williams 2024-05-20 15:15:05 -07:00 committed by GitHub
parent 2872bbe05c
commit c9f79d8b9e
1 changed files with 11 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
engine/src/flutter/impeller/typographer/backends/skia/typographer_context_skia.cc
View File

@ -46,56 +46,6 @@ namespace impeller {
// https://github.com/flutter/flutter/issues/114563
constexpr auto kPadding = 2;
namespace {
class HostBufferAllocator : public SkBitmap::Allocator {
public:
explicit HostBufferAllocator(HostBuffer& host_buffer)
: host_buffer_(host_buffer) {}
[[nodiscard]] BufferView TakeBufferView() {
buffer_view_.buffer->Flush();
return std::move(buffer_view_);
}
// |SkBitmap::Allocator|
bool allocPixelRef(SkBitmap* bitmap) override {
if (!bitmap) {
return false;
}
const SkImageInfo& info = bitmap->info();
if (kUnknown_SkColorType == info.colorType() || info.width() < 0 ||
info.height() < 0 || !info.validRowBytes(bitmap->rowBytes())) {
return false;
}
size_t required_bytes = bitmap->rowBytes() * bitmap->height();
BufferView buffer_view = host_buffer_.Emplace(nullptr, required_bytes,
DefaultUniformAlignment());
// The impeller host buffer is not cleared between frames and may contain
// stale data. The Skia software canvas does not write to pixels without
// any contents, which causes this data to leak through.
::memset(buffer_view.buffer->OnGetContents() + buffer_view.range.offset, 0,
required_bytes);
auto pixel_ref = sk_sp<SkPixelRef>(new SkPixelRef(
info.width(), info.height(),
buffer_view.buffer->OnGetContents() + buffer_view.range.offset,
bitmap->rowBytes()));
bitmap->setPixelRef(std::move(pixel_ref), 0, 0);
buffer_view_ = std::move(buffer_view);
return true;
}
private:
BufferView buffer_view_;
HostBuffer& host_buffer_;
};
} // namespace
std::shared_ptr<TypographerContext> TypographerContextSkia::Make() {
return std::make_shared<TypographerContextSkia>();
}
@ -282,9 +232,8 @@ static bool UpdateAtlasBitmap(const GlyphAtlas& atlas,
}
SkBitmap bitmap;
HostBufferAllocator allocator(host_buffer);
bitmap.setInfo(GetImageInfo(atlas, size));
if (!bitmap.tryAllocPixels(&allocator)) {
if (!bitmap.tryAllocPixels()) {
return false;
}
auto surface = SkSurfaces::WrapPixels(bitmap.pixmap());
@ -298,11 +247,19 @@ static bool UpdateAtlasBitmap(const GlyphAtlas& atlas,
DrawGlyph(canvas, pair.scaled_font, pair.glyph, has_color);
// Writing to a malloc'd buffer and then copying to the staging buffers
// benchmarks as substantially faster on a number of Android devices.
BufferView buffer_view = host_buffer.Emplace(
bitmap.getAddr(0, 0),
size.Area() * BytesPerPixelForPixelFormat(
atlas.GetTexture()->GetTextureDescriptor().format),
DefaultUniformAlignment());
// convert_to_read is set to false so that the texture remains in a transfer
// dst layout until we finish writing to it below. This only has an impact
// on Vulkan where we are responsible for managing image layouts.
if (!blit_pass->AddCopy(allocator.TakeBufferView(), //
texture, //
if (!blit_pass->AddCopy(std::move(buffer_view), //
texture, //
IRect::MakeXYWH(pos->GetLeft(), pos->GetTop(),
size.width, size.height), //
/*label=*/"", //