From b193fe658d120940e02b84170cecafc494fd0bae Mon Sep 17 00:00:00 2001 From: Jelle Raaijmakers Date: Fri, 2 Aug 2024 12:52:14 +0200 Subject: [PATCH] LibGfx: Store alpha type information in `Gfx::Bitmap` We use instances of `Gfx::Bitmap` to move pixel data all the way from raw image bytes up to the Skia renderer. A vital piece of information for correct blending of bitmaps is the alpha type, i.e. are we dealing with premultiplied or unpremultiplied color values? Premultiplied means that the RGB colors have been multiplied with the associated alpha value, i.e. RGB(255, 255, 255) with an alpha of 2% is stored as RGBA(5, 5, 5, 2%). Unpremultiplied means that the original RGB colors are stored, regardless of the alpha value. I.e. RGB(255, 255, 255) with an alpha of 2% is stored as RGBA(255, 255, 255, 2%). It is important to know how the color data is stored in a `Gfx::Bitmap`, because correct blending depends on knowing the alpha type: premultiplied blending uses `S + (1 - A) * D`, while unpremultiplied blending uses `A * S + (1 - A) * D`. This adds the alpha type information to `Gfx::Bitmap` across the board. It isn't used anywhere yet. --- .../main/cpp/WebViewImplementationNative.cpp | 2 +- Userland/Libraries/LibGfx/Bitmap.cpp | 52 +++++++++++++------ Userland/Libraries/LibGfx/Bitmap.h | 16 +++--- Userland/Libraries/LibGfx/Color.h | 10 ++++ Userland/Libraries/LibGfx/ShareableBitmap.cpp | 10 +++- Userland/Libraries/LibWeb/HTML/ImageData.cpp | 4 +- .../LibWeb/Painting/BackingStore.cpp | 2 +- .../LibWebView/ViewImplementation.cpp | 4 +- .../WebContent/BackingStoreManager.cpp | 4 +- 9 files changed, 71 insertions(+), 33 deletions(-) diff --git a/Ladybird/Android/src/main/cpp/WebViewImplementationNative.cpp b/Ladybird/Android/src/main/cpp/WebViewImplementationNative.cpp index e001104a8d7..c4cb12e7595 100644 --- a/Ladybird/Android/src/main/cpp/WebViewImplementationNative.cpp +++ b/Ladybird/Android/src/main/cpp/WebViewImplementationNative.cpp @@ -69,7 +69,7 @@ void WebViewImplementationNative::paint_into_bitmap(void* android_bitmap_raw, An // Software bitmaps only for now! VERIFY((info.flags & ANDROID_BITMAP_FLAGS_IS_HARDWARE) == 0); - auto android_bitmap = MUST(Gfx::Bitmap::create_wrapper(to_gfx_bitmap_format(info.format), { info.width, info.height }, info.stride, android_bitmap_raw)); + auto android_bitmap = MUST(Gfx::Bitmap::create_wrapper(to_gfx_bitmap_format(info.format), Gfx::AlphaType::Premultiplied, { info.width, info.height }, info.stride, android_bitmap_raw)); Gfx::Painter painter(android_bitmap); if (auto* bitmap = m_client_state.has_usable_bitmap ? m_client_state.front_bitmap.bitmap.ptr() : m_backup_bitmap.ptr()) painter.blit({ 0, 0 }, *bitmap, bitmap->rect()); diff --git a/Userland/Libraries/LibGfx/Bitmap.cpp b/Userland/Libraries/LibGfx/Bitmap.cpp index 2c745240bec..0a3e3926d66 100644 --- a/Userland/Libraries/LibGfx/Bitmap.cpp +++ b/Userland/Libraries/LibGfx/Bitmap.cpp @@ -1,6 +1,7 @@ /* * Copyright (c) 2018-2024, Andreas Kling * Copyright (c) 2022, Timothy Slater + * Copyright (c) 2024, Jelle Raaijmakers * * SPDX-License-Identifier: BSD-2-Clause */ @@ -60,11 +61,17 @@ static bool size_would_overflow(BitmapFormat format, IntSize size) ErrorOr> Bitmap::create(BitmapFormat format, IntSize size) { - auto backing_store = TRY(Bitmap::allocate_backing_store(format, size)); - return AK::adopt_nonnull_ref_or_enomem(new (nothrow) Bitmap(format, size, backing_store)); + // For backwards compatibility, premultiplied alpha is assumed + return create(format, AlphaType::Premultiplied, size); } -ErrorOr> Bitmap::create_shareable(BitmapFormat format, IntSize size) +ErrorOr> Bitmap::create(BitmapFormat format, AlphaType alpha_type, IntSize size) +{ + auto backing_store = TRY(Bitmap::allocate_backing_store(format, size)); + return AK::adopt_nonnull_ref_or_enomem(new (nothrow) Bitmap(format, alpha_type, size, backing_store)); +} + +ErrorOr> Bitmap::create_shareable(BitmapFormat format, AlphaType alpha_type, IntSize size) { if (size_would_overflow(format, size)) return Error::from_string_literal("Gfx::Bitmap::create_shareable size overflow"); @@ -73,15 +80,16 @@ ErrorOr> Bitmap::create_shareable(BitmapFormat format, Int auto const data_size = size_in_bytes(pitch, size.height()); auto buffer = TRY(Core::AnonymousBuffer::create_with_size(round_up_to_power_of_two(data_size, PAGE_SIZE))); - auto bitmap = TRY(Bitmap::create_with_anonymous_buffer(format, buffer, size)); + auto bitmap = TRY(Bitmap::create_with_anonymous_buffer(format, alpha_type, buffer, size)); return bitmap; } -Bitmap::Bitmap(BitmapFormat format, IntSize size, BackingStore const& backing_store) +Bitmap::Bitmap(BitmapFormat format, AlphaType alpha_type, IntSize size, BackingStore const& backing_store) : m_size(size) , m_data(backing_store.data) , m_pitch(backing_store.pitch) , m_format(format) + , m_alpha_type(alpha_type) { VERIFY(!m_size.is_empty()); VERIFY(!size_would_overflow(format, size)); @@ -92,11 +100,11 @@ Bitmap::Bitmap(BitmapFormat format, IntSize size, BackingStore const& backing_st }; } -ErrorOr> Bitmap::create_wrapper(BitmapFormat format, IntSize size, size_t pitch, void* data, Function&& destruction_callback) +ErrorOr> Bitmap::create_wrapper(BitmapFormat format, AlphaType alpha_type, IntSize size, size_t pitch, void* data, Function&& destruction_callback) { if (size_would_overflow(format, size)) return Error::from_string_literal("Gfx::Bitmap::create_wrapper size overflow"); - return adopt_ref(*new Bitmap(format, size, pitch, data, move(destruction_callback))); + return adopt_ref(*new Bitmap(format, alpha_type, size, pitch, data, move(destruction_callback))); } ErrorOr> Bitmap::load_from_file(StringView path, Optional ideal_size) @@ -123,11 +131,12 @@ ErrorOr> Bitmap::load_from_bytes(ReadonlyBytes bytes, Opti return Error::from_string_literal("Gfx::Bitmap unable to load from file"); } -Bitmap::Bitmap(BitmapFormat format, IntSize size, size_t pitch, void* data, Function&& destruction_callback) +Bitmap::Bitmap(BitmapFormat format, AlphaType alpha_type, IntSize size, size_t pitch, void* data, Function&& destruction_callback) : m_size(size) , m_data(data) , m_pitch(pitch) , m_format(format) + , m_alpha_type(alpha_type) , m_destruction_callback(move(destruction_callback)) { VERIFY(pitch >= minimum_pitch(size.width(), format)); @@ -135,19 +144,20 @@ Bitmap::Bitmap(BitmapFormat format, IntSize size, size_t pitch, void* data, Func // FIXME: assert that `data` is actually long enough! } -ErrorOr> Bitmap::create_with_anonymous_buffer(BitmapFormat format, Core::AnonymousBuffer buffer, IntSize size) +ErrorOr> Bitmap::create_with_anonymous_buffer(BitmapFormat format, AlphaType alpha_type, Core::AnonymousBuffer buffer, IntSize size) { if (size_would_overflow(format, size)) return Error::from_string_literal("Gfx::Bitmap::create_with_anonymous_buffer size overflow"); - return adopt_nonnull_ref_or_enomem(new (nothrow) Bitmap(format, move(buffer), size)); + return adopt_nonnull_ref_or_enomem(new (nothrow) Bitmap(format, alpha_type, move(buffer), size)); } -Bitmap::Bitmap(BitmapFormat format, Core::AnonymousBuffer buffer, IntSize size) +Bitmap::Bitmap(BitmapFormat format, AlphaType alpha_type, Core::AnonymousBuffer buffer, IntSize size) : m_size(size) , m_data(buffer.data()) , m_pitch(minimum_pitch(size.width(), format)) , m_format(format) + , m_alpha_type(alpha_type) , m_buffer(move(buffer)) { VERIFY(!size_would_overflow(format, size)); @@ -155,7 +165,7 @@ Bitmap::Bitmap(BitmapFormat format, Core::AnonymousBuffer buffer, IntSize size) ErrorOr> Bitmap::clone() const { - auto new_bitmap = TRY(Bitmap::create(format(), size())); + auto new_bitmap = TRY(Bitmap::create(format(), alpha_type(), size())); VERIFY(size_in_bytes() == new_bitmap->size_in_bytes()); memcpy(new_bitmap->scanline(0), scanline(0), size_in_bytes()); @@ -188,7 +198,7 @@ ErrorOr> Bitmap::scaled(int sx, int sy) const if (sx == 1 && sy == 1) return clone(); - auto new_bitmap = TRY(Gfx::Bitmap::create(format(), { width() * sx, height() * sy })); + auto new_bitmap = TRY(Gfx::Bitmap::create(format(), alpha_type(), { width() * sx, height() * sy })); auto old_width = width(); auto old_height = height(); @@ -224,7 +234,7 @@ ErrorOr> Bitmap::scaled(float sx, float sy) const // http://fourier.eng.hmc.edu/e161/lectures/resize/node3.html ErrorOr> Bitmap::scaled_to_size(Gfx::IntSize size) const { - auto new_bitmap = TRY(Gfx::Bitmap::create(format(), size)); + auto new_bitmap = TRY(Gfx::Bitmap::create(format(), alpha_type(), size)); auto old_width = width(); auto old_height = height(); @@ -344,7 +354,7 @@ ErrorOr> Bitmap::scaled_to_size(Gfx::IntSize size) co ErrorOr> Bitmap::cropped(Gfx::IntRect crop, Optional new_bitmap_format) const { - auto new_bitmap = TRY(Gfx::Bitmap::create(new_bitmap_format.value_or(format()), { crop.width(), crop.height() })); + auto new_bitmap = TRY(Gfx::Bitmap::create(new_bitmap_format.value_or(format()), alpha_type(), { crop.width(), crop.height() })); for (int y = 0; y < crop.height(); ++y) { for (int x = 0; x < crop.width(); ++x) { @@ -367,7 +377,7 @@ ErrorOr> Bitmap::to_bitmap_backed_by_anonymous_buffer() co return NonnullRefPtr { const_cast(*this) }; } auto buffer = TRY(Core::AnonymousBuffer::create_with_size(round_up_to_power_of_two(size_in_bytes(), PAGE_SIZE))); - auto bitmap = TRY(Bitmap::create_with_anonymous_buffer(m_format, move(buffer), size())); + auto bitmap = TRY(Bitmap::create_with_anonymous_buffer(format(), alpha_type(), move(buffer), size())); memcpy(bitmap->scanline(0), scanline(0), size_in_bytes()); return bitmap; } @@ -453,6 +463,7 @@ ErrorOr encode(Encoder& encoder, AK::NonnullRefPtr const& bit } TRY(encoder.encode(TRY(IPC::File::clone_fd(buffer.fd())))); TRY(encoder.encode(static_cast(bitmap->format()))); + TRY(encoder.encode(static_cast(bitmap->alpha_type()))); TRY(encoder.encode(bitmap->size_in_bytes())); TRY(encoder.encode(bitmap->pitch())); TRY(encoder.encode(bitmap->size())); @@ -463,15 +474,22 @@ template<> ErrorOr> decode(Decoder& decoder) { auto anon_file = TRY(decoder.decode()); + auto raw_bitmap_format = TRY(decoder.decode()); if (!Gfx::is_valid_bitmap_format(raw_bitmap_format)) return Error::from_string_literal("IPC: Invalid Gfx::ShareableBitmap format"); auto bitmap_format = static_cast(raw_bitmap_format); + + auto raw_alpha_type = TRY(decoder.decode()); + if (!Gfx::is_valid_alpha_type(raw_alpha_type)) + return Error::from_string_literal("IPC: Invalid Gfx::ShareableBitmap alpha type"); + auto alpha_type = static_cast(raw_alpha_type); + auto size_in_bytes = TRY(decoder.decode()); auto pitch = TRY(decoder.decode()); auto size = TRY(decoder.decode()); auto* data = TRY(Core::System::mmap(nullptr, round_up_to_power_of_two(size_in_bytes, PAGE_SIZE), PROT_READ | PROT_WRITE, MAP_SHARED, anon_file.fd(), 0)); - return Gfx::Bitmap::create_wrapper(bitmap_format, size, pitch, data, [data, size_in_bytes] { + return Gfx::Bitmap::create_wrapper(bitmap_format, alpha_type, size, pitch, data, [data, size_in_bytes] { MUST(Core::System::munmap(data, size_in_bytes)); }); } diff --git a/Userland/Libraries/LibGfx/Bitmap.h b/Userland/Libraries/LibGfx/Bitmap.h index 9b8be274c4c..7481a0058e5 100644 --- a/Userland/Libraries/LibGfx/Bitmap.h +++ b/Userland/Libraries/LibGfx/Bitmap.h @@ -63,12 +63,13 @@ struct BackingStore; class Bitmap : public RefCounted { public: [[nodiscard]] static ErrorOr> create(BitmapFormat, IntSize); - [[nodiscard]] static ErrorOr> create_shareable(BitmapFormat, IntSize); - [[nodiscard]] static ErrorOr> create_wrapper(BitmapFormat, IntSize, size_t pitch, void*, Function&& destruction_callback = {}); + [[nodiscard]] static ErrorOr> create(BitmapFormat, AlphaType, IntSize); + [[nodiscard]] static ErrorOr> create_shareable(BitmapFormat, AlphaType, IntSize); + [[nodiscard]] static ErrorOr> create_wrapper(BitmapFormat, AlphaType, IntSize, size_t pitch, void*, Function&& destruction_callback = {}); [[nodiscard]] static ErrorOr> load_from_file(StringView path, Optional ideal_size = {}); [[nodiscard]] static ErrorOr> load_from_file(NonnullOwnPtr, StringView path, Optional ideal_size = {}); [[nodiscard]] static ErrorOr> load_from_bytes(ReadonlyBytes, Optional ideal_size = {}, Optional mine_type = {}); - [[nodiscard]] static ErrorOr> create_with_anonymous_buffer(BitmapFormat, Core::AnonymousBuffer, IntSize); + [[nodiscard]] static ErrorOr> create_with_anonymous_buffer(BitmapFormat, AlphaType, Core::AnonymousBuffer, IntSize); ErrorOr> clone() const; @@ -159,10 +160,12 @@ public: [[nodiscard]] bool visually_equals(Bitmap const&) const; + [[nodiscard]] AlphaType alpha_type() const { return m_alpha_type; } + private: - Bitmap(BitmapFormat, IntSize, BackingStore const&); - Bitmap(BitmapFormat, IntSize, size_t pitch, void*, Function&& destruction_callback); - Bitmap(BitmapFormat, Core::AnonymousBuffer, IntSize); + Bitmap(BitmapFormat, AlphaType, IntSize, BackingStore const&); + Bitmap(BitmapFormat, AlphaType, IntSize, size_t pitch, void*, Function&& destruction_callback); + Bitmap(BitmapFormat, AlphaType, Core::AnonymousBuffer, IntSize); static ErrorOr allocate_backing_store(BitmapFormat format, IntSize size); @@ -170,6 +173,7 @@ private: void* m_data { nullptr }; size_t m_pitch { 0 }; BitmapFormat m_format { BitmapFormat::Invalid }; + AlphaType m_alpha_type { AlphaType::Premultiplied }; Core::AnonymousBuffer m_buffer; Function m_destruction_callback; }; diff --git a/Userland/Libraries/LibGfx/Color.h b/Userland/Libraries/LibGfx/Color.h index 2bb53994949..2b4817fa6c3 100644 --- a/Userland/Libraries/LibGfx/Color.h +++ b/Userland/Libraries/LibGfx/Color.h @@ -25,6 +25,16 @@ enum class AlphaType { Unpremultiplied, }; +inline bool is_valid_alpha_type(u32 alpha_type) +{ + switch (alpha_type) { + case (u32)AlphaType::Premultiplied: + case (u32)AlphaType::Unpremultiplied: + return true; + } + return false; +} + struct HSV { double hue { 0 }; double saturation { 0 }; diff --git a/Userland/Libraries/LibGfx/ShareableBitmap.cpp b/Userland/Libraries/LibGfx/ShareableBitmap.cpp index 372fb2285d0..ce9f020b74a 100644 --- a/Userland/Libraries/LibGfx/ShareableBitmap.cpp +++ b/Userland/Libraries/LibGfx/ShareableBitmap.cpp @@ -33,6 +33,7 @@ ErrorOr encode(Encoder& encoder, Gfx::ShareableBitmap const& shareable_bit TRY(encoder.encode(TRY(IPC::File::clone_fd(bitmap.anonymous_buffer().fd())))); TRY(encoder.encode(bitmap.size())); TRY(encoder.encode(static_cast(bitmap.format()))); + TRY(encoder.encode(static_cast(bitmap.alpha_type()))); return {}; } @@ -44,14 +45,19 @@ ErrorOr decode(Decoder& decoder) auto anon_file = TRY(decoder.decode()); auto size = TRY(decoder.decode()); + auto raw_bitmap_format = TRY(decoder.decode()); if (!Gfx::is_valid_bitmap_format(raw_bitmap_format)) return Error::from_string_literal("IPC: Invalid Gfx::ShareableBitmap format"); - auto bitmap_format = static_cast(raw_bitmap_format); + auto raw_alpha_type = TRY(decoder.decode()); + if (!Gfx::is_valid_alpha_type(raw_alpha_type)) + return Error::from_string_literal("IPC: Invalid Gfx::ShareableBitmap alpha type"); + auto alpha_type = static_cast(raw_alpha_type); + auto buffer = TRY(Core::AnonymousBuffer::create_from_anon_fd(anon_file.take_fd(), Gfx::Bitmap::size_in_bytes(Gfx::Bitmap::minimum_pitch(size.width(), bitmap_format), size.height()))); - auto bitmap = TRY(Gfx::Bitmap::create_with_anonymous_buffer(bitmap_format, move(buffer), size)); + auto bitmap = TRY(Gfx::Bitmap::create_with_anonymous_buffer(bitmap_format, alpha_type, move(buffer), size)); return Gfx::ShareableBitmap { move(bitmap), Gfx::ShareableBitmap::ConstructWithKnownGoodBitmap }; } diff --git a/Userland/Libraries/LibWeb/HTML/ImageData.cpp b/Userland/Libraries/LibWeb/HTML/ImageData.cpp index ff49112f815..dd9af815d5e 100644 --- a/Userland/Libraries/LibWeb/HTML/ImageData.cpp +++ b/Userland/Libraries/LibWeb/HTML/ImageData.cpp @@ -30,7 +30,7 @@ WebIDL::ExceptionOr> ImageData::create(JS::Realm& re // 2. Initialize this given sw, sh, and settings set to settings. // 3. Initialize the image data of this to transparent black. auto data = TRY(JS::Uint8ClampedArray::create(realm, sw * sh * 4)); - auto bitmap = TRY_OR_THROW_OOM(vm, Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::RGBA8888, Gfx::IntSize(sw, sh), sw * sizeof(u32), data->data().data())); + auto bitmap = TRY_OR_THROW_OOM(vm, Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::RGBA8888, Gfx::AlphaType::Premultiplied, Gfx::IntSize(sw, sh), sw * sizeof(u32), data->data().data())); return realm.heap().allocate(realm, realm, bitmap, data); } @@ -74,7 +74,7 @@ WebIDL::ExceptionOr> ImageData::create(JS::Realm& re return WebIDL::IndexSizeError::create(realm, "Source height must be equal to the calculated height of the data."_fly_string); // 7. Initialize this given sw, sh, settings set to settings, and source set to data. - auto bitmap = TRY_OR_THROW_OOM(vm, Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::RGBA8888, Gfx::IntSize(sw, height), sw * sizeof(u32), uint8_clamped_array_data.data().data())); + auto bitmap = TRY_OR_THROW_OOM(vm, Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::RGBA8888, Gfx::AlphaType::Premultiplied, Gfx::IntSize(sw, height), sw * sizeof(u32), uint8_clamped_array_data.data().data())); return realm.heap().allocate(realm, realm, bitmap, uint8_clamped_array_data); } diff --git a/Userland/Libraries/LibWeb/Painting/BackingStore.cpp b/Userland/Libraries/LibWeb/Painting/BackingStore.cpp index df012934297..ccea6c21a60 100644 --- a/Userland/Libraries/LibWeb/Painting/BackingStore.cpp +++ b/Userland/Libraries/LibWeb/Painting/BackingStore.cpp @@ -19,7 +19,7 @@ IOSurfaceBackingStore::IOSurfaceBackingStore(Core::IOSurfaceHandle&& iosurface_h : m_iosurface_handle(move(iosurface_handle)) { auto bytes_per_row = m_iosurface_handle.bytes_per_row(); - auto bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, size(), bytes_per_row, m_iosurface_handle.data()); + auto bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, size(), bytes_per_row, m_iosurface_handle.data()); m_bitmap_wrapper = bitmap.release_value(); } diff --git a/Userland/Libraries/LibWebView/ViewImplementation.cpp b/Userland/Libraries/LibWebView/ViewImplementation.cpp index 6b4366aa332..bfdc7c1af2d 100644 --- a/Userland/Libraries/LibWebView/ViewImplementation.cpp +++ b/Userland/Libraries/LibWebView/ViewImplementation.cpp @@ -431,8 +431,8 @@ void ViewImplementation::did_allocate_iosurface_backing_stores(i32 front_id, Cor auto bytes_per_row = front_iosurface.bytes_per_row(); - auto front_bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, front_size, bytes_per_row, front_iosurface.data(), [handle = move(front_iosurface)] {}); - auto back_bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, back_size, bytes_per_row, back_iosurface.data(), [handle = move(back_iosurface)] {}); + auto front_bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, front_size, bytes_per_row, front_iosurface.data(), [handle = move(front_iosurface)] {}); + auto back_bitmap = Gfx::Bitmap::create_wrapper(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, back_size, bytes_per_row, back_iosurface.data(), [handle = move(back_iosurface)] {}); m_client_state.front_bitmap.bitmap = front_bitmap.release_value_but_fixme_should_propagate_errors(); m_client_state.front_bitmap.id = front_id; diff --git a/Userland/Services/WebContent/BackingStoreManager.cpp b/Userland/Services/WebContent/BackingStoreManager.cpp index 23c67e09551..74ea6e152c5 100644 --- a/Userland/Services/WebContent/BackingStoreManager.cpp +++ b/Userland/Services/WebContent/BackingStoreManager.cpp @@ -93,8 +93,8 @@ void BackingStoreManager::reallocate_backing_stores(Gfx::IntSize size) m_front_bitmap_id = m_next_bitmap_id++; m_back_bitmap_id = m_next_bitmap_id++; - auto front_bitmap = Gfx::Bitmap::create_shareable(Gfx::BitmapFormat::BGRA8888, size).release_value(); - auto back_bitmap = Gfx::Bitmap::create_shareable(Gfx::BitmapFormat::BGRA8888, size).release_value(); + auto front_bitmap = Gfx::Bitmap::create_shareable(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, size).release_value(); + auto back_bitmap = Gfx::Bitmap::create_shareable(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, size).release_value(); m_front_store = make(front_bitmap); m_back_store = make(back_bitmap);