1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-06-08 05:27:14 +09:00
ladybird/Libraries/LibGfx/PaintingSurface.cpp
Jelle Raaijmakers 35efd4d14b LibWeb+LibGfx: Support alpha in CanvasRenderingContext2D
This is implemented by these related changes:

  * The Skia alpha type 'Opaque' is selected for surfaces that were
    created with the intention of not having an alpha channel.
    Previously we were simply creating one with alpha.

  * Clearing now happens through Skia's `clear()` which always uses the
    source color's value for the result, instead of setting all values
    to 0.

  * CanvasRenderingContext2D selects a different clearing color based on
    the `alpha` context attribute's value.
2025-04-29 13:51:23 +02:00

173 lines
5.5 KiB
C++

/*
* Copyright (c) 2024, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGfx/Bitmap.h>
#include <LibGfx/PaintingSurface.h>
#include <LibGfx/SkiaUtils.h>
#include <core/SkColorSpace.h>
#include <core/SkSurface.h>
#include <gpu/GrBackendSurface.h>
#include <gpu/GrDirectContext.h>
#include <gpu/ganesh/SkSurfaceGanesh.h>
#ifdef AK_OS_MACOS
# include <gpu/ganesh/mtl/GrMtlBackendSurface.h>
#endif
namespace Gfx {
struct PaintingSurface::Impl {
RefPtr<SkiaBackendContext> context;
IntSize size;
sk_sp<SkSurface> surface;
RefPtr<Bitmap> bitmap;
};
NonnullRefPtr<PaintingSurface> PaintingSurface::create_with_size(RefPtr<SkiaBackendContext> context, IntSize size, BitmapFormat color_type, AlphaType alpha_type)
{
auto sk_color_type = to_skia_color_type(color_type);
auto sk_alpha_type = to_skia_alpha_type(color_type, alpha_type);
auto image_info = SkImageInfo::Make(size.width(), size.height(), sk_color_type, sk_alpha_type, SkColorSpace::MakeSRGB());
if (!context) {
auto bitmap = Bitmap::create(color_type, alpha_type, size).value();
auto surface = SkSurfaces::WrapPixels(image_info, bitmap->begin(), bitmap->pitch());
VERIFY(surface);
return adopt_ref(*new PaintingSurface(make<Impl>(context, size, surface, bitmap)));
}
context->lock();
auto surface = SkSurfaces::RenderTarget(context->sk_context(), skgpu::Budgeted::kNo, image_info);
VERIFY(surface);
context->unlock();
return adopt_ref(*new PaintingSurface(make<Impl>(context, size, surface, nullptr)));
}
NonnullRefPtr<PaintingSurface> PaintingSurface::wrap_bitmap(Bitmap& bitmap)
{
auto color_type = to_skia_color_type(bitmap.format());
auto alpha_type = to_skia_alpha_type(bitmap.format(), bitmap.alpha_type());
auto size = bitmap.size();
auto image_info = SkImageInfo::Make(bitmap.width(), bitmap.height(), color_type, alpha_type, SkColorSpace::MakeSRGB());
auto surface = SkSurfaces::WrapPixels(image_info, bitmap.begin(), bitmap.pitch());
return adopt_ref(*new PaintingSurface(make<Impl>(RefPtr<SkiaBackendContext> {}, size, surface, bitmap)));
}
#ifdef AK_OS_MACOS
NonnullRefPtr<PaintingSurface> PaintingSurface::wrap_iosurface(Core::IOSurfaceHandle const& iosurface_handle, RefPtr<SkiaBackendContext> context, Origin origin)
{
context->lock();
ScopeGuard unlock_guard([&context] {
context->unlock();
});
auto metal_texture = context->metal_context().create_texture_from_iosurface(iosurface_handle);
IntSize const size { metal_texture->width(), metal_texture->height() };
auto image_info = SkImageInfo::Make(size.width(), size.height(), kBGRA_8888_SkColorType, kPremul_SkAlphaType, SkColorSpace::MakeSRGB());
GrMtlTextureInfo mtl_info;
mtl_info.fTexture = sk_ret_cfp(metal_texture->texture());
auto backend_render_target = GrBackendRenderTargets::MakeMtl(metal_texture->width(), metal_texture->height(), mtl_info);
GrSurfaceOrigin sk_origin;
switch (origin) {
case Origin::TopLeft:
sk_origin = kTopLeft_GrSurfaceOrigin;
break;
case Origin::BottomLeft:
sk_origin = kBottomLeft_GrSurfaceOrigin;
break;
default:
VERIFY_NOT_REACHED();
}
auto surface = SkSurfaces::WrapBackendRenderTarget(context->sk_context(), backend_render_target, sk_origin, kBGRA_8888_SkColorType, nullptr, nullptr);
return adopt_ref(*new PaintingSurface(make<Impl>(context, size, surface, nullptr)));
}
#endif
PaintingSurface::PaintingSurface(NonnullOwnPtr<Impl>&& impl)
: m_impl(move(impl))
{
}
PaintingSurface::~PaintingSurface()
{
lock_context();
m_impl->surface = nullptr;
unlock_context();
}
void PaintingSurface::read_into_bitmap(Bitmap& bitmap)
{
auto color_type = to_skia_color_type(bitmap.format());
auto alpha_type = to_skia_alpha_type(bitmap.format(), bitmap.alpha_type());
auto image_info = SkImageInfo::Make(bitmap.width(), bitmap.height(), color_type, alpha_type, SkColorSpace::MakeSRGB());
SkPixmap const pixmap(image_info, bitmap.begin(), bitmap.pitch());
m_impl->surface->readPixels(pixmap, 0, 0);
}
void PaintingSurface::write_from_bitmap(Bitmap const& bitmap)
{
auto color_type = to_skia_color_type(bitmap.format());
auto alpha_type = to_skia_alpha_type(bitmap.format(), bitmap.alpha_type());
auto image_info = SkImageInfo::Make(bitmap.width(), bitmap.height(), color_type, alpha_type, SkColorSpace::MakeSRGB());
SkPixmap const pixmap(image_info, bitmap.begin(), bitmap.pitch());
m_impl->surface->writePixels(pixmap, 0, 0);
}
IntSize PaintingSurface::size() const
{
return m_impl->size;
}
IntRect PaintingSurface::rect() const
{
return { {}, m_impl->size };
}
SkCanvas& PaintingSurface::canvas() const
{
return *m_impl->surface->getCanvas();
}
SkSurface& PaintingSurface::sk_surface() const
{
return *m_impl->surface;
}
void PaintingSurface::notify_content_will_change()
{
lock_context();
m_impl->surface->notifyContentWillChange(SkSurface::kDiscard_ContentChangeMode);
unlock_context();
}
template<>
sk_sp<SkImage> PaintingSurface::sk_image_snapshot() const
{
return m_impl->surface->makeImageSnapshot();
}
void PaintingSurface::flush()
{
if (on_flush)
on_flush(*this);
}
void PaintingSurface::lock_context() const
{
auto& context = m_impl->context;
if (context)
context->lock();
}
void PaintingSurface::unlock_context() const
{
auto& context = m_impl->context;
if (context)
context->unlock();
}
}