LibWeb: Use box sampling instead of bilinear scaling when downscaling

As a heuristic, either the width or height of the scaled image should
decrease for box sampling to be used. Otherwise, we use bilinear
scaling.
This commit is contained in:
Jelle Raaijmakers 2023-05-19 00:41:12 +02:00 committed by Andreas Kling
parent 81b30ec372
commit b79fd3d1a9
5 changed files with 13 additions and 6 deletions

View file

@ -185,12 +185,14 @@ struct BorderRadiusData {
}; };
// FIXME: Find a better place for this helper. // FIXME: Find a better place for this helper.
inline Gfx::Painter::ScalingMode to_gfx_scaling_mode(CSS::ImageRendering css_value) inline Gfx::Painter::ScalingMode to_gfx_scaling_mode(CSS::ImageRendering css_value, Gfx::IntRect source, Gfx::IntRect target)
{ {
switch (css_value) { switch (css_value) {
case CSS::ImageRendering::Auto: case CSS::ImageRendering::Auto:
case CSS::ImageRendering::HighQuality: case CSS::ImageRendering::HighQuality:
case CSS::ImageRendering::Smooth: case CSS::ImageRendering::Smooth:
if (target.width() < source.width() || target.height() < source.height())
return Gfx::Painter::ScalingMode::BoxSampling;
return Gfx::Painter::ScalingMode::BilinearBlend; return Gfx::Painter::ScalingMode::BilinearBlend;
case CSS::ImageRendering::CrispEdges: case CSS::ImageRendering::CrispEdges:
return Gfx::Painter::ScalingMode::NearestNeighbor; return Gfx::Painter::ScalingMode::NearestNeighbor;

View file

@ -102,8 +102,10 @@ Optional<CSSPixels> ImageStyleValue::natural_height() const
void ImageStyleValue::paint(PaintContext& context, DevicePixelRect const& dest_rect, CSS::ImageRendering image_rendering) const void ImageStyleValue::paint(PaintContext& context, DevicePixelRect const& dest_rect, CSS::ImageRendering image_rendering) const
{ {
if (auto* b = bitmap(m_current_frame_index); b != nullptr) if (auto* b = bitmap(m_current_frame_index); b != nullptr) {
context.painter().draw_scaled_bitmap(dest_rect.to_type<int>(), *b, bitmap(0)->rect(), 1.0f, to_gfx_scaling_mode(image_rendering)); auto scaling_mode = to_gfx_scaling_mode(image_rendering, bitmap(0)->rect(), dest_rect.to_type<int>());
context.painter().draw_scaled_bitmap(dest_rect.to_type<int>(), *b, bitmap(0)->rect(), 1.f, scaling_mode);
}
} }
} }

View file

@ -41,7 +41,8 @@ void CanvasPaintable::paint(PaintContext& context, PaintPhase phase) const
if (layout_box().dom_node().bitmap()) { if (layout_box().dom_node().bitmap()) {
// FIXME: Remove this const_cast. // FIXME: Remove this const_cast.
const_cast<HTML::HTMLCanvasElement&>(layout_box().dom_node()).present(); const_cast<HTML::HTMLCanvasElement&>(layout_box().dom_node()).present();
context.painter().draw_scaled_bitmap(canvas_rect.to_type<int>(), *layout_box().dom_node().bitmap(), layout_box().dom_node().bitmap()->rect(), 1.0f, to_gfx_scaling_mode(computed_values().image_rendering())); auto scaling_mode = to_gfx_scaling_mode(computed_values().image_rendering(), layout_box().dom_node().bitmap()->rect(), canvas_rect.to_type<int>());
context.painter().draw_scaled_bitmap(canvas_rect.to_type<int>(), *layout_box().dom_node().bitmap(), layout_box().dom_node().bitmap()->rect(), 1.0f, scaling_mode);
} }
} }
} }

View file

@ -64,7 +64,8 @@ void ImagePaintable::paint(PaintContext& context, PaintPhase phase) const
} else if (auto bitmap = layout_box().image_provider().current_image_bitmap()) { } else if (auto bitmap = layout_box().image_provider().current_image_bitmap()) {
auto image_rect = context.rounded_device_rect(absolute_rect()); auto image_rect = context.rounded_device_rect(absolute_rect());
ScopedCornerRadiusClip corner_clip { context, context.painter(), image_rect, normalized_border_radii_data(ShrinkRadiiForBorders::Yes) }; ScopedCornerRadiusClip corner_clip { context, context.painter(), image_rect, normalized_border_radii_data(ShrinkRadiiForBorders::Yes) };
context.painter().draw_scaled_bitmap(image_rect.to_type<int>(), *bitmap, bitmap->rect(), 1.0f, to_gfx_scaling_mode(computed_values().image_rendering())); auto scaling_mode = to_gfx_scaling_mode(computed_values().image_rendering(), bitmap->rect(), image_rect.to_type<int>());
context.painter().draw_scaled_bitmap(image_rect.to_type<int>(), *bitmap, bitmap->rect(), 1.f, scaling_mode);
} }
} }
} }

View file

@ -135,7 +135,8 @@ void VideoPaintable::paint(PaintContext& context, PaintPhase phase) const
} }
auto paint_frame = [&](auto const& frame) { auto paint_frame = [&](auto const& frame) {
context.painter().draw_scaled_bitmap(video_rect.to_type<int>(), *frame, frame->rect(), 1.0f, to_gfx_scaling_mode(computed_values().image_rendering())); auto scaling_mode = to_gfx_scaling_mode(computed_values().image_rendering(), frame->rect(), video_rect.to_type<int>());
context.painter().draw_scaled_bitmap(video_rect.to_type<int>(), *frame, frame->rect(), 1.f, scaling_mode);
}; };
auto paint_transparent_black = [&]() { auto paint_transparent_black = [&]() {