Files
UnrealEngine/Engine/Source/Runtime/Slate/Private/Framework/Text/SlateTextUnderlineLineHighlighter.cpp
2025-05-18 13:04:45 +08:00

108 lines
5.7 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "Framework/Text/SlateTextUnderlineLineHighlighter.h"
#include "Rendering/SlateLayoutTransform.h"
#include "Rendering/DrawElements.h"
#include "Fonts/FontCache.h"
#include "Framework/Application/SlateApplication.h"
ISlateTextLineHighlighter::ISlateTextLineHighlighter(const FSlateBrush& InLineBrush, const FSlateFontInfo& InFontInfo, const FSlateColor InColorAndOpacity, const UE::Slate::FDeprecateVector2DParameter InShadowOffset, const FLinearColor InShadowColorAndOpacity)
: LineBrush(InLineBrush)
, FontInfo(InFontInfo)
, ColorAndOpacity(InColorAndOpacity)
, ShadowOffset(InShadowOffset)
, ShadowColorAndOpacity(InShadowColorAndOpacity)
{
}
int32 ISlateTextLineHighlighter::OnPaint(const FPaintArgs& Args, const FTextLayout::FLineView& Line, const FVector2D Offset, const float Width, const FTextBlockStyle& DefaultStyle, const FGeometry& AllottedGeometry, const FSlateRect& MyCullingRect, FSlateWindowElementList& OutDrawElements, int32 LayerId, const FWidgetStyle& InWidgetStyle, bool bParentEnabled) const
{
TSharedRef<FSlateFontCache> FontCache = FSlateApplication::Get().GetRenderer()->GetFontCache();
const uint16 MaxHeight = FontCache->GetMaxCharacterHeight(FontInfo, AllottedGeometry.Scale);
const int16 Baseline = FontCache->GetBaseline(FontInfo, AllottedGeometry.Scale);
int16 LinePos, LineThickness;
GetLineMetrics(AllottedGeometry.Scale, LinePos, LineThickness);
const FVector2f Location(Line.Offset.X + Offset.X, Line.Offset.Y + Offset.Y + MaxHeight + Baseline - (LinePos * 0.5f));
const FVector2f Size(Width, FMath::Max<int16>(1, LineThickness));
// The block size and offset values are pre-scaled, so we need to account for that when converting the block offsets into paint geometry
const float InverseScale = Inverse(AllottedGeometry.Scale);
if (Size.X)
{
const FLinearColor LineColorAndOpacity = ColorAndOpacity.GetColor(InWidgetStyle);
const bool ShouldDropShadow = ShadowColorAndOpacity.A > 0.f && ShadowOffset.SizeSquared() > 0.f;
// A negative shadow offset should be applied as a positive offset to the underline to avoid clipping issues
const FVector2f DrawShadowOffset(
(ShadowOffset.X > 0.0f) ? ShadowOffset.X * AllottedGeometry.Scale : 0.0f,
(ShadowOffset.Y > 0.0f) ? ShadowOffset.Y * AllottedGeometry.Scale : 0.0f
);
const FVector2f DrawUnderlineOffset(
(ShadowOffset.X < 0.0f) ? -ShadowOffset.X * AllottedGeometry.Scale : 0.0f,
(ShadowOffset.Y < 0.0f) ? -ShadowOffset.Y * AllottedGeometry.Scale : 0.0f
);
// Draw the optional shadow
if (ShouldDropShadow)
{
FSlateDrawElement::MakeBox(
OutDrawElements,
++LayerId,
AllottedGeometry.ToPaintGeometry(TransformVector(InverseScale, Size), FSlateLayoutTransform(TransformPoint(InverseScale, Location + DrawShadowOffset))),
&LineBrush,
bParentEnabled ? ESlateDrawEffect::None : ESlateDrawEffect::DisabledEffect,
ShadowColorAndOpacity * InWidgetStyle.GetColorAndOpacityTint()
);
}
// Draw underline/strike
FSlateDrawElement::MakeBox(
OutDrawElements,
++LayerId,
AllottedGeometry.ToPaintGeometry(TransformVector(InverseScale, Size), FSlateLayoutTransform(TransformPoint(InverseScale, Location + DrawUnderlineOffset))),
&LineBrush,
bParentEnabled ? ESlateDrawEffect::None : ESlateDrawEffect::DisabledEffect,
LineColorAndOpacity * InWidgetStyle.GetColorAndOpacityTint()
);
}
return LayerId;
}
FSlateTextUnderlineLineHighlighter::FSlateTextUnderlineLineHighlighter(const FSlateBrush& InUnderlineBrush, const FSlateFontInfo& InFontInfo, const FSlateColor InColorAndOpacity, const UE::Slate::FDeprecateVector2DParameter InShadowOffset, const FLinearColor InShadowColorAndOpacity)
: ISlateTextLineHighlighter(InUnderlineBrush, InFontInfo, InColorAndOpacity, InShadowOffset, InShadowColorAndOpacity)
{
}
TSharedRef<FSlateTextUnderlineLineHighlighter> FSlateTextUnderlineLineHighlighter::Create(const FSlateBrush& InUnderlineBrush, const FSlateFontInfo& InFontInfo, const FSlateColor InColorAndOpacity, const UE::Slate::FDeprecateVector2DParameter InShadowOffset, const FLinearColor InShadowColorAndOpacity)
{
return MakeShareable(new FSlateTextUnderlineLineHighlighter(InUnderlineBrush, InFontInfo, InColorAndOpacity, InShadowOffset, InShadowColorAndOpacity));
}
void FSlateTextUnderlineLineHighlighter::GetLineMetrics(const float InFontScale, int16& OutLinePos, int16& OutLineThickness) const
{
TSharedRef<FSlateFontCache> FontCache = FSlateApplication::Get().GetRenderer()->GetFontCache();
FontCache->GetUnderlineMetrics(FontInfo, InFontScale, OutLinePos, OutLineThickness);
}
FSlateTextStrikeLineHighlighter::FSlateTextStrikeLineHighlighter(const FSlateBrush& InUnderlineBrush, const FSlateFontInfo& InFontInfo, const FSlateColor InColorAndOpacity, const UE::Slate::FDeprecateVector2DParameter InShadowOffset, const FLinearColor InShadowColorAndOpacity)
: ISlateTextLineHighlighter(InUnderlineBrush, InFontInfo, InColorAndOpacity, InShadowOffset, InShadowColorAndOpacity)
{
}
TSharedRef<FSlateTextStrikeLineHighlighter> FSlateTextStrikeLineHighlighter::Create(const FSlateBrush& InUnderlineBrush, const FSlateFontInfo& InFontInfo, const FSlateColor InColorAndOpacity, const UE::Slate::FDeprecateVector2DParameter InShadowOffset, const FLinearColor InShadowColorAndOpacity)
{
return MakeShareable(new FSlateTextStrikeLineHighlighter(InUnderlineBrush, InFontInfo, InColorAndOpacity, InShadowOffset, InShadowColorAndOpacity));
}
void FSlateTextStrikeLineHighlighter::GetLineMetrics(const float InFontScale, int16& OutLinePos, int16& OutLineThickness) const
{
TSharedRef<FSlateFontCache> FontCache = FSlateApplication::Get().GetRenderer()->GetFontCache();
FontCache->GetStrikeMetrics(FontInfo, InFontScale, OutLinePos, OutLineThickness);
}