void USlateBrushThumbnailRenderer::Draw(UObject* Object, int32 X, int32 Y, uint32 Width, uint32 Height, FRenderTarget* RenderTarget, FCanvas* Canvas)
{
USlateBrushAsset* SlateBrushAsset = Cast<USlateBrushAsset>(Object);
if (SlateBrushAsset)
{
FSlateBrush Brush = SlateBrushAsset->Brush;
UTexture2D* Texture = Cast<UTexture2D>( Brush.GetResourceObject() );
// Draw the background checkboard pattern
const int32 CheckerDensity = 8;
auto* Checker = UThumbnailManager::Get().CheckerboardTexture;
Canvas->DrawTile(
0.0f, 0.0f, Width, Height, // Dimensions
0.0f, 0.0f, CheckerDensity, CheckerDensity, // UVs
FLinearColor::White, Checker->Resource); // Tint & Texture
if (Texture)
{
switch(Brush.DrawAs)
{
case ESlateBrushDrawType::Image:
{
FCanvasTileItem CanvasTile( FVector2D( X, Y ), Texture->Resource, FVector2D( Width,Height ), Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
break;
case ESlateBrushDrawType::Border:
{
FCanvasTileItem CanvasTile( FVector2D( X, Y ), Texture->Resource, FVector2D( Width,Height ), Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
break;
case ESlateBrushDrawType::Box:
{
float NaturalWidth = Texture->GetSurfaceWidth();
float NaturalHeight = Texture->GetSurfaceHeight();
float TopPx = FMath::Clamp<float>(NaturalHeight * Brush.Margin.Top, 0, Height);
float BottomPx = FMath::Clamp<float>(NaturalHeight * Brush.Margin.Bottom, 0, Height);
float VerticalCenterPx = FMath::Clamp<float>(Height - TopPx - BottomPx, 0, Height);
float LeftPx = FMath::Clamp<float>(NaturalWidth * Brush.Margin.Left, 0, Width);
float RightPx = FMath::Clamp<float>(NaturalWidth * Brush.Margin.Right, 0, Width);
float HorizontalCenterPx = FMath::Clamp<float>(Width - LeftPx - RightPx, 0, Width);
// Top-Left
FVector2D TopLeftSize( LeftPx, TopPx );
{
FVector2D UV0( 0, 0 );
FVector2D UV1( Brush.Margin.Left, Brush.Margin.Top );
FCanvasTileItem CanvasTile( FVector2D( X, Y ), Texture->Resource, TopLeftSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
// Bottom-Left
FVector2D BottomLeftSize( LeftPx, BottomPx );
{
FVector2D UV0( 0, 1 - Brush.Margin.Bottom );
FVector2D UV1( Brush.Margin.Left, 1 );
FCanvasTileItem CanvasTile( FVector2D( X, Y + Height - BottomPx ), Texture->Resource, BottomLeftSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
// Top-Right
FVector2D TopRightSize( RightPx, TopPx );
{
FVector2D UV0( 1 - Brush.Margin.Right, 0 );
FVector2D UV1( 1, Brush.Margin.Top );
FCanvasTileItem CanvasTile( FVector2D( X + Width - RightPx, Y ), Texture->Resource, TopRightSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
// Bottom-Right
FVector2D BottomRightSize( RightPx, BottomPx );
{
FVector2D UV0( 1 - Brush.Margin.Right, 1 - Brush.Margin.Bottom );
FVector2D UV1( 1, 1 );
FCanvasTileItem CanvasTile( FVector2D( X + Width - RightPx, Y + Height - BottomPx ), Texture->Resource, BottomRightSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
//-----------------------------------------------------------------------
// Center-Vertical-Left
FVector2D CenterVerticalLeftSize( LeftPx, VerticalCenterPx );
{
FVector2D UV0( 0, Brush.Margin.Top );
FVector2D UV1( Brush.Margin.Left, 1 - Brush.Margin.Bottom );
FCanvasTileItem CanvasTile( FVector2D( X, Y + TopPx), Texture->Resource, CenterVerticalLeftSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
// Center-Vertical-Right
FVector2D CenterVerticalRightSize( RightPx, VerticalCenterPx );
{
FVector2D UV0( 1 - Brush.Margin.Right, Brush.Margin.Top );
FVector2D UV1( 1, 1 - Brush.Margin.Bottom );
FCanvasTileItem CanvasTile( FVector2D( X + Width - RightPx, Y + TopPx), Texture->Resource, CenterVerticalRightSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
//-----------------------------------------------------------------------
// Center-Horizontal-Top
FVector2D CenterHorizontalTopSize( HorizontalCenterPx, TopPx );
{
FVector2D UV0( Brush.Margin.Left, 0 );
FVector2D UV1( 1 - Brush.Margin.Right, Brush.Margin.Top );
FCanvasTileItem CanvasTile( FVector2D( X + LeftPx, Y), Texture->Resource, CenterHorizontalTopSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
// Center-Horizontal-Bottom
FVector2D CenterHorizontalBottomSize( HorizontalCenterPx, BottomPx );
{
FVector2D UV0( Brush.Margin.Left, 1 - Brush.Margin.Bottom );
FVector2D UV1( 1 - Brush.Margin.Right, 1 );
FCanvasTileItem CanvasTile( FVector2D( X + LeftPx, Y + Height - BottomPx ), Texture->Resource, CenterHorizontalBottomSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
//-----------------------------------------------------------------------
// Center
FVector2D CenterSize( HorizontalCenterPx, VerticalCenterPx );
{
FVector2D UV0( Brush.Margin.Left, Brush.Margin.Top );
FVector2D UV1( 1 - Brush.Margin.Right, 1 - Brush.Margin.Bottom );
FCanvasTileItem CanvasTile( FVector2D( X + LeftPx, Y + TopPx), Texture->Resource, CenterSize, UV0, UV1, Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
}
break;
case ESlateBrushDrawType::NoDrawType:
{
FCanvasTileItem CanvasTile( FVector2D( X, Y ), Texture->Resource, FVector2D( Width,Height ), Brush.TintColor.GetSpecifiedColor() );
CanvasTile.BlendMode = SE_BLEND_Translucent;
CanvasTile.Draw( Canvas );
}
break;
default:
check(false);
}
}
}
}
void UTextureThumbnailRenderer::Draw(UObject* Object, int32 X, int32 Y, uint32 Width, uint32 Height, FRenderTarget*, FCanvas* Canvas)
{
UTexture* Texture = Cast<UTexture>(Object);
if (Texture != nullptr && Texture->Resource != nullptr)
{
UTexture2D* Texture2D = Cast<UTexture2D>(Texture);
// Take the alpha channel into account for textures that have one.
// This provides a much better preview than just showing RGB,
// Because the RGB content in areas with an alpha of 0 is often garbage that will not be seen in normal conditions.
// Non-UI textures often have uncorrelated data in the alpha channel (like a skin mask, specular power, etc) so we only preview UI textures this way.
const bool bUseTranslucentBlend = Texture2D && Texture2D->HasAlphaChannel() && Texture2D->LODGroup == TEXTUREGROUP_UI;
UTextureCube* TextureCube = Cast<UTextureCube>(Texture);
UTextureRenderTargetCube* RTTextureCube = Cast<UTextureRenderTargetCube>(Texture);
UTextureLightProfile* TextureLightProfile = Cast<UTextureLightProfile>(Texture);
TRefCountPtr<FBatchedElementParameters> BatchedElementParameters;
if(TextureCube || RTTextureCube)
{
// is released by the render thread when it was rendered
BatchedElementParameters = new FMipLevelBatchedElementParameters((float)0);
// If the thumbnail is square then make it 2:1 for cubes.
if(Width == Height)
{
Height = Width / 2;
Y += Height / 2;
}
}
else if (TextureLightProfile)
{
BatchedElementParameters = new FIESLightProfileBatchedElementParameters(TextureLightProfile->Brightness);
}
else if (Texture2D && Texture2D->IsNormalMap())
{
BatchedElementParameters = new FNormalMapBatchedElementParameters();
}
if (bUseTranslucentBlend)
{
// If using alpha, draw a checkerboard underneath first.
const int32 CheckerDensity = 8;
auto* Checker = UThumbnailManager::Get().CheckerboardTexture;
Canvas->DrawTile(
0.0f, 0.0f, Width, Height, // Dimensions
0.0f, 0.0f, CheckerDensity, CheckerDensity, // UVs
FLinearColor::White, Checker->Resource); // Tint & Texture
}
// Use A canvas tile item to draw
FCanvasTileItem CanvasTile( FVector2D( X, Y ), Texture->Resource, FVector2D( Width,Height ), FLinearColor::White );
CanvasTile.BlendMode = bUseTranslucentBlend ? SE_BLEND_Translucent : SE_BLEND_Opaque;
CanvasTile.BatchedElementParameters = BatchedElementParameters;
CanvasTile.Draw( Canvas );
if (TextureLightProfile)
{
float Brightness = TextureLightProfile->Brightness;
// Brightness in Lumens
FText BrightnessText = FText::AsNumber( Brightness );
FCanvasTextItem TextItem( FVector2D( 5.0f, 5.0f ), BrightnessText, GEngine->GetLargeFont(), FLinearColor::White );
TextItem.EnableShadow(FLinearColor::Black);
TextItem.Scale = FVector2D(Width / 128.0f, Height / 128.0f);
TextItem.Draw(Canvas);
}
}
}