RenderingVisualizationUtils.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "SceneRendering.h"
#include "ScreenPass.h"
#include "UnrealEngine.h"
 
template <typename EntryContainerType>
void AddLegendCanvasPass(FRDGBuilder& GraphBuilder, const FViewInfo& View, FScreenPassRenderTarget OutputTarget, const FString& HeaderLabel, FVector2f LegendAnchorPositionLowerLeft, FVector2f LegendMinSize, const EntryContainerType& LegendEntries)
{
    AddDrawCanvasPass(GraphBuilder, RDG_EVENT_NAME("Labels"), View, OutputTarget,
    [&](FCanvas& Canvas)
    {
        UFont* StatsFont = GetStatsFont();
 
        const float DPIScale = Canvas.GetDPIScale();
        Canvas.SetBaseTransform(FMatrix(FScaleMatrix(DPIScale) * Canvas.CalcBaseTransform2D(Canvas.GetViewRect().Width(), Canvas.GetViewRect().Height())));
 
        auto DrawColorTile = [&](float X, float Y, float Width, float Height, const FLinearColor& Color)
        {
            Canvas.DrawTile(X/DPIScale, Y/DPIScale, Width/DPIScale, Height/DPIScale, 0, 0, 0, 0, Color);
        };
 
        auto DrawShadowedString = [&](float X, float Y, FStringView Text, const FLinearColor& Color = FLinearColor::White)
        {
            Canvas.DrawShadowedString(X / DPIScale, Y / DPIScale, Text, StatsFont, Color);
        };
        
        const float YStride = 20.0f * DPIScale;
 
        FVector2f LegendPosition = LegendAnchorPositionLowerLeft;
        auto DrawLegendEntry = [&](const FString& Label, FLinearColor Color)
        {
            DrawColorTile(LegendPosition.X + 7.0f * DPIScale, LegendPosition.Y + 5.0f * DPIScale, 10.0f * DPIScale, 10.0f * DPIScale, Color);
            DrawShadowedString(LegendPosition.X + YStride, LegendPosition.Y + 2.0f * DPIScale, Label);
            LegendPosition.Y += YStride;
        };
 
        auto GetStringWidth = [&](FStringView StringView) -> float
        {
            int32 XL = 0;
            int32 YL = 0;
            StringSize(StatsFont, XL, YL, StringView);
            return float(XL);
        };
 
        float AutoSizeY = FMath::Max(LegendMinSize.Y, float(LegendEntries.Num() + 1) * 20.0f + 10.0f) * DPIScale;
        // using lower left positioning
        LegendPosition.Y -= AutoSizeY;
 
        float AutoSizeX = FMath::Max(LegendMinSize.X, GetStringWidth(HeaderLabel));
        for (const auto& Entry : LegendEntries)
        {
            AutoSizeX = FMath::Max(AutoSizeX, GetStringWidth(Entry.Label.ToString()));
        }
        AutoSizeX += 35.0f;
        AutoSizeX *= DPIScale;
 
        DrawColorTile(LegendPosition.X, LegendPosition.Y, AutoSizeX, AutoSizeY, FLinearColor(0.1f, 0.1f, 0.1f, 0.8f));
        DrawShadowedString(LegendPosition.X + 5.0f * DPIScale, LegendPosition.Y + 5.0f * DPIScale, HeaderLabel);
        LegendPosition.Y += YStride;
 
        for (const auto& Entry : LegendEntries)
        {
            DrawLegendEntry(Entry.Label.ToString(), Entry.Color);
        }
    });
}