From 84e8c25e375006a2661d1f81bdaf1ec2018872d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vojt=C4=9Bch=20Fo=C5=A1n=C3=A1r?= <vfosnar@fosny.eu>
Date: Mon, 9 Jan 2023 22:50:17 +0100
Subject: [PATCH] implemented (limited) darkening of theme colors and fixed
 rendering of the 3D box

---
 d2renderers/d2svg/d2svg.go | 15 ++++++++-------
 lib/color/color.go         | 25 +++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/d2renderers/d2svg/d2svg.go b/d2renderers/d2svg/d2svg.go
index cd0f299a3..1233a6ac6 100644
--- a/d2renderers/d2svg/d2svg.go
+++ b/d2renderers/d2svg/d2svg.go
@@ -618,6 +618,7 @@ func render3dRect(targetShape d2target.Shape) string {
 	)
 	border := svg_style.NewThemableElement("path")
 	border.D = strings.Join(borderSegments, " ")
+	border.Fill = color.None
 	_, borderStroke := svg_style.ShapeTheme(targetShape)
 	border.Stroke = borderStroke
 	borderStyle := svg_style.ShapeStyle(targetShape)
@@ -646,6 +647,7 @@ func render3dRect(targetShape d2target.Shape) string {
 	mainShape.Mask = fmt.Sprintf("url(#%s)", maskID)
 	mainShapeFill, _ := svg_style.ShapeTheme(targetShape)
 	mainShape.Fill = mainShapeFill
+	mainShape.Stroke = color.None
 	mainShape.Style = svg_style.ShapeStyle(targetShape)
 	mainShapeRendered := mainShape.Render()
 
@@ -663,18 +665,17 @@ func render3dRect(targetShape d2target.Shape) string {
 			fmt.Sprintf("%d,%d", v.X+targetShape.Pos.X, v.Y+targetShape.Pos.Y),
 		)
 	}
-	// TODO make darker color part of the theme?
-	darkerColor := targetShape.Fill
-	// darkerColor, err := color.Darken(targetShape.Fill)
-	// if err != nil {
-	// 	darkerColor = targetShape.Fill
-	// }
+	// TODO make darker color part of the theme? or just keep this bypass
+	darkerColor, err := color.Darken(targetShape.Fill)
+	if err != nil {
+		darkerColor = targetShape.Fill
+	}
 	sideShape := svg_style.NewThemableElement("polygon")
 	sideShape.Fill = darkerColor
 	sideShape.Points = strings.Join(sidePoints, " ")
 	sideShape.Mask = fmt.Sprintf("url(#%s)", maskID)
 	sideShape.Style = svg_style.ShapeStyle(targetShape)
-	renderedSides := mainShape.Render()
+	renderedSides := sideShape.Render()
 
 	return borderMask + mainShapeRendered + renderedSides + renderedBorder
 }
diff --git a/lib/color/color.go b/lib/color/color.go
index 3f1109a82..1bb7d854d 100644
--- a/lib/color/color.go
+++ b/lib/color/color.go
@@ -1,11 +1,36 @@
 package color
 
 import (
+	"regexp"
+
 	"github.com/lucasb-eyer/go-colorful"
 	"github.com/mazznoer/csscolorparser"
 )
 
+var themeRegex = regexp.MustCompile("^B[1-6]$")
+
 func Darken(colorString string) (string, error) {
+	if themeRegex.MatchString(colorString) {
+		switch colorString[1] {
+		case '1':
+			return B1, nil
+		case '2':
+			return B1, nil
+		case '3':
+			return B2, nil
+		case '4':
+			return B3, nil
+		case '5':
+			return B4, nil
+		case '6':
+			return B5, nil
+		}
+	}
+
+	return DarkenCSS(colorString)
+}
+
+func DarkenCSS(colorString string) (string, error) {
 	c, err := csscolorparser.Parse(colorString)
 	if err != nil {
 		return "", err