From 096b834771fc3d9ef55f9ca92094d36b55cea4a2 Mon Sep 17 00:00:00 2001
From: Mira Grudzinska <mira@lottiefiles.com>
Date: Tue, 14 Jan 2025 12:35:17 +0100
Subject: [PATCH] lottie: fix text stroke's 'of' property

The text stroke's 'of' property determines whether
the stroke appears above (true) or below (false)
the fill.
Previously, it was incorrectly used to decide whether
the stroke would render.

@Issue: https://github.com/thorvg/thorvg/issues/3126
---
 src/loaders/lottie/tvgLottieBuilder.cpp | 8 +++++---
 src/loaders/lottie/tvgLottieData.h      | 2 +-
 src/loaders/lottie/tvgLottieParser.cpp  | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/loaders/lottie/tvgLottieBuilder.cpp b/src/loaders/lottie/tvgLottieBuilder.cpp
index 87a67939..678337ec 100644
--- a/src/loaders/lottie/tvgLottieBuilder.cpp
+++ b/src/loaders/lottie/tvgLottieBuilder.cpp
@@ -1092,10 +1092,11 @@ void LottieBuilder::updateText(LottieLayer* layer, float frameNo)
                 shape->translate(cursor.x - textGroupMatrix.e13, cursor.y - textGroupMatrix.e23);
                 shape->opacity(255);
 
-                if (doc.stroke.render) {
+                if (doc.stroke.width > 0.0f) {
                     shape->strokeJoin(StrokeJoin::Round);
                     shape->strokeWidth(doc.stroke.width / scale);
                     shape->strokeFill(doc.stroke.color.rgb[0], doc.stroke.color.rgb[1], doc.stroke.color.rgb[2]);
+                    shape->order(doc.stroke.below);
                 }
 
                 auto needGroup = false;
@@ -1137,8 +1138,8 @@ void LottieBuilder::updateText(LottieLayer* layer, float frameNo)
                         fillOpacity = (uint8_t)(fillOpacity - f * (fillOpacity - (*s)->style.fillOpacity(frameNo)));
                         shape->fill(color.rgb[0], color.rgb[1], color.rgb[2], fillOpacity);
 
-                        if (doc.stroke.render) {
-                            shape->strokeWidth(f * (*s)->style.strokeWidth(frameNo) / scale);
+                        shape->strokeWidth(f * (*s)->style.strokeWidth(frameNo) / scale);
+                        if (shape->strokeWidth() > 0.0f) {
                             auto rangeColor = (*s)->style.strokeColor(frameNo); //TODO: use flag to check whether it was really set
                             if (tvg::equal(f, 1.0f)) strokeColor = rangeColor;
                             else {
@@ -1148,6 +1149,7 @@ void LottieBuilder::updateText(LottieLayer* layer, float frameNo)
                             }
                             strokeOpacity = (uint8_t)(strokeOpacity - f * (strokeOpacity - (*s)->style.strokeOpacity(frameNo)));
                             shape->strokeFill(strokeColor.rgb[0], strokeColor.rgb[1], strokeColor.rgb[2], strokeOpacity);
+                            shape->order(doc.stroke.below);
                         }
 
                         cursor.x += f * (*s)->style.letterSpacing(frameNo);
diff --git a/src/loaders/lottie/tvgLottieData.h b/src/loaders/lottie/tvgLottieData.h
index 80b0718a..d1c0f28c 100644
--- a/src/loaders/lottie/tvgLottieData.h
+++ b/src/loaders/lottie/tvgLottieData.h
@@ -62,7 +62,7 @@ struct TextDocument
     struct {
         RGB24 color;
         float width;
-        bool render = false;
+        bool below = false;
     } stroke;
     char* name = nullptr;
     float size;
diff --git a/src/loaders/lottie/tvgLottieParser.cpp b/src/loaders/lottie/tvgLottieParser.cpp
index e7a52afe..1a864414 100644
--- a/src/loaders/lottie/tvgLottieParser.cpp
+++ b/src/loaders/lottie/tvgLottieParser.cpp
@@ -136,7 +136,7 @@ bool LottieParser::getValue(TextDocument& doc)
         else if (KEY_AS("sz")) getValue(doc.bbox.size);
         else if (KEY_AS("sc")) getValue(doc.stroke.color);
         else if (KEY_AS("sw")) doc.stroke.width = getFloat();
-        else if (KEY_AS("of")) doc.stroke.render = getBool();
+        else if (KEY_AS("of")) doc.stroke.below = !getBool();
         else skip();
     }
     return false;