From ed23b432bbb1c4b6a87d0318eeeeaaf22b45a166 Mon Sep 17 00:00:00 2001
From: Hermet Park <hermet@lottiefiles.com>
Date: Tue, 26 Sep 2023 11:08:12 +0900
Subject: [PATCH] tvg: support dash offset property

properly store/restore the dash offset property
from the tvg loader and saver

Issue: https://github.com/thorvg/thorvg/issues/1617
---
 src/loaders/tvg/tvgTvgBinInterpreter.cpp | 7 +++++++
 src/renderer/tvgBinaryDesc.h             | 1 +
 src/savers/tvg/tvgTvgSaver.cpp           | 8 +++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/loaders/tvg/tvgTvgBinInterpreter.cpp b/src/loaders/tvg/tvgTvgBinInterpreter.cpp
index e246af60..eb3f0136 100644
--- a/src/loaders/tvg/tvgTvgBinInterpreter.cpp
+++ b/src/loaders/tvg/tvgTvgBinInterpreter.cpp
@@ -322,6 +322,13 @@ static bool _parseShapeStroke(const char *ptr, const char *end, Shape *shape)
                 shape->strokeMiterlimit(miterlimit);
                 break;
             }
+            case TVG_TAG_SHAPE_STROKE_DASH_OFFSET: {
+                if (block.length != SIZE(float)) return false;
+                float offset;
+                READ_FLOAT(&offset, block.data);
+                P(shape)->rs.stroke->dashOffset = offset;
+                break;
+            }
             default: {
                 TVGLOG("TVG", "Unsupported tag %d (0x%x) used as one of stroke properties, %d bytes skipped", block.type, block.type, block.length);
                 break;
diff --git a/src/renderer/tvgBinaryDesc.h b/src/renderer/tvgBinaryDesc.h
index 3b9dbe89..42969cbc 100644
--- a/src/renderer/tvgBinaryDesc.h
+++ b/src/renderer/tvgBinaryDesc.h
@@ -82,6 +82,7 @@ using TvgBinFlag = TvgBinByte;
 #define TVG_TAG_SHAPE_STROKE_DASHPTRN               (TvgBinTag)0x55
 #define TVG_TAG_SHAPE_STROKE_MITERLIMIT             (TvgBinTag)0x56
 #define TVG_TAG_SHAPE_STROKE_ORDER                  (TvgBinTag)0x57
+#define TVG_TAG_SHAPE_STROKE_DASH_OFFSET            (TvgBinTag)0x58
 
 
 //Fill
diff --git a/src/savers/tvg/tvgTvgSaver.cpp b/src/savers/tvg/tvgTvgSaver.cpp
index fa80f611..da1dc4ad 100644
--- a/src/savers/tvg/tvgTvgSaver.cpp
+++ b/src/savers/tvg/tvgTvgSaver.cpp
@@ -469,7 +469,8 @@ TvgBinCounter TvgSaver::serializeStroke(const Shape* shape, const Matrix* pTrans
 
     //dash
     const float* dashPattern = nullptr;
-    auto dashCnt = shape->strokeDash(&dashPattern);
+    float offset = 0.0f;
+    auto dashCnt = P(shape)->rs.strokeDash(&dashPattern, &offset);
     if (dashPattern && dashCnt > 0) {
         TvgBinCounter dashCntSize = SIZE(dashCnt);
         TvgBinCounter dashPtrnSize = dashCnt * SIZE(dashPattern[0]);
@@ -487,6 +488,11 @@ TvgBinCounter TvgSaver::serializeStroke(const Shape* shape, const Matrix* pTrans
         cnt += writeTagProperty(TVG_TAG_SHAPE_STROKE_MITERLIMIT, SIZE(miterlimit), &miterlimit);
     }
 
+    //dash offset
+    if (!mathZero(offset)) {
+        cnt += writeTagProperty(TVG_TAG_SHAPE_STROKE_DASH_OFFSET, SIZE(offset), &offset);
+    }
+
     writeReservedCount(cnt);
 
     return SERIAL_DONE(cnt);