From 92346c4119f72eea7c7c0d36ab396d7d4af6e94f Mon Sep 17 00:00:00 2001
From: Mira Grudzinska <veleveta@gmail.com>
Date: Sun, 30 Apr 2023 10:41:29 +0200
Subject: [PATCH] svg_loader: handling svg width/height in percentages

The percentages should refer to the size of the viewbox.
This was not the case for not knowing the viewbox before
reading the width/height.

@Issue: https://github.com/thorvg/thorvg/issues/1409
---
 src/loaders/svg/tvgSvgLoader.cpp       | 26 ++++++++++++++++++++++----
 src/loaders/svg/tvgSvgLoaderCommon.h   |  2 ++
 src/loaders/svg/tvgSvgSceneBuilder.cpp |  3 +++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/loaders/svg/tvgSvgLoader.cpp b/src/loaders/svg/tvgSvgLoader.cpp
index cea78ed1..19e52c93 100644
--- a/src/loaders/svg/tvgSvgLoader.cpp
+++ b/src/loaders/svg/tvgSvgLoader.cpp
@@ -861,10 +861,18 @@ static bool _attrParseSvgNode(void* data, const char* key, const char* value)
 
     if (!strcmp(key, "width")) {
         doc->w = _toFloat(loader->svgParse, value, SvgParserLengthType::Horizontal);
-        doc->viewFlag = (doc->viewFlag | SvgViewFlag::Width);
+        if (strstr(value, "%")) {
+            doc->sw = svgUtilStrtof(value, nullptr) / 100.0f;
+        } else {
+            doc->viewFlag = (doc->viewFlag | SvgViewFlag::Width);
+        }
     } else if (!strcmp(key, "height")) {
         doc->h = _toFloat(loader->svgParse, value, SvgParserLengthType::Vertical);
-        doc->viewFlag = (doc->viewFlag | SvgViewFlag::Height);
+        if (strstr(value, "%")) {
+            doc->sh = svgUtilStrtof(value, nullptr) / 100.0f;
+        } else {
+            doc->viewFlag = (doc->viewFlag | SvgViewFlag::Height);
+        }
     } else if (!strcmp(key, "viewBox")) {
         if (_parseNumber(&value, &doc->vx)) {
             if (_parseNumber(&value, &doc->vy)) {
@@ -1347,6 +1355,8 @@ static SvgNode* _createSvgNode(SvgLoaderData* loader, SvgNode* parent, const cha
     doc->align = AspectRatioAlign::XMidYMid;
     doc->meetOrSlice = AspectRatioMeetOrSlice::Meet;
     doc->viewFlag = SvgViewFlag::None;
+    doc->sw = 1.0f;
+    doc->sh = 1.0f;
     func(buf, bufLength, _attrParseSvgNode, loader);
 
     if (!(doc->viewFlag & SvgViewFlag::Viewbox)) {
@@ -3530,8 +3540,16 @@ bool SvgLoader::header()
             vw = loaderData.doc->node.doc.vw;
             vh = loaderData.doc->node.doc.vh;
 
-            if (!(viewFlag & SvgViewFlag::Width)) w = vw;
-            if (!(viewFlag & SvgViewFlag::Height)) h = vh;
+            if (!(viewFlag & SvgViewFlag::Width)) {
+                w = vw * loaderData.doc->node.doc.sw;
+                loaderData.doc->node.doc.sw = 1.0f;
+                viewFlag = (viewFlag | SvgViewFlag::Width);
+            }
+            if (!(viewFlag & SvgViewFlag::Height)) {
+                h = vh * loaderData.doc->node.doc.sh;
+                loaderData.doc->node.doc.sh = 1.0f;
+                viewFlag = (viewFlag | SvgViewFlag::Height);
+            }
         } else {
             vw = w;
             vh = h;
diff --git a/src/loaders/svg/tvgSvgLoaderCommon.h b/src/loaders/svg/tvgSvgLoaderCommon.h
index e66000f6..3e4ff033 100644
--- a/src/loaders/svg/tvgSvgLoaderCommon.h
+++ b/src/loaders/svg/tvgSvgLoaderCommon.h
@@ -260,6 +260,8 @@ struct SvgDocNode
     float vy;
     float vw;
     float vh;
+    float sw;
+    float sh;
     SvgViewFlag viewFlag;
     SvgNode* defs;
     SvgNode* style;
diff --git a/src/loaders/svg/tvgSvgSceneBuilder.cpp b/src/loaders/svg/tvgSvgSceneBuilder.cpp
index 2a33e382..e57c9f4f 100644
--- a/src/loaders/svg/tvgSvgSceneBuilder.cpp
+++ b/src/loaders/svg/tvgSvgSceneBuilder.cpp
@@ -796,7 +796,10 @@ unique_ptr<Scene> svgSceneBuild(SvgNode* node, float& vx, float& vy, float& vw,
 
     Box vBox = {vx, vy, vw, vh};
     auto docNode = _sceneBuildHelper(node, vBox, svgPath, false, 0);
+
     _applySvgViewFlag(docNode.get(), vx, vy, vw, vh, w, h, viewFlag);
+    w *= node->node.doc.sw;
+    h *= node->node.doc.sh;
 
     if (!mathEqual(w, vw) || !mathEqual(h, vh)) {
         Matrix m = _calculateAspectRatioMatrix(align, meetOrSlice, w, h, {vx, vy, vw, vh});