#853 apply scale when decoding SVG

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 ## <a id="unreleased"></a>[Unreleased]
 
+### Fixed
+
+- crash when loading SVG defined with large dimensions
+
 ## <a id="v1.10.1"></a>[v1.10.1] - 2023-12-21
 
 - Cataloguing: detect/filter `Ultra HDR`

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MediaFetchBytesHandler.kt

@@ -89,6 +89,7 @@ class MediaFetchBytesHandler(private val context: Context) : MethodCallHandler {
             MimeTypes.SVG -> SvgRegionFetcher(context).fetch(
                 uri = uri,
                 sizeBytes = sizeBytes,
+                scale = sampleSize,
                 regionRect = regionRect,
                 imageWidth = imageWidth,
                 imageHeight = imageHeight,

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/fetchers/SvgRegionFetcher.kt

@@ -25,6 +25,7 @@ class SvgRegionFetcher internal constructor(
     suspend fun fetch(
         uri: Uri,
         sizeBytes: Long?,
+        scale: Int,
         regionRect: Rect,
         imageWidth: Int,
         imageHeight: Int,
@@ -36,14 +37,6 @@ class SvgRegionFetcher internal constructor(
             return
         }
 
-        // use `Long` as rect size could be unexpectedly large and go beyond `Int` max
-        val targetBitmapSizeBytes: Long = ARGB_8888_BYTE_SIZE.toLong() * regionRect.width() * regionRect.height()
-        if (!MemoryUtils.canAllocate(targetBitmapSizeBytes)) {
-            // decoding a region that large would yield an OOM when creating the bitmap
-            result.error("fetch-read-large-region", "SVG region too large for uri=$uri regionRect=$regionRect", null)
-            return
-        }
-
         var currentSvgRef = lastSvgRef
         if (currentSvgRef != null && currentSvgRef.uri != uri) {
             currentSvgRef = null
@@ -75,8 +68,8 @@ class SvgRegionFetcher internal constructor(
             val viewBox = svg.documentViewBox
             val svgWidth = viewBox.width()
             val svgHeight = viewBox.height()
-            val xf = imageWidth / ceil(svgWidth)
+            val xf = imageWidth / scale / ceil(svgWidth)
-            val yf = imageHeight / ceil(svgHeight)
+            val yf = imageHeight / scale / ceil(svgHeight)
             // some SVG paths do not respect the rendering viewbox and do not reach its edges
             // so we render to a slightly larger bitmap, using a slightly larger viewbox,
             // and crop that bitmap to the target region size
@@ -95,6 +88,15 @@ class SvgRegionFetcher internal constructor(
 
             val targetBitmapWidth = regionRect.width()
             val targetBitmapHeight = regionRect.height()
+
+            // use `Long` as rect size could be unexpectedly large and go beyond `Int` max
+            val targetBitmapSizeBytes: Long = ARGB_8888_BYTE_SIZE.toLong() * targetBitmapWidth * targetBitmapHeight
+            if (!MemoryUtils.canAllocate(targetBitmapSizeBytes)) {
+                // decoding a region that large would yield an OOM when creating the bitmap
+                result.error("fetch-read-large-region", "SVG region too large for uri=$uri regionRect=$regionRect", null)
+                return
+            }
+
             var bitmap = Bitmap.createBitmap(
                 targetBitmapWidth + bleedX * 2,
                 targetBitmapHeight + bleedY * 2,

lib/utils/math_utils.dart

@@ -3,7 +3,9 @@ import 'dart:ui';
 
 int highestPowerOf2(num x) => x < 1 ? 0 : pow(2, (log(x) / ln2).floor()).toInt();
 
-int smallestPowerOf2(num x) => x < 1 ? 1 : pow(2, (log(x) / ln2).ceil()).toInt();
+num smallestPowerOf2(num x, {bool allowNegativePower = false}) {
+  return x < 1 && !allowNegativePower ? 1 : pow(2, (log(x) / ln2).ceil());
+}
 
 double roundToPrecision(final double value, {required final int decimals}) => (value * pow(10, decimals)).round() / pow(10, decimals);
 

lib/widgets/common/map/geo_map.dart

@@ -439,7 +439,7 @@ class _GeoMapState extends State<GeoMap> {
     if (points.length != geoEntry.pointsSize) {
       // `Fluster.points()` method does not always return all the points contained in a cluster
       // the higher `nodeSize` is, the higher the chance to get all the points (i.e. as many as the cluster `pointsSize`)
-      _slowMarkerCluster ??= _buildFluster(nodeSize: smallestPowerOf2(entries.length));
+      _slowMarkerCluster ??= _buildFluster(nodeSize: smallestPowerOf2(entries.length).toInt());
       points = _slowMarkerCluster!.points(clusterId);
       assert(points.length == geoEntry.pointsSize, 'got ${points.length}/${geoEntry.pointsSize} for geoEntry=$geoEntry');
     }

lib/widgets/viewer/visual/vector.dart

@@ -286,7 +286,7 @@ class _VectorImageViewState extends State<VectorImageView> {
     required double scale,
     required double devicePixelRatio,
   }) =>
-      smallestPowerOf2(scale * devicePixelRatio).toDouble();
+      smallestPowerOf2(scale * devicePixelRatio, allowNegativePower: true).toDouble();
 }
 
 typedef _BackgroundFrameBuilder = Widget Function(Widget child, int? frame, Rect tileRect);

test/utils/math_utils_test.dart

@@ -20,6 +20,8 @@ void main() {
     expect(smallestPowerOf2(-42), 1);
     expect(smallestPowerOf2(.5), 1);
     expect(smallestPowerOf2(1.5), 2);
+    expect(smallestPowerOf2(0.5, allowNegativePower: true), 0.5);
+    expect(smallestPowerOf2(0.1, allowNegativePower: true), 0.125);
   });
 
   test('rounding to a given precision after the decimal', () {