feat: optimization of "solid" polygon/polyline display

lib/src/layer/misc/line_patterns/pixel_hiker.dart

@@ -13,6 +13,7 @@ class DottedPixelHiker extends _PixelHiker {
  required super.closePath,
  required super.canvasSize,
  required super.patternFit,
+ required super.strokeWidth,
  required double stepLength,
  }) : super(segmentValues: [stepLength]);
 
@@ -25,7 +26,7 @@ class DottedPixelHiker extends _PixelHiker {
  }
 
  void addVisibleOffset(final Offset offset) {
- if (VisibleSegment.isVisible(offset, canvasSize)) {
+ if (VisibleSegment.isVisible(offset, canvasSize, strokeWidth)) {
  result.add(offset);
  }
  }
@@ -69,8 +70,8 @@ class DottedPixelHiker extends _PixelHiker {
  ///
  /// Most important method of the class.
  List<Offset>? _getVisibleDotList(Offset offset0, Offset offset1) {
- final VisibleSegment? visibleSegment =
- VisibleSegment.getVisibleSegment(offset0, offset1, canvasSize);
+ final VisibleSegment? visibleSegment = VisibleSegment.getVisibleSegment(
+ offset0, offset1, canvasSize, strokeWidth);
  if (visibleSegment == null) {
  addDistance(getDistance(offset0, offset1));
  return null;
@@ -131,6 +132,7 @@ class DashedPixelHiker extends _PixelHiker {
  required super.canvasSize,
  required super.segmentValues,
  required super.patternFit,
+ required super.strokeWidth,
  });
 
  /// Returns all visible segments.
@@ -155,7 +157,7 @@ class DashedPixelHiker extends _PixelHiker {
  if (_segmentIndex.isOdd) {
  if (patternFit == PatternFit.appendDot) {
  if (!closePath) {
- if (VisibleSegment.isVisible(offsets.last, canvasSize)) {
+ if (VisibleSegment.isVisible(offsets.last, canvasSize, strokeWidth)) {
  result.add(VisibleSegment(offsets.last, offsets.last));
  }
  }
@@ -187,10 +189,7 @@ class DashedPixelHiker extends _PixelHiker {
  final Offset offset1,
  ) {
  final VisibleSegment? visibleSegment = VisibleSegment.getVisibleSegment(
- offset0,
- offset1,
- canvasSize,
- );
+ offset0, offset1, canvasSize, strokeWidth);
  if (visibleSegment == null) {
  addDistance(getDistance(offset0, offset1));
  return null;
@@ -257,31 +256,52 @@ class SolidPixelHiker extends _PixelHiker {
  required super.offsets,
  required super.closePath,
  required super.canvasSize,
+ required super.strokeWidth,
  }) : super(
  segmentValues: [],
  patternFit: PatternFit.none,
  );
 
- /// Returns all visible segments.
- List<VisibleSegment> getAllVisibleSegments() {
- final List<VisibleSegment> result = [];
-
+ /// Adds all visible segments to [paths].
+ void addAllVisibleSegments(final List<Path> paths) {
  if (offsets.length < 2) {
- return result;
+ return;
+ }
+
+ double? latestX;
+ double? latestY;
+ List<Offset> polygons = [];
+
+ void addPolygons() {
+ if (polygons.isEmpty) {
+ return;
+ }
+ for (final path in paths) {
+ path.addPolygon(polygons, false);
+ }
+ polygons = [];
  }
 
  for (int i = 0; i < offsets.length - 1 + (closePath ? 1 : 0); i++) {
  final VisibleSegment? visibleSegment = VisibleSegment.getVisibleSegment(
  offsets[i],
  offsets[(i + 1) % offsets.length],
  canvasSize,
+ strokeWidth,
  );
- if (visibleSegment != null) {
- result.add(visibleSegment);
+ if (visibleSegment == null) {
+ continue;
+ }
+ if (latestX != visibleSegment.begin.dx ||
+ latestY != visibleSegment.begin.dy) {
+ addPolygons();
+ polygons.add(visibleSegment.begin);
  }
+ polygons.add(visibleSegment.end);
+ latestX = visibleSegment.end.dx;
+ latestY = visibleSegment.end.dy;
  }
-
- return result;
+ addPolygons();
  }
 
  @override
@@ -296,6 +316,7 @@ sealed class _PixelHiker {
  required this.closePath,
  required this.canvasSize,
  required this.patternFit,
+ required this.strokeWidth,
  }) {
  _polylinePixelDistance = _getPolylinePixelDistance();
  _init();
@@ -314,6 +335,7 @@ sealed class _PixelHiker {
  final List<double> segmentValues;
  final Size canvasSize;
  final PatternFit patternFit;
+ final double strokeWidth;
 
  /// Factor to be used on offset distances.
  late final double _factor;

lib/src/layer/misc/line_patterns/visible_segment.dart

@@ -39,23 +39,28 @@ class VisibleSegment {
  return code;
  }
 
- /// Returns true if the [offset] is inside the [canvasSize].
- static bool isVisible(Offset offset, Size canvasSize) =>
+ /// Returns true if the [offset] is inside the [canvasSize] + [strokeWidth].
+ static bool isVisible(Offset offset, Size canvasSize, double strokeWidth) =>
  _computeOutCode(
- offset.dx, offset.dy, 0, 0, canvasSize.width, canvasSize.height) ==
+ offset.dx,
+ offset.dy,
+ -strokeWidth / 2,
+ -strokeWidth / 2,
+ canvasSize.width + strokeWidth / 2,
+ canvasSize.height + strokeWidth / 2) ==
  _inside;
 
  /// Clips a line segment to a rectangular area (canvas).
  ///
  /// Returns null if the segment is invisible.
  static VisibleSegment? getVisibleSegment(
- Offset p0, Offset p1, Size canvasSize) {
+ Offset p0, Offset p1, Size canvasSize, double strokeWidth) {
  // Function to compute the outCode for a point relative to the canvas
 
- const double xMin = 0;
- const double yMin = 0;
- final double xMax = canvasSize.width;
- final double yMax = canvasSize.height;
+ final double xMin = -strokeWidth / 2;
+ final double yMin = -strokeWidth / 2;
+ final double xMax = canvasSize.width + strokeWidth / 2;
+ final double yMax = canvasSize.height + strokeWidth / 2;
 
  double x0 = p0.dx;
  double y0 = p0.dy;

lib/src/layer/polygon_layer/painter.dart

@@ -215,6 +215,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  size,
  canvas,
  _getBorderPaint(polygon),
+ polygon.borderStrokeWidth,
  );
  }
 
@@ -238,7 +239,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
 
  if (!polygon.disableHolesBorder && polygon.borderStrokeWidth > 0.0) {
  _addHoleBordersToPath(borderPath, polygon, holeOffsetsList, size,
- canvas, _getBorderPaint(polygon));
+ canvas, _getBorderPaint(polygon), polygon.borderStrokeWidth);
  }
  }
 
@@ -314,6 +315,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  Size canvasSize,
  Canvas canvas,
  Paint paint,
+ double strokeWidth,
  ) {
  final isSolid = polygon.pattern == const StrokePattern.solid();
  final isDashed = polygon.pattern.segments != null;
@@ -323,18 +325,17 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  offsets: offsets,
  closePath: true,
  canvasSize: canvasSize,
+ strokeWidth: strokeWidth,
  );
- for (final visibleSegment in hiker.getAllVisibleSegments()) {
- path.moveTo(visibleSegment.begin.dx, visibleSegment.begin.dy);
- path.lineTo(visibleSegment.end.dx, visibleSegment.end.dy);
- }
+ hiker.addAllVisibleSegments([path]);
  } else if (isDotted) {
  final DottedPixelHiker hiker = DottedPixelHiker(
  offsets: offsets,
  stepLength: polygon.borderStrokeWidth * polygon.pattern.spacingFactor!,
  patternFit: polygon.pattern.patternFit!,
  closePath: true,
  canvasSize: canvasSize,
+ strokeWidth: strokeWidth,
  );
  for (final visibleDot in hiker.getAllVisibleDots()) {
  canvas.drawCircle(visibleDot, polygon.borderStrokeWidth / 2, paint);
@@ -346,6 +347,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  patternFit: polygon.pattern.patternFit!,
  closePath: true,
  canvasSize: canvasSize,
+ strokeWidth: strokeWidth,
  );
 
  for (final visibleSegment in hiker.getAllVisibleSegments()) {
@@ -362,6 +364,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  Size canvasSize,
  Canvas canvas,
  Paint paint,
+ double strokeWidth,
  ) {
  for (final offsets in holeOffsetsList) {
  _addBorderToPath(
@@ -371,6 +374,7 @@ class _PolygonPainter<R extends Object> extends CustomPainter {
  canvasSize,
  canvas,
  paint,
+ strokeWidth,
  );
  }
  }

lib/src/layer/polyline_layer/painter.dart

@@ -147,6 +147,9 @@ class _PolylinePainter<R extends Object> extends CustomPainter {
  needsLayerSaving = polyline.color.opacity < 1.0 ||
  (polyline.gradientColors?.any((c) => c.opacity < 1.0) ?? false);
 
+ // strokeWidth, or strokeWidth + borderWidth if relevant.
+ late double largestStrokeWidth;
+
  late final double strokeWidth;
  if (polyline.useStrokeWidthInMeter) {
  strokeWidth = _metersToStrokeWidth(
@@ -158,6 +161,7 @@ class _PolylinePainter<R extends Object> extends CustomPainter {
  } else {
  strokeWidth = polyline.strokeWidth;
  }
+ largestStrokeWidth = strokeWidth;
 
  final isSolid = polyline.pattern == const StrokePattern.solid();
  final isDashed = polyline.pattern.segments != null;
@@ -182,6 +186,7 @@ class _PolylinePainter<R extends Object> extends CustomPainter {
  // Outlined lines are drawn by drawing a thicker path underneath, then
  // stenciling the middle (in case the line fill is transparent), and
  // finally drawing the line fill.
+ largestStrokeWidth = strokeWidth + polyline.borderStrokeWidth;
  borderPaint = Paint()
  ..color = polyline.borderColor
  ..strokeWidth = strokeWidth + polyline.borderStrokeWidth
@@ -213,20 +218,17 @@ class _PolylinePainter<R extends Object> extends CustomPainter {
  offsets: offsets,
  closePath: false,
  canvasSize: size,
+ strokeWidth: largestStrokeWidth,
  );
- for (final visibleSegment in hiker.getAllVisibleSegments()) {
- for (final path in paths) {
- path.moveTo(visibleSegment.begin.dx, visibleSegment.begin.dy);
- path.lineTo(visibleSegment.end.dx, visibleSegment.end.dy);
- }
- }
+ hiker.addAllVisibleSegments(paths);
  } else if (isDotted) {
  final DottedPixelHiker hiker = DottedPixelHiker(
  offsets: offsets,
  stepLength: strokeWidth * polyline.pattern.spacingFactor!,
  patternFit: polyline.pattern.patternFit!,
  closePath: false,
  canvasSize: size,
+ strokeWidth: largestStrokeWidth,
  );
 
  final List<double> radii = [];
@@ -249,6 +251,7 @@ class _PolylinePainter<R extends Object> extends CustomPainter {
  patternFit: polyline.pattern.patternFit!,
  closePath: false,
  canvasSize: size,
+ strokeWidth: largestStrokeWidth,
  );
 
  for (final visibleSegment in hiker.getAllVisibleSegments()) {