Implement rotation for vector lines (#160)

* Implement rotation for vector lines

* wip

* Improve rotations for lines

* add changelog

* add layout attributes to line

.changeset/sour-radios-know.md

@@ -0,0 +1,5 @@
+---
+"penpot-exporter": minor
+---
+
+Apply rotations to lines

plugin-src/transformers/index.ts

@@ -5,6 +5,7 @@ export * from './transformEllipseNode';
 export * from './transformFrameNode';
 export * from './transformGroupNode';
 export * from './transformInstanceNode';
+export * from './transformLineNode';
 export * from './transformPageNode';
 export * from './transformPathNode';
 export * from './transformRectangleNode';

plugin-src/transformers/partials/transformDimensionAndPosition.ts

@@ -11,6 +11,17 @@ export const transformDimension = (
   };
 };
 
+export const transformPosition = (
+  node: DimensionAndPositionMixin,
+  baseX: number,
+  baseY: number
+): Pick<ShapeGeomAttributes, 'x' | 'y'> => {
+  return {
+    x: node.x + baseX,
+    y: node.y + baseY
+  };
+};
+
 export const transformDimensionAndPosition = (
   node: DimensionAndPositionMixin,
   baseX: number,

plugin-src/transformers/partials/transformRotationAndPosition.ts

@@ -1,5 +1,6 @@
+import { applyInverseRotation, hasRotation } from '@plugin/utils';
+
 import { ShapeBaseAttributes, ShapeGeomAttributes } from '@ui/lib/types/shapes/shape';
-import { Point } from '@ui/lib/types/utils/point';
 
 export const transformRotationAndPosition = (
   node: LayoutMixin,
@@ -11,7 +12,7 @@ export const transformRotationAndPosition = (
   const x = node.x + baseX;
   const y = node.y + baseY;
 
-  if (rotation === 0 || !node.absoluteBoundingBox) {
+  if (!hasRotation(rotation) || !node.absoluteBoundingBox) {
     return {
       x,
       y,
@@ -21,10 +22,14 @@ export const transformRotationAndPosition = (
     };
   }
 
-  const point = getRotatedPoint({ x, y }, node.absoluteTransform, node.absoluteBoundingBox);
+  const referencePoint = applyInverseRotation(
+    { x, y },
+    node.absoluteTransform,
+    node.absoluteBoundingBox
+  );
 
   return {
-    ...point,
+    ...referencePoint,
     rotation: -rotation < 0 ? -rotation + 360 : -rotation,
     transform: {
       a: node.absoluteTransform[0][0],
@@ -44,25 +49,3 @@ export const transformRotationAndPosition = (
     }
   };
 };
-
-const getRotatedPoint = (point: Point, transform: Transform, boundingBox: Rect): Point => {
-  const centerPoint = {
-    x: boundingBox.x + boundingBox.width / 2,
-    y: boundingBox.y + boundingBox.height / 2
-  };
-
-  const relativePoint = {
-    x: point.x - centerPoint.x,
-    y: point.y - centerPoint.y
-  };
-
-  const rotatedPoint = {
-    x: relativePoint.x * transform[0][0] + relativePoint.y * transform[1][0],
-    y: relativePoint.x * transform[0][1] + relativePoint.y * transform[1][1]
-  };
-
-  return {
-    x: centerPoint.x + rotatedPoint.x,
-    y: centerPoint.y + rotatedPoint.y
-  };
-};

plugin-src/transformers/partials/transformVectorPaths.ts

@@ -10,26 +10,9 @@ import {
   transformStrokesFromVector
 } from '@plugin/transformers/partials';
 import { translateFills } from '@plugin/translators/fills';
-import {
-  translateCommandsToSegments,
-  translateLineNode,
-  translateVectorPaths,
-  translateWindingRule
-} from '@plugin/translators/vectors';
+import { translateCommandsToSegments, translateWindingRule } from '@plugin/translators/vectors';
 
-import { PathAttributes, PathShape } from '@ui/lib/types/shapes/pathShape';
-
-export const transformVectorPathsAsContent = (
-  node: StarNode | LineNode | PolygonNode,
-  baseX: number,
-  baseY: number
-): PathAttributes => {
-  const vectorPaths = getVectorPaths(node);
-
-  return {
-    content: translateVectorPaths(vectorPaths, baseX + node.x, baseY + node.y)
-  };
-};
+import { PathShape } from '@ui/lib/types/shapes/pathShape';
 
 export const transformVectorPaths = (
   node: VectorNode,
@@ -59,21 +42,12 @@ export const transformVectorPaths = (
   return [...geometryShapes, ...pathShapes];
 };
 
-const getVectorPaths = (node: StarNode | LineNode | PolygonNode): VectorPaths => {
-  switch (node.type) {
-    case 'STAR':
-    case 'POLYGON':
-      return node.fillGeometry;
-    case 'LINE':
-      return translateLineNode(node);
-  }
-};
-
 const normalizePath = (path: string): string => {
   // Round to 2 decimal places all numbers
   const str = path.replace(/(\d+\.\d+|\d+)/g, (match: string) => {
     return parseFloat(match).toFixed(2);
   });
+
   // remove spaces
   return str.replace(/\s/g, '');
 };

plugin-src/transformers/transformLineNode.ts

@@ -0,0 +1,37 @@
+import {
+  transformBlend,
+  transformConstraints,
+  transformEffects,
+  transformFigmaIds,
+  transformLayoutAttributes,
+  transformPosition,
+  transformProportion,
+  transformSceneNode,
+  transformStrokes
+} from '@plugin/transformers/partials';
+import { translateLineNode } from '@plugin/translators/vectors';
+
+import { PathShape } from '@ui/lib/types/shapes/pathShape';
+
+/**
+ * In order to match the normal representation of a line in Penpot, we will assume that
+ * the line is never rotated, so we calculate its normal position.
+ *
+ * To represent the line rotated we do take into account the rotation of the line, but only in its content.
+ */
+export const transformLineNode = (node: LineNode, baseX: number, baseY: number): PathShape => {
+  return {
+    type: 'path',
+    name: node.name,
+    content: translateLineNode(node, baseX, baseY),
+    ...transformFigmaIds(node),
+    ...transformStrokes(node),
+    ...transformEffects(node),
+    ...transformPosition(node, baseX, baseY),
+    ...transformSceneNode(node),
+    ...transformBlend(node),
+    ...transformProportion(node),
+    ...transformLayoutAttributes(node),
+    ...transformConstraints(node)
+  };
+};

plugin-src/transformers/transformPathNode.ts

@@ -8,29 +8,25 @@ import {
   transformLayoutAttributes,
   transformProportion,
   transformSceneNode,
-  transformStrokes,
-  transformVectorPathsAsContent
+  transformStrokes
 } from '@plugin/transformers/partials';
+import { translateVectorPaths } from '@plugin/translators/vectors';
 
 import { PathShape } from '@ui/lib/types/shapes/pathShape';
 
-const hasFillGeometry = (node: StarNode | LineNode | PolygonNode): boolean => {
-  return 'fillGeometry' in node && node.fillGeometry.length > 0;
-};
-
 export const transformPathNode = (
-  node: StarNode | LineNode | PolygonNode,
+  node: StarNode | PolygonNode,
   baseX: number,
   baseY: number
 ): PathShape => {
   return {
     type: 'path',
     name: node.name,
+    content: translateVectorPaths(node.fillGeometry, baseX + node.x, baseY + node.y),
     ...transformFigmaIds(node),
-    ...(hasFillGeometry(node) ? transformFills(node) : []),
+    ...transformFills(node),
     ...transformStrokes(node),
     ...transformEffects(node),
-    ...transformVectorPathsAsContent(node, baseX, baseY),
     ...transformDimensionAndPosition(node, baseX, baseY),
     ...transformSceneNode(node),
     ...transformBlend(node),

plugin-src/transformers/transformSceneNode.ts

@@ -7,6 +7,7 @@ import {
   transformFrameNode,
   transformGroupNode,
   transformInstanceNode,
+  transformLineNode,
   transformPathNode,
   transformRectangleNode,
   transformTextNode,
@@ -46,9 +47,11 @@ export const transformSceneNode = async (
     case 'VECTOR':
       penpotNode = transformVectorNode(node, baseX, baseY);
       break;
+    case 'LINE':
+      penpotNode = transformLineNode(node, baseX, baseY);
+      break;
     case 'STAR':
     case 'POLYGON':
-    case 'LINE':
       penpotNode = transformPathNode(node, baseX, baseY);
       break;
     case 'BOOLEAN_OPERATION':

plugin-src/translators/vectors/index.ts

@@ -1,3 +1,4 @@
+export * from './translateCommandsToSegments';
 export * from './translateLineNode';
 export * from './translateVectorPaths';
 export * from './translateWindingRule';

plugin-src/translators/vectors/translateCommandsToSegments.ts

@@ -0,0 +1,57 @@
+import { Command, CurveToCommand, LineToCommand, MoveToCommand } from 'svg-path-parser';
+
+import { Segment } from '@ui/lib/types/shapes/pathShape';
+
+export const translateCommandsToSegments = (
+  commands: Command[],
+  baseX: number,
+  baseY: number
+): Segment[] => {
+  return commands.map(command => {
+    switch (command.command) {
+      case 'moveto':
+        return translateMoveToCommand(command, baseX, baseY);
+      case 'lineto':
+        return translateLineToCommand(command, baseX, baseY);
+      case 'curveto':
+        return translateCurveToCommand(command, baseX, baseY);
+      case 'closepath':
+      default:
+        return {
+          command: 'close-path'
+        };
+    }
+  });
+};
+
+const translateMoveToCommand = (command: MoveToCommand, baseX: number, baseY: number): Segment => {
+  return {
+    command: 'move-to',
+    params: { x: command.x + baseX, y: command.y + baseY }
+  };
+};
+
+const translateLineToCommand = (command: LineToCommand, baseX: number, baseY: number): Segment => {
+  return {
+    command: 'line-to',
+    params: { x: command.x + baseX, y: command.y + baseY }
+  };
+};
+
+const translateCurveToCommand = (
+  command: CurveToCommand,
+  baseX: number,
+  baseY: number
+): Segment => {
+  return {
+    command: 'curve-to',
+    params: {
+      c1x: command.x1 + baseX,
+      c1y: command.y1 + baseY,
+      c2x: command.x2 + baseX,
+      c2y: command.y2 + baseY,
+      x: command.x + baseX,
+      y: command.y + baseY
+    }
+  };
+};

plugin-src/translators/vectors/translateLineNode.ts

@@ -1,23 +1,65 @@
-export const translateLineNode = (node: LineNode): VectorPaths => {
-  const commands = [
+import { Command } from 'svg-path-parser';
+
+import { applyInverseRotation, applyRotation, hasRotation } from '@plugin/utils';
+
+import { Segment } from '@ui/lib/types/shapes/pathShape';
+
+import { translateCommandsToSegments } from '.';
+
+export const translateLineNode = (node: LineNode, baseX: number, baseY: number): Segment[] => {
+  if (!hasRotation(node.rotation) || !node.absoluteBoundingBox) {
+    return translateCommandsToSegments(
+      [
         {
-      command: 'moveto',
-      code: 'M',
           x: 0,
-      y: 0
+          y: 0,
+          command: 'moveto',
+          code: 'M'
         },
         {
-      command: 'lineto',
-      code: 'L',
           x: node.width,
-      y: node.height
+          y: 0,
+          command: 'lineto',
+          code: 'L'
+        }
+      ],
+      baseX + node.x,
+      baseY + node.y
+    );
+  }
+
+  const startPoint = applyRotation(
+    { x: 0, y: 0 },
+    node.absoluteTransform,
+    node.absoluteBoundingBox
+  );
+
+  const endPoint = applyRotation(
+    { x: node.width, y: 0 },
+    node.absoluteTransform,
+    node.absoluteBoundingBox
+  );
+
+  const commands: Command[] = [
+    {
+      x: startPoint.x,
+      y: startPoint.y,
+      command: 'moveto',
+      code: 'M'
+    },
+    {
+      x: endPoint.x,
+      y: endPoint.y,
+      command: 'lineto',
+      code: 'L'
     }
   ];
 
-  return [
-    {
-      windingRule: 'NONE',
-      data: commands.reduce((acc, { code, x, y }) => acc + `${code} ${x} ${y}`, '')
-    }
-  ];
+  const referencePoint = applyInverseRotation(
+    { x: node.x, y: node.y },
+    node.absoluteTransform,
+    node.absoluteBoundingBox
+  );
+
+  return translateCommandsToSegments(commands, baseX + referencePoint.x, baseY + referencePoint.y);
 };

plugin-src/translators/vectors/translateVectorPaths.ts

@@ -1,73 +1,19 @@
-import { Command, CurveToCommand, LineToCommand, MoveToCommand, parseSVG } from 'svg-path-parser';
+import { parseSVG } from 'svg-path-parser';
 
 import { Segment } from '@ui/lib/types/shapes/pathShape';
 
+import { translateCommandsToSegments } from '.';
+
 export const translateVectorPaths = (
   paths: VectorPaths,
   baseX: number,
   baseY: number
 ): Segment[] => {
-  let segments: Segment[] = [];
+  const segments: Segment[] = [];
 
   for (const path of paths) {
-    const normalizedPaths = parseSVG(path.data);
-
-    segments = [...segments, ...translateCommandsToSegments(normalizedPaths, baseX, baseY)];
+    segments.push(...translateCommandsToSegments(parseSVG(path.data), baseX, baseY));
   }
 
   return segments;
 };
-
-export const translateCommandsToSegments = (
-  commands: Command[],
-  baseX: number,
-  baseY: number
-): Segment[] => {
-  return commands.map(command => {
-    switch (command.command) {
-      case 'moveto':
-        return translateMoveToCommand(command, baseX, baseY);
-      case 'lineto':
-        return translateLineToCommand(command, baseX, baseY);
-      case 'curveto':
-        return translateCurveToCommand(command, baseX, baseY);
-      case 'closepath':
-      default:
-        return {
-          command: 'close-path'
-        };
-    }
-  });
-};
-
-const translateMoveToCommand = (command: MoveToCommand, baseX: number, baseY: number): Segment => {
-  return {
-    command: 'move-to',
-    params: { x: command.x + baseX, y: command.y + baseY }
-  };
-};
-
-const translateLineToCommand = (command: LineToCommand, baseX: number, baseY: number): Segment => {
-  return {
-    command: 'line-to',
-    params: { x: command.x + baseX, y: command.y + baseY }
-  };
-};
-
-const translateCurveToCommand = (
-  command: CurveToCommand,
-  baseX: number,
-  baseY: number
-): Segment => {
-  return {
-    command: 'curve-to',
-    params: {
-      c1x: command.x1 + baseX,
-      c1y: command.y1 + baseY,
-      c2x: command.x2 + baseX,
-      c2y: command.y2 + baseY,
-      x: command.x + baseX,
-      y: command.y + baseY
-    }
-  };
-};

plugin-src/utils/applyRotation.ts

@@ -0,0 +1,40 @@
+import { Point } from '@ui/lib/types/utils/point';
+
+const ROTATION_TOLERANCE = 0.000001;
+
+export const applyRotation = (point: Point, transform: Transform, boundingBox: Rect): Point => {
+  const centerPoint = calculateCenter(boundingBox);
+
+  const rotatedPoint = applyMatrix(transform, {
+    x: point.x - centerPoint.x,
+    y: point.y - centerPoint.y
+  });
+
+  return {
+    x: centerPoint.x + rotatedPoint.x,
+    y: centerPoint.y + rotatedPoint.y
+  };
+};
+
+export const applyInverseRotation = (
+  point: Point,
+  transform: Transform,
+  boundingBox: Rect
+): Point => applyRotation(point, inverseMatrix(transform), boundingBox);
+
+export const hasRotation = (rotation: number): boolean => Math.abs(rotation) > ROTATION_TOLERANCE;
+
+const inverseMatrix = (matrix: Transform): Transform => [
+  [matrix[0][0], matrix[1][0], matrix[0][2]],
+  [matrix[0][1], matrix[1][1], matrix[1][2]]
+];
+
+const applyMatrix = (matrix: Transform, point: Point): Point => ({
+  x: point.x * matrix[0][0] + point.y * matrix[0][1],
+  y: point.x * matrix[1][0] + point.y * matrix[1][1]
+});
+
+const calculateCenter = (boundingBox: Rect): Point => ({
+  x: boundingBox.x + boundingBox.width / 2,
+  y: boundingBox.y + boundingBox.height / 2
+});

plugin-src/utils/index.ts

@@ -1,4 +1,5 @@
 export * from './applyMatrixToPoint';
+export * from './applyRotation';
 export * from './calculateAdjustment';
 export * from './calculateLinearGradient';
 export * from './calculateRadialGradient';