Move boolean composition out of kits.

font-src/support/curve-util.js

@@ -4,6 +4,7 @@ const TypoGeom = require("typo-geom");
 const Point = require("./point");
 const Transform = require("./transform");
 
+exports.SPIRO_PRECISION = 1 / 2;
 exports.GEOMETRY_PRECISION = 1 / 4;
 exports.RECIP_GEOMETRY_PRECISION = 4;
 exports.BOOLE_RESOLUTION = 0x4000;
@@ -34,6 +35,18 @@ exports.OffsetCurve = class OffsetCurve {
 	}
 };
 
+exports.ReverseCurve = class ReverseCurve {
+	constructor(original) {
+		this.m_original = original;
+	}
+	eval(t) {
+		return this.m_original.eval(1 - t);
+	}
+	derivative(t) {
+		return -this.m_original.derivative(1 - t);
+	}
+};
+
 exports.convertShapeToArcs = function convertShapeToArcs(shape) {
 	return shape.map(convertContourToArcs);
 };

font-src/support/geometry.js

@@ -2,6 +2,8 @@
 
 const Point = require("./point");
 const Transform = require("./transform");
+const CurveUtil = require("./curve-util");
+const TypoGeom = require("typo-geom");
 
 class GeometryBase {
 	asContours() {
@@ -132,7 +134,9 @@ class TransformedGeometry extends GeometryBase {
 		return result;
 	}
 	filterTag(fn) {
-		return new TransformedGeometry(this.m_geom.filterTag(fn), this.m_transform);
+		const e = this.m_geom.filterTag(fn);
+		if (!e) return null;
+		return new TransformedGeometry(e, this.m_transform);
 	}
 	isEmpty() {
 		return this.m_geom.isEmpty();
@@ -192,6 +196,62 @@ class CombineGeometry extends GeometryBase {
 	}
 }
 
+class BooleanGeometry extends GeometryBase {
+	constructor(operator, operands) {
+		super();
+		this.m_operator = operator;
+		this.m_operands = operands;
+		this.m_resolved = null;
+	}
+	asContours() {
+		if (this.m_resolved) return this.m_resolved;
+		this.m_resolved = this.asContoursImpl();
+		return this.m_resolved;
+	}
+	asContoursImpl() {
+		let arcs = CurveUtil.convertShapeToArcs(this.m_operands[0].asContours());
+		if (this.m_operands.length < 2) {
+			arcs = TypoGeom.Boolean.removeOverlap(
+				arcs,
+				TypoGeom.Boolean.PolyFillType.pftNonZero,
+				CurveUtil.BOOLE_RESOLUTION
+			);
+		}
+		for (let j = 1; j < this.m_operands.length; j++) {
+			arcs = TypoGeom.Boolean.combine(
+				this.m_operator,
+				arcs,
+				CurveUtil.convertShapeToArcs(this.m_operands[j].asContours()),
+				TypoGeom.Boolean.PolyFillType.pftNonZero,
+				TypoGeom.Boolean.PolyFillType.pftNonZero,
+				CurveUtil.BOOLE_RESOLUTION
+			);
+		}
+		const ctx = new CurveUtil.BezToContoursSink();
+		TypoGeom.ShapeConv.transferBezArcShape(arcs, ctx);
+		return ctx.contours;
+	}
+	asReferences() {
+		return null;
+	}
+	filterTag(fn) {
+		let filtered = [];
+		for (const operand of this.m_operands) {
+			const fp = operand.filterTag(fn);
+			if (fp) filtered.push(fp);
+		}
+		return new BooleanGeometry(this.m_operator, filtered);
+	}
+	isEmpty() {
+		for (const operand of this.m_operands) if (!operand.isEmpty()) return false;
+		return true;
+	}
+	measureComplexity() {
+		let s = 0;
+		for (const operand of this.m_operands) s += operand.measureComplexity();
+	}
+}
+
 function combineWith(a, b) {
 	if (a instanceof CombineGeometry) {
 		return a.with(b);
@@ -206,5 +266,6 @@ exports.ReferenceGeometry = ReferenceGeometry;
 exports.TaggedGeometry = TaggedGeometry;
 exports.TransformedGeometry = TransformedGeometry;
 exports.CombineGeometry = CombineGeometry;
+exports.BooleanGeometry = BooleanGeometry;
 
 exports.combineWith = combineWith;

font-src/support/glyph.js

@@ -95,15 +95,15 @@ module.exports = class Glyph {
 		this.avoidBeingComposite = g.avoidBeingComposite;
 	}
 
-	combineGeometryImpl(g) {
+	includeGeometry(g) {
 		if (this.ctxTag) g = new Geom.TaggedGeometry(g, this.ctxTag);
 		this.geometry = Geom.combineWith(this.geometry, g);
 	}
 	includeGlyphImpl(g, shiftX, shiftY) {
 		if (g._m_identifier) {
-			this.combineGeometryImpl(new Geom.ReferenceGeometry(g, shiftX, shiftY));
+			this.includeGeometry(new Geom.ReferenceGeometry(g, shiftX, shiftY));
 		} else {
-			this.combineGeometryImpl(
+			this.includeGeometry(
 				new Geom.TransformedGeometry(g.geometry, Transform.Translate(shiftX, shiftY))
 			);
 		}
@@ -116,7 +116,7 @@ module.exports = class Glyph {
 			for (const z of contour) c.push(Point.translated(z, shiftX, shiftY));
 			parts.push(new Geom.ContourGeometry(c));
 		}
-		this.combineGeometryImpl(new Geom.CombineGeometry(parts));
+		this.includeGeometry(new Geom.CombineGeometry(parts));
 	}
 
 	applyTransform(tfm, alsoAnchors) {

font-src/support/spiro-expand.js

@@ -53,6 +53,10 @@ module.exports = class SpiroExpansionContext {
 		const k0 = this.controlKnots[this.controlKnots.length - 1];
 		if (k0) k0.type = type;
 	}
+	setUnimportant() {
+		const k0 = this.controlKnots[this.controlKnots.length - 1];
+		if (k0) k0.unimportant = true;
+	}
 	expand(contrast) {
 		if (contrast == null) contrast = 1 / 0.9;
 		const lhs = [],
@@ -100,6 +104,7 @@ module.exports = class SpiroExpansionContext {
 				rhsAfter = this.gizmo.unapply(rhs[jAfter]);
 
 			lhs[j] = {
+				unimportant: true,
 				type: knot.type,
 				...this.gizmo.apply({
 					x: linreg(knotBefore.x, lhsBefore.x, knotAfter.x, lhsAfter.x, ref.x),
@@ -107,6 +112,7 @@ module.exports = class SpiroExpansionContext {
 				})
 			};
 			rhs[j] = {
+				unimportant: true,
 				type: reverseKnotType(knot.type),
 				...this.gizmo.apply({
 					x: linreg(knotBefore.x, rhsBefore.x, knotAfter.x, rhsAfter.x, ref.x),