From 5b31aee8bbc77491130bc4ef01ac73f83000a01c Mon Sep 17 00:00:00 2001 From: iconexperience Date: Fri, 5 Feb 2016 14:48:27 +0100 Subject: [PATCH] Change the implementation of getWinding() again, so we pass all tests. This new version does not count any intersections if the point is on a y-monotonic curve, but at the final calculation it sets the winding to at least 1 if the point is on a curve. --- src/path/PathItem.Boolean.js | 87 +++++++++++++++++++----------------- 1 file changed, 45 insertions(+), 42 deletions(-) diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js index c1e40c94..a1c48959 100644 --- a/src/path/PathItem.Boolean.js +++ b/src/path/PathItem.Boolean.js @@ -314,10 +314,10 @@ PathItem.inject(new function() { py = point.y, windLeft = 0, windRight = 0, - isOnCurve = false, length = curves.length, roots = [], - abs = Math.abs; + abs = Math.abs, + isOnCurve = false; // Horizontal curves may return wrong results, since the curves are // monotonic in y direction and this is an indeterminate state. if (horizontal) { @@ -357,12 +357,13 @@ PathItem.inject(new function() { values = curve.values, yStart = values[1], yEnd = values[7]; - // The first curve of a loop holds the last curve with non-zero - // winding. Retrieve and use it here (See _getMonoCurve()). + // The first curve of a loop holds the last curve with + // non-zero winding. + // Retrieve and use it here (See _getMonoCurve()). if (curve.last) { // Get the end x coordinate and winding of the last // non-horizontal curve, which will be the previous - // non-horizontal curve for first curve in the loop. + // non-horizontal curve for the first curve in the loop. prevWinding = curve.last.winding; prevXEnd = curve.last.values[6]; } @@ -370,51 +371,53 @@ PathItem.inject(new function() { // compare the endpoints of the curve to determine if the // ray from query point along +-x direction will intersect // the monotone curve. - // Horizontal curves with winding == 0 will be completely - // ignored. - if (winding && (py >= yStart && py <= yEnd - || py >= yEnd && py <= yStart)) { - // Calculate the x value for the ray's intersection. - var x = py === yStart ? values[0] - : py === yEnd ? values[6] - : Curve.solveCubic(values, 1, py, roots, 0, 1) === 1 + if (py >= yStart && py <= yEnd || py >= yEnd && py <= yStart) { + if (winding) { + // Calculate the x value for the ray's intersection. + var x = py === yStart ? values[0] + : py === yEnd ? values[6] + : Curve.solveCubic(values, 1, py, roots, 0, 1) === 1 ? Curve.getPoint(values, roots[0]).x : null; - if (x != null) { - // If the point is between the curve's start point and - // the previous curve's end point, it must be on a - // horizontal curve in between. - var isOnHorizontal = - py === yStart && (px - x) * (px - prevXEnd) < 0; - // Test if the point is on a y-monotonic curve - if ((x >= xBefore && x <= xAfter) || isOnHorizontal) - isOnCurve = true; - // Count the intersection of the ray with the - // y-monotonic curve if: - // - the crossing is not the start or end of the curve - // - or the crossing is at the start of the curve and - // the winding did not change between curves - if (py != yEnd - && (py != yStart || winding === prevWinding)) { - if (x < xBefore) { - windLeft += winding; - } else if (x > xAfter) { - windRight += winding; + if (x != null) { + // determine if the point is on the horizontal + // connection between the last non-horizontal curve's + // end point and the current curve's start point + var isOnHorizontal = + (py === yStart && (px - x) * (px - prevXEnd) < 0); + // Test if the point is on the current monocurve + if (x >= xBefore && x <= xAfter) { + isOnCurve = true; + // Count the intersection of the ray with the + // monotonic curve if: + // - the crossing is not the start of the curve + // except if the winding changes. + // - and the point is not on the curve or on the + // horizontal connection between the previous + // curve and the current curve + } else if ((py != yStart || winding !== prevWinding) + && !isOnHorizontal) { + if (x < xBefore) { + windLeft += winding; + } else if (x > xAfter) { + windRight += winding; + } } } + // Update previous winding and end coordinate whenever + // the ray intersects a non-horizontal curve. + prevWinding = winding; + prevXEnd = values[6]; + // Test if the point is on the horizontal curve + } else if ((px - values[0]) * (px - values[6]) <= 0) { + isOnCurve = true; } - // Update previous winding and end coordinate whenever - // the ray intersects a non-horizontal curve. - prevWinding = winding; - prevXEnd = values[6]; } } } - // If the point is on a monotonic curve, ensure that the winding is odd - // by applying bit-wise or `| 1` to the bigger absolute winding number: - // If winding is an even number and the point is on a curve, this will - // add up to the next uneven number, otherwise it remains the same. - return Math.max(abs(windLeft), abs(windRight)) | (isOnCurve ? 1 : 0 ); + // If the point was on a monocurve, we are on the path by definition. + // In this case ensure that the winding is at least 1. + return Math.max(abs(windLeft), abs(windRight), isOnCurve ? 1 : 0); } function propagateWinding(segment, path1, path2, monoCurves, operator) {