/* * Copyright 2012 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "src/pathops/SkPathOpsLine.h" SkDPoint SkDLine::ptAtT(double t) const { if (0 == t) { return fPts[0]; } if (1 == t) { return fPts[1]; } double one_t = 1 - t; SkDPoint result = { one_t * fPts[0].fX + t * fPts[1].fX, one_t * fPts[0].fY + t * fPts[1].fY }; return result; } double SkDLine::exactPoint(const SkDPoint& xy) const { if (xy == fPts[0]) { // do cheapest test first return 0; } if (xy == fPts[1]) { return 1; } return -1; } double SkDLine::nearPoint(const SkDPoint& xy, bool* unequal) const { if (!AlmostBetweenUlps(fPts[0].fX, xy.fX, fPts[1].fX) || !AlmostBetweenUlps(fPts[0].fY, xy.fY, fPts[1].fY)) { return -1; } // project a perpendicular ray from the point to the line; find the T on the line SkDVector len = fPts[1] - fPts[0]; // the x/y magnitudes of the line double denom = len.fX * len.fX + len.fY * len.fY; // see DLine intersectRay SkDVector ab0 = xy - fPts[0]; double numer = len.fX * ab0.fX + ab0.fY * len.fY; if (!between(0, numer, denom)) { return -1; } if (!denom) { return 0; } double t = numer / denom; SkDPoint realPt = ptAtT(t); double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ? // find the ordinal in the original line with the largest unsigned exponent double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); largest = SkTMax(largest, -tiniest); if (!AlmostEqualUlps_Pin(largest, largest + dist)) { // is the dist within ULPS tolerance? return -1; } if (unequal) { *unequal = (float) largest != (float) (largest + dist); } t = SkPinT(t); // a looser pin breaks skpwww_lptemp_com_3 SkASSERT(between(0, t, 1)); return t; } bool SkDLine::nearRay(const SkDPoint& xy) const { // project a perpendicular ray from the point to the line; find the T on the line SkDVector len = fPts[1] - fPts[0]; // the x/y magnitudes of the line double denom = len.fX * len.fX + len.fY * len.fY; // see DLine intersectRay SkDVector ab0 = xy - fPts[0]; double numer = len.fX * ab0.fX + ab0.fY * len.fY; double t = numer / denom; SkDPoint realPt = ptAtT(t); double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ? // find the ordinal in the original line with the largest unsigned exponent double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); largest = SkTMax(largest, -tiniest); return RoughlyEqualUlps(largest, largest + dist); // is the dist within ULPS tolerance? } double SkDLine::ExactPointH(const SkDPoint& xy, double left, double right, double y) { if (xy.fY == y) { if (xy.fX == left) { return 0; } if (xy.fX == right) { return 1; } } return -1; } double SkDLine::NearPointH(const SkDPoint& xy, double left, double right, double y) { if (!AlmostBequalUlps(xy.fY, y)) { return -1; } if (!AlmostBetweenUlps(left, xy.fX, right)) { return -1; } double t = (xy.fX - left) / (right - left); t = SkPinT(t); SkASSERT(between(0, t, 1)); double realPtX = (1 - t) * left + t * right; SkDVector distU = {xy.fY - y, xy.fX - realPtX}; double distSq = distU.fX * distU.fX + distU.fY * distU.fY; double dist = sqrt(distSq); // OPTIMIZATION: can we compare against distSq instead ? double tiniest = SkTMin(SkTMin(y, left), right); double largest = SkTMax(SkTMax(y, left), right); largest = SkTMax(largest, -tiniest); if (!AlmostEqualUlps(largest, largest + dist)) { // is the dist within ULPS tolerance? return -1; } return t; } double SkDLine::ExactPointV(const SkDPoint& xy, double top, double bottom, double x) { if (xy.fX == x) { if (xy.fY == top) { return 0; } if (xy.fY == bottom) { return 1; } } return -1; } double SkDLine::NearPointV(const SkDPoint& xy, double top, double bottom, double x) { if (!AlmostBequalUlps(xy.fX, x)) { return -1; } if (!AlmostBetweenUlps(top, xy.fY, bottom)) { return -1; } double t = (xy.fY - top) / (bottom - top); t = SkPinT(t); SkASSERT(between(0, t, 1)); double realPtY = (1 - t) * top + t * bottom; SkDVector distU = {xy.fX - x, xy.fY - realPtY}; double distSq = distU.fX * distU.fX + distU.fY * distU.fY; double dist = sqrt(distSq); // OPTIMIZATION: can we compare against distSq instead ? double tiniest = SkTMin(SkTMin(x, top), bottom); double largest = SkTMax(SkTMax(x, top), bottom); largest = SkTMax(largest, -tiniest); if (!AlmostEqualUlps(largest, largest + dist)) { // is the dist within ULPS tolerance? return -1; } return t; }