4  * Use of this source code is governed by a BSD-style license that can be
12 void SkIntersections::cleanUpParallelLines(bool parallel) {  in cleanUpParallelLines()  argument
16     if (fUsed == 2 && !parallel) {  in cleanUpParallelLines()
43     SkDVector aLen = a[1] - a[0];  in intersectRay()
44     SkDVector bLen = b[1] - b[0];  in intersectRay()
49              byLen  * axLen         -   ayLen          * bxLen == 0 ( == denom )  in intersectRay()
51     double denom = bLen.fY * aLen.fX - aLen.fY * bLen.fX;  in intersectRay()
54         SkDVector ab0 = a[0] - b[0];  in intersectRay()
55         double numerA = ab0.fY * bLen.fX - bLen.fY * ab0.fX;  in intersectRay()
56         double numerB = ab0.fY * aLen.fX - aLen.fY * ab0.fX;  in intersectRay()
64                   ay - ax * ayLen / axLen  ==          by - bx * ayLen / axLen  in intersectRay()
65          axLen * (ay - ax * ayLen / axLen) == axLen * (by - bx * ayLen / axLen)  in intersectRay()
66          axLen *  ay - ax * ayLen          == axLen *  by - bx * ayLen  in intersectRay()
68         if (!AlmostEqualUlps(aLen.fX * a[0].fY - aLen.fY * a[0].fX,  in intersectRay()
69                 aLen.fX * b[0].fY - aLen.fY * b[0].fX)) {  in intersectRay()
99     double axLen = a[1].fX - a[0].fX;  in intersect()
100     double ayLen = a[1].fY - a[0].fY;  in intersect()
101     double bxLen = b[1].fX - b[0].fX;  in intersect()
102     double byLen = b[1].fY - b[0].fY;  in intersect()
107              byLen  * axLen         -   ayLen          * bxLen == 0 ( == denom )  in intersect()
111     // detect parallel lines the same way here and in SkOpAngle operator <  in intersect()
112     // so that non-parallel means they are also sortable  in intersect()
116         double ab0y = a[0].fY - b[0].fY;  in intersect()
117         double ab0x = a[0].fX - b[0].fX;  in intersect()
118         double numerA = ab0y * bxLen - byLen * ab0x;  in intersect()
119         double numerB = ab0y * axLen - ayLen * ab0x;  in intersect()
120         double denom = axByLen - ayBxLen;  in intersect()
127 /* Allow tracking that both sets of end points are near each other -- the lines are entirely  in intersect()
128    coincident -- even when the end points are not exactly the same.  in intersect()
159                     aNearB[iA] = -1;  in intersect()
160                     bNearA[nearer] = -1;  in intersect()
161                     nearCount -= 2;  in intersect()
185     double max = line[1].fY;  in horizontal_coincident()  local
186     if (min > max) {  in horizontal_coincident()
188         swap(min, max);  in horizontal_coincident()
190     if (min > y || max < y) {  in horizontal_coincident()
193     if (AlmostEqualUlps(min, max) && max - min < fabs(line[0].fX - line[1].fX)) {  in horizontal_coincident()
201     return SkPinT((y - line[0].fY) / (line[1].fY - line[0].fY));  in HorizontalIntercept()
206     fMax = 3;  // clean up parallel at the end will limit the result to 2 at the most  in horizontal()
220                 insert((double) index, flipped ? 1 - t : t, line[index]);  in horizontal()
227         double xIntercept = line[0].fX + fT[0][0] * (line[1].fX - line[0].fX);  in horizontal()
229             fT[1][0] = (xIntercept - left) / (right - left);  in horizontal()
231                 // OPTIMIZATION: ? instead of swapping, pass original line, use [1].fX - [0].fX  in horizontal()
233                     fT[1][index] = 1 - fT[1][index];  in horizontal()
252                     insert((double) index, flipped ? 1 - t : t, line[index]);  in horizontal()
263     double max = line[1].fX;  in vertical_coincident()  local
264     if (min > max) {  in vertical_coincident()
266         swap(min, max);  in vertical_coincident()
268     if (!precisely_between(min, x, max)) {  in vertical_coincident()
271     if (AlmostEqualUlps(min, max)) {  in vertical_coincident()
279     return SkPinT((x - line[0].fX) / (line[1].fX - line[0].fX));  in VerticalIntercept()
284     fMax = 3;  // cleanup parallel lines will bring this back line  in vertical()
298                 insert((double) index, flipped ? 1 - t : t, line[index]);  in vertical()
305         double yIntercept = line[0].fY + fT[0][0] * (line[1].fY - line[0].fY);  in vertical()
307             fT[1][0] = (yIntercept - top) / (bottom - top);  in vertical()
309                 // OPTIMIZATION: instead of swapping, pass original line, use [1].fY - [0].fY  in vertical()
311                     fT[1][index] = 1 - fT[1][index];  in vertical()
330                     insert((double) index, flipped ? 1 - t : t, line[index]);  in vertical()