path ops work in progress

src/pathops/SkIntersections.cpp

 /*
  * 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 "SkIntersections.h"
 
 int (SkIntersections::*CurveVertical[])(const SkPoint[], SkScalar, SkScalar, SkScalar, bool) = {
@@ skipping 38 matching lines @@
 }
 
 void SkIntersections::flip() {
     for (int index = 0; index < fUsed; ++index) {
         fT[1][index] = 1 - fT[1][index];
     }
 }
 
 void SkIntersections::insertCoincidentPair(double s1, double e1, double s2, double e2,
         const SkDPoint& startPt, const SkDPoint& endPt) {
-    if (fSwap) {
-        remove(s2, e2, startPt, endPt);
-    } else {
-        remove(s1, e1, startPt, endPt);
+    SkASSERT(s1 < e1);
+    SkASSERT(s2 != e2);
+    if (coincidentUsed() != fUsed) { // if the curve is partially coincident, treat it as fully so
+        for (int index = fUsed - 1; index >= 0; --index) {
+            if (fIsCoincident[0] & (1 << index)) {
+                continue;
+            }
+            double nonCoinT = fT[0][index];
+            if (!between(s1, nonCoinT, e1)) {
+                if (s1 > nonCoinT) {
+                    s1 = nonCoinT;
+                } else {
+                    e1 = nonCoinT;
+                }
+            }
+            nonCoinT = fT[1][index];
+            if (!between(s2, nonCoinT, e2)) {
+                if ((s2 > nonCoinT) ^ (s2 > e2)) {
+                    s2 = nonCoinT;
+                } else {
+                    e2 = nonCoinT;
+                }
+            }
+            removeOne(index);
+        }
     }
     SkASSERT(coincidentUsed() == fUsed);
     SkASSERT((coincidentUsed() & 1) != 1);
     int i1 = 0;
     int i2 = 0;
     do {
         while (i1 < fUsed && !(fIsCoincident[fSwap] & (1 << i1))) {
             ++i1;
         }
         if (i1 == fUsed) {
@@ skipping 55 matching lines @@
                 fT[fSwap ^ 1][iEnd2] = e2;
             }
             return;
         }
     } while (true);
     SkASSERT(fUsed < 9);
     insertCoincident(s1, s2, startPt);
     insertCoincident(e1, e2, endPt);
 }
 
-int SkIntersections::insert(double one, double two, const SkDPoint& pt) {
+int SkIntersections::insert(double one, double two, double x, double y) {
     if (fIsCoincident[0] == 3 && between(fT[0][0], one, fT[0][1])) {
         // For now, don't allow a mix of coincident and non-coincident intersections
         return -1;
     }
     SkASSERT(fUsed <= 1 || fT[0][0] <= fT[0][1]);
     int index;
     for (index = 0; index < fUsed; ++index) {
         double oldOne = fT[0][index];
         double oldTwo = fT[1][index];
         if (roughly_equal(oldOne, one) && roughly_equal(oldTwo, two)) {
             if ((precisely_zero(one) && !precisely_zero(oldOne))
                     || (precisely_equal(one, 1) && !precisely_equal(oldOne, 1))
                     || (precisely_zero(two) && !precisely_zero(oldTwo))
                     || (precisely_equal(two, 1) && !precisely_equal(oldTwo, 1))) {
                 fT[0][index] = one;
                 fT[1][index] = two;
-                fPt[index] = pt;
+                fPt[index].fX = x;
+                fPt[index].fY = y;
             }
             return -1;
         }
     #if ONE_OFF_DEBUG
         if (pt.roughlyEqual(fPt[index])) {
             SkDebugf("%s t=%1.9g pts roughly equal\n", __FUNCTION__, one);
         }
     #endif
         if (fT[0][index] > one) {
             break;
         }
     }
     SkASSERT(fUsed < 9);
     int remaining = fUsed - index;
     if (remaining > 0) {
         memmove(&fPt[index + 1], &fPt[index], sizeof(fPt[0]) * remaining);
         memmove(&fT[0][index + 1], &fT[0][index], sizeof(fT[0][0]) * remaining);
         memmove(&fT[1][index + 1], &fT[1][index], sizeof(fT[1][0]) * remaining);
         fIsCoincident[0] += fIsCoincident[0] & ~((1 << index) - 1);
         fIsCoincident[1] += fIsCoincident[1] & ~((1 << index) - 1);
     }
-    fPt[index] = pt;
+    fPt[index].fX = x;
+    fPt[index].fY = y;
     fT[0][index] = one;
     fT[1][index] = two;
     ++fUsed;
     return index;
 }
 
+int SkIntersections::insert(double one, double two, const SkDPoint& pt) {
+    return insert(one, two, pt.fX, pt.fY);
+}
+
 void SkIntersections::insertCoincident(double one, double two, const SkDPoint& pt) {
     int index = insertSwap(one, two, pt);
     int bit = 1 << index;
     fIsCoincident[0] |= bit;
     fIsCoincident[1] |= bit;
 }
 
 void SkIntersections::offset(int base, double start, double end) {
     for (int index = base; index < fUsed; ++index) {
         double val = fT[fSwap][index];
         val *= end - start;
         val += start;
         fT[fSwap][index] = val;
     }
 }
 
 int SkIntersections::quadRay(const SkPoint pts[3], const SkDLine& line) {
     SkDQuad quad;
     quad.set(pts);
     return intersectRay(quad, line);
 }
 
 void SkIntersections::quickRemoveOne(int index, int replace) {
     if (index < replace) {
         fT[0][index] = fT[0][replace];
     }
 }
 
+#if 0
 void SkIntersections::remove(double one, double two, const SkDPoint& startPt,
         const SkDPoint& endPt) {
     for (int index = fUsed - 1; index >= 0; --index) {
         if (!(fIsCoincident[0] & (1 << index)) && (between(one, fT[fSwap][index], two)
                 || startPt.approximatelyEqual(fPt[index])
                 || endPt.approximatelyEqual(fPt[index]))) {
             SkASSERT(fUsed > 0);
             removeOne(index);
         }
     }
 }
+#endif
 
 void SkIntersections::removeOne(int index) {
     int remaining = --fUsed - index;
     if (remaining <= 0) {
         return;
     }
     memmove(&fPt[index], &fPt[index + 1], sizeof(fPt[0]) * remaining);
     memmove(&fT[0][index], &fT[0][index + 1], sizeof(fT[0][0]) * remaining);
     memmove(&fT[1][index], &fT[1][index + 1], sizeof(fT[1][0]) * remaining);
     SkASSERT(fIsCoincident[0] == 0);
@@ skipping 23 matching lines @@
     quad.set(a);
     return vertical(quad, top, bottom, x, flipped);
 }
 
 int SkIntersections::verticalCubic(const SkPoint a[4], SkScalar top, SkScalar bottom,
         SkScalar x, bool flipped) {
     SkDCubic cubic;
     cubic.set(a);
     return vertical(cubic, top, bottom, x, flipped);
 }