align top and bounds computations

src/pathops/SkPathOpsQuad.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"
 #include "SkLineParameters.h"
 #include "SkPathOpsCubic.h"
 #include "SkPathOpsCurve.h"
@@ skipping 222 matching lines @@
     return result;
 }
 
 static double interp_quad_coords(const double* src, double t) {
     double ab = SkDInterp(src[0], src[2], t);
     double bc = SkDInterp(src[2], src[4], t);
     double abc = SkDInterp(ab, bc, t);
     return abc;
 }
 
+bool SkDQuad::monotonicInX() const {
+    return between(fPts[0].fX, fPts[1].fX, fPts[2].fX);
+}
+
 bool SkDQuad::monotonicInY() const {
     return between(fPts[0].fY, fPts[1].fY, fPts[2].fY);
 }
 
 /*
 Given a quadratic q, t1, and t2, find a small quadratic segment.
 
 The new quadratic is defined by A, B, and C, where
  A = c[0]*(1 - t1)*(1 - t1) + 2*c[1]*t1*(1 - t1) + c[2]*t1*t1
  C = c[3]*(1 - t1)*(1 - t1) + 2*c[2]*t1*(1 - t1) + c[1]*t1*t1
@@ skipping 63 matching lines @@
         b.fX = c.fX;
     }
     if (AlmostBequalUlps(b.fY, a.fY)) {
         b.fY = a.fY;
     } else if (AlmostBequalUlps(b.fY, c.fY)) {
         b.fY = c.fY;
     }
     return b;
 }
 
-SkDPoint SkDQuad::top(double startT, double endT, double* topT) const {
-    SkDQuad sub = subDivide(startT, endT);
-    SkDPoint topPt = sub[0];
-    *topT = startT;
-    if (topPt.fY > sub[2].fY || (topPt.fY == sub[2].fY && topPt.fX > sub[2].fX)) {
-        *topT = endT;
-        topPt = sub[2];
-    }
-    if (!between(sub[0].fY, sub[1].fY, sub[2].fY)) {
-        double extremeT;
-        if (FindExtrema(sub[0].fY, sub[1].fY, sub[2].fY, &extremeT)) {
-            extremeT = startT + (endT - startT) * extremeT;
-            SkDPoint test = ptAtT(extremeT);
-            if (topPt.fY > test.fY || (topPt.fY == test.fY && topPt.fX > test.fX)) {
-                *topT = extremeT;
-                topPt = test;
-            }
-        }
-    }
-    return topPt;
-}
-
 /* classic one t subdivision */
 static void interp_quad_coords(const double* src, double* dst, double t) {
     double ab = SkDInterp(src[0], src[2], t);
     double bc = SkDInterp(src[2], src[4], t);
     dst[0] = src[0];
     dst[2] = ab;
     dst[4] = SkDInterp(ab, bc, t);
     dst[6] = bc;
     dst[8] = src[4];
 }
@@ skipping 32 matching lines @@
     }
     *ratio = r;
     return 1;
 }
 
 /** Quad'(t) = At + B, where
     A = 2(a - 2b + c)
     B = 2(b - a)
     Solve for t, only if it fits between 0 < t < 1
 */
-int SkDQuad::FindExtrema(double a, double b, double c, double tValue[1]) {
+int SkDQuad::FindExtrema(const double src[], double tValue[1]) {
     /*  At + B == 0
         t = -B / A
     */
+    double a = src[0];
+    double b = src[2];
+    double c = src[4];
     return valid_unit_divide(a - b, a - b - b + c, tValue);
 }
 
 /* Parameterization form, given A*t*t + 2*B*t*(1-t) + C*(1-t)*(1-t)
  *
  * a = A - 2*B +   C
  * b =     2*B - 2*C
  * c =             C
  */
 void SkDQuad::SetABC(const double* quad, double* a, double* b, double* c) {
     *a = quad[0];      // a = A
     *b = 2 * quad[2];  // b =     2*B
     *c = quad[4];      // c =             C
     *b -= *c;          // b =     2*B -   C
     *a -= *b;          // a = A - 2*B +   C
     *b -= *c;          // b =     2*B - 2*C
 }