The Tor Browser: gfx/skia/trunk/include/core/SkGeometry.h@129ffea94266 (annotated)

gfx/skia/trunk/include/core/SkGeometry.h@129ffea94266 (annotated)

gfx/skia/trunk/include/core/SkGeometry.h

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkGeometry_DEFINED
 #define SkGeometry_DEFINED
 #include "SkMatrix.h"
 /** An XRay is a half-line that runs from the specific point/origin to
     +infinity in the X direction. e.g. XRay(3,5) is the half-line
     (3,5)....(infinity, 5)
  */
 typedef SkPoint SkXRay;
 /** Given a line segment from pts[0] to pts[1], and an xray, return true if
     they intersect. Optional outgoing "ambiguous" argument indicates
     whether the answer is ambiguous because the query occurred exactly at
     one of the endpoints' y coordinates, indicating that another query y
     coordinate is preferred for robustness.
 */
 bool SkXRayCrossesLine(const SkXRay& pt, const SkPoint pts[2],
                        bool* ambiguous = NULL);
 /** Given a quadratic equation Ax^2 + Bx + C = 0, return 0, 1, 2 roots for the
     equation.
 */
 int SkFindUnitQuadRoots(SkScalar A, SkScalar B, SkScalar C, SkScalar roots[2]);
 ///////////////////////////////////////////////////////////////////////////////
 /** Set pt to the point on the src quadratic specified by t. t must be
 <= t <= 1.0
 */
 void SkEvalQuadAt(const SkPoint src[3], SkScalar t, SkPoint* pt,
                   SkVector* tangent = NULL);
 void SkEvalQuadAtHalf(const SkPoint src[3], SkPoint* pt,
                       SkVector* tangent = NULL);
 /** Given a src quadratic bezier, chop it at the specified t value,
     where 0 < t < 1, and return the two new quadratics in dst:
     dst[0..2] and dst[2..4]
 */
 void SkChopQuadAt(const SkPoint src[3], SkPoint dst[5], SkScalar t);
 /** Given a src quadratic bezier, chop it at the specified t == 1/2,
     The new quads are returned in dst[0..2] and dst[2..4]
 */
 void SkChopQuadAtHalf(const SkPoint src[3], SkPoint dst[5]);
 /** Given the 3 coefficients for a quadratic bezier (either X or Y values), look
     for extrema, and return the number of t-values that are found that represent
     these extrema. If the quadratic has no extrema betwee (0..1) exclusive, the
     function returns 0.
     Returned count      tValues[]
 ignored
 0 < tValues[0] < 1
 */
 int SkFindQuadExtrema(SkScalar a, SkScalar b, SkScalar c, SkScalar tValues[1]);
 /** Given 3 points on a quadratic bezier, chop it into 1, 2 beziers such that
     the resulting beziers are monotonic in Y. This is called by the scan converter.
     Depending on what is returned, dst[] is treated as follows
 dst[0..2] is the original quad
 dst[0..2] and dst[2..4] are the two new quads
 */
 int SkChopQuadAtYExtrema(const SkPoint src[3], SkPoint dst[5]);
 int SkChopQuadAtXExtrema(const SkPoint src[3], SkPoint dst[5]);
 /** Given 3 points on a quadratic bezier, if the point of maximum
     curvature exists on the segment, returns the t value for this
     point along the curve. Otherwise it will return a value of 0.
 */
 float SkFindQuadMaxCurvature(const SkPoint src[3]);
 /** Given 3 points on a quadratic bezier, divide it into 2 quadratics
     if the point of maximum curvature exists on the quad segment.
     Depending on what is returned, dst[] is treated as follows
 dst[0..2] is the original quad
 dst[0..2] and dst[2..4] are the two new quads
     If dst == null, it is ignored and only the count is returned.
 */
 int SkChopQuadAtMaxCurvature(const SkPoint src[3], SkPoint dst[5]);
 /** Given 3 points on a quadratic bezier, use degree elevation to
     convert it into the cubic fitting the same curve. The new cubic
     curve is returned in dst[0..3].
 */
 SK_API void SkConvertQuadToCubic(const SkPoint src[3], SkPoint dst[4]);
 ///////////////////////////////////////////////////////////////////////////////
 /** Convert from parametric from (pts) to polynomial coefficients
     coeff[0]*T^3 + coeff[1]*T^2 + coeff[2]*T + coeff[3]
 */
 void SkGetCubicCoeff(const SkPoint pts[4], SkScalar cx[4], SkScalar cy[4]);
 /** Set pt to the point on the src cubic specified by t. t must be
 <= t <= 1.0
 */
 void SkEvalCubicAt(const SkPoint src[4], SkScalar t, SkPoint* locOrNull,
                    SkVector* tangentOrNull, SkVector* curvatureOrNull);
 /** Given a src cubic bezier, chop it at the specified t value,
     where 0 < t < 1, and return the two new cubics in dst:
     dst[0..3] and dst[3..6]
 */
 void SkChopCubicAt(const SkPoint src[4], SkPoint dst[7], SkScalar t);
 /** Given a src cubic bezier, chop it at the specified t values,
     where 0 < t < 1, and return the new cubics in dst:
     dst[0..3],dst[3..6],...,dst[3*t_count..3*(t_count+1)]
 */
 void SkChopCubicAt(const SkPoint src[4], SkPoint dst[], const SkScalar t[],
                    int t_count);
 /** Given a src cubic bezier, chop it at the specified t == 1/2,
     The new cubics are returned in dst[0..3] and dst[3..6]
 */
 void SkChopCubicAtHalf(const SkPoint src[4], SkPoint dst[7]);
 /** Given the 4 coefficients for a cubic bezier (either X or Y values), look
     for extrema, and return the number of t-values that are found that represent
     these extrema. If the cubic has no extrema betwee (0..1) exclusive, the
     function returns 0.
     Returned count      tValues[]
 ignored
 0 < tValues[0] < 1
 0 < tValues[0] < tValues[1] < 1
 */
 int SkFindCubicExtrema(SkScalar a, SkScalar b, SkScalar c, SkScalar d,
                        SkScalar tValues[2]);
 /** Given 4 points on a cubic bezier, chop it into 1, 2, 3 beziers such that
     the resulting beziers are monotonic in Y. This is called by the scan converter.
     Depending on what is returned, dst[] is treated as follows
 dst[0..3] is the original cubic
 dst[0..3] and dst[3..6] are the two new cubics
 dst[0..3], dst[3..6], dst[6..9] are the three new cubics
     If dst == null, it is ignored and only the count is returned.
 */
 int SkChopCubicAtYExtrema(const SkPoint src[4], SkPoint dst[10]);
 int SkChopCubicAtXExtrema(const SkPoint src[4], SkPoint dst[10]);
 /** Given a cubic bezier, return 0, 1, or 2 t-values that represent the
     inflection points.
 */
 int SkFindCubicInflections(const SkPoint src[4], SkScalar tValues[2]);
 /** Return 1 for no chop, 2 for having chopped the cubic at a single
     inflection point, 3 for having chopped at 2 inflection points.
     dst will hold the resulting 1, 2, or 3 cubics.
 */
 int SkChopCubicAtInflections(const SkPoint src[4], SkPoint dst[10]);
 int SkFindCubicMaxCurvature(const SkPoint src[4], SkScalar tValues[3]);
 int SkChopCubicAtMaxCurvature(const SkPoint src[4], SkPoint dst[13],
                               SkScalar tValues[3] = NULL);
 /** Given a monotonic cubic bezier, determine whether an xray intersects the
     cubic.
     By definition the cubic is open at the starting point; in other
     words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
     left of the curve, the line is not considered to cross the curve,
     but if it is equal to cubic[3].fY then it is considered to
     cross.
     Optional outgoing "ambiguous" argument indicates whether the answer is
     ambiguous because the query occurred exactly at one of the endpoints' y
     coordinates, indicating that another query y coordinate is preferred
     for robustness.
  */
 bool SkXRayCrossesMonotonicCubic(const SkXRay& pt, const SkPoint cubic[4],
                                  bool* ambiguous = NULL);
 /** Given an arbitrary cubic bezier, return the number of times an xray crosses
     the cubic. Valid return values are [0..3]
     By definition the cubic is open at the starting point; in other
     words, if pt.fY is equivalent to cubic[0].fY, and pt.fX is to the
     left of the curve, the line is not considered to cross the curve,
     but if it is equal to cubic[3].fY then it is considered to
     cross.
     Optional outgoing "ambiguous" argument indicates whether the answer is
     ambiguous because the query occurred exactly at one of the endpoints' y
     coordinates or at a tangent point, indicating that another query y
     coordinate is preferred for robustness.
  */
 int SkNumXRayCrossingsForCubic(const SkXRay& pt, const SkPoint cubic[4],
                                bool* ambiguous = NULL);
 ///////////////////////////////////////////////////////////////////////////////
 enum SkRotationDirection {
     kCW_SkRotationDirection,
     kCCW_SkRotationDirection
 };
 /** Maximum number of points needed in the quadPoints[] parameter for
     SkBuildQuadArc()
 */
 #define kSkBuildQuadArcStorage  17
 /** Given 2 unit vectors and a rotation direction, fill out the specified
     array of points with quadratic segments. Return is the number of points
     written to, which will be { 0, 3, 5, 7, ... kSkBuildQuadArcStorage }
     matrix, if not null, is appled to the points before they are returned.
 */
 int SkBuildQuadArc(const SkVector& unitStart, const SkVector& unitStop,
                    SkRotationDirection, const SkMatrix*, SkPoint quadPoints[]);
 // experimental
 struct SkConic {
     SkPoint  fPts[3];
     SkScalar fW;
     void set(const SkPoint pts[3], SkScalar w) {
         memcpy(fPts, pts, 3 * sizeof(SkPoint));
         fW = w;
     }
     /**
      *  Given a t-value [0...1] return its position and/or tangent.
      *  If pos is not null, return its position at the t-value.
      *  If tangent is not null, return its tangent at the t-value. NOTE the
      *  tangent value's length is arbitrary, and only its direction should
      *  be used.
      */
     void evalAt(SkScalar t, SkPoint* pos, SkVector* tangent = NULL) const;
     void chopAt(SkScalar t, SkConic dst[2]) const;
     void chop(SkConic dst[2]) const;
     void computeAsQuadError(SkVector* err) const;
     bool asQuadTol(SkScalar tol) const;
     /**
      *  return the power-of-2 number of quads needed to approximate this conic
      *  with a sequence of quads. Will be >= 0.
      */
     int computeQuadPOW2(SkScalar tol) const;
     /**
      *  Chop this conic into N quads, stored continguously in pts[], where
      *  N = 1 << pow2. The amount of storage needed is (1 + 2 * N)
      */
     int chopIntoQuadsPOW2(SkPoint pts[], int pow2) const;
     bool findXExtrema(SkScalar* t) const;
     bool findYExtrema(SkScalar* t) const;
     bool chopAtXExtrema(SkConic dst[2]) const;
     bool chopAtYExtrema(SkConic dst[2]) const;
     void computeTightBounds(SkRect* bounds) const;
     void computeFastBounds(SkRect* bounds) const;
     /** Find the parameter value where the conic takes on its maximum curvature.
      *
      *  @param t   output scalar for max curvature.  Will be unchanged if
      *             max curvature outside 0..1 range.
      *
      *  @return  true if max curvature found inside 0..1 range, false otherwise
      */
     bool findMaxCurvature(SkScalar* t) const;
 };
 #include "SkTemplates.h"
 /**
  *  Help class to allocate storage for approximating a conic with N quads.
  */
 class SkAutoConicToQuads {
 public:
     SkAutoConicToQuads() : fQuadCount(0) {}
     /**
      *  Given a conic and a tolerance, return the array of points for the
      *  approximating quad(s). Call countQuads() to know the number of quads
      *  represented in these points.
      *
      *  The quads are allocated to share end-points. e.g. if there are 4 quads,
      *  there will be 9 points allocated as follows
      *      quad[0] == pts[0..2]
      *      quad[1] == pts[2..4]
      *      quad[2] == pts[4..6]
      *      quad[3] == pts[6..8]
      */
     const SkPoint* computeQuads(const SkConic& conic, SkScalar tol) {
         int pow2 = conic.computeQuadPOW2(tol);
         fQuadCount = 1 << pow2;
         SkPoint* pts = fStorage.reset(1 + 2 * fQuadCount);
         conic.chopIntoQuadsPOW2(pts, pow2);
         return pts;
     }
     const SkPoint* computeQuads(const SkPoint pts[3], SkScalar weight,
                                 SkScalar tol) {
         SkConic conic;
         conic.set(pts, weight);
         return computeQuads(conic, tol);
     }
     int countQuads() const { return fQuadCount; }
 private:
     enum {
         kQuadCount = 8, // should handle most conics
         kPointCount = 1 + 2 * kQuadCount,
     };
     SkAutoSTMalloc<kPointCount, SkPoint> fStorage;
     int fQuadCount; // #quads for current usage
 };
 #endif

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gfx/skia/trunk/include/core/SkGeometry.h@129ffea94266 (annotated)

gfx/skia/trunk/include/core/SkGeometry.h