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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPathPriv_DEFINED
#define SkPathPriv_DEFINED
#include "SkPath.h"
class SkPathPriv {
public:
enum FirstDirection {
kCW_FirstDirection, // == SkPath::kCW_Direction
kCCW_FirstDirection, // == SkPath::kCCW_Direction
kUnknown_FirstDirection,
};
static FirstDirection AsFirstDirection(SkPath::Direction dir) {
// since we agree numerically for the values in Direction, we can just cast.
return (FirstDirection)dir;
}
/**
* Return the opposite of the specified direction. kUnknown is its own
* opposite.
*/
static FirstDirection OppositeFirstDirection(FirstDirection dir) {
static const FirstDirection gOppositeDir[] = {
kCCW_FirstDirection, kCW_FirstDirection, kUnknown_FirstDirection,
};
return gOppositeDir[dir];
}
/**
* Tries to quickly compute the direction of the first non-degenerate
* contour. If it can be computed, return true and set dir to that
* direction. If it cannot be (quickly) determined, return false and ignore
* the dir parameter. If the direction was determined, it is cached to make
* subsequent calls return quickly.
*/
static bool CheapComputeFirstDirection(const SkPath&, FirstDirection* dir);
/**
* Returns true if the path's direction can be computed via
* cheapComputDirection() and if that computed direction matches the
* specified direction. If dir is kUnknown, returns true if the direction
* cannot be computed.
*/
static bool CheapIsFirstDirection(const SkPath& path, FirstDirection dir) {
FirstDirection computedDir = kUnknown_FirstDirection;
(void)CheapComputeFirstDirection(path, &computedDir);
return computedDir == dir;
}
static bool IsClosedSingleContour(const SkPath& path) {
int verbCount = path.countVerbs();
if (verbCount == 0)
return false;
int moveCount = 0;
auto verbs = path.fPathRef->verbs();
for (int i = 0; i < verbCount; i++) {
switch (verbs[~i]) { // verbs are stored backwards; we use [~i] to get the i'th verb
case SkPath::Verb::kMove_Verb:
moveCount += 1;
if (moveCount > 1) {
return false;
}
break;
case SkPath::Verb::kClose_Verb:
if (i == verbCount - 1) {
return true;
}
return false;
default: break;
}
}
return false;
}
static void AddGenIDChangeListener(const SkPath& path, SkPathRef::GenIDChangeListener* listener) {
path.fPathRef->addGenIDChangeListener(listener);
}
/**
* This returns true for a rect that begins and ends at the same corner and has either a move
* followed by four lines or a move followed by 3 lines and a close. None of the parameters are
* optional. This does not permit degenerate line or point rectangles.
*/
static bool IsSimpleClosedRect(const SkPath& path, SkRect* rect, SkPath::Direction* direction,
unsigned* start);
/**
* Creates a path from arc params using the semantics of SkCanvas::drawArc. This function
* assumes empty ovals and zero sweeps have already been filtered out.
*/
static void CreateDrawArcPath(SkPath* path, const SkRect& oval, SkScalar startAngle,
SkScalar sweepAngle, bool useCenter, bool isFillNoPathEffect);
/**
* Returns a C++11-iterable object that traverses a path's verbs in order. e.g:
*
* for (SkPath::Verb verb : SkPathPriv::Verbs(path)) {
* ...
* }
*/
struct Verbs {
public:
Verbs(const SkPath& path) : fPathRef(path.fPathRef.get()) {}
struct Iter {
void operator++() { --fVerb; } // verbs are laid out backwards in memory.
bool operator!=(const Iter& b) { return fVerb != b.fVerb; }
SkPath::Verb operator*() { return static_cast<SkPath::Verb>(*fVerb); }
const uint8_t* fVerb;
};
Iter begin() { return Iter{fPathRef->verbs() - 1}; }
Iter end() { return Iter{fPathRef->verbs() - fPathRef->countVerbs() - 1}; }
private:
Verbs(const Verbs&) = delete;
Verbs& operator=(const Verbs&) = delete;
SkPathRef* fPathRef;
};
/**
* Returns a pointer to the verb data. Note that the verbs are stored backwards in memory and
* thus the returned pointer is the last verb.
*/
static const uint8_t* VerbData(const SkPath& path) {
return path.fPathRef->verbsMemBegin();
}
/** Returns a raw pointer to the path points */
static const SkPoint* PointData(const SkPath& path) {
return path.fPathRef->points();
}
/** Returns the number of conic weights in the path */
static int ConicWeightCnt(const SkPath& path) {
return path.fPathRef->countWeights();
}
/** Returns a raw pointer to the path conic weights. */
static const SkScalar* ConicWeightData(const SkPath& path) {
return path.fPathRef->conicWeights();
}
};
#endif