skia2/src/core/SkQuadClipper.h

70 lines
1.9 KiB
C++

/*
* Copyright 2009 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 SkQuadClipper_DEFINED
#define SkQuadClipper_DEFINED
#include "SkPath.h"
/** This class is initialized with a clip rectangle, and then can be fed quads,
which must already be monotonic in Y.
In the future, it might return a series of segments, allowing it to clip
also in X, to ensure that all segments fit in a finite coordinate system.
*/
class SkQuadClipper {
public:
SkQuadClipper();
void setClip(const SkIRect& clip);
bool clipQuad(const SkPoint src[3], SkPoint dst[3]);
private:
SkRect fClip;
};
/** Iterator that returns the clipped segements of a quad clipped to a rect.
The segments will be either lines or quads (based on SkPath::Verb), and
will all be monotonic in Y
*/
class SkQuadClipper2 {
public:
bool clipQuad(const SkPoint pts[3], const SkRect& clip);
bool clipCubic(const SkPoint pts[4], const SkRect& clip);
SkPath::Verb next(SkPoint pts[]);
private:
SkPoint* fCurrPoint;
SkPath::Verb* fCurrVerb;
enum {
kMaxVerbs = 13,
kMaxPoints = 32
};
SkPoint fPoints[kMaxPoints];
SkPath::Verb fVerbs[kMaxVerbs];
void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip);
void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip);
void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse);
void appendQuad(const SkPoint pts[3], bool reverse);
void appendCubic(const SkPoint pts[4], bool reverse);
};
#ifdef SK_DEBUG
void sk_assert_monotonic_x(const SkPoint pts[], int count);
void sk_assert_monotonic_y(const SkPoint pts[], int count);
#else
#define sk_assert_monotonic_x(pts, count)
#define sk_assert_monotonic_y(pts, count)
#endif
#endif