michael@0: 
michael@0: /*
michael@0:  * Copyright 2009 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkQuadClipper_DEFINED
michael@0: #define SkQuadClipper_DEFINED
michael@0: 
michael@0: #include "SkPath.h"
michael@0: 
michael@0: /** This class is initialized with a clip rectangle, and then can be fed quads,
michael@0:     which must already be monotonic in Y.
michael@0: 
michael@0:     In the future, it might return a series of segments, allowing it to clip
michael@0:     also in X, to ensure that all segments fit in a finite coordinate system.
michael@0:  */
michael@0: class SkQuadClipper {
michael@0: public:
michael@0:     SkQuadClipper();
michael@0: 
michael@0:     void setClip(const SkIRect& clip);
michael@0: 
michael@0:     bool clipQuad(const SkPoint src[3], SkPoint dst[3]);
michael@0: 
michael@0: private:
michael@0:     SkRect      fClip;
michael@0: };
michael@0: 
michael@0: /** Iterator that returns the clipped segements of a quad clipped to a rect.
michael@0:     The segments will be either lines or quads (based on SkPath::Verb), and
michael@0:     will all be monotonic in Y
michael@0:  */
michael@0: class SkQuadClipper2 {
michael@0: public:
michael@0:     bool clipQuad(const SkPoint pts[3], const SkRect& clip);
michael@0:     bool clipCubic(const SkPoint pts[4], const SkRect& clip);
michael@0: 
michael@0:     SkPath::Verb next(SkPoint pts[]);
michael@0: 
michael@0: private:
michael@0:     SkPoint*        fCurrPoint;
michael@0:     SkPath::Verb*   fCurrVerb;
michael@0: 
michael@0:     enum {
michael@0:         kMaxVerbs = 13,
michael@0:         kMaxPoints = 32
michael@0:     };
michael@0:     SkPoint         fPoints[kMaxPoints];
michael@0:     SkPath::Verb    fVerbs[kMaxVerbs];
michael@0: 
michael@0:     void clipMonoQuad(const SkPoint srcPts[3], const SkRect& clip);
michael@0:     void clipMonoCubic(const SkPoint srcPts[4], const SkRect& clip);
michael@0:     void appendVLine(SkScalar x, SkScalar y0, SkScalar y1, bool reverse);
michael@0:     void appendQuad(const SkPoint pts[3], bool reverse);
michael@0:     void appendCubic(const SkPoint pts[4], bool reverse);
michael@0: };
michael@0: 
michael@0: #ifdef SK_DEBUG
michael@0:     void sk_assert_monotonic_x(const SkPoint pts[], int count);
michael@0:     void sk_assert_monotonic_y(const SkPoint pts[], int count);
michael@0: #else
michael@0:     #define sk_assert_monotonic_x(pts, count)
michael@0:     #define sk_assert_monotonic_y(pts, count)
michael@0: #endif
michael@0: 
michael@0: #endif