1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkStrokeRec_DEFINED
9#define SkStrokeRec_DEFINED
10
11#include "SkPaint.h"
12
13class SkPath;
14
15SK_BEGIN_REQUIRE_DENSE
16class SkStrokeRec {
17public:
18    enum InitStyle {
19        kHairline_InitStyle,
20        kFill_InitStyle
21    };
22    SkStrokeRec(InitStyle style);
23    SkStrokeRec(const SkPaint&, SkPaint::Style, SkScalar resScale = 1);
24    explicit SkStrokeRec(const SkPaint&, SkScalar resScale = 1);
25
26    enum Style {
27        kHairline_Style,
28        kFill_Style,
29        kStroke_Style,
30        kStrokeAndFill_Style
31    };
32    enum {
33        kStyleCount = kStrokeAndFill_Style + 1
34    };
35
36    Style getStyle() const;
37    SkScalar getWidth() const { return fWidth; }
38    SkScalar getMiter() const { return fMiterLimit; }
39    SkPaint::Cap getCap() const { return (SkPaint::Cap)fCap; }
40    SkPaint::Join getJoin() const { return (SkPaint::Join)fJoin; }
41
42    bool isHairlineStyle() const {
43        return kHairline_Style == this->getStyle();
44    }
45
46    bool isFillStyle() const {
47        return kFill_Style == this->getStyle();
48    }
49
50    void setFillStyle();
51    void setHairlineStyle();
52    /**
53     *  Specify the strokewidth, and optionally if you want stroke + fill.
54     *  Note, if width==0, then this request is taken to mean:
55     *      strokeAndFill==true -> new style will be Fill
56     *      strokeAndFill==false -> new style will be Hairline
57     */
58    void setStrokeStyle(SkScalar width, bool strokeAndFill = false);
59
60    void setStrokeParams(SkPaint::Cap cap, SkPaint::Join join, SkScalar miterLimit) {
61        fCap = cap;
62        fJoin = join;
63        fMiterLimit = miterLimit;
64    }
65
66    SkScalar getResScale() const {
67        return fResScale;
68    }
69
70    void setResScale(SkScalar rs) {
71        SkASSERT(rs > 0 && SkScalarIsFinite(rs));
72        fResScale = rs;
73    }
74
75    /**
76     *  Returns true if this specifes any thick stroking, i.e. applyToPath()
77     *  will return true.
78     */
79    bool needToApply() const {
80        Style style = this->getStyle();
81        return (kStroke_Style == style) || (kStrokeAndFill_Style == style);
82    }
83
84    /**
85     *  Apply these stroke parameters to the src path, returning the result
86     *  in dst.
87     *
88     *  If there was no change (i.e. style == hairline or fill) this returns
89     *  false and dst is unchanged. Otherwise returns true and the result is
90     *  stored in dst.
91     *
92     *  src and dst may be the same path.
93     */
94    bool applyToPath(SkPath* dst, const SkPath& src) const;
95
96    /**
97     *  Apply these stroke parameters to a paint.
98     */
99    void applyToPaint(SkPaint* paint) const;
100
101    /**
102     * Gives a conservative value for the outset that should applied to a
103     * geometries bounds to account for any inflation due to applying this
104     * strokeRec to the geometry.
105     */
106    SkScalar getInflationRadius() const;
107
108    /**
109     * Equivalent to:
110     *   SkStrokeRec rec(paint, style);
111     *   rec.getInflationRadius();
112     * This does not account for other effects on the paint (i.e. path
113     * effect).
114     */
115    static SkScalar GetInflationRadius(const SkPaint&, SkPaint::Style);
116
117    /**
118     * Compare if two SkStrokeRecs have an equal effect on a path.
119     * Equal SkStrokeRecs produce equal paths. Equality of produced
120     * paths does not take the ResScale parameter into account.
121     */
122    bool hasEqualEffect(const SkStrokeRec& other) const {
123        if (!this->needToApply()) {
124            return this->getStyle() == other.getStyle();
125        }
126        return fWidth == other.fWidth &&
127               fMiterLimit == other.fMiterLimit &&
128               fCap == other.fCap &&
129               fJoin == other.fJoin &&
130               fStrokeAndFill == other.fStrokeAndFill;
131    }
132
133private:
134    void init(const SkPaint&, SkPaint::Style, SkScalar resScale);
135
136    SkScalar        fResScale;
137    SkScalar        fWidth;
138    SkScalar        fMiterLimit;
139    // The following three members are packed together into a single u32.
140    // This is to avoid unnecessary padding and ensure binary equality for
141    // hashing (because the padded areas might contain garbage values).
142    //
143    // fCap and fJoin are larger than needed to avoid having to initialize
144    // any pad values
145    uint32_t        fCap : 16;             // SkPaint::Cap
146    uint32_t        fJoin : 15;            // SkPaint::Join
147    uint32_t        fStrokeAndFill : 1;    // bool
148};
149SK_END_REQUIRE_DENSE
150
151#endif
152