1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkPathEffect.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,219 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2006 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#ifndef SkPathEffect_DEFINED
1.14 +#define SkPathEffect_DEFINED
1.15 +
1.16 +#include "SkFlattenable.h"
1.17 +#include "SkPath.h"
1.18 +#include "SkPoint.h"
1.19 +#include "SkRect.h"
1.20 +#include "SkStrokeRec.h"
1.21 +#include "SkTDArray.h"
1.22 +
1.23 +class SkPath;
1.24 +
1.25 +/** \class SkPathEffect
1.26 +
1.27 + SkPathEffect is the base class for objects in the SkPaint that affect
1.28 + the geometry of a drawing primitive before it is transformed by the
1.29 + canvas' matrix and drawn.
1.30 +
1.31 + Dashing is implemented as a subclass of SkPathEffect.
1.32 +*/
1.33 +class SK_API SkPathEffect : public SkFlattenable {
1.34 +public:
1.35 + SK_DECLARE_INST_COUNT(SkPathEffect)
1.36 +
1.37 + /**
1.38 + * Given a src path (input) and a stroke-rec (input and output), apply
1.39 + * this effect to the src path, returning the new path in dst, and return
1.40 + * true. If this effect cannot be applied, return false and ignore dst
1.41 + * and stroke-rec.
1.42 + *
1.43 + * The stroke-rec specifies the initial request for stroking (if any).
1.44 + * The effect can treat this as input only, or it can choose to change
1.45 + * the rec as well. For example, the effect can decide to change the
1.46 + * stroke's width or join, or the effect can change the rec from stroke
1.47 + * to fill (or fill to stroke) in addition to returning a new (dst) path.
1.48 + *
1.49 + * If this method returns true, the caller will apply (as needed) the
1.50 + * resulting stroke-rec to dst and then draw.
1.51 + */
1.52 + virtual bool filterPath(SkPath* dst, const SkPath& src,
1.53 + SkStrokeRec*, const SkRect* cullR) const = 0;
1.54 +
1.55 + /**
1.56 + * Compute a conservative bounds for its effect, given the src bounds.
1.57 + * The baseline implementation just assigns src to dst.
1.58 + */
1.59 + virtual void computeFastBounds(SkRect* dst, const SkRect& src) const;
1.60 +
1.61 + /** \class PointData
1.62 +
1.63 + PointData aggregates all the information needed to draw the point
1.64 + primitives returned by an 'asPoints' call.
1.65 + */
1.66 + class PointData {
1.67 + public:
1.68 + PointData()
1.69 + : fFlags(0)
1.70 + , fPoints(NULL)
1.71 + , fNumPoints(0) {
1.72 + fSize.set(SK_Scalar1, SK_Scalar1);
1.73 + // 'asPoints' needs to initialize/fill-in 'fClipRect' if it sets
1.74 + // the kUseClip flag
1.75 + };
1.76 + ~PointData() {
1.77 + delete [] fPoints;
1.78 + }
1.79 +
1.80 + // TODO: consider using passed-in flags to limit the work asPoints does.
1.81 + // For example, a kNoPath flag could indicate don't bother generating
1.82 + // stamped solutions.
1.83 +
1.84 + // Currently none of these flags are supported.
1.85 + enum PointFlags {
1.86 + kCircles_PointFlag = 0x01, // draw points as circles (instead of rects)
1.87 + kUsePath_PointFlag = 0x02, // draw points as stamps of the returned path
1.88 + kUseClip_PointFlag = 0x04, // apply 'fClipRect' before drawing the points
1.89 + };
1.90 +
1.91 + uint32_t fFlags; // flags that impact the drawing of the points
1.92 + SkPoint* fPoints; // the center point of each generated point
1.93 + int fNumPoints; // number of points in fPoints
1.94 + SkVector fSize; // the size to draw the points
1.95 + SkRect fClipRect; // clip required to draw the points (if kUseClip is set)
1.96 + SkPath fPath; // 'stamp' to be used at each point (if kUsePath is set)
1.97 +
1.98 + SkPath fFirst; // If not empty, contains geometry for first point
1.99 + SkPath fLast; // If not empty, contains geometry for last point
1.100 + };
1.101 +
1.102 + /**
1.103 + * Does applying this path effect to 'src' yield a set of points? If so,
1.104 + * optionally return the points in 'results'.
1.105 + */
1.106 + virtual bool asPoints(PointData* results, const SkPath& src,
1.107 + const SkStrokeRec&, const SkMatrix&,
1.108 + const SkRect* cullR) const;
1.109 +
1.110 + SK_DEFINE_FLATTENABLE_TYPE(SkPathEffect)
1.111 +
1.112 +protected:
1.113 + SkPathEffect() {}
1.114 + SkPathEffect(SkReadBuffer& buffer) : INHERITED(buffer) {}
1.115 +
1.116 +private:
1.117 + // illegal
1.118 + SkPathEffect(const SkPathEffect&);
1.119 + SkPathEffect& operator=(const SkPathEffect&);
1.120 +
1.121 + typedef SkFlattenable INHERITED;
1.122 +};
1.123 +
1.124 +/** \class SkPairPathEffect
1.125 +
1.126 + Common baseclass for Compose and Sum. This subclass manages two pathEffects,
1.127 + including flattening them. It does nothing in filterPath, and is only useful
1.128 + for managing the lifetimes of its two arguments.
1.129 +*/
1.130 +class SkPairPathEffect : public SkPathEffect {
1.131 +public:
1.132 + virtual ~SkPairPathEffect();
1.133 +
1.134 +protected:
1.135 + SkPairPathEffect(SkPathEffect* pe0, SkPathEffect* pe1);
1.136 + SkPairPathEffect(SkReadBuffer&);
1.137 + virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
1.138 +
1.139 + // these are visible to our subclasses
1.140 + SkPathEffect* fPE0, *fPE1;
1.141 +
1.142 +private:
1.143 + typedef SkPathEffect INHERITED;
1.144 +};
1.145 +
1.146 +/** \class SkComposePathEffect
1.147 +
1.148 + This subclass of SkPathEffect composes its two arguments, to create
1.149 + a compound pathEffect.
1.150 +*/
1.151 +class SkComposePathEffect : public SkPairPathEffect {
1.152 +public:
1.153 + /** Construct a pathEffect whose effect is to apply first the inner pathEffect
1.154 + and the the outer pathEffect (e.g. outer(inner(path)))
1.155 + The reference counts for outer and inner are both incremented in the constructor,
1.156 + and decremented in the destructor.
1.157 + */
1.158 + static SkComposePathEffect* Create(SkPathEffect* outer, SkPathEffect* inner) {
1.159 + return SkNEW_ARGS(SkComposePathEffect, (outer, inner));
1.160 + }
1.161 +
1.162 + virtual bool filterPath(SkPath* dst, const SkPath& src,
1.163 + SkStrokeRec*, const SkRect*) const SK_OVERRIDE;
1.164 +
1.165 + SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposePathEffect)
1.166 +
1.167 +protected:
1.168 + SkComposePathEffect(SkReadBuffer& buffer) : INHERITED(buffer) {}
1.169 +
1.170 +#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
1.171 +public:
1.172 +#endif
1.173 + SkComposePathEffect(SkPathEffect* outer, SkPathEffect* inner)
1.174 + : INHERITED(outer, inner) {}
1.175 +
1.176 +private:
1.177 + // illegal
1.178 + SkComposePathEffect(const SkComposePathEffect&);
1.179 + SkComposePathEffect& operator=(const SkComposePathEffect&);
1.180 +
1.181 + typedef SkPairPathEffect INHERITED;
1.182 +};
1.183 +
1.184 +/** \class SkSumPathEffect
1.185 +
1.186 + This subclass of SkPathEffect applies two pathEffects, one after the other.
1.187 + Its filterPath() returns true if either of the effects succeeded.
1.188 +*/
1.189 +class SkSumPathEffect : public SkPairPathEffect {
1.190 +public:
1.191 + /** Construct a pathEffect whose effect is to apply two effects, in sequence.
1.192 + (e.g. first(path) + second(path))
1.193 + The reference counts for first and second are both incremented in the constructor,
1.194 + and decremented in the destructor.
1.195 + */
1.196 + static SkSumPathEffect* Create(SkPathEffect* first, SkPathEffect* second) {
1.197 + return SkNEW_ARGS(SkSumPathEffect, (first, second));
1.198 + }
1.199 +
1.200 + virtual bool filterPath(SkPath* dst, const SkPath& src,
1.201 + SkStrokeRec*, const SkRect*) const SK_OVERRIDE;
1.202 +
1.203 + SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSumPathEffect)
1.204 +
1.205 +protected:
1.206 + SkSumPathEffect(SkReadBuffer& buffer) : INHERITED(buffer) {}
1.207 +
1.208 +#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
1.209 +public:
1.210 +#endif
1.211 + SkSumPathEffect(SkPathEffect* first, SkPathEffect* second)
1.212 + : INHERITED(first, second) {}
1.213 +
1.214 +private:
1.215 + // illegal
1.216 + SkSumPathEffect(const SkSumPathEffect&);
1.217 + SkSumPathEffect& operator=(const SkSumPathEffect&);
1.218 +
1.219 + typedef SkPairPathEffect INHERITED;
1.220 +};
1.221 +
1.222 +#endif
