1
2/*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkDraw_DEFINED
11#define SkDraw_DEFINED
12
13#include "SkCanvas.h"
14#include "SkMask.h"
15#include "SkPaint.h"
16
17class SkBitmap;
18class SkClipStack;
19class SkBaseDevice;
20class SkBlitter;
21class SkMatrix;
22class SkPath;
23class SkRegion;
24class SkRasterClip;
25struct SkDrawProcs;
26struct SkRect;
27class SkRRect;
28
29class SkDraw {
30public:
31    SkDraw();
32    SkDraw(const SkDraw& src);
33
34    void    drawPaint(const SkPaint&) const;
35    void    drawPoints(SkCanvas::PointMode, size_t count, const SkPoint[],
36                       const SkPaint&, bool forceUseDevice = false) const;
37    void    drawRect(const SkRect&, const SkPaint&) const;
38    void    drawRRect(const SkRRect&, const SkPaint&) const;
39    /**
40     *  To save on mallocs, we allow a flag that tells us that srcPath is
41     *  mutable, so that we don't have to make copies of it as we transform it.
42     *
43     *  If prePathMatrix is not null, it should logically be applied before any
44     *  stroking or other effects. If there are no effects on the paint that
45     *  affect the geometry/rasterization, then the pre matrix can just be
46     *  pre-concated with the current matrix.
47     */
48    void    drawPath(const SkPath& path, const SkPaint& paint,
49                     const SkMatrix* prePathMatrix, bool pathIsMutable) const {
50        this->drawPath(path, paint, prePathMatrix, pathIsMutable, false);
51    }
52
53    void drawPath(const SkPath& path, const SkPaint& paint,
54                  SkBlitter* customBlitter = NULL) const {
55        this->drawPath(path, paint, NULL, false, false, customBlitter);
56    }
57
58    void    drawBitmap(const SkBitmap&, const SkMatrix&, const SkPaint&) const;
59    void    drawSprite(const SkBitmap&, int x, int y, const SkPaint&) const;
60    void    drawText(const char text[], size_t byteLength, SkScalar x,
61                     SkScalar y, const SkPaint& paint) const;
62    void    drawPosText(const char text[], size_t byteLength,
63                        const SkScalar pos[], SkScalar constY,
64                        int scalarsPerPosition, const SkPaint& paint) const;
65    void    drawTextOnPath(const char text[], size_t byteLength,
66                        const SkPath&, const SkMatrix*, const SkPaint&) const;
67    void    drawVertices(SkCanvas::VertexMode mode, int count,
68                         const SkPoint vertices[], const SkPoint textures[],
69                         const SkColor colors[], SkXfermode* xmode,
70                         const uint16_t indices[], int ptCount,
71                         const SkPaint& paint) const;
72
73    /**
74     *  Overwrite the target with the path's coverage (i.e. its mask).
75     *  Will overwrite the entire device, so it need not be zero'd first.
76     *
77     *  Only device A8 is supported right now.
78     */
79    void drawPathCoverage(const SkPath& src, const SkPaint& paint,
80                          SkBlitter* customBlitter = NULL) const {
81        this->drawPath(src, paint, NULL, false, true, customBlitter);
82    }
83
84    /** Helper function that creates a mask from a path and an optional maskfilter.
85        Note however, that the resulting mask will not have been actually filtered,
86        that must be done afterwards (by calling filterMask). The maskfilter is provided
87        solely to assist in computing the mask's bounds (if the mode requests that).
88    */
89    static bool DrawToMask(const SkPath& devPath, const SkIRect* clipBounds,
90                           const SkMaskFilter*, const SkMatrix* filterMatrix,
91                           SkMask* mask, SkMask::CreateMode mode,
92                           SkPaint::Style style);
93
94    enum RectType {
95        kHair_RectType,
96        kFill_RectType,
97        kStroke_RectType,
98        kPath_RectType
99    };
100
101    /**
102     *  Based on the paint's style, strokeWidth, and the matrix, classify how
103     *  to draw the rect. If no special-case is available, returns
104     *  kPath_RectType.
105     *
106     *  Iff RectType == kStroke_RectType, then strokeSize is set to the device
107     *  width and height of the stroke.
108     */
109    static RectType ComputeRectType(const SkPaint&, const SkMatrix&,
110                                    SkPoint* strokeSize);
111
112    static bool ShouldDrawTextAsPaths(const SkPaint&, const SkMatrix&);
113    void        drawText_asPaths(const char text[], size_t byteLength,
114                                 SkScalar x, SkScalar y, const SkPaint&) const;
115    void        drawPosText_asPaths(const char text[], size_t byteLength,
116                                    const SkScalar pos[], SkScalar constY,
117                                    int scalarsPerPosition, const SkPaint&) const;
118
119private:
120    void    drawDevMask(const SkMask& mask, const SkPaint&) const;
121    void    drawBitmapAsMask(const SkBitmap&, const SkPaint&) const;
122
123    void    drawPath(const SkPath&, const SkPaint&, const SkMatrix* preMatrix,
124                     bool pathIsMutable, bool drawCoverage,
125                     SkBlitter* customBlitter = NULL) const;
126
127    /**
128     *  Return the current clip bounds, in local coordinates, with slop to account
129     *  for antialiasing or hairlines (i.e. device-bounds outset by 1, and then
130     *  run through the inverse of the matrix).
131     *
132     *  If the matrix cannot be inverted, or the current clip is empty, return
133     *  false and ignore bounds parameter.
134     */
135    bool SK_WARN_UNUSED_RESULT
136    computeConservativeLocalClipBounds(SkRect* bounds) const;
137
138public:
139    const SkBitmap* fBitmap;        // required
140    const SkMatrix* fMatrix;        // required
141    const SkRegion* fClip;          // DEPRECATED
142    const SkRasterClip* fRC;        // required
143
144    const SkClipStack* fClipStack;  // optional
145    SkBaseDevice*   fDevice;        // optional
146    SkDrawProcs*    fProcs;         // optional
147
148#ifdef SK_DEBUG
149    void validate() const;
150#else
151    void validate() const {}
152#endif
153};
154
155#endif
156