xref: /aosp_15_r20/external/skia/src/core/SkDrawBase.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2023 Google LLC
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 SkDrawBase_DEFINED
9 #define SkDrawBase_DEFINED
10 
11 #include "include/core/SkCanvas.h"
12 #include "include/core/SkPaint.h"
13 #include "include/core/SkPixmap.h"
14 #include "include/core/SkRefCnt.h"
15 #include "include/core/SkSamplingOptions.h"
16 #include "include/core/SkStrokeRec.h"
17 #include "include/private/base/SkDebug.h"
18 #include "src/base/SkZip.h"
19 #include "src/core/SkGlyphRunPainter.h"
20 #include "src/core/SkMask.h"
21 
22 #include <cstddef>
23 
24 class SkArenaAlloc;
25 class SkBitmap;
26 class SkBlitter;
27 class SkDevice;
28 class SkGlyph;
29 class SkMaskFilter;
30 class SkMatrix;
31 class SkPath;
32 class SkRRect;
33 class SkRasterClip;
34 class SkShader;
35 class SkSurfaceProps;
36 struct SkIRect;
37 struct SkPoint;
38 struct SkRect;
39 
40 class SkDrawBase : public SkGlyphRunListPainterCPU::BitmapDevicePainter {
41 public:
42     SkDrawBase();
43 
44     void    drawPaint(const SkPaint&) const;
45     void    drawRect(const SkRect& prePaintRect, const SkPaint&, const SkMatrix* paintMatrix,
46                      const SkRect* postPaintRect) const;
drawRect(const SkRect & rect,const SkPaint & paint)47     void    drawRect(const SkRect& rect, const SkPaint& paint) const {
48         this->drawRect(rect, paint, nullptr, nullptr);
49     }
50     void    drawRRect(const SkRRect&, const SkPaint&) const;
51     /**
52      *  To save on mallocs, we allow a flag that tells us that srcPath is
53      *  mutable, so that we don't have to make copies of it as we transform it.
54      *
55      *  If prePathMatrix is not null, it should logically be applied before any
56      *  stroking or other effects. If there are no effects on the paint that
57      *  affect the geometry/rasterization, then the pre matrix can just be
58      *  pre-concated with the current matrix.
59      */
60     void    drawPath(const SkPath& path, const SkPaint& paint,
61                      const SkMatrix* prePathMatrix = nullptr, bool pathIsMutable = false) const {
62         this->drawPath(path, paint, prePathMatrix, pathIsMutable, false);
63     }
64 
65     /**
66      *  Overwrite the target with the path's coverage (i.e. its mask).
67      *  Will overwrite the entire device, so it need not be zero'd first.
68      *
69      *  Only device A8 is supported right now.
70      */
71     void drawPathCoverage(const SkPath& src, const SkPaint& paint,
72                           SkBlitter* customBlitter = nullptr) const {
73         bool isHairline = paint.getStyle() == SkPaint::kStroke_Style &&
74                           paint.getStrokeWidth() == 0;
75         this->drawPath(src, paint, nullptr, false, !isHairline, customBlitter);
76     }
77 
78     void drawDevicePoints(SkCanvas::PointMode, size_t count, const SkPoint[], const SkPaint&,
79                           SkDevice*) const;
80 
81     static bool ComputeMaskBounds(const SkRect& devPathBounds, const SkIRect& clipBounds,
82                                   const SkMaskFilter* filter, const SkMatrix* filterMatrix,
83                                   SkIRect* bounds);
84 
85     /** Helper function that creates a mask from a path and an optional maskfilter.
86         Note however, that the resulting mask will not have been actually filtered,
87         that must be done afterwards (by calling filterMask). The maskfilter is provided
88         solely to assist in computing the mask's bounds (if the mode requests that).
89     */
90     static bool DrawToMask(const SkPath& devPath, const SkIRect& clipBounds,
91                            const SkMaskFilter*, const SkMatrix* filterMatrix,
92                            SkMaskBuilder* dst, SkMaskBuilder::CreateMode mode,
93                            SkStrokeRec::InitStyle style);
94 
95     enum RectType {
96         kHair_RectType,
97         kFill_RectType,
98         kStroke_RectType,
99         kPath_RectType
100     };
101 
102     /**
103      *  Based on the paint's style, strokeWidth, and the matrix, classify how
104      *  to draw the rect. If no special-case is available, returns
105      *  kPath_RectType.
106      *
107      *  Iff RectType == kStroke_RectType, then strokeSize is set to the device
108      *  width and height of the stroke.
109      */
110     static RectType ComputeRectType(const SkRect&, const SkPaint&, const SkMatrix&,
111                                     SkPoint* strokeSize);
112 
113     using BlitterChooser = SkBlitter* (const SkPixmap& dst,
114                                        const SkMatrix& ctm,
115                                        const SkPaint&,
116                                        SkArenaAlloc*,
117                                        bool drawCoverage,
118                                        sk_sp<SkShader> clipShader,
119                                        const SkSurfaceProps&);
120 
121 
122 private:
123     // not supported
124     void paintMasks(SkZip<const SkGlyph*, SkPoint> accepted, const SkPaint& paint) const override;
125     void drawBitmap(const SkBitmap&, const SkMatrix&, const SkRect* dstOrNull,
126                     const SkSamplingOptions&, const SkPaint&) const override;
127 
128     void drawPath(const SkPath&,
129                   const SkPaint&,
130                   const SkMatrix* preMatrix,
131                   bool pathIsMutable,
132                   bool drawCoverage,
133                   SkBlitter* customBlitter = nullptr) const;
134 
135     void drawLine(const SkPoint[2], const SkPaint&) const;
136 
137     void drawDevPath(const SkPath& devPath,
138                      const SkPaint& paint,
139                      bool drawCoverage,
140                      SkBlitter* customBlitter,
141                      bool doFill) const;
142     /**
143      *  Return the current clip bounds, in local coordinates, with slop to account
144      *  for antialiasing or hairlines (i.e. device-bounds outset by 1, and then
145      *  run through the inverse of the matrix).
146      *
147      *  If the matrix cannot be inverted, or the current clip is empty, return
148      *  false and ignore bounds parameter.
149      */
150     [[nodiscard]] bool computeConservativeLocalClipBounds(SkRect* bounds) const;
151 
152 public:
153     SkPixmap                fDst;
154     BlitterChooser*         fBlitterChooser{nullptr};  // required
155     const SkMatrix*         fCTM{nullptr};             // required
156     const SkRasterClip*     fRC{nullptr};              // required
157     const SkSurfaceProps*   fProps{nullptr};           // optional
158 
159 #ifdef SK_DEBUG
160     void validate() const;
161 #else
validate()162     void validate() const {}
163 #endif
164 };
165 
166 #endif  // SkDrawBase_DEFINED
167