xref: /third_party/skia/src/core/SkScan.h (revision cb93a386)
1/*
2 * Copyright 2011 The Android Open Source Project
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
9#ifndef SkScan_DEFINED
10#define SkScan_DEFINED
11
12#include "include/core/SkRect.h"
13#include "include/private/SkFixed.h"
14#include <atomic>
15
16class SkRasterClip;
17class SkRegion;
18class SkBlitter;
19class SkPath;
20
21/** Defines a fixed-point rectangle, identical to the integer SkIRect, but its
22    coordinates are treated as SkFixed rather than int32_t.
23*/
24typedef SkIRect SkXRect;
25
26extern std::atomic<bool> gSkUseAnalyticAA;
27extern std::atomic<bool> gSkForceAnalyticAA;
28
29class AdditiveBlitter;
30
31class SkScan {
32public:
33    /*
34     *  Draws count-1 line segments, one at a time:
35     *      line(pts[0], pts[1])
36     *      line(pts[1], pts[2])
37     *      line(......, pts[count - 1])
38     */
39    typedef void (*HairRgnProc)(const SkPoint[], int count, const SkRegion*, SkBlitter*);
40    typedef void (*HairRCProc)(const SkPoint[], int count, const SkRasterClip&, SkBlitter*);
41
42    static void FillPath(const SkPath&, const SkIRect&, SkBlitter*);
43
44    // Paths of a certain size cannot be anti-aliased unless externally tiled (handled by SkDraw).
45    // AA clipping doesn't do that, so it's better for the clip stack to adjust AA state early
46    // rather than clip to the internal limits of the blitter.
47    static bool DowngradeClipAA(const SkIRect& bounds);
48
49    ///////////////////////////////////////////////////////////////////////////
50    // rasterclip
51
52    static void FillIRect(const SkIRect&, const SkRasterClip&, SkBlitter*);
53    static void FillXRect(const SkXRect&, const SkRasterClip&, SkBlitter*);
54    static void FillRect(const SkRect&, const SkRasterClip&, SkBlitter*);
55    static void AntiFillRect(const SkRect&, const SkRasterClip&, SkBlitter*);
56    static void AntiFillXRect(const SkXRect&, const SkRasterClip&, SkBlitter*);
57    static void FillPath(const SkPath&, const SkRasterClip&, SkBlitter*);
58    static void AntiFillPath(const SkPath&, const SkRasterClip&, SkBlitter*);
59    static void FrameRect(const SkRect&, const SkPoint& strokeSize,
60                          const SkRasterClip&, SkBlitter*);
61    static void AntiFrameRect(const SkRect&, const SkPoint& strokeSize,
62                              const SkRasterClip&, SkBlitter*);
63    static void FillTriangle(const SkPoint pts[], const SkRasterClip&, SkBlitter*);
64    static void HairLine(const SkPoint[], int count, const SkRasterClip&, SkBlitter*);
65    static void AntiHairLine(const SkPoint[], int count, const SkRasterClip&, SkBlitter*);
66    static void HairRect(const SkRect&, const SkRasterClip&, SkBlitter*);
67    static void AntiHairRect(const SkRect&, const SkRasterClip&, SkBlitter*);
68    static void HairPath(const SkPath&, const SkRasterClip&, SkBlitter*);
69    static void AntiHairPath(const SkPath&, const SkRasterClip&, SkBlitter*);
70    static void HairSquarePath(const SkPath&, const SkRasterClip&, SkBlitter*);
71    static void AntiHairSquarePath(const SkPath&, const SkRasterClip&, SkBlitter*);
72    static void HairRoundPath(const SkPath&, const SkRasterClip&, SkBlitter*);
73    static void AntiHairRoundPath(const SkPath&, const SkRasterClip&, SkBlitter*);
74
75    // Needed by do_fill_path in SkScanPriv.h
76    static void FillPath(const SkPath&, const SkRegion& clip, SkBlitter*);
77
78private:
79    friend class SkAAClip;
80    friend class SkRegion;
81
82    static void FillIRect(const SkIRect&, const SkRegion* clip, SkBlitter*);
83    static void FillXRect(const SkXRect&, const SkRegion* clip, SkBlitter*);
84    static void FillRect(const SkRect&, const SkRegion* clip, SkBlitter*);
85    static void AntiFillRect(const SkRect&, const SkRegion* clip, SkBlitter*);
86    static void AntiFillXRect(const SkXRect&, const SkRegion*, SkBlitter*);
87    static void AntiFillPath(const SkPath&, const SkRegion& clip, SkBlitter*, bool forceRLE);
88    static void FillTriangle(const SkPoint pts[], const SkRegion*, SkBlitter*);
89
90    static void AntiFrameRect(const SkRect&, const SkPoint& strokeSize,
91                              const SkRegion*, SkBlitter*);
92    static void HairLineRgn(const SkPoint[], int count, const SkRegion*, SkBlitter*);
93    static void AntiHairLineRgn(const SkPoint[], int count, const SkRegion*, SkBlitter*);
94    static void AAAFillPath(const SkPath& path, SkBlitter* blitter, const SkIRect& pathIR,
95                            const SkIRect& clipBounds, bool forceRLE);
96    static void SAAFillPath(const SkPath& path, SkBlitter* blitter, const SkIRect& pathIR,
97                            const SkIRect& clipBounds, bool forceRLE);
98};
99
100/** Assign an SkXRect from a SkIRect, by promoting the src rect's coordinates
101    from int to SkFixed. Does not check for overflow if the src coordinates
102    exceed 32K
103*/
104static inline void XRect_set(SkXRect* xr, const SkIRect& src) {
105    xr->fLeft = SkIntToFixed(src.fLeft);
106    xr->fTop = SkIntToFixed(src.fTop);
107    xr->fRight = SkIntToFixed(src.fRight);
108    xr->fBottom = SkIntToFixed(src.fBottom);
109}
110
111/** Assign an SkXRect from a SkRect, by promoting the src rect's coordinates
112    from SkScalar to SkFixed. Does not check for overflow if the src coordinates
113    exceed 32K
114*/
115static inline void XRect_set(SkXRect* xr, const SkRect& src) {
116    xr->fLeft = SkScalarToFixed(src.fLeft);
117    xr->fTop = SkScalarToFixed(src.fTop);
118    xr->fRight = SkScalarToFixed(src.fRight);
119    xr->fBottom = SkScalarToFixed(src.fBottom);
120}
121
122/** Round the SkXRect coordinates, and store the result in the SkIRect.
123*/
124static inline void XRect_round(const SkXRect& xr, SkIRect* dst) {
125    dst->fLeft = SkFixedRoundToInt(xr.fLeft);
126    dst->fTop = SkFixedRoundToInt(xr.fTop);
127    dst->fRight = SkFixedRoundToInt(xr.fRight);
128    dst->fBottom = SkFixedRoundToInt(xr.fBottom);
129}
130
131/** Round the SkXRect coordinates out (i.e. use floor for left/top, and ceiling
132    for right/bottom), and store the result in the SkIRect.
133*/
134static inline void XRect_roundOut(const SkXRect& xr, SkIRect* dst) {
135    dst->fLeft = SkFixedFloorToInt(xr.fLeft);
136    dst->fTop = SkFixedFloorToInt(xr.fTop);
137    dst->fRight = SkFixedCeilToInt(xr.fRight);
138    dst->fBottom = SkFixedCeilToInt(xr.fBottom);
139}
140
141#endif
142