1/*
2 * Copyright 2011 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 SkBlitRow_DEFINED
9#define SkBlitRow_DEFINED
10
11#include "SkBitmap.h"
12#include "SkColor.h"
13
14class SkBlitRow {
15public:
16    enum Flags16 {
17        //! If set, the alpha parameter will be != 255
18        kGlobalAlpha_Flag   = 0x01,
19        //! If set, the src colors may have alpha != 255
20        kSrcPixelAlpha_Flag = 0x02,
21        //! If set, the resulting 16bit colors should be dithered
22        kDither_Flag        = 0x04
23    };
24
25    /** Function pointer that reads a scanline of src SkPMColors, and writes
26        a corresponding scanline of 16bit colors (specific format based on the
27        config passed to the Factory.
28
29        The x,y params are useful just for dithering
30
31        @param alpha A global alpha to be applied to all of the src colors
32        @param x The x coordinate of the beginning of the scanline
33        @param y THe y coordinate of the scanline
34     */
35    typedef void (*Proc)(uint16_t* dst,
36                         const SkPMColor* src,
37                         int count, U8CPU alpha, int x, int y);
38
39   /** Function pointer that blends a single color with a row of 32-bit colors
40       onto a 32-bit destination
41   */
42   typedef void (*ColorProc)(SkPMColor* dst, const SkPMColor* src, int count,
43                             SkPMColor color);
44
45    //! Public entry-point to return a blit function ptr
46    static Proc Factory(unsigned flags, SkBitmap::Config);
47
48    ///////////// D32 version
49
50    enum Flags32 {
51        kGlobalAlpha_Flag32     = 1 << 0,
52        kSrcPixelAlpha_Flag32   = 1 << 1,
53    };
54
55    /** Function pointer that blends 32bit colors onto a 32bit destination.
56        @param dst  array of dst 32bit colors
57        @param src  array of src 32bit colors (w/ or w/o alpha)
58        @param count number of colors to blend
59        @param alpha global alpha to be applied to all src colors
60     */
61    typedef void (*Proc32)(uint32_t* dst,
62                         const SkPMColor* src,
63                         int count, U8CPU alpha);
64
65    static Proc32 Factory32(unsigned flags32);
66
67    /** Blend a single color onto a row of S32 pixels, writing the result
68        into a row of D32 pixels. src and dst may be the same memory, but
69        if they are not, they may not overlap.
70     */
71    static void Color32(SkPMColor dst[], const SkPMColor src[],
72                        int count, SkPMColor color);
73
74    static ColorProc ColorProcFactory();
75
76    /** These static functions are called by the Factory and Factory32
77        functions, and should return either NULL, or a
78        platform-specific function-ptr to be used in place of the
79        system default.
80     */
81
82    static Proc32 PlatformProcs32(unsigned flags);
83    static Proc PlatformProcs565(unsigned flags);
84    static Proc PlatformProcs4444(unsigned flags);
85    static ColorProc PlatformColorProc();
86
87private:
88    enum {
89        kFlags16_Mask = 7,
90        kFlags32_Mask = 3
91    };
92};
93
94#endif
95