1 /*
2  * Copyright 2013 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 #include "SkImageEncoder.h"
9 #include "SkBitmap.h"
10 #include "SkColorPriv.h"
11 #include "SkStream.h"
12 #include "SkTemplates.h"
13 
14 class SkARGBImageEncoder : public SkImageEncoder {
15 protected:
16     bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) override;
17 
18 private:
19     typedef SkImageEncoder INHERITED;
20 };
21 
22 typedef void (*ScanlineImporter)(const uint8_t* in, uint8_t* argb, int width,
23                                  const SkPMColor* SK_RESTRICT ctable);
24 
ARGB_8888_To_ARGB(const uint8_t * in,uint8_t * argb,int width,const SkPMColor *)25 static void ARGB_8888_To_ARGB(const uint8_t* in, uint8_t* argb, int width, const SkPMColor*) {
26   const uint32_t* SK_RESTRICT src = (const uint32_t*)in;
27   for (int i = 0; i < width; ++i) {
28       const uint32_t c = *src++;
29       argb[0] = SkGetPackedA32(c);
30       argb[1] = SkGetPackedR32(c);
31       argb[2] = SkGetPackedG32(c);
32       argb[3] = SkGetPackedB32(c);
33       argb += 4;
34   }
35 }
36 
RGB_565_To_ARGB(const uint8_t * in,uint8_t * argb,int width,const SkPMColor *)37 static void RGB_565_To_ARGB(const uint8_t* in, uint8_t* argb, int width, const SkPMColor*) {
38   const uint16_t* SK_RESTRICT src = (const uint16_t*)in;
39   for (int i = 0; i < width; ++i) {
40       const uint16_t c = *src++;
41       argb[0] = 0xFF;
42       argb[1] = SkPacked16ToR32(c);
43       argb[2] = SkPacked16ToG32(c);
44       argb[3] = SkPacked16ToB32(c);
45       argb += 4;
46   }
47 }
48 
ARGB_4444_To_ARGB(const uint8_t * in,uint8_t * argb,int width,const SkPMColor *)49 static void ARGB_4444_To_ARGB(const uint8_t* in, uint8_t* argb, int width, const SkPMColor*) {
50   const SkPMColor16* SK_RESTRICT src = (const SkPMColor16*)in;
51   for (int i = 0; i < width; ++i) {
52       const SkPMColor16 c = *src++;
53       argb[0] = SkPacked4444ToA32(c);
54       argb[1] = SkPacked4444ToR32(c);
55       argb[2] = SkPacked4444ToG32(c);
56       argb[3] = SkPacked4444ToB32(c);
57       argb += 4;
58   }
59 }
60 
Index8_To_ARGB(const uint8_t * in,uint8_t * argb,int width,const SkPMColor * SK_RESTRICT ctable)61 static void Index8_To_ARGB(const uint8_t* in, uint8_t* argb, int width,
62                            const SkPMColor* SK_RESTRICT ctable) {
63   const uint8_t* SK_RESTRICT src = (const uint8_t*)in;
64   for (int i = 0; i < width; ++i) {
65       const uint32_t c = ctable[*src++];
66       argb[0] = SkGetPackedA32(c);
67       argb[1] = SkGetPackedR32(c);
68       argb[2] = SkGetPackedG32(c);
69       argb[3] = SkGetPackedB32(c);
70       argb += 4;
71   }
72 }
73 
ChooseImporter(SkColorType ct)74 static ScanlineImporter ChooseImporter(SkColorType ct) {
75     switch (ct) {
76         case kN32_SkColorType:
77             return ARGB_8888_To_ARGB;
78         case kRGB_565_SkColorType:
79             return RGB_565_To_ARGB;
80         case kARGB_4444_SkColorType:
81             return ARGB_4444_To_ARGB;
82         case kIndex_8_SkColorType:
83             return Index8_To_ARGB;
84         default:
85             return nullptr;
86     }
87 }
88 
onEncode(SkWStream * stream,const SkBitmap & bitmap,int)89 bool SkARGBImageEncoder::onEncode(SkWStream* stream, const SkBitmap& bitmap, int) {
90     const ScanlineImporter scanline_import = ChooseImporter(bitmap.colorType());
91     if (nullptr == scanline_import) {
92         return false;
93     }
94 
95     SkAutoLockPixels alp(bitmap);
96     const uint8_t* src = (uint8_t*)bitmap.getPixels();
97     if (nullptr == bitmap.getPixels()) {
98         return false;
99     }
100 
101     const SkPMColor* colors = bitmap.getColorTable() ? bitmap.getColorTable()->readColors() : nullptr;
102 
103     const int argbStride = bitmap.width() * 4;
104     SkAutoTDeleteArray<uint8_t> ada(new uint8_t[argbStride]);
105     uint8_t* argb = ada.get();
106     for (int y = 0; y < bitmap.height(); ++y) {
107         scanline_import(src + y * bitmap.rowBytes(), argb, bitmap.width(), colors);
108         stream->write(argb, argbStride);
109     }
110 
111     return true;
112 }
113 
114 
115 ///////////////////////////////////////////////////////////////////////////////
116 DEFINE_ENCODER_CREATOR(ARGBImageEncoder);
117 ///////////////////////////////////////////////////////////////////////////////
118