33 {
34
35
36 const bool kLittleEndian = false;
37 const uint8_t kSig[] = {
38 'A', 'p', 'p', 'l', 'e', ' ', 'i', 'O', 'S', 0, 0, 1, 'M', 'M',
39 };
40 if (!data ||
data->size() <
sizeof(kSig)) {
41 return false;
42 }
43 if (memcmp(
data->data(), kSig,
sizeof(kSig)) != 0) {
44 return false;
45 }
46 auto ifd =
48 if (!ifd) {
49 return false;
50 }
51
52
53
54 bool hasMaker33 = false;
55 bool hasMaker48 = false;
56 float maker33 = 0.f;
57 float maker48 = 0.f;
58 for (uint32_t i = 0; i < ifd->getNumEntries(); ++i) {
59 switch (ifd->getEntryTag(i)) {
60 case 33:
61 if (!hasMaker33) {
62 hasMaker33 = ifd->getEntrySignedRational(i, 1, &maker33);
63 }
64 break;
65 case 48:
66 if (!hasMaker48) {
67 hasMaker48 = ifd->getEntrySignedRational(i, 1, &maker48);
68 }
69 break;
70 default:
71 break;
72 }
73 }
74 if (!hasMaker33 || !hasMaker48) {
75 return false;
76 }
77 float stops = 0.f;
78 if (maker33 < 1.0f) {
79 if (maker48 <= 0.01f) {
80 stops = -20.0f * maker48 + 1.8f;
81 } else {
82 stops = -0.101f * maker48 + 1.601f;
83 }
84 } else {
85 if (maker48 <= 0.01f) {
86 stops = -70.0f * maker48 + 3.0f;
87 } else {
88 stops = -0.303f * maker48 + 2.303f;
89 }
90 }
91 *hdrHeadroom = std::pow(2.f, std::max(stops, 0.f));
92 return true;
93}
static std::unique_ptr< SkTiffImageFileDirectory > MakeFromOffset(sk_sp< SkData > data, bool littleEndian, uint32_t ifdOffset)
DEF_SWITCHES_START aot vmservice shared library Name of the *so containing AOT compiled Dart assets for launching the service isolate vm snapshot data
1.9.8