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39
40#include "qpkmhandler_p.h"
41#include "qtexturefiledata_p.h"
42
43#include <QFile>
44#include <QDebug>
45#include <QSize>
46#include <qendian.h>
47
48//#define ETC_DEBUG
49
50QT_BEGIN_NAMESPACE
51
52static const int headerSize = 16;
53
54struct PkmType
55{
56 quint32 glFormat;
57 quint32 bytesPerBlock;
58};
59
60static PkmType typeMap[5] = {
61 { 0x8D64, 8 }, // GL_ETC1_RGB8_OES
62 { 0x9274, 8 }, // GL_COMPRESSED_RGB8_ETC2
63 { 0, 0 }, // unused (obsolete)
64 { 0x9278, 16}, // GL_COMPRESSED_RGBA8_ETC2_EAC
65 { 0x9276, 8 } // GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
66};
67
68bool QPkmHandler::canRead(const QByteArray &suffix, const QByteArray &block)
69{
70 Q_UNUSED(suffix);
71
72 return block.startsWith("PKM ");
73}
74
75QTextureFileData QPkmHandler::read()
76{
77 QTextureFileData texData;
78
79 if (!device())
80 return texData;
81
82 QByteArray fileData = device()->readAll();
83 if (fileData.size() < headerSize || !canRead(QByteArray(), fileData)) {
84 qCDebug(lcQtGuiTextureIO, "Invalid PKM file %s", logName().constData());
85 return QTextureFileData();
86 }
87 texData.setData(fileData);
88
89 const char *rawData = fileData.constData();
90
91 // ignore version (rawData + 4 & 5)
92
93 // texture type
94 quint16 type = qFromBigEndian<quint16>(rawData + 6);
95 if (type >= sizeof(typeMap)/sizeof(typeMap[0])) {
96 qCDebug(lcQtGuiTextureIO, "Unknown compression format in PKM file %s", logName().constData());
97 return QTextureFileData();
98 }
99 texData.setGLFormat(0); // 0 for compressed textures
100 texData.setGLInternalFormat(typeMap[type].glFormat);
101 //### setBaseInternalFormat
102
103 // texture size
104 texData.setNumLevels(1);
105 const int bpb = typeMap[type].bytesPerBlock;
106 QSize paddedSize(qFromBigEndian<quint16>(rawData + 8), qFromBigEndian<quint16>(rawData + 10));
107 texData.setDataLength((paddedSize.width() / 4) * (paddedSize.height() / 4) * bpb);
108 QSize texSize(qFromBigEndian<quint16>(rawData + 12), qFromBigEndian<quint16>(rawData + 14));
109 texData.setSize(texSize);
110
111 texData.setDataOffset(headerSize);
112
113 if (!texData.isValid()) {
114 qCDebug(lcQtGuiTextureIO, "Invalid values in header of PKM file %s", logName().constData());
115 return QTextureFileData();
116 }
117
118 texData.setLogName(logName());
119
120#ifdef ETC_DEBUG
121 qDebug() << "PKM file handler read" << texData;
122#endif
123 return texData;
124}
125
126QT_END_NAMESPACE
127