Differential D19696 Diff 53820 blend/blendercreator.cpp

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blend/blendercreator.cpp

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1​/*
2​ * Copyright (c) 2019 Chinmoy Ranjan Pradhan <chinmoyrp65@gmail.com>
3​ *
4​ * This library is free software; you can redistribute it and/or
5​ * modify it under the terms of the GNU Lesser General Public
6​ * License as published by the Free Software Foundation; either
7​ * version 2.1 of the License, or (at your option) version 3, or any
8​ * later version accepted by the membership of KDE e.V. (or its
9​ * successor approved by the membership of KDE e.V.), which shall
10​ * act as a proxy defined in Section 6 of version 3 of the license.
11​ *
12​ * This library is distributed in the hope that it will be useful,
13​ * but WITHOUT ANY WARRANTY; without even the implied warranty of
14​ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15​ * Lesser General Public License for more details.
16​ *
17​ * You should have received a copy of the GNU Lesser General Public
18​ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
19​ */
20​
21​#include "blendercreator.h"
22​
23​#include <assert.h>
24​#include <zlib.h>
25​
brunsUnsubmitted
Not Done

Really required?

bruns: Really required?
26​#include <QFile>
27​#include <QImage>
28​#include <QPointer>
29​#include <QDebug>
30​#include <QtEndian>
brunsUnsubmitted
Not Done

Unused ...

bruns: Unused ...
31​#include <KCompressionDevice>
32​
33​extern "C"
34​{
35​ Q_DECL_EXPORT ThumbCreator *new_creator()
36​ {
37​ return new BlenderCreator;
38​ }
39​}
40​
41​BlenderCreator::BlenderCreator() = default;
42​
43​BlenderCreator::~BlenderCreator() = default;
44​
45​static void abgr_to_argb(char *buf, int size)
46​{
47​ char tmp;
48​ for (int i=0; i < size; i+=4) {
49​ tmp = buf[i];
50​ buf[i] = buf[i + 2];
51​ buf[i + 2] = tmp;
52​ }
53​}
54​
55​// For more info. see https://developer.blender.org/diffusion/B/browse/master/release/bin/blender-thumbnailer.py
56​
57​bool BlenderCreator::create(const QString &path, int width , int height, QImage &img)
58​{
59​ QFile file (path);
60​ if(!file.open(QIODevice::ReadOnly)) {
61​ return false;
62​ }
63​
64​ QDataStream blendStream;
65​ blendStream.setDevice(&file);
66​ QPointer<KCompressionDevice> gzFile;
67​ if(file.peek(2).startsWith("\x1F\x8B")) { // gzip magic (each gzip member starts with ID1(0x1f) and ID2(0x8b))
brunsUnsubmitted
Done

This requires a comment, stating gzip compression is optional.

bruns: This requires a comment, stating gzip compression is optional.
68​ file.close();
69​ gzFile = new KCompressionDevice(path, KCompressionDevice::GZip);
70​ if (gzFile->open(QIODevice::ReadOnly)) {
71​ blendStream.setDevice(gzFile);
72​ } else {
73​ return false;
74​ }
75​ }
76​
77​ // First to check is file header.
78​ // BLEND file header format
79​ // Reference Content Size
80​ // id "BLENDER" 7
81​ // pointer-size _ (underscore)(32 bit)/ - (minus)(64 bit) 1
82​ // endianness v (little) / V (big) 1
83​ // version "248" = 2.48 etc. 3
84​
85​ // Example header: "BLENDER-257"
brunsUnsubmitted
Done

Still wrong, "BLENDER-v257", missing 'v'/'V'

bruns: Still wrong, "BLENDER-v257", missing 'v'/'V'
86​
87​ QByteArray head(12, '\0');
88​ blendStream.readRawData(head.data(), 12);
89​ if(!head.startsWith("BLENDER") || head.right(3).toInt() < 250 /*blender pre 2.5 had no thumbs*/) {
90​ blendStream.device()->close();
91​ return false;
92​ }
93​
94​ // Next is file block. This we have to skip.
95​ // File block header format
96​ // Reference Content Size
97​ // 1. id "REND","TEST", etc. 4
98​ // 2. size Total length of the data after the file-block-header 4
99​ // 3. old mem. addr Mem. address. pointer-size i.e, 4(32bit)/8(64bit)
100​ // 4. SDNA index Index of SDNA struct 4
101​ // 5. count No. of struct in file-block 4
102​
103​ const bool isLittleEndian = head[8] == 'v';
104​ if(isLittleEndian) {
105​ blendStream.setByteOrder(QDataStream::LittleEndian);
brunsUnsubmitted
Not Done

Not relevant, as you only read using readRawData()

bruns: Not relevant, as you only read using `readRawData()`
106​ } else {
107​ blendStream.setByteOrder(QDataStream::BigEndian);
108​ }
109​
110​ auto toInt32 = [isLittleEndian](const QByteArray &bytes) -> qint32 {
brunsUnsubmitted
Done

Coding style, no trailing return type.

bruns: Coding style, no trailing return type.
111​ return isLittleEndian ? qFromLittleEndian<qint32>(bytes.constData())
112​ : qFromBigEndian<qint32>(bytes.constData());
113​ };
114​
115​ const bool is64Bit = head[7] == '-';
116​ const int fileBlockHeaderSize = is64Bit ? 24 : 20; // size of file block header fields 1 to 5
117​ QByteArray fileBlockHeader(fileBlockHeaderSize, '\0');
118​ qint32 fileBlockSize = 0;
119​ while (true) {
120​ const int read = blendStream.readRawData(fileBlockHeader.data(), fileBlockHeaderSize);
121​ if (read != fileBlockHeaderSize) {
122​ return false;
123​ }
124​ fileBlockSize = toInt32(fileBlockHeader.mid(4, 4)); // second header field
125​ // skip actual file-block data.
126​ if (fileBlockHeader.startsWith("REND")) {
127​ blendStream.skipRawData(fileBlockSize);
128​ } else {
129​ break;
130​ }
131​ }
132​
133​ if(!fileBlockHeader.startsWith("TEST")) {
134​ blendStream.device()->close();
135​ return false;
136​ }
137​
138​ // Now comes actual thumbnail image data.
139​ QByteArray xy(8, '\0');
140​ blendStream.readRawData(xy.data(), 8);
141​ const qint32 x = toInt32(xy.left(4));
142​ const qint32 y = toInt32(xy.right(4));
143​
144​ qint32 imgSize = fileBlockSize - 8;
145​ if (imgSize != x * y * 4) {
146​ blendStream.device()->close();
147​ return false;
148​ }
149​
150​ QByteArray imgBuffer(imgSize, '\0');
151​ blendStream.readRawData(imgBuffer.data(), imgSize);
152​ abgr_to_argb(imgBuffer.data(), imgSize);
153​ QImage thumbnail((const uchar*)imgBuffer.constData(), x, y, QImage::Format_ARGB32);
154​ if(width != 128) {
155​ thumbnail = thumbnail.scaledToWidth(width, Qt::SmoothTransformation);
156​ }
157​ if(height != 128) {
158​ thumbnail = thumbnail.scaledToHeight(height, Qt::SmoothTransformation);
159​ }
160​ thumbnail = thumbnail.mirrored();
161​ img = thumbnail.convertToFormat(QImage::Format_ARGB32_Premultiplied);
162​
163​ blendStream.device()->close();
164​ return true;
165​}