1/****************************************************************************
2**
3** Copyright (C) 2016 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the demonstration applications of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:BSD$
9** Commercial License Usage
10** Licensees holding valid commercial Qt licenses may use this file in
11** accordance with the commercial license agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and The Qt Company. For licensing terms
14** and conditions see https://www.qt.io/terms-conditions. For further
15** information use the contact form at https://www.qt.io/contact-us.
16**
17** BSD License Usage
18** Alternatively, you may use this file under the terms of the BSD license
19** as follows:
20**
21** "Redistribution and use in source and binary forms, with or without
22** modification, are permitted provided that the following conditions are
23** met:
24** * Redistributions of source code must retain the above copyright
25** notice, this list of conditions and the following disclaimer.
26** * Redistributions in binary form must reproduce the above copyright
27** notice, this list of conditions and the following disclaimer in
28** the documentation and/or other materials provided with the
29** distribution.
30** * Neither the name of The Qt Company Ltd nor the names of its
31** contributors may be used to endorse or promote products derived
32** from this software without specific prior written permission.
33**
34**
35** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
39** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
42** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
43** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
44** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
45** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
46**
47** $QT_END_LICENSE$
48**
49****************************************************************************/
50
51#include "etcprovider.h"
52
53#include <QFile>
54#include <QDebug>
55#include <qopenglfunctions.h>
56#include <qqmlfile.h>
57
58//#define ETC_DEBUG
59
60#ifndef GL_ETC1_RGB8_OES
61 #define GL_ETC1_RGB8_OES 0x8d64
62#endif
63
64typedef struct {
65 char aName[6];
66 unsigned short iBlank;
67 /* NB: Beware endianness issues here. */
68 unsigned char iPaddedWidthMSB;
69 unsigned char iPaddedWidthLSB;
70 unsigned char iPaddedHeightMSB;
71 unsigned char iPaddedHeightLSB;
72 unsigned char iWidthMSB;
73 unsigned char iWidthLSB;
74 unsigned char iHeightMSB;
75 unsigned char iHeightLSB;
76} ETCHeader;
77
78unsigned short getWidth(ETCHeader *pHeader)
79{
80 return (pHeader->iWidthMSB << 8) | pHeader->iWidthLSB;
81}
82
83unsigned short getHeight(ETCHeader *pHeader)
84{
85 return (pHeader->iHeightMSB << 8) | pHeader->iHeightLSB;
86}
87
88unsigned short getPaddedWidth(ETCHeader *pHeader)
89{
90 return (pHeader->iPaddedWidthMSB << 8) | pHeader->iPaddedWidthLSB;
91}
92
93unsigned short getPaddedHeight(ETCHeader *pHeader)
94{
95 return (pHeader->iPaddedHeightMSB << 8) | pHeader->iPaddedHeightLSB;
96}
97
98EtcTexture::EtcTexture()
99 : m_texture_id(0), m_uploaded(false)
100{
101 initializeOpenGLFunctions();
102}
103
104EtcTexture::~EtcTexture()
105{
106 if (m_texture_id)
107 glDeleteTextures(n: 1, textures: &m_texture_id);
108}
109
110int EtcTexture::textureId() const
111{
112 if (m_texture_id == 0) {
113 EtcTexture *texture = const_cast<EtcTexture*>(this);
114 texture->glGenTextures(n: 1, textures: &texture->m_texture_id);
115 }
116 return m_texture_id;
117}
118
119void EtcTexture::bind()
120{
121 if (m_uploaded && m_texture_id) {
122 glBindTexture(GL_TEXTURE_2D, texture: m_texture_id);
123 return;
124 }
125
126 if (m_texture_id == 0)
127 glGenTextures(n: 1, textures: &m_texture_id);
128 glBindTexture(GL_TEXTURE_2D, texture: m_texture_id);
129
130#ifdef ETC_DEBUG
131 qDebug() << "glCompressedTexImage2D, width: " << m_size.width() << "height" << m_size.height() <<
132 "paddedWidth: " << m_paddedSize.width() << "paddedHeight: " << m_paddedSize.height();
133#endif
134
135#ifndef QT_NO_DEBUG
136 while (glGetError() != GL_NO_ERROR) { }
137#endif
138
139 QOpenGLContext *ctx = QOpenGLContext::currentContext();
140 Q_ASSERT(ctx != nullptr);
141 ctx->functions()->glCompressedTexImage2D(GL_TEXTURE_2D, level: 0, GL_ETC1_RGB8_OES,
142 width: m_size.width(), height: m_size.height(), border: 0,
143 imageSize: (m_paddedSize.width() * m_paddedSize.height()) >> 1,
144 data: m_data.data() + 16);
145
146#ifndef QT_NO_DEBUG
147 // Gracefully fail in case of an error...
148 GLuint error = glGetError();
149 if (error != GL_NO_ERROR) {
150 qDebug () << "glCompressedTexImage2D for compressed texture failed, error: " << error;
151 glBindTexture(GL_TEXTURE_2D, texture: 0);
152 glDeleteTextures(n: 1, textures: &m_texture_id);
153 m_texture_id = 0;
154 return;
155 }
156#endif
157
158 m_uploaded = true;
159 updateBindOptions(force: true);
160}
161
162class QEtcTextureFactory : public QQuickTextureFactory
163{
164public:
165 QByteArray m_data;
166 QSize m_size;
167 QSize m_paddedSize;
168
169 QSize textureSize() const override { return m_size; }
170 int textureByteCount() const override { return m_data.size(); }
171
172 QSGTexture *createTexture(QQuickWindow *) const override {
173 EtcTexture *texture = new EtcTexture;
174 texture->m_data = m_data;
175 texture->m_size = m_size;
176 texture->m_paddedSize = m_paddedSize;
177 return texture;
178 }
179};
180
181QQuickTextureFactory *EtcProvider::requestTexture(const QString &id, QSize *size, const QSize &requestedSize)
182{
183 Q_UNUSED(requestedSize);
184 QEtcTextureFactory *ret = nullptr;
185
186 size->setHeight(0);
187 size->setWidth(0);
188
189 QUrl url = QUrl(id);
190 if (url.isRelative() && !m_baseUrl.isEmpty())
191 url = m_baseUrl.resolved(relative: url);
192 QString path = QQmlFile::urlToLocalFileOrQrc(url);
193
194 QFile file(path);
195#ifdef ETC_DEBUG
196 qDebug() << "requestTexture opening file: " << path;
197#endif
198 if (file.open(flags: QIODevice::ReadOnly)) {
199 ret = new QEtcTextureFactory;
200 ret->m_data = file.readAll();
201 if (!ret->m_data.isEmpty()) {
202 ETCHeader *pETCHeader = nullptr;
203 pETCHeader = (ETCHeader *)ret->m_data.data();
204 size->setHeight(getHeight(pHeader: pETCHeader));
205 size->setWidth(getWidth(pHeader: pETCHeader));
206 ret->m_size = *size;
207 ret->m_paddedSize.setHeight(getPaddedHeight(pHeader: pETCHeader));
208 ret->m_paddedSize.setWidth(getPaddedWidth(pHeader: pETCHeader));
209 }
210 else {
211 delete ret;
212 ret = nullptr;
213 }
214 }
215
216#ifdef ETC_DEBUG
217 if (ret)
218 qDebug() << "requestTexture returning: " << ret->m_data.length() << ", bytes; width: " << size->width() << ", height: " << size->height();
219 else
220 qDebug () << "File not found.";
221#endif
222
223 return ret;
224}
225
226void EtcProvider::setBaseUrl(const QUrl &base)
227{
228 m_baseUrl = base;
229}
230

source code of qtdeclarative/examples/quick/textureprovider/etcprovider.cpp