QTextureFileReader: backport ASTC support

Add support for astc format files as an experimental feature.
To enable, configure with "-feature-texture_format_astc_experimental"

(Backported from commit 5a4db421bd94acd12a4ac1f77031996b95f85dbf)

Change-Id: I9a2f7b1fa20ba344b79637bafb50ff2bd0596747
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

9 files changed, 311 insertions, 25 deletions

diff --git a/src/gui/configure.json b/src/gui/configure.json
index c51e3ceee3..6dd6f5b16c 100644
--- a/src/gui/configure.json
+++ b/src/gui/configure.json
@@ -1748,6 +1748,11 @@
             "section": "Images",
             "output": [ "publicFeature", "feature" ]
         },
+        "texture_format_astc_experimental" : {
+            "label": "ASTC Texture format (experimental)",
+            "autoDetect": "false",
+            "output": [ "privateFeature" ]
+        },
         "picture": {
             "label": "QPicture",
             "purpose": "Supports recording and replaying QPainter commands.",
diff --git a/src/gui/util/qastchandler.cpp b/src/gui/util/qastchandler.cpp
new file mode 100644
index 0000000000..6d163c6701
--- /dev/null
+++ b/src/gui/util/qastchandler.cpp
@@ -0,0 +1,168 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qastchandler_p.h"
+#include "qtexturefiledata_p.h"
+
+#include <private/qnumeric_p.h>
+
+#include <QFile>
+#include <QDebug>
+#include <QSize>
+
+QT_BEGIN_NAMESPACE
+
+struct AstcHeader
+{
+    quint8 magic[4];
+    quint8 blockDimX;
+    quint8 blockDimY;
+    quint8 blockDimZ;
+    quint8 xSize[3];
+    quint8 ySize[3];
+    quint8 zSize[3];
+};
+
+bool QAstcHandler::canRead(const QByteArray &suffix, const QByteArray &block)
+{
+    Q_UNUSED(suffix)
+
+    return block.startsWith("\x13\xAB\xA1\x5C");
+}
+
+quint32 QAstcHandler::astcGLFormat(quint8 xBlockDim, quint8 yBlockDim) const
+{
+    static const quint32 glFormatRGBABase = 0x93B0;    // GL_COMPRESSED_RGBA_ASTC_4x4_KHR
+    static const quint32 glFormatSRGBBase = 0x93D0;    // GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR
+
+    static QSize dims[14] = {
+        {  4, 4  },     // GL_COMPRESSED_xxx_ASTC_4x4_KHR
+        {  5, 4  },     // GL_COMPRESSED_xxx_ASTC_5x4_KHR
+        {  5, 5  },     // GL_COMPRESSED_xxx_ASTC_5x5_KHR
+        {  6, 5  },     // GL_COMPRESSED_xxx_ASTC_6x5_KHR
+        {  6, 6  },     // GL_COMPRESSED_xxx_ASTC_6x6_KHR
+        {  8, 5  },     // GL_COMPRESSED_xxx_ASTC_8x5_KHR
+        {  8, 6  },     // GL_COMPRESSED_xxx_ASTC_8x6_KHR
+        {  8, 8  },     // GL_COMPRESSED_xxx_ASTC_8x8_KHR
+        { 10, 5  },     // GL_COMPRESSED_xxx_ASTC_10x5_KHR
+        { 10, 6  },     // GL_COMPRESSED_xxx_ASTC_10x6_KHR
+        { 10, 8  },     // GL_COMPRESSED_xxx_ASTC_10x8_KHR
+        { 10, 10 },     // GL_COMPRESSED_xxx_ASTC_10x10_KHR
+        { 12, 10 },     // GL_COMPRESSED_xxx_ASTC_12x10_KHR
+        { 12, 12 }      // GL_COMPRESSED_xxx_ASTC_12x12_KHR
+    };
+
+    const QSize dim(xBlockDim, yBlockDim);
+    int index = -1;
+    for (int i = 0; i < 14; i++) {
+        if (dim == dims[i]) {
+            index = i;
+            break;
+        }
+    }
+    if (index < 0)
+        return 0;
+
+    bool useSrgb = qEnvironmentVariableIsSet("QT_ASTCHANDLER_USE_SRGB")
+                   || logName().toLower().contains("srgb");
+
+    return useSrgb ? (glFormatSRGBBase + index) : (glFormatRGBABase + index);
+}
+
+QTextureFileData QAstcHandler::read()
+{
+    QTextureFileData nullData;
+    QTextureFileData res;
+
+    if (!device())
+        return nullData;
+
+    QByteArray fileData = device()->readAll();
+    if (fileData.size() < int(sizeof(AstcHeader)) || !canRead(QByteArray(), fileData)) {
+        qCDebug(lcQtGuiTextureIO, "Not an ASTC file: %s", logName().constData());
+        return nullData;
+    }
+    res.setData(fileData);
+
+    const AstcHeader *header = reinterpret_cast<const AstcHeader *>(fileData.constData());
+
+    int xSz = int(header->xSize[0]) | int(header->xSize[1]) << 8 | int(header->xSize[2]) << 16;
+    int ySz = int(header->ySize[0]) | int(header->ySize[1]) << 8 | int(header->ySize[2]) << 16;
+    int zSz = int(header->zSize[0]) | int(header->zSize[1]) << 8 | int(header->zSize[2]) << 16;
+
+    quint32 glFmt = astcGLFormat(header->blockDimX, header->blockDimY);
+
+    if (!xSz || !ySz || !zSz || !glFmt || header->blockDimZ != 1) {
+        qCDebug(lcQtGuiTextureIO, "Invalid ASTC header data in file %s", logName().constData());
+        return nullData;
+    }
+
+    res.setSize(QSize(xSz, ySz));
+    res.setGLFormat(0);                    // 0 for compressed textures
+    res.setGLInternalFormat(glFmt);
+    //? BaseInternalFormat
+
+    int xBlocks = (xSz + header->blockDimX - 1) / header->blockDimX;
+    int yBlocks = (ySz + header->blockDimY - 1) / header->blockDimY;
+    int zBlocks = (zSz + header->blockDimZ - 1) / header->blockDimZ;
+
+    int byteCount = 0;
+    bool oob = mul_overflow(xBlocks, yBlocks, &byteCount)
+               || mul_overflow(byteCount, zBlocks, &byteCount)
+               || mul_overflow(byteCount, 16, &byteCount);
+
+
+    res.setDataOffset(sizeof(AstcHeader));
+    res.setNumLevels(1);
+    res.setDataLength(byteCount);
+
+    if (oob || !res.isValid()) {
+        qCDebug(lcQtGuiTextureIO, "Invalid ASTC file %s", logName().constData());
+        return nullData;
+    }
+
+    res.setLogName(logName());
+
+#if 0
+    qDebug() << "ASTC file handler read" << res << res.dataOffset() << res.dataLength();
+#endif
+    return res;
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/util/qastchandler_p.h b/src/gui/util/qastchandler_p.h
new file mode 100644
index 0000000000..398f1833b6
--- /dev/null
+++ b/src/gui/util/qastchandler_p.h
@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QASTCHANDLER_H
+#define QASTCHANDLER_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qtexturefilehandler_p.h"
+
+QT_BEGIN_NAMESPACE
+
+class QAstcHandler : public QTextureFileHandler
+{
+public:
+    using QTextureFileHandler::QTextureFileHandler;
+
+    static bool canRead(const QByteArray &suffix, const QByteArray &block);
+
+    QTextureFileData read() override;
+
+private:
+    quint32 astcGLFormat(quint8 xBlockDim, quint8 yBlockDim) const;
+};
+
+QT_END_NAMESPACE
+
+#endif // QASTCHANDLER_H
diff --git a/src/gui/util/qtexturefilereader.cpp b/src/gui/util/qtexturefilereader.cpp
index 5d4bd600e0..73d6b6811a 100644
--- a/src/gui/util/qtexturefilereader.cpp
+++ b/src/gui/util/qtexturefilereader.cpp
@@ -37,10 +37,14 @@
 **
 ****************************************************************************/
 
+#include <QtGui/private/qtguiglobal_p.h>
 #include "qtexturefilereader_p.h"
 
 #include "qpkmhandler_p.h"
 #include "qktxhandler_p.h"
+#if QT_CONFIG(texture_format_astc_experimental)
+#include "qastchandler_p.h"
+#endif
 
 #include <QFileInfo>
 
@@ -80,6 +84,10 @@ bool QTextureFileReader::canRead()
             m_handler = new QPkmHandler(m_device, logName);
         } else if (QKtxHandler::canRead(suffix, headerBlock)) {
             m_handler = new QKtxHandler(m_device, logName);
+#if QT_CONFIG(texture_format_astc_experimental)
+        } else if (QAstcHandler::canRead(suffix, headerBlock)) {
+            m_handler = new QAstcHandler(m_device, logName);
+#endif
         }
         // else if OtherHandler::canRead() ...etc.
     }
@@ -89,7 +97,7 @@ bool QTextureFileReader::canRead()
 QList<QByteArray> QTextureFileReader::supportedFileFormats()
 {
     // Hardcoded for now
-    return {QByteArrayLiteral("pkm"), QByteArrayLiteral("ktx")};
+    return {QByteArrayLiteral("pkm"), QByteArrayLiteral("ktx"), QByteArrayLiteral("astc")};
 }
 
 bool QTextureFileReader::init()
diff --git a/src/gui/util/util.pri b/src/gui/util/util.pri
index 6324642505..b36ee60a97 100644
--- a/src/gui/util/util.pri
+++ b/src/gui/util/util.pri
@@ -39,3 +39,8 @@ SOURCES += \
         util/qtexturefilereader.cpp \
         util/qpkmhandler.cpp \
         util/qktxhandler.cpp
+
+qtConfig(texture_format_astc_experimental) {
+        HEADERS += util/qastchandler_p.h
+        SOURCES += util/qastchandler.cpp
+}
diff --git a/tests/auto/gui/util/qtexturefilereader/qtexturefilereader.qrc b/tests/auto/gui/util/qtexturefilereader/qtexturefilereader.qrc
index ab882b5db2..8aab86e1ff 100644
--- a/tests/auto/gui/util/qtexturefilereader/qtexturefilereader.qrc
+++ b/tests/auto/gui/util/qtexturefilereader/qtexturefilereader.qrc
@@ -3,5 +3,7 @@
         <file>texturefiles/car.ktx</file>
         <file>texturefiles/pattern.pkm</file>
         <file>texturefiles/car_mips.ktx</file>
+        <file>texturefiles/newlogo_srgb.astc</file>
+        <file>texturefiles/newlogo.astc</file>
     </qresource>
 </RCC>
diff --git a/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo.astc b/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo.astc
new file mode 100644
index 0000000000..39bf3f1734
--- /dev/null
+++ b/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo.astc
diff --git a/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo_srgb.astc b/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo_srgb.astc
new file mode 100644
index 0000000000..38e876829b
--- /dev/null
+++ b/tests/auto/gui/util/qtexturefilereader/texturefiles/newlogo_srgb.astc
diff --git a/tests/auto/gui/util/qtexturefilereader/tst_qtexturefilereader.cpp b/tests/auto/gui/util/qtexturefilereader/tst_qtexturefilereader.cpp
index 9ff4f0ccf2..7939b688af 100644
--- a/tests/auto/gui/util/qtexturefilereader/tst_qtexturefilereader.cpp
+++ b/tests/auto/gui/util/qtexturefilereader/tst_qtexturefilereader.cpp
@@ -27,6 +27,7 @@
 ****************************************************************************/
 
 #include <private/qtexturefilereader_p.h>
+#include <private/qtguiglobal_p.h>
 #include <QtTest>
 
 class tst_qtexturefilereader : public QObject
@@ -49,33 +50,57 @@ void tst_qtexturefilereader::checkHandlers_data()
     QTest::addColumn<QList<int>>("dataOffsets");
     QTest::addColumn<QList<int>>("dataLengths");
 
-    QTest::addRow("pattern.pkm") << QStringLiteral(":/texturefiles/pattern.pkm")
-                                 << QSize(64, 64)
-                                 << quint32(0x0)
-                                 << quint32(0x8d64)
-                                 << quint32(0x0)
-                                 << 1
-                                 << (QList<int>() << 16)
-                                 << (QList<int>() << 2048);
+    QTest::addRow("pattern.pkm")
+            << QStringLiteral(":/texturefiles/pattern.pkm")
+            << QSize(64, 64)
+            << quint32(0x0)
+            << quint32(0x8d64)
+            << quint32(0x0)
+            << 1
+            << (QList<int>() << 16)
+            << (QList<int>() << 2048);
 
-    QTest::addRow("car.ktx") << QStringLiteral(":/texturefiles/car.ktx")
-                             << QSize(146, 80)
-                             << quint32(0x0)
-                             << quint32(0x9278)
-                             << quint32(0x1908)
-                             << 1
-                             << (QList<int>() << 68)
-                             << (QList<int>() << 11840);
+    QTest::addRow("car.ktx")
+            << QStringLiteral(":/texturefiles/car.ktx")
+            << QSize(146, 80)
+            << quint32(0x0)
+            << quint32(0x9278)
+            << quint32(0x1908)
+            << 1
+            << (QList<int>() << 68)
+            << (QList<int>() << 11840);
 
-    QTest::addRow("car_mips.ktx") << QStringLiteral(":/texturefiles/car_mips.ktx")
-                                  << QSize(146, 80)
-                                  << quint32(0x0)
-                                  << quint32(0x9274)
-                                  << quint32(0x1907)
-                                  << 8
-                                  << (QList<int>() << 68 << 5992 << 7516 << 7880 << 8004 << 8056 << 8068 << 8080)
-                                  << (QList<int>() << 5920 << 1520 << 360 << 120 << 48 << 8 << 8 << 8);
+    QTest::addRow("car_mips.ktx")
+            << QStringLiteral(":/texturefiles/car_mips.ktx")
+            << QSize(146, 80)
+            << quint32(0x0)
+            << quint32(0x9274)
+            << quint32(0x1907)
+            << 8
+            << (QList<int>() << 68 << 5992 << 7516 << 7880 << 8004 << 8056 << 8068 << 8080)
+            << (QList<int>() << 5920 << 1520 << 360 << 120 << 48 << 8 << 8 << 8);
 
+#if QT_CONFIG(texture_format_astc_experimental)
+    QTest::addRow("newlogo.astc")
+            << QStringLiteral(":/texturefiles/newlogo.astc")
+            << QSize(111, 78)
+            << quint32(0x0)
+            << quint32(0x93b9)
+            << quint32(0x0)
+            << 1
+            << (QList<int>() << 16)
+            << (QList<int>() << 2496);
+
+    QTest::addRow("newlogo_srgb.astc")
+            << QStringLiteral(":/texturefiles/newlogo_srgb.astc")
+            << QSize(111, 78)
+            << quint32(0x0)
+            << quint32(0x93d9)
+            << quint32(0x0)
+            << 1
+            << (QList<int>() << 16)
+            << (QList<int>() << 2496);
+#endif // QT_CONFIG(texture_format_astc_experimental)
 }
 
 void tst_qtexturefilereader::checkHandlers()