GPU texture compression

CMakeLists.txt

@@ -25,6 +25,7 @@ option(ALP_BUILD_UNITTESTS "include unit test targets in the buildsystem" ON)
 option(ALP_BUILD_GL_ENGINE "include the gl engine in the buildsystem" OFF)
 option(ALP_BUILD_PLAIN_RENDERER "include the plain renderer in the buildsystem" ON)
 option(ALP_BUILD_ALPINEAPP "include the qml app in the buildsystem" ON)
+option(ALP_BUILD_TEXTURE_COMPRESSION_PREVIEW "include the texture compression preview application" OFF)
 set(ALP_WEBGPU_DEFAULT ON)
 if (APPLE OR ANDROID)
     set(ALP_WEBGPU_DEFAULT OFF)
@@ -124,7 +125,7 @@ endif()
 
 add_subdirectory(nucleus)
 
-if (ALP_BUILD_GL_ENGINE OR ALP_BUILD_PLAIN_RENDERER OR ALP_BUILD_ALPINEAPP)
+if (ALP_BUILD_GL_ENGINE OR ALP_BUILD_PLAIN_RENDERER OR ALP_BUILD_ALPINEAPP OR ALP_BUILD_TEXTURE_COMPRESSION_PREVIEW)
     add_subdirectory(gl_engine)
 endif()
 if (ALP_BUILD_PLAIN_RENDERER)
@@ -139,6 +140,9 @@ if (ALP_BUILD_ALPINEAPP)
     endif()
     add_subdirectory(app)
 endif()
+if (ALP_BUILD_TEXTURE_COMPRESSION_PREVIEW)
+    add_subdirectory(apps/texture_compression_benchmark)
+endif()
 
 if (ALP_BUILD_WEBGPU_BASE OR ALP_BUILD_WEBGPU_ENGINE OR ALP_BUILD_WEBGPU_COMPUTE OR ALP_BUILD_WEBGPU_APP)
     include(${CMAKE_SOURCE_DIR}/cmake/SetupWebGPUPlatform.cmake)

app/main.cpp

@@ -65,6 +65,25 @@ int main(int argc, char **argv)
 {
     // originalHandler = qInstallMessageHandler(filter_log);
     QQuickWindow::setGraphicsApi(QSGRendererInterface::GraphicsApi::OpenGLRhi);
+
+    QSurfaceFormat fmt;
+    fmt.setDepthBufferSize(24);
+#ifdef ALP_ENABLE_DEV_TOOLS
+    fmt.setOption(QSurfaceFormat::DebugContext);
+#endif
+
+    if (QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGL) {
+        qDebug("Requesting 3.3 core context");
+        fmt.setRenderableType(QSurfaceFormat::OpenGL);
+        fmt.setVersion(3, 3);
+        fmt.setProfile(QSurfaceFormat::CoreProfile);
+    } else {
+        qDebug("Requesting 3.0 context");
+        fmt.setVersion(3, 0);
+    }
+
+    QSurfaceFormat::setDefaultFormat(fmt);
+
 #if defined(ALP_ENABLE_DEV_TOOLS) || defined(__ANDROID__)
     QApplication app(argc, argv);
 #else
@@ -121,23 +140,6 @@ int main(int argc, char **argv)
         }
     }
 
-    QSurfaceFormat fmt;
-    fmt.setDepthBufferSize(24);
-#ifdef ALP_ENABLE_DEV_TOOLS
-    fmt.setOption(QSurfaceFormat::DebugContext);
-#endif
-
-    if (QOpenGLContext::openGLModuleType() == QOpenGLContext::LibGL) {
-        qDebug("Requesting 3.3 core context");
-        fmt.setVersion(3, 3);
-        fmt.setProfile(QSurfaceFormat::CoreProfile);
-    } else {
-        qDebug("Requesting 3.0 context");
-        fmt.setVersion(3, 0);
-    }
-
-    QSurfaceFormat::setDefaultFormat(fmt);
-
     // create in main thread
 #ifdef ALP_ENABLE_DEV_TOOLS
     TimerFrontendManager::instance();
@@ -192,4 +194,3 @@ int main(int argc, char **argv)
 
     return app.exec();
 }
-

apps/texture_compression_benchmark/CMakeLists.txt

@@ -0,0 +1,59 @@
+#############################################################################
+# AlpineMaps.org
+# Copyright (C) 2026 Adam Celarek
+# SPDX-License-Identifier: GPL-3.0-or-later
+#############################################################################
+
+project(texture-compression-preview LANGUAGES CXX)
+
+qt_add_executable(texture_compression_preview
+    main.cpp
+    TextureCompressionData.h
+    TexturePreviewItem.h
+    TexturePreviewItem.cpp
+)
+
+qt_add_qml_module(texture_compression_preview
+    URI TextureCompressionPreview
+    VERSION 1.0
+    RESOURCE_PREFIX /qt/qml
+    QML_FILES Main.qml
+)
+
+qt_add_resources(texture_compression_preview "fonts"
+    BASE "${alpineapp_fonts_SOURCE_DIR}"
+    PREFIX "/fonts"
+    FILES "${alpineapp_fonts_SOURCE_DIR}/Roboto/Roboto-Regular.ttf"
+)
+
+target_link_libraries(texture_compression_preview PUBLIC gl_engine Qt::Network Qt::Quick Qt::QuickControls2)
+alp_configure_target(texture_compression_preview)
+
+if (ANDROID)
+    add_android_openssl_libraries(texture_compression_preview)
+    set_target_properties(texture_compression_preview PROPERTIES
+        QT_ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android"
+        QT_ANDROID_PACKAGE_NAME "org.alpinemaps.texturecompressionpreview"
+        QT_ANDROID_VERSION_NAME "1.0"
+        QT_ANDROID_VERSION_CODE 1
+    )
+    install(TARGETS texture_compression_preview
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+endif()
+
+if (EMSCRIPTEN)
+    install(
+        FILES
+            "$<TARGET_FILE_DIR:texture_compression_preview>/texture_compression_preview.js"
+            "$<TARGET_FILE_DIR:texture_compression_preview>/texture_compression_preview.wasm"
+            "$<TARGET_FILE_DIR:texture_compression_preview>/texture_compression_preview.html"
+            "$<TARGET_FILE_DIR:texture_compression_preview>/qtloader.js"
+        DESTINATION "${ALP_WWW_INSTALL_DIR}/texture_compression_preview"
+    )
+    install(
+        FILES "$<TARGET_FILE_DIR:texture_compression_preview>/texture_compression_preview.worker.js"
+        DESTINATION "${ALP_WWW_INSTALL_DIR}/texture_compression_preview"
+        OPTIONAL
+    )
+endif()

apps/texture_compression_benchmark/Main.qml

@@ -0,0 +1,158 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import TextureCompressionPreview
+
+ApplicationWindow {
+    id: root
+
+    width: 900
+    height: 900
+    minimumWidth: 360
+    minimumHeight: 480
+    visible: true
+    title: qsTr("Texture Compression Preview")
+    LayoutMirroring.enabled: Qt.application.layoutDirection === Qt.RightToLeft
+    LayoutMirroring.childrenInherit: true
+
+    ColumnLayout {
+        anchors.fill: parent
+        anchors.margins: 20
+        spacing: 12
+
+        Label {
+            Layout.fillWidth: true
+            text: qsTr("Texture compression preview")
+            font.pointSize: 20
+            font.weight: Font.Medium
+            wrapMode: Text.Wrap
+        }
+
+        Label {
+            Layout.fillWidth: true
+            text: preview.status
+            wrapMode: Text.Wrap
+        }
+
+        GridLayout {
+            Layout.fillWidth: true
+            columns: width >= 760 ? 9 : width >= 500 ? 5 : 3
+            columnSpacing: 6
+            rowSpacing: 6
+
+            Repeater {
+                model: preview.previewEncoders
+
+                Button {
+                    required property int index
+                    required property string modelData
+
+                    Layout.fillWidth: true
+                    text: modelData
+                    enabled: preview.ready
+                    highlighted: preview.previewEncoder === index
+                    onClicked: preview.previewEncoder = index
+                }
+            }
+        }
+
+        Item {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            Layout.minimumHeight: 300
+
+            Flickable {
+                id: previewViewport
+
+                anchors.fill: parent
+                clip: true
+                boundsBehavior: Flickable.StopAtBounds
+                contentWidth: Math.max(width, previewHost.width * previewHost.scale)
+                contentHeight: Math.max(height, previewHost.height * previewHost.scale)
+
+                Item {
+                    id: previewHost
+
+                    readonly property real fittedSize: Math.min(previewViewport.width, previewViewport.height)
+
+                    x: (previewViewport.contentWidth - width) / 2
+                    y: (previewViewport.contentHeight - height) / 2
+                    width: fittedSize
+                    height: width
+
+                    TexturePreviewItem {
+                        id: preview
+                        anchors.fill: parent
+                    }
+
+                    PinchHandler {
+                        target: previewHost
+                        rotationAxis.enabled: false
+                        xAxis.enabled: false
+                        yAxis.enabled: false
+                        scaleAxis.minimum: 1
+                        scaleAxis.maximum: 8
+                    }
+                }
+            }
+
+            BusyIndicator {
+                anchors.centerIn: parent
+                running: preview.loading
+                visible: running
+            }
+        }
+
+        RowLayout {
+            Layout.fillWidth: true
+
+            Label {
+                Layout.fillWidth: true
+                text: preview.ready
+                    ? (Number.isFinite(preview.previewPsnr)
+                        ? qsTr("%1 — PSNR: %2 dB").arg(preview.previewName).arg(preview.previewPsnr.toFixed(2))
+                        : qsTr("%1 — PSNR: ∞").arg(preview.previewName))
+                    : ""
+                wrapMode: Text.Wrap
+            }
+
+            Button {
+                text: qsTr("Description")
+                enabled: preview.ready
+                onClicked: {
+                    if (descriptionDialogLoader.status === Loader.Ready)
+                        descriptionDialogLoader.item.open()
+                    else
+                        descriptionDialogLoader.active = true
+                }
+            }
+        }
+    }
+
+    Loader {
+        id: descriptionDialogLoader
+
+        active: false
+        asynchronous: true
+        onLoaded: {
+            if (status === Loader.Ready)
+                item.open()
+        }
+
+        sourceComponent: Component {
+            Dialog {
+                parent: Overlay.overlay
+                anchors.centerIn: parent
+                width: Math.min(root.width - 40, 560)
+                modal: true
+                title: preview.previewName
+                standardButtons: Dialog.Close
+
+                contentItem: Label {
+                    text: preview.previewDescription
+                    wrapMode: Text.Wrap
+                }
+            }
+        }
+    }
+}

apps/texture_compression_benchmark/TextureCompressionData.h

@@ -0,0 +1,47 @@
+/*****************************************************************************
+ * AlpineMaps.org
+ * Copyright (C) 2026 Adam Celarek
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *****************************************************************************/
+
+#pragma once
+
+#include <QString>
+#include <array>
+
+namespace texture_compression_data {
+
+struct TileGroup {
+    int zoom;
+    int y;
+    int x;
+};
+
+constexpr std::array<TileGroup, 16> tile_groups { {
+    { 17, 45448, 71496 },
+    { 16, 22832, 35144 },
+    { 16, 23030, 35578 },
+    { 13, 2852, 4476 },
+    { 14, 5702, 8808 },
+    { 15, 11574, 17670 },
+    { 16, 23030, 35078 },
+    { 15, 11460, 17622 },
+    { 14, 5752, 8656 },
+    { 16, 23084, 34746 },
+    { 14, 5684, 8926 },
+    { 15, 11418, 17692 },
+    { 16, 22956, 34570 },
+    { 15, 11358, 17904 },
+    { 16, 22910, 35770 },
+    { 14, 5656, 8938 },
+} };
+
+inline QString tile_url(const TileGroup& group, int x_offset, int y_offset)
+{
+    return QStringLiteral("https://gataki.cg.tuwien.ac.at/raw/basemap/tiles/%1/%2/%3.jpeg")
+        .arg(group.zoom)
+        .arg(group.y + y_offset)
+        .arg(group.x + x_offset);
+}
+
+} // namespace texture_compression_data