Add tile cache, avoid flickering

DCGM · Feb 2, 2025 · 45a2f09 · 45a2f09
1 parent e3d9e8f
commit 45a2f09
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Showing 2 changed files with 39 additions and 4 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -30,9 +30,7 @@ add_definitions( -DGIT_VERSION="${GIT_VERSION}" )
 
 find_package(Qt5 COMPONENTS Core Quick Xml Widgets Charts LinguistTools REQUIRED)
 find_package(Qt5QuickCompiler)
-qtquick_compiler_add_resources(RESOURCES viewer.qrc)
-#qt5_add_resources(RESOURCES viewer.qrc)
-
+SET(RESOURCES viewer.qrc)
 
 file(GLOB TS_FILES i18n/*.ts)
 

diff --git a/src/qml/PinchMap.qml b/src/qml/PinchMap.qml
@@ -384,6 +384,7 @@ Rectangle {
         var l = getCenter()
         longitude = l[1]
         latitude = l[0]
+        cleanCache();
         canvas.requestPaint()
 
     }
@@ -495,9 +496,45 @@ Rectangle {
     }
 
     function tileUrl(tx, ty) {
-        return tileUrlMultiple(tx, ty, url, true);
+        var imageUrl = tileUrlMultiple(tx, ty, url, true)
+        for (var i = 0; i < imageCache.length; i++) {
+            if (imageCache[i].cacheUrl === imageUrl) {
+                // console.log("Cache hit:", imageUrl)
+                imageCache[i].lastHit = new Date();
+                return imageCache[i].source
+            }
+        }
+
+        console.log("cache miss ("+imageCache.length+"): " + imageUrl )
+        var newImage = Qt.createQmlObject(
+            'import QtQuick 2.15;
+                Image {
+                    property var lastHit: new Date();
+                    property string cacheUrl: "'+imageUrl+'";
+                    visible: false;
+                    source: "' + imageUrl + '"
+                }', parent, "dynamicImage")
+        imageCache.push(newImage)
+        return newImage.source;
+    }
+
+    function cleanCache() {
+        if (imageCache.length < 100) {
+            return;
+        }
+        var someTimeAgo = new Date().getTime() - 60000;
+
+        for (var i = 0; i < imageCache.length; i++) {
+            if (imageCache[i].lastHit.getTime() < someTimeAgo) {
+                // console.log("Removing stale cache item: " + imageCache[i].cacheUrl);
+                imageCache[i].destroy();
+                imageCache.splice(i, 1);
+            }
+        }
+        console.log("after cleanup imageCache.length: " + imageCache.length)
     }
 
+    property var imageCache: []
 
     function tileUrlMultiple(tx, ty, baseUrl, first) {