Decouple QSGDistanceFieldGlyphNode from it's cache manager.

To implement a custom distance field glyph node currently it's
necessary to also provide a duplicate implementation of
QSGContext::createDistanceFieldGlyphCache() as the default implemention
references the cache manager created by createGlyphNode().  By isolating
references to the cache manager to just createDistanceFieldGlyph() cache
it becomes possible to just overwrite createGlyphNode() and still use
the default cache.

Change-Id: I7261bdbf247966b55512d2671e2ee85239bcca05
Reviewed-by: Yoann Lopes <yoann.lopes@nokia.com>

1 files changed, 55 insertions, 43 deletions

diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index 6eae5c3abd..37a49f9ed8 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -97,6 +97,11 @@ public:
     QSGContextPrivate()
         : gl(0)
         , distanceFieldCacheManager(0)
+    #ifndef QT_OPENGL_ES
+        , distanceFieldAntialiasing(QSGGlyphNode::HighQualitySubPixelAntialiasing)
+    #else
+        , distanceFieldAntialiasing(QSGGlyphNode::GrayAntialiasing)
+    #endif
         , flashMode(qmlFlashMode())
         , distanceFieldDisabled(qmlDisableDistanceField())
     {
@@ -115,6 +120,8 @@ public:
 
     QSGDistanceFieldGlyphCacheManager *distanceFieldCacheManager;
 
+    QSGDistanceFieldGlyphNode::AntialiasingMode distanceFieldAntialiasing;
+
     bool flashMode;
     float renderAlpha;
     bool distanceFieldDisabled;
@@ -142,6 +149,17 @@ public:
 QSGContext::QSGContext(QObject *parent) :
     QObject(*(new QSGContextPrivate), parent)
 {
+    Q_D(QSGContext);
+    // ### Do something with these before final release...
+    static bool doSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing"));
+    static bool doLowQualSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing-lowq"));
+    static bool doGray = qApp->arguments().contains(QLatin1String("--text-gray-antialiasing"));
+    if (doSubpixel)
+        d->distanceFieldAntialiasing = QSGGlyphNode::HighQualitySubPixelAntialiasing;
+    else if (doLowQualSubpixel)
+        d->distanceFieldAntialiasing = QSGGlyphNode::LowQualitySubPixelAntialiasing;
+    else if (doGray)
+       d->distanceFieldAntialiasing = QSGGlyphNode::GrayAntialiasing;
 }
 
 
@@ -271,39 +289,47 @@ QSGImageNode *QSGContext::createImageNode()
 /*!
     Factory function for scene graph backends of the distance-field glyph cache.
  */
-QSGDistanceFieldGlyphCache *QSGContext::createDistanceFieldGlyphCache(const QRawFont &font)
+QSGDistanceFieldGlyphCache *QSGContext::distanceFieldGlyphCache(const QRawFont &font)
 {
     Q_D(QSGContext);
 
-    QPlatformIntegration *platformIntegration = QGuiApplicationPrivate::platformIntegration();
-    if (platformIntegration != 0
-        && platformIntegration->hasCapability(QPlatformIntegration::SharedGraphicsCache)) {
-        QFontEngine *fe = QRawFontPrivate::get(font)->fontEngine;
-        if (!fe->faceId().filename.isEmpty()) {
-            QByteArray keyName = fe->faceId().filename;
-            if (font.style() != QFont::StyleNormal)
-                keyName += QByteArray(" I");
-            if (font.weight() != QFont::Normal)
-                keyName += " " + QByteArray::number(font.weight());
-            keyName += QByteArray(" DF");
-            QPlatformSharedGraphicsCache *sharedGraphicsCache =
-                    platformIntegration->createPlatformSharedGraphicsCache(keyName);
-
-            if (sharedGraphicsCache != 0) {
-                sharedGraphicsCache->ensureCacheInitialized(keyName,
-                                                            QPlatformSharedGraphicsCache::OpenGLTexture,
-                                                            QPlatformSharedGraphicsCache::Alpha8);
-
-                return new QSGSharedDistanceFieldGlyphCache(keyName,
-                                                            sharedGraphicsCache,
-                                                            d->distanceFieldCacheManager,
-                                                            glContext(),
-                                                            font);
+    if (!d->distanceFieldCacheManager)
+        d->distanceFieldCacheManager = new QSGDistanceFieldGlyphCacheManager;
+
+    QSGDistanceFieldGlyphCache *cache = d->distanceFieldCacheManager->cache(font);
+    if (!cache) {
+        QPlatformIntegration *platformIntegration = QGuiApplicationPrivate::platformIntegration();
+        if (platformIntegration != 0
+            && platformIntegration->hasCapability(QPlatformIntegration::SharedGraphicsCache)) {
+            QFontEngine *fe = QRawFontPrivate::get(font)->fontEngine;
+            if (!fe->faceId().filename.isEmpty()) {
+                QByteArray keyName = fe->faceId().filename;
+                if (font.style() != QFont::StyleNormal)
+                    keyName += QByteArray(" I");
+                if (font.weight() != QFont::Normal)
+                    keyName += " " + QByteArray::number(font.weight());
+                keyName += QByteArray(" DF");
+                QPlatformSharedGraphicsCache *sharedGraphicsCache =
+                        platformIntegration->createPlatformSharedGraphicsCache(keyName);
+
+                if (sharedGraphicsCache != 0) {
+                    sharedGraphicsCache->ensureCacheInitialized(keyName,
+                                                                QPlatformSharedGraphicsCache::OpenGLTexture,
+                                                                QPlatformSharedGraphicsCache::Alpha8);
+
+                    cache = new QSGSharedDistanceFieldGlyphCache(keyName,
+                                                                sharedGraphicsCache,
+                                                                d->distanceFieldCacheManager,
+                                                                glContext(),
+                                                                font);
+                }
             }
         }
+        if (!cache)
+            cache = new QSGDefaultDistanceFieldGlyphCache(d->distanceFieldCacheManager, glContext(), font);
+        d->distanceFieldCacheManager->insertCache(font, cache);
     }
-
-    return new QSGDefaultDistanceFieldGlyphCache(d->distanceFieldCacheManager, glContext(), font);
+    return cache;
 }
 
 /*!
@@ -313,25 +339,11 @@ QSGGlyphNode *QSGContext::createGlyphNode()
 {
     Q_D(QSGContext);
 
-    // ### Do something with these before final release...
-    static bool doSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing"));
-    static bool doLowQualSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing-lowq"));
-    static bool doGray = qApp->arguments().contains(QLatin1String("--text-gray-antialiasing"));
-
     if (d->distanceFieldDisabled) {
         return new QSGDefaultGlyphNode;
     } else {
-        if (!d->distanceFieldCacheManager) {
-            d->distanceFieldCacheManager = new QSGDistanceFieldGlyphCacheManager(this);
-            if (doSubpixel)
-                d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::HighQualitySubPixelAntialiasing);
-            else if (doLowQualSubpixel)
-                d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::LowQualitySubPixelAntialiasing);
-            else if (doGray)
-               d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::GrayAntialiasing);
-        }
-
-        QSGGlyphNode *node = new QSGDistanceFieldGlyphNode(d->distanceFieldCacheManager);
+        QSGDistanceFieldGlyphNode *node = new QSGDistanceFieldGlyphNode(this);
+        node->setPreferredAntialiasingMode(d->distanceFieldAntialiasing);
         return node;
     }
 }