HYL_OK3568_LINUX/buildroot/package/qt5/qt5base/0016-HACK-linuxfb-Support-direct-painting.patch

From 762b506da170480bb101c4d7841850cc2aba3825 Mon Sep 17 00:00:00 2001
From: Jeffy Chen <jeffy.chen@rock-chips.com>
Date: Thu, 11 Jun 2020 10:27:16 +0800
Subject: [PATCH 16/28] HACK: linuxfb: Support direct painting

Doing direct painting on fully update single window case.

Define QT_FB_DIRECT_PAINTING macro to enable.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
 .../fbconvenience/qfbbackingstore.cpp         | 29 +++++++++--
 .../fbconvenience/qfbbackingstore_p.h         | 12 ++++-
 .../fbconvenience/qfbscreen.cpp               | 49 +++++++++++++++++--
 .../fbconvenience/qfbscreen_p.h               |  2 +
 .../platforms/linuxfb/qlinuxfbdrmscreen.cpp   | 14 ++++++
 5 files changed, 98 insertions(+), 8 deletions(-)

diff --git a/src/platformsupport/fbconvenience/qfbbackingstore.cpp b/src/platformsupport/fbconvenience/qfbbackingstore.cpp
index e2d94406..92c2d92c 100644
--- a/src/platformsupport/fbconvenience/qfbbackingstore.cpp
+++ b/src/platformsupport/fbconvenience/qfbbackingstore.cpp
@@ -47,6 +47,9 @@
 
 QT_BEGIN_NAMESPACE
 
+QImage * QFbBackingStore::gScreenImage = NULL;
+QImage * QFbBackingStore::gFbImage = NULL;
+
 QFbBackingStore::QFbBackingStore(QWindow *window)
     : QPlatformBackingStore(window)
 {
@@ -76,15 +79,33 @@ void QFbBackingStore::resize(const QSize &size, const QRegion &staticContents)
         mImage = QImage(size, window()->screen()->handle()->format());
 }
 
-const QImage QFbBackingStore::image()
+QPaintDevice *QFbBackingStore::paintDevice()
 {
-    return mImage;
-}
+    // HACK: gScreenImage available means allowing directly painting
+    if (!gScreenImage)
+        return &mImage;
 
+    // HACK: Prefer directly painting to fb when it's available
+    if (gFbImage)
+        return gFbImage;
+
+    return gScreenImage;
+}
 
 QImage QFbBackingStore::toImage() const
 {
-    return mImage;
+    if (!gScreenImage)
+        return mImage;
+
+    if (gFbImage)
+        return *gFbImage;
+
+    return *gScreenImage;
+}
+
+const QImage QFbBackingStore::image()
+{
+    return toImage();
 }
 
 void QFbBackingStore::lock()
diff --git a/src/platformsupport/fbconvenience/qfbbackingstore_p.h b/src/platformsupport/fbconvenience/qfbbackingstore_p.h
index c4762c93..214d85c2 100644
--- a/src/platformsupport/fbconvenience/qfbbackingstore_p.h
+++ b/src/platformsupport/fbconvenience/qfbbackingstore_p.h
@@ -66,7 +66,7 @@ public:
     QFbBackingStore(QWindow *window);
     ~QFbBackingStore();
 
-    QPaintDevice *paintDevice() override { return &mImage; }
+    QPaintDevice *paintDevice() override;
     void flush(QWindow *window, const QRegion &region, const QPoint &offset) override;
 
     void resize(const QSize &size, const QRegion &region) override;
@@ -80,11 +80,21 @@ public:
     void beginPaint(const QRegion &) override;
     void endPaint() override;
 
+    static void setScreenImage(QImage *screenImage)
+        { gScreenImage = screenImage; };
+    static void setFbImage(QImage *fbImage) { gFbImage = fbImage; }
+
+    static bool hasScreenImage() { return gScreenImage != NULL; };
+    static bool hasFbImage() { return gFbImage != NULL; };
+
 protected:
     friend class QFbWindow;
 
     QImage mImage;
     QMutex mImageMutex;
+
+    static QImage *gScreenImage;
+    static QImage *gFbImage;
 };
 
 QT_END_NAMESPACE
diff --git a/src/platformsupport/fbconvenience/qfbscreen.cpp b/src/platformsupport/fbconvenience/qfbscreen.cpp
index 76984dfe..21308067 100644
--- a/src/platformsupport/fbconvenience/qfbscreen.cpp
+++ b/src/platformsupport/fbconvenience/qfbscreen.cpp
@@ -56,7 +56,8 @@ QFbScreen::QFbScreen()
       mCursor(0),
       mDepth(16),
       mFormat(QImage::Format_RGB16),
-      mPainter(nullptr)
+      mPainter(nullptr),
+      mDirectPainting(false)
 {
 }
 
@@ -84,6 +85,15 @@ bool QFbScreen::event(QEvent *event)
 void QFbScreen::addWindow(QFbWindow *window)
 {
     mWindowStack.prepend(window);
+
+#ifdef QT_FB_DIRECT_PAINTING
+    // HACK: Only allow direct painting for single window
+    if (windowCount() == 1)
+        QFbBackingStore::setScreenImage(&mScreenImage);
+    else
+        QFbBackingStore::setScreenImage(NULL);
+#endif
+
     if (!mPendingBackingStores.isEmpty()) {
         //check if we have a backing store for this window
         for (int i = 0; i < mPendingBackingStores.size(); ++i) {
@@ -106,6 +116,15 @@ void QFbScreen::addWindow(QFbWindow *window)
 void QFbScreen::removeWindow(QFbWindow *window)
 {
     mWindowStack.removeOne(window);
+
+#ifdef QT_FB_DIRECT_PAINTING
+    // HACK: Only allow direct painting for single window
+    if (windowCount() == 1)
+        QFbBackingStore::setScreenImage(&mScreenImage);
+    else
+        QFbBackingStore::setScreenImage(NULL);
+#endif
+
     setDirty(window->geometry());
     QWindow *w = topWindow();
     QWindowSystemInterface::handleWindowActivated(w);
@@ -208,16 +227,35 @@ QRegion QFbScreen::doRedraw()
         return touchedRegion;
 
     if (!mPainter)
-        mPainter = new QPainter(&mScreenImage);
+        mPainter = new QPainter();
 
     const QRect screenRect = mGeometry.translated(-screenOffset);
+    bool fully_repainted = mRepaintRegion.rectCount() == 1 &&
+        mRepaintRegion.boundingRect().contains(screenRect);
+
+    if (fully_repainted && QFbBackingStore::hasScreenImage()) {
+        // HACK: The screen(or fb) has been fully repainted
+        touchedRegion += mRepaintRegion;
+        mRepaintRegion = QRegion();
+        mDirectPainting = true;
+        return touchedRegion;
+    }
+
+    // HACK: Ignore partial update in direct paiting mode
+    if (mDirectPainting && !fully_repainted)
+        return touchedRegion;
+
+    mPainter->begin(&mScreenImage);
+
     for (QRect rect : mRepaintRegion) {
         rect = rect.intersected(screenRect);
         if (rect.isEmpty())
             continue;
 
         mPainter->setCompositionMode(QPainter::CompositionMode_Source);
-        mPainter->fillRect(rect, mScreenImage.hasAlphaChannel() ? Qt::transparent : Qt::black);
+
+        if (!QFbBackingStore::hasScreenImage())
+            mPainter->fillRect(rect, mScreenImage.hasAlphaChannel() ? Qt::transparent : Qt::black);
 
         for (int layerIndex = mWindowStack.size() - 1; layerIndex != -1; layerIndex--) {
             if (!mWindowStack[layerIndex]->window()->isVisible())
@@ -241,6 +279,11 @@ QRegion QFbScreen::doRedraw()
     touchedRegion += mRepaintRegion;
     mRepaintRegion = QRegion();
 
+    // HACK: Force updating fb when not doing direct painting
+    QFbBackingStore::setFbImage(NULL);
+
+    mPainter->end();
+
     return touchedRegion;
 }
 
diff --git a/src/platformsupport/fbconvenience/qfbscreen_p.h b/src/platformsupport/fbconvenience/qfbscreen_p.h
index eed615de..48ee4c23 100644
--- a/src/platformsupport/fbconvenience/qfbscreen_p.h
+++ b/src/platformsupport/fbconvenience/qfbscreen_p.h
@@ -124,6 +124,8 @@ protected:
     QSizeF mPhysicalSize;
     QImage mScreenImage;
 
+    bool mDirectPainting;
+
 private:
     QPainter *mPainter;
     QList<QFbBackingStore*> mPendingBackingStores;
diff --git a/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp
index 0c4f6d2c..5745ef06 100644
--- a/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp
+++ b/src/plugins/platforms/linuxfb/qlinuxfbdrmscreen.cpp
@@ -52,6 +52,7 @@
 #include <QtCore/QRegularExpression>
 #include <QtFbSupport/private/qfbcursor_p.h>
 #include <QtFbSupport/private/qfbwindow_p.h>
+#include <QtFbSupport/private/qfbbackingstore_p.h>
 #include <QtKmsSupport/private/qkmsdevice_p.h>
 #include <QtCore/private/qcore_unix_p.h>
 #include <sys/mman.h>
@@ -486,6 +487,10 @@ QRegion QLinuxFbDrmScreen::doRedraw()
         return dirty;
 
     QPainter pntr(&output->fb[output->backFb].wrapper);
+
+    if (QFbBackingStore::hasScreenImage() && QFbBackingStore::hasFbImage())
+        goto swap;
+
     // Image has alpha but no need for blending at this stage.
     // Do not waste time with the default SourceOver.
     pntr.setCompositionMode(QPainter::CompositionMode_Source);
@@ -506,10 +511,19 @@ QRegion QLinuxFbDrmScreen::doRedraw()
     }
     pntr.end();
 
+swap:
     output->dirty[output->backFb] = QRegion();
 
     m_device->swapBuffers(output);
 
+    static int count_down = BUFFER_COUNT;
+    if (count_down || m_rotation || m_device->outputCount() > 1) {
+        count_down --;
+        QFbBackingStore::setFbImage(NULL);
+    } else {
+        QFbBackingStore::setFbImage(&output->fb[output->backFb].wrapper);
+    }
+
     return dirty;
 }
 
-- 
2.20.1