Changeset 203145 in webkit

Timestamp:

Jul 12, 2016, 5:55:47 PM (9 years ago)

Author:

Simon Fraser

Message:

[iOS WK2] After zooming and when under memory pressure, page tiles sometimes don't redraw while panning
​https://bugs.webkit.org/show_bug.cgi?id=159697
rdar://problem/26314075

Reviewed by Benjamin Poulain.

When under memory pressure, and after pinching back to minimum scale, WebPage::updateVisibleContentRects()
would sometimes always bail under the "boundedScale != currentScale..." condition.

This happened because the visibleContentRectUpdateInfo.scale() is a double, but m_page->pageScaleFactor()
is a float, and the constraining between min and max scale (which are doubles) caused boundedScale
to be always different from currentScale.

Fix by using floats throughout.

No test because there's no way to simulate memory pressure for testing.

• WebProcess/WebPage/ios/WebPageIOS.mm:

(WebKit::WebPage::updateVisibleContentRects):

Location:

trunk/Source/WebKit2

Files:

• ChangeLog (modified) (1 diff)
• WebProcess/WebPage/ios/WebPageIOS.mm (modified) (4 diffs)

trunk/Source/WebKit2/ChangeLog

@@ +1 @@
+2016-07-12  Simon Fraser  <simon.fraser@apple.com>
+
+        [iOS WK2] After zooming and when under memory pressure, page tiles sometimes don't redraw while panning
+        https://bugs.webkit.org/show_bug.cgi?id=159697
+        rdar://problem/26314075
+
+        Reviewed by Benjamin Poulain.
+
+        When under memory pressure, and after pinching back to minimum scale, WebPage::updateVisibleContentRects()
+        would sometimes always bail under the "boundedScale != currentScale..." condition.
+
+        This happened because the visibleContentRectUpdateInfo.scale() is a double, but m_page->pageScaleFactor()
+        is a float, and the constraining between min and max scale (which are doubles) caused boundedScale
+        to be always different from currentScale.
+
+        Fix by using floats throughout.
+
+        No test because there's no way to simulate memory pressure for testing.
+
+        * WebProcess/WebPage/ios/WebPageIOS.mm:
+        (WebKit::WebPage::updateVisibleContentRects):
+
 2016-07-12  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebKit2/WebProcess/WebPage/ios/WebPageIOS.mm

@@ -3021 +3021 @@
 
     double scaleNoiseThreshold = 0.005;
-    double filteredScale = visibleContentRectUpdateInfo.scale();
-    double currentScale = m_page->pageScaleFactor();
-    if (!m_isInStableState && fabs(filteredScale - m_page->pageScaleFactor()) < scaleNoiseThreshold) {
+    float filteredScale = visibleContentRectUpdateInfo.scale();
+    float currentScale = m_page->pageScaleFactor();
+
+    if (!m_isInStableState && fabs(filteredScale - currentScale) < scaleNoiseThreshold) {
         // Tiny changes of scale during interactive zoom cause content to jump by one pixel, creating
         // visual noise. We filter those useless updates.
@@ -3029 +3030 @@
     }
 
-    double boundedScale = std::min(m_viewportConfiguration.maximumScale(), std::max(m_viewportConfiguration.minimumScale(), filteredScale));
+    float boundedScale = std::min<float>(m_viewportConfiguration.maximumScale(), std::max<float>(m_viewportConfiguration.minimumScale(), filteredScale));
 
     // Skip progressively redrawing tiles if pinch-zooming while the system is under memory pressure.
@@ -3048 +3049 @@
     IntPoint scrollPosition = roundedIntPoint(visibleContentRectUpdateInfo.unobscuredContentRect().location());
 
-    float floatBoundedScale = boundedScale;
     bool hasSetPageScale = false;
-    if (floatBoundedScale != currentScale) {
+    if (boundedScale != currentScale) {
         m_scaleWasSetByUIProcess = true;
         m_hasStablePageScaleFactor = m_isInStableState;
@@ -3056 +3056 @@
         m_dynamicSizeUpdateHistory.clear();
 
-        m_page->setPageScaleFactor(floatBoundedScale, scrollPosition, m_isInStableState);
+        m_page->setPageScaleFactor(boundedScale, scrollPosition, m_isInStableState);
         hasSetPageScale = true;
-        send(Messages::WebPageProxy::PageScaleFactorDidChange(floatBoundedScale));
+        send(Messages::WebPageProxy::PageScaleFactorDidChange(boundedScale));
     }
 
     if (!hasSetPageScale && m_isInStableState) {
-        m_page->setPageScaleFactor(floatBoundedScale, scrollPosition, true);
+        m_page->setPageScaleFactor(boundedScale, scrollPosition, true);
         hasSetPageScale = true;
     }