Skater flickers (disappears and reappears 20-30ms later) on moveToFront()

[samreid]

The WebGL skater flickers (disappears and reappears some 15-20ms later) on moveToFront(). In ESPB, you can see this if you connect two tracks. If you comment out this code in EnergySkateParkBasicsScreenView.js, the flicker disappears

        if ( skaterNode ) {
          skaterNode.moveToFront();
          pieChartNode.moveToFront();
        }

Not sure what is causing this, @jonathanolson can you take a look?

[jonathanolson]

Not able to reproduce in Chrome 37 (OS X), after confirming that it was using WebGL.

moveToFront() will remove and re-add the skaterNode from its parent, which WILL trigger it being removed and added to a (possibly different) WebGLLayer.

[jonathanolson]

Also, can you see if this happens when the pie chart is open? There are two push buttons and the TrackNodes in-between the SkaterNode and BarGraphForeground:

-Layer 13 svg trails: [Trail 0.0.0 8-624-625-626],[Trail 0.15.0.1 8-624-840-837-836]
GaugeNeedleNode 852 [Trail 0.16 8-624-852] invisible renderer:webgl translated
Node 851 [Trail 0.16.0 8-624-852-851] affine
+Layer 14 webgl trails: [Trail 0.16.0.0 8-624-852-851-850],[Trail 0.17.3 8-624-857-856]
Image 850 [Trail 0.16.0.0 8-624-852-851-850] translated
BarGraphForeground 857 [Trail 0.17 8-624-857] invisible renderer:webgl translated
Rectangle 853 [Trail 0.17.0 8-624-857-853] unpickable renderer:webgl
Rectangle 854 [Trail 0.17.1 8-624-857-854] unpickable renderer:webgl
Rectangle 855 [Trail 0.17.2 8-624-857-855] unpickable renderer:webgl
Rectangle 856 [Trail 0.17.3 8-624-857-856] unpickable renderer:webgl
-Layer 14 webgl trails: [Trail 0.16.0.0 8-624-852-851-850],[Trail 0.17.3 8-624-857-856]
RectangularPushButton 864 [Trail 0.18 8-624-864] invisible mouseArea touchArea inputListeners
+Layer 15 svg trails: [Trail 0.18.0 8-624-864-865],[Trail 0.21.4 8-624-993-996]
Rectangle 865 [Trail 0.18.0 8-624-864-865]
Rectangle 866 [Trail 0.18.0.0 8-624-864-865-866]
Image 863 [Trail 0.18.1 8-624-864-863] affine
RectangularPushButton 868 [Trail 0.19 8-624-868] invisible mouseArea touchArea inputListeners translated
Rectangle 869 [Trail 0.19.0 8-624-868-869]
Rectangle 870 [Trail 0.19.0.0 8-624-868-869-870]
Image 867 [Trail 0.19.1 8-624-868-867] affine
TrackNode 987 [Trail 0.20 8-624-987] hits
Path 985 [Trail 0.20.0 8-624-987-985] hits inputListeners
Path 986 [Trail 0.20.1 8-624-987-986] hits
ControlPointNode 988 [Trail 0.20.2 8-624-987-988] pickable hits inputListeners opacity:0.7 translated
ControlPointNode 989 [Trail 0.20.3 8-624-987-989] pickable hits inputListeners opacity:0.7 translated
ControlPointNode 990 [Trail 0.20.4 8-624-987-990] pickable hits inputListeners opacity:0.7 translated
TrackNode 993 [Trail 0.21 8-624-993] hits
Path 991 [Trail 0.21.0 8-624-993-991] hits inputListeners
Path 992 [Trail 0.21.1 8-624-993-992] hits
ControlPointNode 994 [Trail 0.21.2 8-624-993-994] pickable hits inputListeners opacity:0.7 translated
ControlPointNode 995 [Trail 0.21.3 8-624-993-995] pickable hits inputListeners opacity:0.7 translated
ControlPointNode 996 [Trail 0.21.4 8-624-993-996] pickable hits inputListeners opacity:0.7 translated
-Layer 15 svg trails: [Trail 0.18.0 8-624-864-865],[Trail 0.21.4 8-624-993-996]
SkaterNode 843 [Trail 0.22 8-624-843] hits inputListeners renderer:webgl affine
+Layer 38 webgl trails: [Trail 0.22.0 8-624-843-841],[Trail 0.23.3 8-624-858-862]
Image 841 [Trail 0.22.0 8-624-843-841] hits
Image 842 [Trail 0.22.1 8-624-843-842] invisible
Node 847 [Trail 0.22.2 8-624-843-847] hits
Image 846 [Trail 0.22.2.0 8-624-843-847-846] hits translated
PieChartWebGLNode 858 [Trail 0.23 8-624-858] invisible translated
PieChartWebGLSliceNode 859 [Trail 0.23.0 8-624-858-859]
PieChartWebGLSliceNode 860 [Trail 0.23.1 8-624-858-860]
PieChartWebGLSliceNode 861 [Trail 0.23.2 8-624-858-861]
PieChartWebGLSliceNode 862 [Trail 0.23.3 8-624-858-862]
-Layer 38 webgl trails: [Trail 0.22.0 8-624-843-841],[Trail 0.23.3 8-624-858-862]
NavigationBar 9 [Trail 1 8-9] hits renderer:svg translated
+Layer 12 svg trails: [Trail 1.0 8-9-10],[Trail 1.4.3 8-9-86-85]

[samreid]

This doesn't seem essential to fix for 1.0 (and would automatically get fixed if the entire scene gets rendered in WebGL), so I'll mark it for 1.1+

[samreid]

I saw a flickering skater on iPad3/iOS8.0.2. The flickering went away when I dragged the skater. Discovered in #279.

[samreid]

I got rid of all the moveToFront above, and haven't seen any flickering since. Closing for now.