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Bug 4509

Summary: Single finger events "jump around" to other fingers during multitouch instead of sticking with first finger
Product: SDL Reporter: Ellie <etc0de>
Component: eventsAssignee: Sam Lantinga <slouken>
Status: RESOLVED FIXED QA Contact: Sam Lantinga <slouken>
Severity: normal    
Priority: P2    
Version: 2.0.9   
Hardware: x86_64   
OS: Android (All)   

Description Ellie 2019-02-16 13:51:12 UTC 
Single finger events "jump around" to other fingers during multitouch: as soon as a second finger is pressed, the single finger mouse emulation (SDL_TOUCH_MOUSEID) will JUMP to that new finger, and if it's released, jump back.

Can this possibly be removed? This behavior leads for me to insane jerkiness and jumps related to scrolling and just about anything else and I see no benefit, so this seems, if not a bug, then like a poor choice to me.

Expected behavior would be that the "virtual single finger mouse" reported via SDL_TOUCH_MOUSEID always sticks with the finger that was pressed down first unless that one is released, instead of needlessly jumping to other fingers once 2+ fingers are used
Comment 1 Sam Lantinga 2019-03-17 02:21:26 UTC 
Yes, that makes sense. Can you provide a tested patch?

Thanks!
Comment 2 Ellie 2019-04-04 15:20:41 UTC 
This was fixed by Sylvian's awesome revamp of SDL_TOUCH_MOUSEID code for https://bugzilla.libsdl.org/show_bug.cgi?id=4572 !