[Scummvm-tracker] [ScummVM :: Bugs] #13767: GRAPHICS: OpenGL screenshots not capturing latest frame if no input (was: SCI: QFG1VGA - Screenshots exclude message boxes in OpenGL mode)

[ScummVM :: Bugs]

#13767: GRAPHICS: OpenGL screenshots not capturing latest frame if no input
-------------------+--------------------------------
Reporter:  lwcorp  |       Owner:  (none)
    Type:  defect  |      Status:  new
Priority:  normal  |   Component:  Graphics
 Version:          |  Resolution:
Keywords:          |        Game:  Quest for Glory 1
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Changes (by sluicebox):

 * component:  Engine: SCI => Graphics
 * summary:  SCI: QFG1VGA - Screenshots exclude message boxes in OpenGL mode
     => GRAPHICS: OpenGL screenshots not capturing latest frame if no input

Comment:

 This occurs in multiple engines so it appears to be an OpenGL backend
 issue. If the screenshot hotkey is pressed after a modal message box
 appears but before the mouse is moved or another key is pressed, then
 `glad_glReadPixels()` returns the image before the message box was
 displayed.

 To reproduce in an SCI game or AGI game:

 - Set graphics mode to OpenGL
 - During game, click or press a key that brings up a simple modal message
 box (as opposed to one with an animated portrait)
 - Don't move the mouse or press another key
 - Press ALT+S to take a screenshot

 I've reproduced this in Black Cauldron (AGI), KQ4, KQ6, LB1. Occurs on at
 least Windows and Mac.

 In KQ4, typing "look", pressing enter, and then taking a screenshot gets
 the input box with the word "look" instead of the message box with the
 response that replaced it, so a stale frame.

 I don't know OpenGL and this isn't SCI specific so I'm renaming and
 changing component so that the right people see it.
-- 
Ticket URL: <https://bugs.scummvm.org/ticket/13767#comment:5>
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