Erk: Adventures in Stone Age Real Estate - Wall painting

[Max833]

Game
Erk: Adventures in Stone Age Real Estate

Download
https://archive.org/details/erk-adventures-in-stone-age-real-estate

Desktop
Windows 10 Pro, 22H2

AGS Version
AGS 3.02.1025 vs. AGS 3.6.3.1 (newest github build version)

Describe the bug

Don't worry ivan, that's the last game I'll test for now. Sorry. I tested... a lot. xD

This one is a little bit hard to describe. Basically, you scribble something on the wall. In the old version, you can see the result in real time, while in the new version you only see it after you leave the screen ("exit").

• Right click to open the inventory
• Use "Charcoal" with "Cave wall" (you will see the background in the screenshot below )
• Try to write. Like I said, in the old version you'll see it in real time and in the new version you'll just see it when you leave the screen and look at the wall.

Save game AGS 3.02.1025: agssave_old.zip
Save game AGS 3.6.3.1: agssave_NEW.zip

[ivan-mogilko]

It looks like they do not make a required call to DrawingSurface::Release in their game, until leaving this scene. This call is meant to commit the drawing changes. That's why the image is not updated to the sprite on screen.

But one thing that I cannot explain is why this works for Direct3D in the original game, as that normally requires to have a texture to be updated. There's a slight chance that they do have a DrawingSurface::Release in script but it's not getting called for some reason.
EDIT: oh, that might be because the sprite is on GUI. And older engines did not have any optimizations that we have now, so they kept updating and redrawing all GUIs whenever a mouse moved. Hmm or maybe not.
EDIT2: It keeps setting this dynamic sprite as a BackgroundGraphic to GUI. Probably this forces GUI updates, which results in edited drawing to get on screen as a effect.

There are various ways how this may be emulated in compatibility mode, I need to think which will be the optimal one.