GSoC Week 5

GSoC 2017: Sludge Engine Week 5

Week task conclusion

Generally, this 5th week of GSoC project was going smoothly: The z-Buffer zone (multi-layer effect) has been reproduced and fall back detection has been added

Again, thanks to my mentors _sev(Eugene Sandulenko), t0by(Tobia Tesan) and all scummvm team members that has helped me on z-Buffer during this week.

To make a brief conclusion about what we have and have not achieved for this week :

Tasks completed:

  1. z-BufferZone : load z-Buffer sprites + reproduce multi-layer effects
  2. fall back detection for sludge games


To resolve later:

  1. There is a segmentation fault when Robin’s Rescue starts. It may result from the game logo reading in the initilization, which is not implemented yet

What’s for next week: Bug fixes in Robin’s Rescue

Tasks for next week :

  1. Fix the segmentation error in Robin’s Rescue
  2. Clear all bugs in Robin’s Rescue

Also, the first GSoc evaluation will take place next week.

Some findings about sludge

z-Buffer Zone

In sludge, z-Buffer zones are different areas of a scene which can obscure character graphics, such as foreground silhouettes, doorframes and furniture. Their display has been ordered by a y-value to create different image layers (up to 16).

The above room image has the following z-buffer image (3 layers) :


And characters will change the image layer it lies in, when its own y-value changes. To reproduce this effect in scummvm, we used an array of 16 Lists for different layers.