(this is a breakdown of all possible layer priorities)
No. Layer Name Priority/Notes
$00 - Canvas Color BK
$01 - SpecialFX G (back) --
$02 - Sprites G P0
$03 - Sprites G P1
$04 - Sprites G P2
$05 - Sprites G P3
$06 - SpecialFX G (front) --
$07 - Backgrounds P0
$08 - SpecialFX F (back) --
$09 - Sprites F P0
$0A - Sprites F P1
$0B - Sprites F P2
$0C - Sprites F P3
$0D - SpecialFX F (front) --
$0E - Backgrounds P1
$0F - SpecialFX E (back) --
$10 - Sprites E P0
$11 - Sprites E P1
$12 - Sprites E P2
$13 - Sprites E P3
$14 - SpecialFX E (front) --
$15 - Main Grounds P0 - DEFAULT MAIN LAYER
$16 - SpecialFX D (back) --
$17 - Sprites D P0
$18 - Sprites D P1
$19 - Sprites D P2
$1A - Sprites D P3
$1B - SpecialFX D (front) --
$1C - Main Grounds P1
$1D - SpecialFX C (back) --
$1E - Sprites C P0
$1F - Sprites C P1
$20 - Sprites C P2
$21 - Sprites C P3
$22 - SpecialFX C (front) --
$23 - Foregrounds P0
$24 - SpecialFX B (back) --
$25 - Sprites B P0
$26 - Sprites B P1
$27 - Sprites B P2
$28 - Sprites B P3
$29 - SpecialFX B (front) --
$2A - Foregrounds P1
$2B - SpecialFX A (back) --
$2C - Sprites A P0
$2D - Sprites A P1
$2E - Sprites A P2
$2F - Sprites A P3
$30 - SpecialFX A (front) --
$31 - Stats Layer SL
$32 - SpecialFX S (back) --
$33 - Sprites S P0
$34 - Sprites S P1
$35 - Sprites S P2
$36 - Sprites S P3
$37 - SpecialFX S (front) FT
____Only visible while paused:____
$38 - Pause Screen Layer PL
$39 - SpecialFX P (back) --
$3A - Sprites P P0
$3B - Sprites P P1
$3C - Sprites P P2
$3D - Sprites P P3
$3E - SpecialFX P (front) --
----------------------------------
$3F - DELTA Error Messages FM
$00 - Canvas Color BK
$01 - SpecialFX G (back) --
$02 - Sprites G P0
$03 - Sprites G P1
$04 - Sprites G P2
$05 - Sprites G P3
$06 - SpecialFX G (front) --
$07 - Backgrounds P0
$08 - SpecialFX F (back) --
$09 - Sprites F P0
$0A - Sprites F P1
$0B - Sprites F P2
$0C - Sprites F P3
$0D - SpecialFX F (front) --
$0E - Backgrounds P1
$0F - SpecialFX E (back) --
$10 - Sprites E P0
$11 - Sprites E P1
$12 - Sprites E P2
$13 - Sprites E P3
$14 - SpecialFX E (front) --
$15 - Main Grounds P0 - DEFAULT MAIN LAYER
$16 - SpecialFX D (back) --
$17 - Sprites D P0
$18 - Sprites D P1
$19 - Sprites D P2
$1A - Sprites D P3
$1B - SpecialFX D (front) --
$1C - Main Grounds P1
$1D - SpecialFX C (back) --
$1E - Sprites C P0
$1F - Sprites C P1
$20 - Sprites C P2
$21 - Sprites C P3
$22 - SpecialFX C (front) --
$23 - Foregrounds P0
$24 - SpecialFX B (back) --
$25 - Sprites B P0
$26 - Sprites B P1
$27 - Sprites B P2
$28 - Sprites B P3
$29 - SpecialFX B (front) --
$2A - Foregrounds P1
$2B - SpecialFX A (back) --
$2C - Sprites A P0
$2D - Sprites A P1
$2E - Sprites A P2
$2F - Sprites A P3
$30 - SpecialFX A (front) --
$31 - Stats Layer SL
$32 - SpecialFX S (back) --
$33 - Sprites S P0
$34 - Sprites S P1
$35 - Sprites S P2
$36 - Sprites S P3
$37 - SpecialFX S (front) FT
____Only visible while paused:____
$38 - Pause Screen Layer PL
$39 - SpecialFX P (back) --
$3A - Sprites P P0
$3B - Sprites P P1
$3C - Sprites P P2
$3D - Sprites P P3
$3E - SpecialFX P (front) --
----------------------------------
$3F - DELTA Error Messages FM
[Sprites] must be above the Canvas Color. Each sprite has a priority number of 0-3 within its placement zone.
[Special Effects] have a placement zone for in front of and behind each sprites zone.
---------------------------------------------------------
This is a breakdown of all the possible places that things could go in the layering stack.
Any comments on it or suggestions for improvement would be nice, thanks.
If I find a reason to change something I will update this main post.
About The Pause Screen Layer:
The pause screen acts as an overlay, and all game play will stop while the game is paused. This behavior cannot be changed. However, it will be possible to run animated tiles or special effects (such as water) in the background while the game is still paused, though doing this is not recommended. The default behavior is to stop the game completely and use the last rendered frame as a background for the pause screen. You can have either (1) the snapshot background, (2) a custom image, (3) a solid color, or (4) continue running graphics behind the pause screen to act as the background. The pause screen acts much like the stats layer and uses specially-designed objects to display options and whatever else (perhaps collected item counts).
About DELTA Error Messages:
Any errors that DELTA wants to spit out at you will appear on top of everything else so that the various layers, sprites, and effects cannot mask them. Errors that do not involve the Pause Screen will not appear there while the game is paused. Likewise errors with the Pause Screen cannot interrupt game play, and are only shown on the Pause Screen.
Error messages will likely have some form of color-coding to let you know what kind of error happened, and will usually only show up if a file DELTA needs is missing or if a DLL fails for some reason.
As for program crashes, you'll definitely know when that kind of thing happens.