Rm2k3 battle scene: Bugged boss attack animations in "Wolfenhain"

[florianessl]

Game: Wolfenhain (v4) (https://realtroll.hpage.com/)
Save: Save15.zip

The boss enemy "Zyklop" has distinct battle animations that need to align correctly with its sprite.
To be more specific, the eye of the cyclop is its own enemy entity & the affected boss attacks are "Augenaufschlag" & "Augenschein".

Heres how the battle animations are shown in RPG_RT:

EasyRPG not only misaligns them, but it seems the animations get completely messed up:

[Ghabry]

I'm really surprised that nobody ever reported these bugs in all these realtroll games before :/

[florianessl]

Seems like this is a regression that was introduced via PR #3049
(Turns out this battle animation is actually flipped & it would play out fine if the source material was the other way around)

Reverting this one line fixes the animation:

diff --git a/src/battle_animation.cpp b/src/battle_animation.cpp
index 12a97c8ab..9acd30943 100644
--- a/src/battle_animation.cpp
+++ b/src/battle_animation.cpp
@@ -107,10 +107,9 @@ void BattleAnimation::DrawAt(Bitmap& dst, int x, int y) {
 			continue;
 		}
 
-		SetX(cell.x + x);
+		SetX(invert ? x - cell.x : cell.x + x);
 		SetY(cell.y + y);
 		int sx = cell.cell_id % 5;

[Ghabry]

I think the bug could be that there are two ways to play a battle animation: through the event command and as a CBA animation.

Likely one of these cases is broken.

[Ghabry]

Your patch is correct. Good job. I'll create a PR. This one is worth including for 0.8.1.1.

The "inverting" of a battle animation (obviously) also inverts the coordinate system. This was just not noticed in the test game because the animation is at a fixed location.

Wolfenhain has the cells at different locations so this calculation error becomes visible.

---

Also tested this in CBA animations and they have the same behaviour their.