The Problem with EasyRPG Player

Oct 13, 2025 by wbrum.org 69 views

Introduction

Genkido is a classic platformer game that has been around since 2006. However, despite its age, the game still has its share of issues, particularly when it comes to collision detection. In this article, we will delve into the issue of wrong collision for events with tile graphics in Genkido, and explore how to reproduce it.

The Issue

The issue arises when the player tries to access the platforms on the right side of the game by avoiding enemies and touching both barrels to create a passable way on the left platform. In RPG_RT, this new passageway can be used to walk to the exit, but in EasyRPG, it remains inaccessible. The player cannot walk over the barrel, despite the fact that the barrel event itself is based on a non-passable tile (EV0022).

Reproducing the Issue

To reproduce the issue, follow these steps:

Access the platforms on the right side by avoiding the enemies and touch both barrels to create a passable way on the left platform.
Drop the lower one of the barrels, then go up the ladder and sacrifice some HP by touching the pig enemy.
Then, you have access to the other barrel and can make your way back.

Notes

In this specific example, the barrel event itself is based on a non-passable tile (EV0022), but on the spot where it lands, another event (EV0023) is activated which would take precedence for collision detection. Tested across a few different RPG_RT versions, including 2k3 & the newest MP build, all seem to interpret this the same way.

Also, moving EV0023 to a lower ID makes the tile impossible to pass on any version. Event ID takes precedence here.

The Problem with EasyRPG Player

For some reason, EasyRPG Player has another special condition in its collision detection. When checking for passability by examining all events with "below" status on the target spot X/Y, it only considers events when the tile_id is greater than zero. This filters out EV0023 & makes walking over the this spot impossible.

Patch

Patching this should be quite simple. But one has to wonder, why this specific check is there & if this was introduced to fix some other rare issue?

 src/game_map.cpp | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/game_map.cpp b/src/game_map.cpp
index 5180fdd43..e47162820 100644
--- a/src/game_map.cpp
+++ b/src/game_map.cpp
@@ -1018,7 +1018,7 @@ bool Game_Map::IsPassableTile(
 			}
 		}
 
-		// Highest ID event with layer=below, not through, and a tile graphic wins.
+		// Highest ID event with layer=below and not 'through' wins.
 		int event_tile_id = 0;
 		for (auto& ev: events) {
 			if (self == &ev) {
@@ -1028,10 +1028,7 @@ bool Game_Map::IsPassableTile(
 				continue;
 			}
 			if (ev.IsInPosition(x, y) && ev.GetLayer() == lcf::rpg::EventPage::Layers_below) {
-				int tile_id = ev.GetTileId();
-				if (tile_id > 0) {
-					event_tile_id = tile_id;
-				}
+				event_tile_id = ev.GetTileId();
 			}
 		}

Conclusion

In conclusion, the issue of wrong collision for events with tile graphics in Genkido is a complex one, and requires a deep understanding of the game's mechanics and collision detection system. By reproducing the issue and analyzing the code, we can see that the problem lies in the way EasyRPG Player checks for passability. By patching the code, we can fix the issue and make the game more accessible to players.

Future Work

In the future, it would be beneficial to investigate why this specific check was introduced in EasyRPG Player, and whether it was intended to fix some other rare issue. Additionally, further testing and debugging may be necessary to ensure that the patch does not introduce any new issues.

References

Game & Savefile
RPG_RT
EasyRPG Player
Genkido: Wrong Collision for Event with Tile Graphic - Q&A =====================================================

Introduction

In our previous article, we explored the issue of wrong collision for events with tile graphics in Genkido. In this article, we will answer some of the most frequently asked questions about this issue.

Q: What is the issue with Genkido's collision detection?

A: The issue arises when the player tries to access the platforms on the right side of the game by avoiding enemies and touching both barrels to create a passable way on the left platform. In RPG_RT, this new passageway can be used to walk to the exit, but in EasyRPG, it remains inaccessible. The player cannot walk over the barrel, despite the fact that the barrel event itself is based on a non-passable tile (EV0022).

Q: Why does this issue only occur in EasyRPG?

A: The issue is caused by a special condition in EasyRPG Player's collision detection. When checking for passability by examining all events with "below" status on the target spot X/Y, it only considers events when the tile_id is greater than zero. This filters out EV0023 & makes walking over the this spot impossible.

Q: Can I fix this issue myself?

A: Yes, you can fix this issue by patching the code. The patch is relatively simple and only requires changing a few lines of code in the game_map.cpp file.

Q: Why was this check introduced in EasyRPG Player?

A: Unfortunately, the reason for introducing this check is not clear. It is possible that it was intended to fix some other rare issue, but it has had the unintended consequence of causing this problem.

Q: Will this issue be fixed in future versions of EasyRPG?

A: We hope so! The EasyRPG team is always working to improve the game and fix issues like this. However, we cannot guarantee that this issue will be fixed in future versions.

Q: Can I use a different version of RPG_RT to play Genkido?

A: Yes, you can use a different version of RPG_RT to play Genkido. In fact, the issue only occurs in EasyRPG, so you may be able to play the game without any problems using RPG_RT.

Q: Are there any other games that have this issue?

A: We are not aware of any other games that have this specific issue. However, it is possible that other games may have similar issues with collision detection.

Q: Can I report this issue to the EasyRPG team?

A: Yes, you can report this issue to the EasyRPG team. They are always happy to hear from players and fix issues like this.

Conclusion

In conclusion, the issue of wrong collision for events with tile graphics in Genkido is a complex one, and requires a deep understanding of the game's mechanics and collision detection system. By answering some of the most frequently asked questions about this issue, we hope to have provided some clarity and help players who are experiencing this problem.