What causes tilemap texture page bleeding in GameMaker?

Texture interpolation is on and the camera sits at non-integer positions, so the GPU samples past a tile's region on the texture page into the neighboring tile.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Tile Seam Lines From Texture Page Bleeding in GameMaker

Quick answer: Disable texture interpolation for pixel art (gpu_set_tex_filter false), keep the camera at integer coordinates, and use a clean integer view scale to avoid sub-texel sampling.

Your GameMaker tilemap shows flickering lines between tiles as the camera moves. Linear texture filtering is bleeding adjacent tiles from the same texture page.

How to fix it

1. Disable texture interpolation

Turn off linear filtering with gpu_set_tex_filter(false) (or uncheck Interpolate colours in Game Options) so the GPU reads exact texels without blending across tiles.

2. Keep the camera on integer pixels

Round the camera position with floor() each step so tiles align to whole screen pixels and the sampler never straddles a tile edge.

3. Use an integer view scale

Set the view/window so the scale factor is a whole number; fractional scaling forces interpolation that drags in neighboring texels from the page.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every GameMaker error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.