Weird behavior with Flame Shaders compared to pure flutter shader

[stilnat]

What happened?

Trying to use a shader that works in pure Flutter, it doesn't in Flame. My picture gets scaled down and asymmetrically deformed. This might be simply something I don't understand with how to pass data to the shader in Flame, or a bug, I'm unsure.

What do you expect?

I'm trying to reproduce the same behavior in pure flutter and in Flame, On the right
the expected result and on the left the one I'm getting with Flame.

How can we reproduce this?

I made a public repo to work on the issue you can take a look at
https://github.com/stilnat/shader-flame-test

What steps should take to fix this?

I don't know at all

[stilnat]

updated the issue to add a public repository with an example showing the issue

[stilnat]

I have some update on this, in the shader, setting
vec3 col = texture(uTexture, uv * 0.5 + vec2(0, 0.5)).rgb;
Instead of vec3 col = texture(uTexture, uv).rgb
Will give the proper result, I can't explain why though.

[luanpotter]

@renancaraujo maybe you would know?

[stilnat]

this repo might be relevant too, here I just tried with an "identity shader" (that should return exactly what it gets in) to see what would happen and the text gets scaled down for some reason

https://github.com/stilnat/flame_identity_shader