Iris reports incorrect emissive entity data for shaders depending on items in hotbar

[setzke]

What happened?

Shader + an enchanting table resource pack (includes optifine-styled emissive textures) + continuity (does not touch entities) with emissive textures on causes some entities to have emissive textures when they shouldn't. The pixels change depending on hotbar items.

Minecraft 1.21.1

Fabric 0.16.10
Continuity 3.0.0+1.21 or 3.0.0-beta.5+1.21
Complementary Shaders - Reimagined r5.2.2
- RP Support: Integrated PBR+
- Performance Settings > Shadow Sample Quality: Off or Very Low
Fabric API 0.115.0+1.21.1
Iris Shaders 1.8.1+1.21.1-fabric
Sodium mc1.21.1-0.6.5-fabric

Better Enchanting Table 1.2 by Jacosvaldo

Texture pack: https://modrinth.com/resourcepack/enchanting-table-magic-circle

The last piece to this enigma is that the mob emissions are dependent on what item is right-most in your hotbar. Angle of view, such as having entity on edge of your screen, can also influence the effect.

Bug is removed by turning off emissive textures in continuity settings, changing one of the two shader settings mentioned, turning off the shader, unequipping the resource pack, having most items right-most in hotbar, or pressing F1 to disable GUI.

Screenshots

Screenshots below show an affected mob. The item does not need to be held for this effect to activate, it just needs to be right-most in hotbar. Held to show what item was causing what effect (it's curious!). Additionally, effect is removed if F1 is pressed to hide GUI.

Log output

No response

Minecraft Version

1.21.1

Iris Version

1.8.1

Operating System

Windows 11

What is your GPU?

Nvidia GeForce RTX 4090 Laptop GPU

Additional context

Authors of the shader pack and mod both said to report here to Iris.