TrackingItemStackRenderState in `GuiGraphics#renderItem` can be reused for less GC

[MukjepScarlet]

Request Description

version: mc1.21.11-0.8.2-fabric

On invocation of GuiGraphics.renderItem this method is called, and creates new int[]. In my game profiler this init allocated 40.38GB and the whole game took 239.57GB. There should be a way to reuse these arrays.

[douira]

This is not a feature request. Please complete the bug report by sending us a log file and confirming that this

• Happens even when every mod other than sodium is removed
• Does not happen without sodium (assuming this isn't a bug report in which you want us to fix a vanilla issue)

[MukjepScarlet]

I will run another profiler with fewer mods added, and try to figure out how much this affects.

[MukjepScarlet]

	private void renderItem(@Nullable LivingEntity entity, @Nullable Level level, ItemStack stack, int x, int y, int seed) {
		if (!stack.isEmpty()) {
			TrackingItemStackRenderState trackingItemStackRenderState = new TrackingItemStackRenderState();
			this.minecraft.getItemModelResolver().updateForTopItem(trackingItemStackRenderState, stack, ItemDisplayContext.GUI, level, entity, seed);

			try {
				this.guiRenderState
					.submitItem(
						new GuiItemRenderState(stack.getItem().getName().toString(), new Matrix3x2f(this.pose), trackingItemStackRenderState, x, y, this.scissorStack.peek())
					);
			} catch (Throwable var11) {// Crash reports
			}
		}
	}

I thinks it's better to cache (pool) trackingItemStackRenderState which causes this, so this issue becomes a vanilla enhancement request.

[douira]

So you have confirmed that this memory allocation volume occurs regardless of Sodium's presence and is not caused by any other mod in particular?

[MukjepScarlet]

Basically this allocation is caused by this new TrackingItemStackRenderState() invocation, as a mutable state, if we make this pooled, the underlying "issue" will also be gone.

The trace is:

• (mc) GuiGraphics.renderItem
• (mc) TrackingItemStackRenderState. (local)
• (mc) ItemStackRenderState. (parent class)
• (mc) ItemStackRenderState.LayerRenderState[] (member)
• (sodium-frapi) MutableMeshImpl. (mixin member)

[MukjepScarlet]

I'm sorry but I don't know how to define it as vanilla issue or Sodium issue.