Use eye coordinates when checking if the camera is within a loaded chunk

Fixes #2159

src/main/java/me/jellysquid/mods/sodium/mixin/core/gui/DownloadingTerrainScreenMixin.java

@@ -0,0 +1,20 @@
+package me.jellysquid.mods.sodium.mixin.core.gui;
+
+import net.minecraft.client.gui.screen.DownloadingTerrainScreen;
+import net.minecraft.client.network.ClientPlayerEntity;
+import net.minecraft.util.math.BlockPos;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(DownloadingTerrainScreen.class)
+public class DownloadingTerrainScreenMixin {
+    @Redirect(method = "tick", at = @At(value = "INVOKE", target = "Lnet/minecraft/client/network/ClientPlayerEntity;getBlockPos()Lnet/minecraft/util/math/BlockPos;"))
+    private BlockPos redirect$getPlayerBlockPosition(ClientPlayerEntity instance) {
+        // Ensure the "eye" position (which the chunk rendering code is actually concerned about) is used instead of
+        // the "feet" position. This solves a problem where the loading screen can become stuck waiting for the chunk
+        // at the player's feet to load, when it is determined to not be visible due to the true location of the
+        // player's eyes.
+        return BlockPos.ofFloored(instance.getX(), instance.getEyeY(), instance.getY());
+    }
+}

src/main/resources/sodium.mixins.json

@@ -27,6 +27,7 @@
     "core.checks.VertexBufferMixin",
     "core.checks.VertexFormatMixin",
     "core.checks.WindowFramebufferMixin",
+    "core.gui.DownloadingTerrainScreenMixin",
     "core.model.colors.BlockColorsMixin",
     "core.model.colors.ItemColorsMixin",
     "core.model.quad.BakedQuadMixin",