Fix canvas rendering bugs

src/main/java/dev/hephaestus/glowcase/client/render/block/entity/BakedBlockEntityRenderer.java

@@ -5,6 +5,7 @@
 import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import it.unimi.dsi.fastutil.objects.ObjectArraySet;
 import net.fabricmc.fabric.api.client.rendering.v1.InvalidateRenderStateCallback;
+import net.fabricmc.loader.api.FabricLoader;
 import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.gl.VertexBuffer;
@@ -16,13 +17,17 @@
 import net.minecraft.client.world.ClientWorld;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Matrix4f;
+import net.minecraft.util.math.Quaternion;
 import net.minecraft.util.math.Vec3d;
+import net.minecraft.util.math.Vec3f;
 import net.minecraft.world.World;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 
 public abstract class BakedBlockEntityRenderer<T extends BlockEntity> implements BlockEntityRenderer<T> {
+	private static final boolean USE_CANVAS_HACK = FabricLoader.getInstance().isModLoaded("canvas");
+
 	protected final BlockEntityRendererFactory.Context context;
 
 	protected BakedBlockEntityRenderer(BlockEntityRendererFactory.Context context) {
@@ -229,6 +234,14 @@ public void render(MatrixStack matrices, Matrix4f projectionMatrix, Camera camer
 			double camZ = vec3d.getZ();
 			RenderRegionPos centerRegion = new RenderRegionPos((int)camX >> REGION_SHIFT, (int)camZ >> REGION_SHIFT);
 
+			if (USE_CANVAS_HACK) {
+				float pitch = camera.getPitch();
+				float yaw = camera.getYaw();
+				matrices.push();
+				matrices.multiply(new Quaternion(Vec3f.POSITIVE_X, pitch, true));
+				matrices.multiply(new Quaternion(Vec3f.POSITIVE_Y, yaw + 180, true));
+			}
+
 			// Iterate over all RegionBuilders, render and upload to RegionBuffers
 			Set<RenderLayer> usedRenderLayers = new ObjectArraySet<>();
 			List<BlockEntity> blockEntities = new ArrayList<>();
@@ -293,6 +306,10 @@ public void render(MatrixStack matrices, Matrix4f projectionMatrix, Camera camer
 				}
 				layer.endDrawing();
 			}
+
+			if (USE_CANVAS_HACK) {
+				matrices.pop();
+			}
 		}
 
 		public void activateRegion(BlockPos pos) {

src/main/java/dev/hephaestus/glowcase/client/render/block/entity/HyperlinkBlockEntityRenderer.java

@@ -32,9 +32,10 @@ public void render(HyperlinkBlockEntity entity, float f, MatrixStack matrices, V
 		HitResult hitResult = MinecraftClient.getInstance().crosshairTarget;
 		if (hitResult instanceof BlockHitResult && ((BlockHitResult) hitResult).getBlockPos().equals(entity.getPos())) {
 			float scale = 0.025F;
-			matrices.scale(scale, scale, scale);
+			matrices.scale(scale, scale, -scale);
 			matrices.translate(-MinecraftClient.getInstance().textRenderer.getWidth(entity.url) / 2F, -4, 0);
-			MinecraftClient.getInstance().textRenderer.drawWithShadow(matrices, entity.url, 0, 0, 0xFFFFFF);
+
+			MinecraftClient.getInstance().textRenderer.draw(entity.url, 0, 0, -1, true, matrices.peek().getModel(), vertexConsumers, false, 0, 0xF000F0);
 		}
 		matrices.pop();
 	}

src/main/java/dev/hephaestus/glowcase/client/render/block/entity/ItemDisplayBlockEntityRenderer.java

@@ -95,11 +95,12 @@ public void render(ItemDisplayBlockEntity entity, float tickDelta, MatrixStack m
 				matrices.translate(0, 0, -0.4);
 
 				float scale = 0.025F;
-				matrices.scale(scale, scale, scale);
+				matrices.scale(scale, scale, -scale);
 
 				int color = name.getStyle().getColor() == null ? 0xFFFFFF : name.getStyle().getColor().getRgb();
 				matrices.translate(-MinecraftClient.getInstance().textRenderer.getWidth(name) / 2F, -4, 0);
-				MinecraftClient.getInstance().textRenderer.drawWithShadow(matrices, name, 0, 0, color);
+
+				MinecraftClient.getInstance().textRenderer.draw(name, 0, 0, color, true, matrices.peek().getModel(), vertexConsumers, false, 0, 0xF000F0);
 			}
 		}
 

src/main/java/dev/hephaestus/glowcase/mixin/client/TextRendererMixin.java

@@ -0,0 +1,38 @@
+package dev.hephaestus.glowcase.mixin.client;
+
+import net.minecraft.client.font.TextRenderer;
+import net.minecraft.util.math.Matrix4f;
+import net.minecraft.util.math.Vec3f;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(TextRenderer.class)
+public class TextRendererMixin {
+    // These addToLastColumn calls are originally used for offsetting the text
+    // shadow, however simply adding to the last column of the matrix to produce
+    // an offset is wrong since it will ignore any previous transformations made
+    // and will only work correctly in special cases (the transformation matrix
+    // having no rotation).
+    // So since what's actually wanted here is a translation, that's what we do.
+    // Another option would be to modify addToLastColumn directly because these
+    // two lines of code are the only thing that ever calls that method, but
+    // then its name would be wrong.
+
+    @Redirect(
+        method = "drawInternal(Ljava/lang/String;FFIZLnet/minecraft/util/math/Matrix4f;Lnet/minecraft/client/render/VertexConsumerProvider;ZIIZ)I",
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/util/math/Matrix4f;addToLastColumn(Lnet/minecraft/util/math/Vec3f;)V")
+    )
+    private void fixTranslation1(Matrix4f matrix4f, Vec3f vector) {
+        matrix4f.multiplyByTranslation(vector.getX(), vector.getY(), vector.getZ());
+    }
+
+    @Redirect(
+        method = "drawInternal(Lnet/minecraft/text/OrderedText;FFIZLnet/minecraft/util/math/Matrix4f;Lnet/minecraft/client/render/VertexConsumerProvider;ZII)I",
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/util/math/Matrix4f;addToLastColumn(Lnet/minecraft/util/math/Vec3f;)V")
+    )
+    private void fixTranslation2(Matrix4f matrix4f, Vec3f vector) {
+        matrix4f.multiplyByTranslation(vector.getX(), vector.getY(), vector.getZ());
+    }
+}

src/main/resources/glowcase.mixins.json

@@ -3,13 +3,14 @@
   "package": "dev.hephaestus.glowcase.mixin",
   "compatibilityLevel": "JAVA_8",
   "mixins": [
-    "block.EntityShapeContextAccessor",
+    "block.EntityShapeContextAccessor"
   ],
   "client": [
     "client.MinecraftClientAccessor",
     "client.render.ber.RenderPhaseAccessor",
     "client.render.ber.WorldRendererMixin",
-    "client.render.entity.EntityRenderDispatcherAccessor"
+    "client.render.entity.EntityRenderDispatcherAccessor",
+    "client.TextRendererMixin"
   ],
   "injectors": {
     "defaultRequire": 1