Re-add support for emissive item models

Author: PepperCode1

src/main/java/me/pepperbell/continuity/client/mixin/BasicItemModelMixin.java

@@ -0,0 +1,54 @@
+package me.pepperbell.continuity.client.mixin;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.llamalad7.mixinextras.sugar.Local;
+
+import me.pepperbell.continuity.client.config.ContinuityConfig;
+import me.pepperbell.continuity.client.mixinterface.SpriteExtension;
+import me.pepperbell.continuity.client.util.QuadUtil;
+import net.minecraft.client.render.item.ItemRenderState;
+import net.minecraft.client.render.item.model.BasicItemModel;
+import net.minecraft.client.render.item.tint.TintSource;
+import net.minecraft.client.render.model.BakedQuad;
+import net.minecraft.client.render.model.ModelSettings;
+import net.minecraft.client.texture.Sprite;
+
+@Mixin(BasicItemModel.class)
+abstract class BasicItemModelMixin {
+	@Unique
+	@Nullable
+	private List<BakedQuad> emissiveQuads;
+
+	@Inject(method = "<init>(Ljava/util/List;Ljava/util/List;Lnet/minecraft/client/render/model/ModelSettings;)V", at = @At("RETURN"))
+	private void onReturnInit(List<TintSource> tints, List<BakedQuad> quads, ModelSettings settings, CallbackInfo ci) {
+		for (BakedQuad quad : quads) {
+			Sprite emissiveSprite = ((SpriteExtension) quad.sprite()).continuity$getEmissiveSprite();
+			if (emissiveSprite != null) {
+				int[] emissiveVertexData = quad.vertexData().clone();
+				QuadUtil.interpolate(emissiveVertexData, quad.sprite(), emissiveSprite);
+				BakedQuad emissiveQuad = new BakedQuad(emissiveVertexData, quad.tintIndex(), quad.face(), emissiveSprite, false, 15);
+
+				if (emissiveQuads == null) {
+					emissiveQuads = new ArrayList<>();
+				}
+				emissiveQuads.add(emissiveQuad);
+			}
+		}
+	}
+
+	@Inject(method = "update(Lnet/minecraft/client/render/item/ItemRenderState;Lnet/minecraft/item/ItemStack;Lnet/minecraft/client/item/ItemModelManager;Lnet/minecraft/item/ItemDisplayContext;Lnet/minecraft/client/world/ClientWorld;Lnet/minecraft/entity/LivingEntity;I)V", at = @At(value = "INVOKE", target = "java/util/List.addAll(Ljava/util/Collection;)Z", remap = false, shift = At.Shift.AFTER))
+	private void afterAddVanillaQuads(CallbackInfo ci, @Local ItemRenderState.LayerRenderState layerRenderState) {
+		if (emissiveQuads != null && ContinuityConfig.INSTANCE.emissiveTextures.get()) {
+			layerRenderState.getQuads().addAll(emissiveQuads);
+		}
+	}
+}

src/main/java/me/pepperbell/continuity/client/util/QuadUtil.java

@@ -24,6 +24,23 @@ public static void interpolate(MutableQuadView quad, Sprite oldSprite, Sprite ne
 		}
 	}
 
+	public static void interpolate(int[] vertexData, Sprite oldSprite, Sprite newSprite) {
+		float oldMinU = oldSprite.getMinU();
+		float oldMinV = oldSprite.getMinV();
+		float newMinU = newSprite.getMinU();
+		float newMinV = newSprite.getMinV();
+		float uFactor = (newSprite.getMaxU() - newMinU) / (oldSprite.getMaxU() - oldMinU);
+		float vFactor = (newSprite.getMaxV() - newMinV) / (oldSprite.getMaxV() - oldMinV);
+		for (int i = 0; i < 4; i++) {
+			float u = Float.intBitsToFloat(vertexData[i * 8 + 4]);
+			float v = Float.intBitsToFloat(vertexData[i * 8 + 5]);
+			u = newMinU + (u - oldMinU) * uFactor;
+			v = newMinV + (v - oldMinV) * vFactor;
+			vertexData[i * 8 + 4] = Float.floatToRawIntBits(u);
+			vertexData[i * 8 + 5] = Float.floatToRawIntBits(v);
+		}
+	}
+
 	public static void assignLerpedUvs(MutableQuadView quad, Sprite sprite) {
 		float delta = sprite.getUvScaleDelta();
 		float centerU = (sprite.getMinU() + sprite.getMaxU()) * 0.5f;

src/main/resources/continuity.mixins.json

@@ -6,6 +6,7 @@
   "client": [
     "AtlasLoaderMixin",
     "BakedModelManagerMixin",
+    "BasicItemModelMixin",
     "LifecycledResourceManagerImplMixin",
     "RenderLayersMixin",
     "SpriteLoaderMixin",