[Feature] Armor Render Helper based on Fabric ArmorRenderer-API

src/main/java/org/betterx/bclib/client/render/HumanoidArmorRenderer.java

@@ -0,0 +1,117 @@
+package org.betterx.bclib.client.render;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import com.mojang.blaze3d.vertex.VertexConsumer;
+import net.minecraft.client.model.HumanoidModel;
+import net.minecraft.client.renderer.MultiBufferSource;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.renderer.texture.OverlayTexture;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.entity.LivingEntity;
+import net.minecraft.world.item.ArmorItem;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.item.ItemStack;
+
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.fabricmc.fabric.api.client.rendering.v1.ArmorRenderer;
+
+import org.jetbrains.annotations.NotNull;
+
+@Environment(EnvType.CLIENT)
+public abstract class HumanoidArmorRenderer implements ArmorRenderer {
+    public interface CopyExtraState {
+        void copyPropertiesFrom(HumanoidModel<LivingEntity> parentModel);
+    }
+
+    @Override
+    public void render(
+            PoseStack pose, MultiBufferSource buffer,
+            ItemStack stack, LivingEntity entity, EquipmentSlot slot,
+            int light, HumanoidModel<LivingEntity> parentModel
+    ) {
+        HumanoidModel<LivingEntity> model = getModelForSlot(entity, slot);
+        if (model != null) {
+            Item item = stack.getItem();
+            if (!(item instanceof ArmorItem)) {
+                return;
+            }
+            ArmorItem armorItem = (ArmorItem) item;
+            if (armorItem.getEquipmentSlot() != slot) {
+                return;
+            }
+            parentModel.copyPropertiesTo(model);
+            if (model instanceof CopyExtraState mdl) {
+                mdl.copyPropertiesFrom(parentModel);
+            }
+            setPartVisibility(model, slot);
+            renderModel(
+                    pose, buffer, light, model,
+                    getTextureForSlot(slot, usesInnerModel(slot)),
+                    1.0f, 1.0f, 1.0f
+            );
+
+            if (stack.hasFoil()) {
+                this.renderGlint(pose, buffer, light, model);
+            }
+        }
+    }
+
+    @NotNull
+    protected abstract ResourceLocation getTextureForSlot(EquipmentSlot slot, boolean innerLayer);
+    protected abstract HumanoidModel<LivingEntity> getModelForSlot(LivingEntity entity, EquipmentSlot slot);
+
+    protected boolean usesInnerModel(EquipmentSlot equipmentSlot) {
+        return equipmentSlot == EquipmentSlot.LEGS;
+    }
+
+    protected void renderModel(
+            PoseStack pose, MultiBufferSource buffer,
+            int light,
+            HumanoidModel<LivingEntity> humanoidModel, ResourceLocation texture,
+            float r, float g, float b
+    ) {
+        VertexConsumer vertexConsumer = buffer.getBuffer(RenderType.armorCutoutNoCull(texture));
+        humanoidModel.renderToBuffer(pose, vertexConsumer, light, OverlayTexture.NO_OVERLAY, r, g, b, 1.0f);
+    }
+
+    protected void renderGlint(
+            PoseStack pose,
+            MultiBufferSource buffer,
+            int light,
+            HumanoidModel<LivingEntity> humanoidModel
+    ) {
+        humanoidModel.renderToBuffer(
+                pose, buffer.getBuffer(RenderType.armorEntityGlint()), light, OverlayTexture.NO_OVERLAY,
+                1.0f, 1.0f, 1.0f, 1.0f
+        );
+    }
+
+    protected void setPartVisibility(HumanoidModel<LivingEntity> humanoidModel, EquipmentSlot equipmentSlot) {
+        humanoidModel.setAllVisible(false);
+        switch (equipmentSlot) {
+            case HEAD: {
+                humanoidModel.head.visible = true;
+                humanoidModel.hat.visible = true;
+                break;
+            }
+            case CHEST: {
+                humanoidModel.body.visible = true;
+                humanoidModel.rightArm.visible = true;
+                humanoidModel.leftArm.visible = true;
+                break;
+            }
+            case LEGS: {
+                humanoidModel.body.visible = true;
+                humanoidModel.rightLeg.visible = true;
+                humanoidModel.leftLeg.visible = true;
+                break;
+            }
+            case FEET: {
+                humanoidModel.rightLeg.visible = true;
+                humanoidModel.leftLeg.visible = true;
+            }
+        }
+    }
+}