[MC-270530] Horses, donkeys, mules, llamas and camels all use the same inventory texture file

The bug

Horses, donkeys, mules, llamas and camels all use the file textures/gui/container/horse.png. Not only is this intuitive by name terms, it's also inconsistent with:

furnaces, blast furnaces and smokers, which all use different texture files despite appearing identical
shulker boxes, which have an identical looking inventory to single chests/trapped chests, ender chests, barrels and minecarts with chests, but are handled by a dedicated texture file

How to fix

Introduce new, dedicated files for each of these entities.

Further notes

Fixing this should also make fixing MC-265033 easier - for the type of entity in question, the saddle/carpet/armor slot could be made part of the inventory texture itself rather than an external sprite, and the slot outline could be split into its own file as to behave correctly when items are in the slot.

Linked issues

discovered while testing

MC-165182 Inventory/GUI textures no longer handle translucent pixels correctly

relates to

MC-271334 The twelve rods of a blaze cannot be independently retextured

MC-271983 The right/left ears, front legs, and back legs of a polar bear cannot be independently retextured

Comments

[Mod] Jingy 2024-04-09T23:30:33Z

Can confirm with code analysis of 24w14a.

The resource location of the inventory:

. . .
private static final ResourceLocation HORSE_INVENTORY_LOCATION = new ResourceLocation("textures/gui/container/horse.png");
. . .

The code which controls how the 'horse' GUI should behave depending on which entity is being ridden:

protected void renderBg(GuiGraphics var1, float var2, int var3, int var4) {
      int var5 = (this.width - this.imageWidth) / 2;
      int var6 = (this.height - this.imageHeight) / 2;
      var1.blit(HORSE_INVENTORY_LOCATION, var5, var6, 0, 0, this.imageWidth, this.imageHeight);
      AbstractHorse var8 = this.horse;
      if (var8 instanceof AbstractChestedHorse) {
         AbstractChestedHorse var7 = (AbstractChestedHorse)var8;
         if (var7.hasChest()) {
            var1.blitSprite(CHEST_SLOTS_SPRITE, 90, 54, 0, 0, var5 + 79, var6 + 17, var7.getInventoryColumns() * 18, 54);
         }
      }

      if (this.horse.isSaddleable()) {
         var1.blitSprite(SADDLE_SLOT_SPRITE, var5 + 7, var6 + 35 - 18, 18, 18);
      }

      if (this.horse.canWearBodyArmor()) {
         if (this.horse instanceof Llama) {
            var1.blitSprite(LLAMA_ARMOR_SLOT_SPRITE, var5 + 7, var6 + 35, 18, 18);
         } else {
            var1.blitSprite(ARMOR_SLOT_SPRITE, var5 + 7, var6 + 35, 18, 18);
         }
      }

      InventoryScreen.renderEntityInInventoryFollowsMouse(var1, var5 + 26, var6 + 18, var5 + 78, var6 + 70, 17, 0.25F, this.xMouse, this.yMouse, this.horse);
   }