Let BackgroundRenderedSlots override the background atlas

Author: Swedz

src/client/java/aztech/modern_industrialization/machines/gui/MachineScreen.java

@@ -211,10 +211,15 @@ protected void renderBg(GuiGraphics guiGraphics, float delta, int mouseX, int mo
 
     private void renderConfigurableSlotBackgrounds(GuiGraphics guiGraphics) {
         for (Slot slot : this.menu.slots) {
-            if (slot instanceof BackgroundRenderedSlot brs) {
+            if (slot.isActive() && slot instanceof BackgroundRenderedSlot brs) {
                 int px = leftPos + slot.x - 1;
                 int py = topPos + slot.y - 1;
-                guiGraphics.blit(SLOT_ATLAS, px, py, brs.getBackgroundU(), brs.getBackgroundV(), 18, 18);
+                if (slot.getItem().isEmpty()) {
+                    var atlas = brs.getBackgroundAtlasLocation();
+                    guiGraphics.blit(atlas == null ? SLOT_ATLAS : atlas, px, py, brs.getBackgroundU(), brs.getBackgroundV(), 18, 18);
+                } else {
+                    guiGraphics.blit(SLOT_ATLAS, px, py, 0, 0, 18, 18);
+                }
             }
         }
     }

src/main/java/aztech/modern_industrialization/inventory/BackgroundRenderedSlot.java

@@ -23,10 +23,21 @@
  */
 package aztech.modern_industrialization.inventory;
 
+import net.minecraft.resources.ResourceLocation;
+import org.jetbrains.annotations.Nullable;
+
 /**
  * Implement this on a slot to render its background automatically.
  */
 public interface BackgroundRenderedSlot {
+    /**
+     * @return the {@link ResourceLocation} of the slot atlas texture to use for the slot background. When null, uses the MI slot atlas
+     */
+    @Nullable
+    default ResourceLocation getBackgroundAtlasLocation() {
+        return null;
+    }
+
     default int getBackgroundU() {
         return 0;
     }