HUD inventory: allow custom background per element (#17359)

doc/lua_api.md

@@ -2117,6 +2117,8 @@ Displays a horizontal bar made up of half-images with an optional background.
 ### `inventory`
 
 * `text`: The name of the inventory list to be displayed.
+* `text2`: Optional texture name for the inventory background. If not specified,
+  the player's hotbar background is used.
 * `number`: Amount of item slots in the inventory to be displayed.
   Integer in range [u16].
 * `item`: The slot at this index is rendered as if it were selected

games/devtest/mods/testhud/init.lua

@@ -342,8 +342,9 @@ local hud_inventory_defs = {
 		position = {x=0.7, y=0.5},
 		direction = 3,
 		text = "main",
-		number = 4,
-		item = 2,
+		text2 = "testhud_inventory_bg.png",
+		number = 1,
+		item = 0,
 	},
 }
 

src/client/hud.cpp

@@ -234,7 +234,7 @@ void Hud::drawItem(const ItemStack &item, const core::rect<s32>& rect,
 // mainlist can be NULL, but draw the frame anyway.
 void Hud::drawItems(v2s32 screen_pos, v2s32 screen_offset, s32 itemcount, v2f alignment,
 		s32 inv_offset, InventoryList *mainlist, u16 selectitem, u16 direction,
-		bool is_hotbar)
+		bool is_hotbar, const std::string &background_image)
 {
 	s32 height  = m_hotbar_imagesize + m_padding * 2;
 	s32 width   = (itemcount - inv_offset) * (m_hotbar_imagesize + m_padding * 2);
@@ -251,11 +251,11 @@ void Hud::drawItems(v2s32 screen_pos, v2s32 screen_offset, s32 itemcount, v2f al
 	pos.X += (alignment.X - 1.0f) * (width * 0.5f);
 	pos.Y += (alignment.Y - 1.0f) * (height * 0.5f);
 
-	// Store hotbar_image in member variable, used by drawItem()
-	if (hotbar_image != player->hotbar_image) {
-		hotbar_image = player->hotbar_image;
-		use_hotbar_image = !hotbar_image.empty();
-	}
+	// Store the effective background image in a member variable, used by drawItem().
+	// An inventory HUD element can override the player's hotbar image with text2.
+	hotbar_image = background_image.empty() ?
+			player->hotbar_image : background_image;
+	use_hotbar_image = !hotbar_image.empty();
 
 	// Store hotbar_selected_image in member variable, used by drawItem()
 	if (hotbar_selected_image != player->hotbar_selected_image) {
@@ -447,7 +447,7 @@ void Hud::drawLuaElements(const v3s16 &camera_offset, bool only_unhidable)
 				if (!inv)
 					warningstream << "HUD: Unknown inventory list. name=" << e->text << std::endl;
 				drawItems(pos, v2s32(e->offset.X, e->offset.Y), e->number, e->align, 0,
-					inv, e->item, e->dir, false);
+					inv, e->item, e->dir, false, e->text2);
 				break; }
 			case HUD_ELEM_WAYPOINT: {
 				if (!calculateScreenPos(camera_offset, e, &pos))

src/client/hud.h

@@ -106,7 +106,7 @@ private:
 
 	void drawItems(v2s32 screen_pos, v2s32 screen_offset, s32 itemcount, v2f alignment,
 			s32 inv_offset, InventoryList *mainlist, u16 selectitem,
-			u16 direction, bool is_hotbar);
+			u16 direction, bool is_hotbar, const std::string &background_image = "");
 
 	void drawItem(const ItemStack &item, const core::rect<s32> &rect, bool selected);