Replace default palette PCX files with PAL files

These PCX files were only used to load the default palette.
Replaces them with PAL files.

CMake/Assets.cmake

@@ -161,8 +161,8 @@ set(devilutionx_assets
   levels/l2data/bonechat.dun
   nlevels/l5data/cornerstone.dun
   nlevels/l5data/uberroom.dun
-  ui_art/black_diablo.pcx
-  ui_art/black_hellfire.pcx
+  ui_art/diablo.pal
+  ui_art/hellfire.pal
   ui_art/creditsw.clx
   ui_art/dvl_but_sml.clx
   ui_art/dvl_lrpopup.clx

Source/DiabloUI/diabloui.cpp

@@ -319,6 +319,23 @@ bool HandleMenuAction(MenuAction menuAction)
 	}
 }
 
+void UiOnBackgroundChange()
+{
+	fadeTc = 0;
+	fadeValue = 0;
+
+	if (IsHardwareCursorEnabled() && ArtCursor && ControlDevice == ControlTypes::KeyboardAndMouse && GetCurrentCursorInfo().type() != CursorType::UserInterface) {
+		SetHardwareCursor(CursorInfo::UserInterfaceCursor());
+	}
+
+	BlackPalette();
+
+	SDL_FillRect(DiabloUiSurface(), nullptr, 0x000000);
+	if (DiabloUiSurface() == PalSurface)
+		BltFast(nullptr, nullptr);
+	RenderPresent();
+}
+
 } // namespace
 
 void UiFocusNavigation(SDL_Event *event)
@@ -664,16 +681,17 @@ Sint16 GetCenterOffset(Sint16 w, Sint16 bw)
 	return (bw - w) / 2;
 }
 
-bool UiLoadBlackBackground()
+void UiLoadDefaultPalette()
 {
-	LoadBackgroundArt(gbIsHellfire ? "ui_art\\black_hellfire.pcx" : "ui_art\\black_diablo.pcx");
-
-	if (!ArtBackground)
-		return false;
+	LoadPalette(gbIsHellfire ? "ui_art\\hellfire.pal" : "ui_art\\diablo.pal", /*blend=*/false);
+	ApplyGamma(logical_palette, orig_palette, 256);
+}
 
-	// We only needed the black background for the palette, can now deallocate it.
+bool UiLoadBlackBackground()
+{
 	ArtBackground = std::nullopt;
-
+	UiLoadDefaultPalette();
+	UiOnBackgroundChange();
 	return true;
 }
 
@@ -687,20 +705,7 @@ void LoadBackgroundArt(const char *pszFile, int frames)
 
 	LoadPalInMem(pPal);
 	ApplyGamma(logical_palette, orig_palette, 256);
-
-	fadeTc = 0;
-	fadeValue = 0;
-
-	if (IsHardwareCursorEnabled() && ArtCursor && ControlDevice == ControlTypes::KeyboardAndMouse && GetCurrentCursorInfo().type() != CursorType::UserInterface) {
-		SetHardwareCursor(CursorInfo::UserInterfaceCursor());
-	}
-
-	BlackPalette();
-
-	SDL_FillRect(DiabloUiSurface(), nullptr, 0x000000);
-	if (DiabloUiSurface() == PalSurface)
-		BltFast(nullptr, nullptr);
-	RenderPresent();
+	UiOnBackgroundChange();
 }
 
 void UiAddBackground(std::vector<std::unique_ptr<UiItemBase>> *vecDialog)

Source/DiabloUI/diabloui.h

@@ -94,6 +94,7 @@ bool UiItemMouseEvents(SDL_Event *event, const std::vector<std::unique_ptr<UiIte
 Sint16 GetCenterOffset(Sint16 w, Sint16 bw = 0);
 void LoadPalInMem(const SDL_Color *pPal);
 void DrawMouse();
+void UiLoadDefaultPalette();
 bool UiLoadBlackBackground();
 void LoadBackgroundArt(const char *pszFile, int frames = 1);
 void UiAddBackground(std::vector<std::unique_ptr<UiItemBase>> *vecDialog);