Fix black background palette (#4831)

Diablo and Hellfire have different palettes in `ui_art\black.pcx`.

We now ship our own tiny `black.pcx` that takes priority over the
other ones. This `black.pcx` had the Diablo palette which resulted in an
incorrect palette in the Settings screen.

Split our own `black.pcx` file into `black_diablo.pcx` and
`black_hellfire.pcx` and load the correct one depending on the mode.

CMake/Assets.cmake

@@ -159,7 +159,8 @@ set(devilutionx_assets
   gendata/cutstartw.pcx
   Levels/L1Data/SklKngT.dun
   Levels/L2Data/BonechaT.dun
-  ui_art/black.pcx
+  ui_art/black_diablo.pcx
+  ui_art/black_hellfire.pcx
   ui_art/creditsw.pcx
   ui_art/dvl_but_sml.pcx
   ui_art/dvl_lrpopup.pcx

Source/DiabloUI/diabloui.cpp

@@ -673,8 +673,22 @@ Sint16 GetCenterOffset(Sint16 w, Sint16 bw)
 	return (bw - w) / 2;
 }
 
+bool UiLoadBlackBackground()
+{
+	LoadBackgroundArt(gbIsHellfire ? "ui_art\\black_hellfire.pcx" : "ui_art\\black_diablo.pcx");
+
+	if (!ArtBackground)
+		return false;
+
+	// We only needed the black background for the palette, can now deallocate it.
+	ArtBackground = std::nullopt;
+
+	return true;
+}
+
 void LoadBackgroundArt(const char *pszFile, int frames)
 {
+	ArtBackground = std::nullopt;
 	SDL_Color pPal[256];
 	ArtBackground = LoadPcxSpriteSheetAsset(pszFile, static_cast<uint16_t>(frames), /*transparentColor=*/std::nullopt, pPal);
 	if (!ArtBackground)
@@ -700,14 +714,13 @@ void LoadBackgroundArt(const char *pszFile, int frames)
 
 void UiAddBackground(std::vector<std::unique_ptr<UiItemBase>> *vecDialog)
 {
-	int uiPositionY = GetUIRectangle().position.y;
+	const SDL_Rect rect = MakeSdlRect(0, GetUIRectangle().position.y, 0, 0);
 	if (ArtBackgroundWidescreen) {
-		SDL_Rect rectw = MakeSdlRect(0, uiPositionY, 0, 0);
-		vecDialog->push_back(std::make_unique<UiImagePcx>(PcxSprite { *ArtBackgroundWidescreen }, rectw, UiFlags::AlignCenter));
+		vecDialog->push_back(std::make_unique<UiImagePcx>(PcxSprite { *ArtBackgroundWidescreen }, rect, UiFlags::AlignCenter));
+	}
+	if (ArtBackground) {
+		vecDialog->push_back(std::make_unique<UiImagePcx>(PcxSpriteSheet { *ArtBackground }.sprite(0), rect, UiFlags::AlignCenter));
 	}
-
-	SDL_Rect rect = MakeSdlRect(0, uiPositionY, 0, 0);
-	vecDialog->push_back(std::make_unique<UiImagePcx>(PcxSpriteSheet { *ArtBackground }.sprite(0), rect, UiFlags::AlignCenter));
 }
 
 void UiAddLogo(std::vector<std::unique_ptr<UiItemBase>> *vecDialog)
@@ -769,7 +782,7 @@ void DrawSelector(const SDL_Rect &rect)
 
 void UiClearScreen()
 {
-	if (gnScreenWidth > 640) // Background size
+	if (!ArtBackground || gnScreenWidth > PcxSpriteSheet { *ArtBackground }.width() || gnScreenHeight > PcxSpriteSheet { *ArtBackground }.frameHeight())
 		SDL_FillRect(DiabloUiSurface(), nullptr, 0x000000);
 }
 

Source/DiabloUI/diabloui.h

@@ -96,6 +96,7 @@ 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();
+bool UiLoadBlackBackground();
 void LoadBackgroundArt(const char *pszFile, int frames = 1);
 void UiAddBackground(std::vector<std::unique_ptr<UiItemBase>> *vecDialog);
 void UiAddLogo(std::vector<std::unique_ptr<UiItemBase>> *vecDialog);

Source/DiabloUI/dialogs.cpp

@@ -55,9 +55,7 @@ std::optional<PcxSprite> LoadDialogSprite(bool hasCaption, bool isError)
 bool Init(string_view caption, string_view text, bool error, bool renderBehind)
 {
 	if (!renderBehind) {
-		ArtBackground = std::nullopt;
-		LoadBackgroundArt("ui_art\\black.pcx");
-		if (!ArtBackground) {
+		if (!UiLoadBlackBackground()) {
 			if (SDL_ShowCursor(SDL_ENABLE) <= -1)
 				LogError("{}", SDL_GetError());
 		}

Source/DiabloUI/progress.cpp

@@ -30,7 +30,7 @@ void DialogActionCancel()
 
 void ProgressLoadBackground()
 {
-	LoadBackgroundArt("ui_art\\black.pcx");
+	UiLoadBlackBackground();
 	ArtPopupSm = LoadPcxAsset("ui_art\\spopup.pcx");
 	ArtProgBG = LoadPcxAsset("ui_art\\prog_bg.pcx");
 }

Source/DiabloUI/selok.cpp

@@ -43,7 +43,7 @@ void selok_Esc()
 void UiSelOkDialog(const char *title, const char *body, bool background)
 {
 	if (!background) {
-		LoadBackgroundArt("ui_art\\black.pcx");
+		UiLoadBlackBackground();
 	} else {
 		if (!gbIsSpawn) {
 			LoadBackgroundArt("ui_art\\mainmenu.pcx");

Source/DiabloUI/selyesno.cpp

@@ -42,7 +42,7 @@ void SelyesnoEsc()
 
 bool UiSelHeroYesNoDialog(const char *title, const char *body)
 {
-	LoadBackgroundArt("ui_art\\black.pcx");
+	UiLoadBlackBackground();
 	UiAddBackground(&vecSelYesNoDialog);
 	UiAddLogo(&vecSelYesNoDialog);
 

Source/DiabloUI/settingsmenu.cpp

@@ -247,7 +247,7 @@ void UiSettingsMenu()
 	do {
 		endMenu = false;
 
-		LoadBackgroundArt("ui_art\\black.pcx");
+		UiLoadBlackBackground();
 		LoadScrollBar();
 		UiAddBackground(&vecDialog);
 		UiAddLogo(&vecDialog);