Implement scroll wheel navigation

up/down/left/right = arrow keys
ctrl+up/down = zoom automap in/out

SourceS/sdl_compat.h

@@ -3,6 +3,8 @@
 #include <SDL.h>
 
 #ifndef USE_SDL1
+#define SDLC_KEYSTATE_LEFTCTRL SDL_SCANCODE_LCTRL
+#define SDLC_KEYSTATE_RIGHTCTRL SDL_SCANCODE_RCTRL
 #define SDLC_KEYSTATE_LEFTSHIFT SDL_SCANCODE_LSHIFT
 #define SDLC_KEYSTATE_RIGHTSHIFT SDL_SCANCODE_RSHIFT
 #define SDLC_KEYSTATE_MENU SDL_SCANCODE_MENU
@@ -11,6 +13,8 @@
 #define SDLC_KEYSTATE_LEFT SDL_SCANCODE_LEFT
 #define SDLC_KEYSTATE_RIGHT SDL_SCANCODE_RIGHT
 #else
+#define SDLC_KEYSTATE_LEFTCTRL SDLK_LCTRL
+#define SDLC_KEYSTATE_RIGHTCTRL SDLK_RCTRL
 #define SDLC_KEYSTATE_LEFTSHIFT SDLK_LSHIFT
 #define SDLC_KEYSTATE_RIGHTSHIFT SDLK_LSHIFT
 #define SDLC_KEYSTATE_MENU SDLK_MENU

SourceX/DiabloUI/diabloui.cpp

@@ -240,6 +240,15 @@ void UiFocusNavigation(SDL_Event *event)
 		break;
 	}
 
+	if (event->type == SDL_MOUSEWHEEL) {
+		if (event->wheel.y > 0) {
+			UiFocus(SelectedItem - 1, UiItemsWraps);
+		} else if (event->wheel.y < 0) {
+			UiFocus(SelectedItem + 1, UiItemsWraps);
+		}
+		return;
+	}
+
 	if (SDL_IsTextInputActive()) {
 		switch (event->type) {
 		case SDL_KEYDOWN: {

SourceX/miniwin/misc_msg.cpp

@@ -549,6 +549,18 @@ WINBOOL PeekMessageA(LPMSG lpMsg)
 		}
 	} break;
 #ifndef USE_SDL1
+	case SDL_MOUSEWHEEL:
+		lpMsg->message = DVL_WM_KEYDOWN;
+		if (e.wheel.y > 0) {
+			lpMsg->wParam = GetAsyncKeyState(DVL_VK_CONTROL) ? DVL_VK_OEM_PLUS : DVL_VK_UP;
+		} else if (e.wheel.y < 0) {
+			lpMsg->wParam = GetAsyncKeyState(DVL_VK_CONTROL) ? DVL_VK_OEM_MINUS : DVL_VK_DOWN;
+		} else if (e.wheel.x > 0) {
+			lpMsg->wParam = DVL_VK_LEFT;
+		} else if (e.wheel.x < 0) {
+			lpMsg->wParam = DVL_VK_RIGHT;
+		}
+		break;
 #if SDL_VERSION_ATLEAST(2, 0, 4)
 	case SDL_AUDIODEVICEADDED:
 		return false_avail("SDL_AUDIODEVICEADDED", e.adevice.which);
@@ -696,6 +708,8 @@ SHORT GetAsyncKeyState(int vKey)
 		return SDL_GetMouseState(NULL, NULL) & SDL_BUTTON(SDL_BUTTON_RIGHT);
 	const Uint8 *state = SDLC_GetKeyState();
 	switch (vKey) {
+	case DVL_VK_CONTROL:
+		return state[SDLC_KEYSTATE_LEFTCTRL] || state[SDLC_KEYSTATE_RIGHTCTRL] ? 0x8000 : 0;
 	case DVL_VK_SHIFT:
 		return state[SDLC_KEYSTATE_LEFTSHIFT] || state[SDLC_KEYSTATE_RIGHTSHIFT] ? 0x8000 : 0;
 	case DVL_VK_MENU: