Various palette and screen improvements (nw)

- Use device_resolve_objects to remove the need for resolve_palette
- Palette format no longer depends on configuration of first screen

src/emu/dipalette.cpp

@@ -26,7 +26,7 @@ device_palette_interface::device_palette_interface(const machine_config &mconfig
 	: device_interface(device, "palette"),
 		m_palette(nullptr),
 		m_pens(nullptr),
-		m_format(),
+		m_format(BITMAP_FORMAT_RGB32),
 		m_shadow_table(nullptr),
 		m_shadow_group(0),
 		m_hilight_group(0),
@@ -57,10 +57,6 @@ void device_palette_interface::interface_validity_check(validity_checker &valid)
 
 void device_palette_interface::interface_pre_start()
 {
-	// reset all our data
-	screen_device *screen = device().machine().first_screen();
-	m_format = (screen != nullptr) ? screen->format() : BITMAP_FORMAT_INVALID;
-
 	// allocate the palette
 	u32 numentries = palette_entries();
 	allocate_palette(numentries);

src/emu/dipalette.h

@@ -37,6 +37,8 @@ typedef u16 indirect_pen_t;
 
 class device_palette_interface : public device_interface
 {
+	friend class screen_device;
+
 	static constexpr int MAX_SHADOW_PRESETS = 4;
 
 public:

src/emu/divideo.cpp

@@ -134,9 +134,6 @@ void device_video_interface::interface_pre_start()
 			throw device_missing_dependencies();
 		else
 		{
-			// resolve the palette for the sake of register_screen_bitmap
-			m_screen->resolve_palette();
-
 			// no other palette may be specified
 			if (m_screen->has_palette() && palintf != &m_screen->palette())
 				throw emu_fatalerror("Device '%s' cannot control screen '%s' with palette '%s'", device().tag(), m_screen_tag, m_screen->palette().device().tag());

src/emu/screen.cpp

@@ -803,6 +803,39 @@ void screen_device::device_validity_check(validity_checker &valid) const
 }
 
 
+//-------------------------------------------------
+//  device_resolve_objects - resolve objects that
+//  may be needed for other devices to set
+//  initial conditions at start time
+//-------------------------------------------------
+
+void screen_device::device_resolve_objects()
+{
+	// bind our handlers
+	m_screen_update_ind16.bind_relative_to(*owner());
+	m_screen_update_rgb32.bind_relative_to(*owner());
+	m_screen_vblank.resolve_safe();
+
+	// find the specified palette
+	if (m_palette_tag != nullptr && m_palette == nullptr)
+	{
+		// find our palette as a sibling device
+		device_t *palette = owner()->subdevice(m_palette_tag);
+		if (palette == nullptr)
+			fatalerror("Screen '%s' specifies nonexistent device '%s' as palette\n",
+									tag(),
+									m_palette_tag);
+		if (!palette->interface(m_palette))
+			fatalerror("Screen '%s' specifies device '%s' as palette, but it has no palette interface\n",
+									tag(),
+									m_palette_tag);
+
+		// assign our format to the palette before it starts
+		m_palette->m_format = format();
+	}
+}
+
+
 //-------------------------------------------------
 //  device_start - device-specific startup
 //-------------------------------------------------
@@ -826,13 +859,7 @@ void screen_device::device_start()
 		}
 	}
 
-	// bind our handlers
-	m_screen_update_ind16.bind_relative_to(*owner());
-	m_screen_update_rgb32.bind_relative_to(*owner());
-	m_screen_vblank.resolve_safe();
-
 	// if we have a palette and it's not started, wait for it
-	resolve_palette();
 	if (m_palette != nullptr && !m_palette->device().started())
 		throw device_missing_dependencies();
 
@@ -1481,28 +1508,6 @@ void screen_device::register_screen_bitmap(bitmap_t &bitmap)
 }
 
 
-//-------------------------------------------------
-//  resolve_palette - find the specified palette
-//-------------------------------------------------
-
-void screen_device::resolve_palette()
-{
-	if (m_palette_tag != nullptr && m_palette == nullptr)
-	{
-		// find our palette as a sibling device
-		device_t *palette = owner()->subdevice(m_palette_tag);
-		if (palette == nullptr)
-			fatalerror("Screen '%s' specifies nonexistent device '%s' as palette\n",
-									tag(),
-									m_palette_tag);
-		if (!palette->interface(m_palette))
-			fatalerror("Screen '%s' specifies device '%s' as palette, but it has no palette interface\n",
-									tag(),
-									m_palette_tag);
-	}
-}
-
-
 //-------------------------------------------------
 //  vblank_begin - call any external callbacks to
 //  signal the VBLANK period has begun

src/emu/screen.h

@@ -239,7 +239,6 @@ public:
 	// additional helpers
 	void register_vblank_callback(vblank_state_delegate vblank_callback);
 	void register_screen_bitmap(bitmap_t &bitmap);
-	void resolve_palette();
 
 	// internal to the video system
 	bool update_quads();
@@ -263,6 +262,7 @@ private:
 
 	// device-level overrides
 	virtual void device_validity_check(validity_checker &valid) const override;
+	virtual void device_resolve_objects() override;
 	virtual void device_start() override;
 	virtual void device_reset() override;
 	virtual void device_stop() override;