Guide 08

Button hints

How to make "△ = Accept" say <Enter> = Accept on a keyboard, Ⓐ on an Xbox pad and ✕ on a PlayStation one, following the bindings and switching the moment you touch another device.

GoalEvery hint in every menu and level shows what you have to press, on the device you're holding.

Keyboard: <code><Up>/<Down> = Select <Enter> = Accept</code>. — Keyboard: `<Up>/<Down> = Select <Enter> = Accept`.

1Find out why everything was a triangle

Text draws \b<n> as glyph n of the buttons font, and \m<n> through a meta table first. The PC port only loaded ButtonsPs2. Dumping both fonts shows glyphs 0–18 and nothing more:

Glyph	`ButtonsPs2`	`ButtonsXbox`
0–3	△ □ ○ ✕	Y X B A
4–7	↓ → ← ↑	↓ → ← ↑
8, 9	Start, Select	START, BACK
10–13	↘ ↖ ↙ ↗	↘ ↖ ↙ ↗
14–17	L1 R1 L2 R2	L trigger, R trigger, White, Black
18	L1+R1	L+R
19+	nothing: falls back to glyph 0

Same index, same position: 0 is the top face button, 3 the bottom one. (Found by dumping the fonts' glyph tables: header, char map, 8-bit texture, palette, sub-texture rects.)

The PC scripts use codes 19 and up (\bm = Accept, \bn = Back) that no font has, and a missing glyph falls back to glyph 0. Hence: a triangle, on a keyboard.

The original PC exe must have mapped those codes to key names. We don't have that exe's code, so: archaeology.

2Decode the tag zoo

Tag	Means	Example
`\b0`–`\bi`	PS2 buttons by position, D-pad, diagonals, L1/R1/L2/R2	`\b7/\b4 = Select`
`\bm \bn \bo \bp`	PC only: Xbox A, B, X, Y	`\bm = Accept`
`\bq \br \bs \bt`	PC only: Black, White, left/right trigger	`\bs/\bt = Rotate`
`\bk`	PC only: the right stick	colour menu
`\m<n>`	An action, through `meta_button_map_xbox` to an Xbox button	`\m5 to talk` → B

3Resolve a tag the way the game reads it

Each tag becomes the PS2 pad bit the game expects there (B is Back in menus, Grab when skating), then whatever is bound to that bit for the device: a key name, or a glyph from the right font, written as new tags \x (Xbox font) and \p (PlayStation font).

new fileWn32/Code/Plat/Sys/SIO/p_buttonglyphs.cpp · working tree

+// The pad button the Xbox button presses, by default, where it's pressed (as set up in p_siodev.cpp)
+static EPadBit s_xbox_button_bit( EXboxButton button, unsigned int context )
+{
+	bool menu = ( context & mBIND_MENU ) != 0;
+	bool editor = ( context & mBIND_PARK_EDITOR ) != 0;
+	switch( button )
+	{
+		case vXBOX_A:				return vBIT_CROSS;
+		case vXBOX_B:				return menu ? vBIT_TRIANGLE : vBIT_CIRCLE;
+		case vXBOX_LEFT_TRIGGER:	return editor ? vBIT_L2 : vBIT_L1;
+		...
+	}
+}
+
+// A pad button on the keyboard, where it's pressed (as set up in read_keyboard in p_siodev.cpp)
+static std::string s_keyboard_bit_text( EPadBit bit, unsigned int context )
+{
+	switch( bit )
+	{
+		// In menus, Enter and Escape accept and go back
+		case vBIT_CROSS:	return menu ? s_key_text( "Enter" ) : s_key_action_text( vKA_OLLIE );
+		case vBIT_CIRCLE:	return s_key_action_text( vKA_GRAB );
+		...

The fonts have no [ ]. They do have < >. So keys look like <Num 6> to talk, which is at least unambiguous: "A to talk" reads like the Xbox button.

4Follow the last device

new fileWn32/Code/Plat/Sys/SIO/p_buttonglyphs.cpp

static EGlyphDevice s_device_for_controller_type( SDL_GameControllerType type )
{
	switch( type )
	{
		case SDL_CONTROLLER_TYPE_PS3:
		case SDL_CONTROLLER_TYPE_PS4:
		case SDL_CONTROLLER_TYPE_PS5:
			return vGLYPH_PLAYSTATION;
		default:
			// Xbox, and the others whose buttons SDL names by the Xbox positions
			return vGLYPH_XBOX;
	}
}

void ButtonGlyphsHandleEvent( const SDL_Event &event )
{
	switch( event.type )
	{
		case SDL_KEYDOWN:					if( !event.key.repeat ) s_set_device( vGLYPH_KEYBOARD ); break;
		case SDL_CONTROLLERBUTTONDOWN:		s_set_controller( event.cbutton.which ); break;
		case SDL_CONTROLLERAXISMOTION:		if( abs( event.caxis.value ) > 16384 ) s_set_controller( event.caxis.which ); break;
	}
}

In a level, PlayStation pad: ○ = Back, ✕ = Accept (B is Back in menus, so it's Circle here).

Keyboard on the save screen: the fourth hint was a Square glyph, it's the Flip key now.

5Draw the new tags, load both fonts

diffWn32/Code/Plat/Gfx/nx/chars.cpp · working tree

 				case 'b':
 				case 'B':
+				case 'x':
+				case 'X':
+				case 'p':
+				case 'P':
 				{
-					// 'B' stands for button, accesses the button font
+					// 'B' stands for button, accesses the button font ('X' / 'P' the Xbox / PlayStation one)
+					p_font = s_buttons_font( *pLetter );

diffCode/Gfx/NxFontMan.cpp · working tree

 	Nx::CFontManager::sLoadFont(p_name, (int) char_spacing, (int) space_spacing, p_rgba_tab, is_buttons_font);

+	// PC: the Xbox buttons too, the button hints show the controller in use (see SIO::ExpandButtonTags)
+	if (is_buttons_font)
+		Nx::CFontManager::sLoadFont("ButtonsXbox", (int) char_spacing, (int) space_spacing, p_rgba_tab, true);

6Expand on SetText, re-expand on switch, re-layout the menu

Text elements keep the original string and where it was set. When the device or a binding changes, they re-expand, re-measure, and nudge their menu (menus only lay out children when locked), so the helper bar re-spaces itself.

diffCode/Gfx/2D/TextElement.cpp · working tree

 void CTextElement::SetText(const char *pText)
 {
+	// Button hints show the keys / buttons of the device used last, as they work where the text is set
+	if (SIO::HasButtonTags(pText))
+	{
+		m_button_source = pText;
+		m_button_context = SIO::GetCurrentBindingContext();
+		refresh_button_tags();
+	}
+	else
+	{
+		m_button_source.clear();
+		set_expanded_text(pText);
+	}
+}
@@ void CTextElement::update() @@
+	// The device used last or the bindings changed: show the new keys / buttons
+	if (!m_button_source.empty() && m_button_generation != SIO::GetButtonGlyphGeneration())
+	{
+		float old_w = m_base_w;
+		refresh_button_tags();
+		if (m_base_w != old_w)
+			s_relayout_menu(mp_parent);
+	}

diffCode/Gfx/NxFont.h · working tree

-		vMAX_TEXT_CHARS = 96
+		vMAX_TEXT_CHARS = 256	// PC: 96 on consoles; button tags expand to key names (see SIO::ExpandButtonTags)

7Shrink a hint bar that got too wide

Key names are wider than icons; five keyboard hints ran off the screen. Horizontal menus now scale themselves down to fit, and back up when they fit again.

diffCode/Gfx/2D/Menu2.cpp · working tree

+// PC: button hints with key names (see SIO::ExpandButtonTags) can make a row of them, the helper text,
+// wider than the screen. Shrink such a row to fit, and give it back its scale when it fits again.
+void CBaseMenu::fit_to_screen()
+{
+	const float max_w = 600.0f;		// of the 640 wide screen
+	...
+	if (m_base_w * scale_x > max_w)
+	{
+		float fit = max_w / (m_base_w * scale_x);
+		SetScale(scale_x * fit, scale_y * fit, false, FORCE_INSTANT);
+	}
@@ void CBaseMenu::reposition() @@
+	if (!m_is_vertical_menu)
+		fit_to_screen();
 	compute_ul_pos(m_target_local_props);

\bm is 3 bytes. <Num\_Enter> is 14. A 96-byte strcpy buffer had opinions about that.

FOR EDUCATION PURPOSES ONLY. Screenshots are captured from the port running the reader's own copy of the game. The diffs are trimmed to the interesting lines (unchanged context is cut, marked ⋯); the repository has the full changes. Paths are relative to the THUG/ folder.