Align font height, capHeight to FreeType metrics

Previously, `height` was derived from a manually chosen glyph (typically
"I", Standard Cap Height) using FontBuilder, and `lineSpacing` was used
inconsistently for layout logic as a height.

Now, with the FreeType-based system:
- `height` uses `face->size->metrics.height`, which includes the
  recommended line height with internal leading/line gap as defined by
  the font designer.
- `lineSpacing` was removed
- `GetCapHeight` uses the standard cap height + ascender to have a
  visual virtual alignment

This change standardizes font metric usage:
- Use `height` for vertical layout and line progression.
- Use `GetCapheight` in layout engines like `CGUIText` or `CGUIString`,

This ensures better alignment across fonts and consistent spacing in
multiline text rendering.

Fixes: #7962

source/graphics/Font.cpp

@@ -28,6 +28,7 @@
 #include <numeric>
 #include <string>
 #include <vector>
+#include <cstdlib>
 
 namespace
 {
@@ -74,14 +75,16 @@ void CFont::GlyphMap::set(u16 codepoint, const GlyphData& glyph)
 	(*m_Data[codepoint >> 8])[codepoint & 0xff].defined = 1;
 }
 
-float CFont::GetLineSpacing() const {
-	return m_LineSpacing / m_Scale;
-}
-
 float CFont::GetHeight() const {
 	return m_Height / m_Scale;
 }
 
+float CFont::GetCapHeight()
+{
+	const CFont::GlyphData* g{GetGlyph(L'I')};
+	return (g ? g->yadvance : 0) + std::abs(FPosF26Dot6ToFloat(m_Faces.front()->size->metrics.descender));
+}
+
 float CFont::GetCharacterWidth(wchar_t c)
 {
 	PROFILE2("GetCharacterWidth font texture generate");
@@ -94,11 +97,13 @@ void CFont::CalculateStringSize(const wchar_t* string, float& width, float& heig
 {
 	PROFILE2("CalculateStringSize font texture generate");
 	width = 0;
-	height = GetHeight();
+	height = 0;
 
 	// Compute the width as the width of the longest line.
+	std::wstring original{string};
 	std::wistringstream stream{string};
 	std::wstring line;
+	bool firstLine{true};
 	while (std::getline(stream, line))
 	{
 		FT_UInt glyphIndexStorage{0};
@@ -129,8 +134,15 @@ void CFont::CalculateStringSize(const wchar_t* string, float& width, float& heig
 		};
 
 		width = std::max(width, lineWidth);
-		height += GetLineSpacing();
+
+		if (!firstLine || !line.empty())
+			height += firstLine ? GetCapHeight() : GetHeight();
+
+		firstLine = false;
 	}
+
+	if (original.back() == L'\n')
+		height += GetHeight();
 }
 
 bool CFont::SetFontParams(const std::string& fontName, float size, float strokeWidth, float scale)
@@ -204,15 +216,10 @@ bool CFont::AddFontFromPath(const OsPath& fontPath)
 		return false;
 	}
 
+	// Get the height of the font.
 	if(m_Faces.empty())
-	{
-		// Get the height of the font.
 		m_Height = FPosF26Dot6ToFloat(face->size->metrics.height);
 
-		// Get the line spacing of the font.
-		m_LineSpacing = FPosF26Dot6ToFloat(face->size->metrics.ascender - face->size->metrics.descender);
-	}
-
 	// Add the fallback font to the list.
 	m_Faces.push_back({face, &ftFaceDeleter});
 
@@ -385,6 +392,7 @@ const CFont::GlyphData* CFont::ExtractAndGenerateGlyph(u16 codepoint)
 	gd.y1 = m_StrokeWidth / m_Scale;
 
 	gd.xadvance = glyphW / m_Scale;
+	gd.yadvance = FPosF26Dot6ToFloat(slot->metrics.height) / m_Scale;
 	gd.defined = 1;
 	gd.face = faceToUse;
 

source/graphics/Font.h

@@ -45,6 +45,7 @@ public:
 		float u0, v0, u1, v1;
 		float x0, y0, x1, y1;
 		float xadvance;
+		float yadvance;
 		u8 defined{0};
 		FT_Face face;
 	};
@@ -77,8 +78,16 @@ public:
 	};
 
 	bool HasRGB() const { return m_HasRGB; }
-	float GetLineSpacing() const;
 	float GetHeight() const;
+
+	/**
+	* In typography, cap height is the height of a capital letter above the baseline for a particular typeface.
+	* It specifically is the height of capital letters that are flat—such as H or I—as opposed to round letters such as O, or pointed letters like A,
+	* both of which may display overshoot. The height of the small letters is the x-height.
+	* REf: https://en.wikipedia.org/wiki/Cap_height
+	*/
+	float GetCapHeight();
+
 	float GetCharacterWidth(wchar_t c);
 	float GetStrokeWidth() const { return m_StrokeWidth; }
 	void CalculateStringSize(const wchar_t* string, float& w, float& h);
@@ -127,8 +136,6 @@ private:
 
 	GlyphMap m_Glyphs;
 
-	float m_LineSpacing;
-
 	// Height of a capital letter, roughly.
 	float m_Height;
 

source/graphics/FontMetrics.cpp

@@ -29,15 +29,6 @@ CFontMetrics::CFontMetrics(CStrIntern font)
 	m_Font = g_Renderer.GetFontManager().LoadFont(font);
 }
 
-float CFontMetrics::GetLineSpacing() const
-{
-	// Return some arbitrary default if the font failed to load, so that the
-	// user of CFontMetrics doesn't have to care about failures
-	if (!m_Font)
-		return 12;
-	return m_Font->GetLineSpacing();
-}
-
 float CFontMetrics::GetHeight() const
 {
 	if (!m_Font)
@@ -59,3 +50,10 @@ void CFontMetrics::CalculateStringSize(const wchar_t* string, float& w, float& h
 	else
 		m_Font->CalculateStringSize(string, w, h);
 }
+
+float CFontMetrics::GetCapHeight()
+{
+	if (!m_Font)
+		return 0.0f;
+	return m_Font->GetCapHeight();
+}

source/graphics/FontMetrics.h

@@ -31,8 +31,8 @@ class CFontMetrics
 public:
 	CFontMetrics(CStrIntern font);
 
-	float GetLineSpacing() const;
 	float GetHeight() const;
+	float GetCapHeight();
 	float GetCharacterWidth(wchar_t c) const;
 	void CalculateStringSize(const wchar_t* string, float& w, float& h) const;
 

source/gui/ObjectTypes/CInput.cpp

@@ -33,6 +33,8 @@
 #include "ps/Hotkey.h"
 
 #include <sstream>
+#include <maths/Size2D.h>
+#include <cstdlib>
 
 extern int g_yres;
 
@@ -1232,8 +1234,8 @@ void CInput::DrawContent(CCanvas2D& canvas)
 	}
 
 	// Get the height of this font.
-	float h = (float)font.GetHeight();
+	const float h{font.GetCapHeight()};
-	float ls = (float)font.GetLineSpacing();
+	const float ls{font.GetHeight()};
 
 	CTextRenderer textRenderer;
 	textRenderer.SetCurrentFont(font_name);
@@ -1880,7 +1882,7 @@ void CInput::UpdateText(int from, int to_before, int to_after)
 
 	if (m_ScrollBar)
 	{
-		GetScrollBar(0).SetScrollRange(m_CharacterPositions.size() * font.GetLineSpacing() + m_BufferZone * 2.f);
+		GetScrollBar(0).SetScrollRange(m_CharacterPositions.size() * font.GetHeight() + m_BufferZone * 2.f);
 		GetScrollBar(0).SetScrollSpace(m_CachedActualSize.GetHeight());
 	}
 }
@@ -1903,10 +1905,8 @@ int CInput::GetMouseHoveringTextPosition() const
 		if (m_ScrollBar)
 			scroll = GetScrollBarPos(0);
 
-		// Now get the height of the font.
+		const CFontMetrics font{CStrIntern{m_Font->ToUTF8()}};
-						// TODO: Get the real font
+		const float spacing{font.GetHeight()};
-		CFontMetrics font(CStrIntern(m_Font->ToUTF8()));
-		float spacing = (float)font.GetLineSpacing();
 
 		// Change mouse position relative to text.
 		mouse -= m_CachedActualSize.TopLeft();
@@ -2032,11 +2032,8 @@ void CInput::UpdateAutoScroll()
 
 		const float scroll = GetScrollBar(0).GetPos();
 
-		// Now get the height of the font.
+		const CFontMetrics font{CStrIntern{m_Font->ToUTF8()}};
-						// TODO: Get the real font
+		const float spacing{font.GetHeight()};
-		CFontMetrics font(CStrIntern(m_Font->ToUTF8()));
-		float spacing = (float)font.GetLineSpacing();
-		//float height = font.GetHeight();
 
 		// TODO Gee (2004-11-21): Okay, I need a 'std::list' for some reasons, but I would really like to
 		//  be able to get the specific element here. This is hopefully a temporary hack.

source/gui/SettingTypes/CGUIString.cpp

@@ -27,6 +27,7 @@
 
 #include <algorithm>
 #include <array>
+#include <cstdlib>
 
 // List of word delimiter bounds
 // The list contains ranges of word delimiters. The odd indexed chars are the start
@@ -217,9 +218,9 @@ void CGUIString::GenerateTextCall(const CGUI& pGUI, SFeedback& Feedback, CStrInt
 			// For anything other than the first line, the line spacing
 			// needs to be considered rather than just the height of the text.
 			if (FirstLine)
-				size.Height = font.GetHeight();
+				size.Height = font.GetCapHeight();
 			else
-				size.Height = font.GetLineSpacing();
+				size.Height = font.GetHeight();
 
 			// Append width, and make maximum height the height.
 			Feedback.m_Size.Width += size.Width;

source/gui/tests/test_CGUIText.h

@@ -95,10 +95,10 @@ public:
 		CGUI gui{*g_ScriptContext};
 
 		const CStrW font{L"mono-10"};
-		const CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
+		CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
 
-		const float lineHeight{fontMetrics.GetHeight()};
+		const float lineHeight{fontMetrics.GetCapHeight()};
-		const float lineSpacing{fontMetrics.GetLineSpacing()};
+		const float lineSpacing{fontMetrics.GetHeight()};
 
 		CGUIString string;
 		CGUIText text;
@@ -219,8 +219,8 @@ public:
 		TS_ASSERT(firstWordWidth < secondWordWidth);
 		const float spaceWidth = fontMetrics.GetCharacterWidth(L' ');
 
-		const float lineHeight = fontMetrics.GetHeight();
+		const float lineHeight{fontMetrics.GetCapHeight()};
-		const float lineSpacing = fontMetrics.GetLineSpacing();
+		const float lineSpacing{fontMetrics.GetHeight()};
 
 		auto layoutText = [&gui, &string, &font, lineHeight, firstWordWidth](const float width)
 		{
@@ -284,9 +284,9 @@ public:
 		CGUI gui{*g_ScriptContext};
 
 		const CStrW font{L"mono-10"};
-		const CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
+		CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
-		const float lineHeight{fontMetrics.GetHeight()};
+		const float lineHeight{fontMetrics.GetCapHeight()};
-		const float lineSpacing{fontMetrics.GetLineSpacing()};
+		const float lineSpacing{fontMetrics.GetHeight()};
 
 		float renderedWidth = 0.f;
 		const float width = 200.f;
@@ -334,8 +334,8 @@ public:
 
 		const CStrW font{L"sans-bold-13"};
 		CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
-		const float lineHeight = fontMetrics.GetHeight();
+		const float lineHeight{fontMetrics.GetCapHeight()};
-		const float lineSpacing = fontMetrics.GetLineSpacing();
+		const float lineSpacing{fontMetrics.GetHeight()};
 
 		CGUIString string;
 		CGUIText text;
@@ -353,9 +353,9 @@ public:
 		CGUI gui{*g_ScriptContext};
 
 		const CStrW font{L"mono-10"};
-		const CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
+		CFontMetrics fontMetrics{CStrIntern(font.ToUTF8())};
-		const float lineHeight{fontMetrics.GetHeight()};
+		const float lineHeight{fontMetrics.GetCapHeight()};
-		const float lineSpacing{fontMetrics.GetLineSpacing()};
+		const float lineSpacing{fontMetrics.GetHeight()};
 
 		CGUIString string;
 		CGUIText text;

source/ps/CConsole.cpp

@@ -42,6 +42,7 @@
 #include "scriptinterface/JSON.h"
 
 #include <algorithm>
+#include <cmath>
 #include <string_view>
 #include <vector>
 #include <wctype.h>
@@ -95,19 +96,19 @@ void CConsole::Init()
 
 	// Calculate and store the line spacing
 	const CFontMetrics font{CStrIntern(m_consoleFont)};
-	m_FontHeight = font.GetLineSpacing();
+	m_FontHeight = font.GetHeight();
 	m_FontWidth = font.GetCharacterWidth(L'C');
 	m_CharsPerPage = static_cast<size_t>(g_xres / m_FontWidth);
 	// Offset by an arbitrary amount, to make it fit more nicely
-	m_FontOffset = 7;
+	m_FontOffset = 7.0f;
 
 	m_CursorBlinkRate = g_ConfigDB.Get("gui.cursorblinkrate", 0.5);
 }
 
 void CConsole::UpdateScreenSize(int w, int h)
 {
-	m_X = 0;
+	m_X = 0.0f;
-	m_Y = 0;
+	m_Y = 0.0f;
 	float height = h * 0.6f;
 	m_Width = w / g_VideoMode.GetScale();
 	m_Height = height / g_VideoMode.GetScale();
@@ -230,8 +231,8 @@ void CConsole::DrawWindow(CCanvas2D& canvas)
 	if (m_Height > m_FontHeight + 4)
 	{
 		points = {
-			CVector2D{0.0f, m_Height - static_cast<float>(m_FontHeight) - 4.0f},
+			CVector2D{0.0f, m_Height - m_FontHeight - 4.0f},
-			CVector2D{m_Width, m_Height - static_cast<float>(m_FontHeight) - 4.0f}
+			CVector2D{m_Width, m_Height - m_FontHeight - 4.0f}
 		};
 		for (CVector2D& point : points)
 			point += CVector2D{m_X, m_Y - (1.0f - m_VisibleFrac) * m_Height};
@@ -258,7 +259,7 @@ void CConsole::DrawHistory(CTextRenderer& textRenderer)
 		{
 			textRenderer.Put(
 				9.0f,
-				m_Height - static_cast<float>(m_FontOffset) - static_cast<float>(m_FontHeight) * (i - m_MsgHistPos + 1),
+				m_Height - m_FontOffset - m_FontHeight * (i - m_MsgHistPos + 1),
 				it->c_str());
 		}
 
@@ -274,7 +275,7 @@ void CConsole::DrawBuffer(CTextRenderer& textRenderer)
 
 	const CVector2D savedTranslate = textRenderer.GetTranslate();
 
-	textRenderer.Translate(2.0f, m_Height - static_cast<float>(m_FontOffset) + 1.0f);
+	textRenderer.Translate(2.0f, m_Height - m_FontOffset + 1.0f);
 
 	textRenderer.SetCurrentColor(CColor(1.0f, 1.0f, 0.0f, 1.0f));
 	textRenderer.PutAdvance(L"]");
@@ -415,7 +416,7 @@ void CConsole::InsertChar(const int szChar, const wchar_t cooked)
 		{
 			std::lock_guard<std::mutex> lock(m_Mutex); // needed for safe access to m_deqMsgHistory
 
-			const int linesShown = static_cast<int>(m_Height / m_FontHeight) - 4;
+			const int linesShown = static_cast<int>(std::ceil(m_Height / m_FontHeight)) - 4;
 			m_MsgHistPos = Clamp(static_cast<int>(m_MsgHistory.size()) - linesShown, 1, static_cast<int>(m_MsgHistory.size()));
 		}
 		else

source/ps/CConsole.h

@@ -78,9 +78,9 @@ private:
 	// Lock for all state modified by InsertMessage
 	std::mutex m_Mutex;
 
-	int m_FontHeight;
+	float m_FontHeight;
-	int m_FontWidth;
+	float m_FontWidth;
-	int m_FontOffset; // distance to move up before drawing
+	float m_FontOffset; // distance to move up before drawing
 	size_t m_CharsPerPage;
 
 	float m_X;

source/ps/CLogger.cpp

@@ -173,16 +173,16 @@ void CLogger::Render(CCanvas2D& canvas)
 
 	CleanupRenderQueue();
 
-	CStrIntern font_name("mono-stroke-10");
+	CStrIntern font_name{"mono-stroke-10"};
-	CFontMetrics font(font_name);
+	CFontMetrics font{font_name};
-	int lineSpacing = font.GetLineSpacing();
+	float height{font.GetHeight()};
 
 	CTextRenderer textRenderer;
 	textRenderer.SetCurrentFont(font_name);
 	textRenderer.SetCurrentColor(CColor(1.0f, 1.0f, 1.0f, 1.0f));
 
 	// Offset by an extra 35px vertically to avoid the top bar.
-	textRenderer.Translate(4.0f, 35.0f + lineSpacing);
+	textRenderer.Translate(4.0f, 35.0f + height);
 
 	// (Lock must come after loading the CFont, since that might log error messages
 	// and attempt to lock the mutex recursively which is forbidden)
@@ -216,7 +216,7 @@ void CLogger::Render(CCanvas2D& canvas)
 
 		textRenderer.ResetTranslate(savedTranslate);
 
-		textRenderer.Translate(0.0f, (float)lineSpacing);
+		textRenderer.Translate(0.0f, height);
 	}
 
 	canvas.DrawText(textRenderer);

source/ps/ProfileViewer.cpp

@@ -162,7 +162,7 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 
 	CStrIntern font_name("mono-stroke-10");
 	CFontMetrics font(font_name);
-	int lineSpacing = font.GetLineSpacing();
+	int height = font.GetHeight();
 
 	// Render background.
 	float estimateWidth = 50.0f;
@@ -172,7 +172,7 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 	float estimateHeight = 3 + static_cast<float>(numrows);
 	if (m->path.size() > 1)
 		estimateHeight += 2;
-	estimateHeight *= lineSpacing;
+	estimateHeight *= height;
 
 	canvas.DrawRect(CRect(CSize2D(estimateWidth, estimateHeight)), CColor(0.0f, 0.0f, 0.0f, 0.5f));
 
@@ -180,7 +180,7 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 	for (size_t row = 0; row < numrows; ++row)
 	{
 		canvas.DrawRect(
-			CRect(CVector2D(0.0f, lineSpacing * (2.0f + row) + 2.0f), CSize2D(estimateWidth, lineSpacing)),
+			CRect(CVector2D(0.0f, height * (2.0f + row) + 2.0f), CSize2D(estimateWidth, height)),
 			row % 2 ? CColor(1.0f, 1.0f, 1.0f, 0.1f): CColor(0.0f, 0.0f, 0.0f, 0.1f));
 	}
 
@@ -188,8 +188,8 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 	CTextRenderer textRenderer;
 	textRenderer.SetCurrentFont(font_name);
 	textRenderer.SetCurrentColor(CColor(1.0f, 1.0f, 1.0f, 1.0f));
-	textRenderer.PrintfAt(2.0f, lineSpacing, L"%hs", table->GetTitle().c_str());
+	textRenderer.PrintfAt(2.0f, height, L"%hs", table->GetTitle().c_str());
-	textRenderer.Translate(22.0f, lineSpacing*2.0f);
+	textRenderer.Translate(22.0f, height*2.0f);
 
 	float colX = 0.0f;
 	for (size_t col = 0; col < columns.size(); ++col)
@@ -206,7 +206,7 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 		colX += columns[col].width;
 	}
 
-	textRenderer.Translate(0.0f, lineSpacing);
+	textRenderer.Translate(0.0f, height);
 
 	// Print rows
 	int currentExpandId = 1;
@@ -239,14 +239,14 @@ void CProfileViewer::RenderProfile(CCanvas2D& canvas)
 			rowColX += columns[col].width;
 		}
 
-		textRenderer.Translate(0.0f, lineSpacing);
+		textRenderer.Translate(0.0f, height);
 	}
 
 	textRenderer.SetCurrentColor(CColor(1.0f, 1.0f, 1.0f, 1.0f));
 
 	if (m->path.size() > 1)
 	{
-		textRenderer.Translate(0.0f, lineSpacing);
+		textRenderer.Translate(0.0f, height);
 		textRenderer.Put(-15.0f, 0.0f, L"0");
 		textRenderer.Put(0.0f, 0.0f, L"back to parent");
 	}