Font: Add a ApplyStyle function that allows to temporarely change how…

… the font is rendered

The returned value is a ScopeGuard to ensure it is always reverted because fonts are shared.

Mostly useful for FreeType to allow reusing the same font for different sizes.

src/font.cpp

@@ -139,6 +139,7 @@ namespace {
 		GlyphRet vRenderShaped(char32_t glyph) const override;
 		bool vCanShape() const override;
 		std::vector<ShapeRet> vShape(U32StringView txt) const override;
+		void vApplyStyle(const Style& style) override;
 
 	private:
 		FT_Face face = nullptr;
@@ -284,6 +285,7 @@ FTFont::FTFont(Filesystem_Stream::InputStream is, int size, bool bold, bool ital
 	}
 
 	if (FT_HAS_COLOR(face)) {
+		// FIXME: Find the best size
 		FT_Select_Size(face, 0);
 	} else {
 		FT_Set_Pixel_Sizes(face, 0, size);
@@ -313,6 +315,10 @@ FTFont::~FTFont() {
 	if (hb_buffer) {
 		hb_buffer_destroy(hb_buffer);
 	}
+
+	if (hb_font) {
+		hb_font_destroy(hb_font);
+	}
 #endif
 
 	if (face) {
@@ -489,6 +495,26 @@ std::vector<Font::ShapeRet> FTFont::vShape(U32StringView txt) const {
 }
 #endif
 
+void FTFont::vApplyStyle(const Style& style) {
+	if (current_style.size == style.size) {
+		return;
+	}
+
+	if (FT_HAS_COLOR(face)) {
+		// FIXME: Find the best size
+		FT_Select_Size(face, 0);
+	} else {
+		FT_Set_Pixel_Sizes(face, 0, style.size);
+	}
+
+#ifdef HAVE_HARFBUZZ
+	// Without this the sizes become desynchronized
+	hb_font_destroy(hb_font);
+	hb_font = hb_ft_font_create_referenced(face);
+	hb_ft_font_set_funcs(hb_font);
+#endif
+}
+
 #endif
 
 FontRef Font::Default() {
@@ -583,16 +609,15 @@ void Font::Dispose() {
 // Constructor.
 Font::Font(StringView name, int size, bool bold, bool italic)
 	: name(ToString(name))
-	, size(size)
-	, bold(bold)
-	, italic(italic)
 {
+	original_style = {size, bold, italic, true};
+	current_style = original_style;
 }
 
 Rect Font::GetSize(char32_t glyph) const {
 	if (EP_UNLIKELY(Utils::IsControlCharacter(glyph))) {
 		if (glyph == '\n') {
-			return {0, 0, 0, static_cast<int>(size)};
+			return {0, 0, 0, static_cast<int>(current_style.size)};
 		}
 
 		return {};
@@ -620,7 +645,7 @@ Point Font::Render(Bitmap& dest, int const x, int const y, const Bitmap& sys, in
 	unsigned src_y;
 
 	if (color != ColorShadow) {
-		if (!gret.has_color) {
+		if (!gret.has_color && current_style.draw_shadow) {
 			auto shadow_rect = Rect(rect.x + 1, rect.y + 1, rect.width, rect.height);
 			dest.MaskedBlit(shadow_rect, *gret.bitmap, 0, 0, sys, 16, 32);
 		}
@@ -667,7 +692,7 @@ Point Font::Render(Bitmap& dest, int const x, int const y, const Bitmap& sys, in
 	unsigned src_y;
 
 	if (color != ColorShadow) {
-		if (!gret.has_color) {
+		if (!gret.has_color && current_style.draw_shadow) {
 			auto shadow_rect = Rect(rect.x + 1, rect.y + 1, rect.width, rect.height);
 			dest.MaskedBlit(shadow_rect, *gret.bitmap, 0, 0, sys, 16, 32);
 		}
@@ -722,6 +747,20 @@ void Font::SetFallbackFont(FontRef fallback_font) {
 	this->fallback_font = fallback_font;
 }
 
+Font::Style Font::GetCurrentStyle() const {
+	return current_style;
+}
+
+Font::StyleScopeGuard Font::ApplyStyle(Style new_style) {
+	vApplyStyle(new_style);
+	current_style = new_style;
+
+	return lcf::ScopeGuard<std::function<void()>>([&]() {
+		vApplyStyle(original_style);
+		current_style = original_style;
+	});
+}
+
 ExFont::ExFont() : Font("exfont", 12, false, false) {
 }
 

src/font.h

@@ -26,6 +26,7 @@
 #include "rect.h"
 #include "string_view.h"
 #include <string>
+#include <lcf/scope_guard.h>
 
 class Color;
 class Rect;
@@ -69,6 +70,13 @@ class Font {
 		bool not_found;
 	};
 
+	struct Style {
+		int size = -1;
+		bool bold = false;
+		bool italic = false;
+		bool draw_shadow = false;
+	};
+
 	virtual ~Font() = default;
 
 	/**
@@ -149,6 +157,24 @@ class Font {
 	 */
 	void SetFallbackFont(FontRef fallback_font);
 
+	using StyleScopeGuard = lcf::ScopeGuard<std::function<void()>>;
+
+	/**
+	 * Returns the current font style used for rendering.
+	 *
+	 * @return current style
+	 */
+	Style GetCurrentStyle() const;
+
+	/**
+	 * Applies a new text style for rendering.
+	 * The style is reverted to the original style afterwards through the returned scope guard.
+	 *
+	 * @param new_style new style to apply
+	 * @return StyleScopeGuard When destroyed, reverts to the old style
+	 */
+	StyleScopeGuard ApplyStyle(Style new_style);
+
 	/**
 	 * Uses the FreeType library to load a font from the provided stream.
 	 *
@@ -178,21 +204,19 @@ class Font {
 		ColorHeal = 9
 	};
 
-	size_t pixel_size() const { return size * 96 / 72; }
-
 	virtual Rect vGetSize(char32_t glyph) const = 0;
 	virtual GlyphRet vRender(char32_t glyph) const = 0;
 	virtual GlyphRet vRenderShaped(char32_t glyph) const { return vRender(glyph); };
 	virtual bool vCanShape() const { return false; }
 	virtual std::vector<ShapeRet> vShape(U32StringView) const { return {}; }
+	virtual void vApplyStyle(const Style& style) { (void)style; };
 
  protected:
 	Font(StringView name, int size, bool bold, bool italic);
 
 	std::string name;
-	unsigned size;
-	bool bold;
-	bool italic;
+	Style original_style;
+	Style current_style;
 	FontRef fallback_font;
 };
 

src/game_windows.cpp

@@ -207,6 +207,10 @@ void Game_Windows::Window_User::Refresh() {
 			const auto& pm = messages[i];
 			const auto& text = data.texts[i];
 
+			auto style = font->GetCurrentStyle();
+			style.size = text.font_size;
+			auto sg = font->ApplyStyle(style);
+
 			int x = text.position_x;
 			int y = text.position_y;
 			for (const auto& line: pm.GetLines()) {
@@ -308,6 +312,11 @@ void Game_Windows::Window_User::Refresh() {
 		const auto& pm = messages[i];
 		const auto& text = data.texts[i];
 
+		auto style = font->GetCurrentStyle();
+		style.size = text.font_size;
+		style.draw_shadow = text.flags.draw_shadow;
+		auto sg = font->ApplyStyle(style);
+
 		int x = text.position_x;
 		int y = text.position_y;
 		int text_color = 0;

src/game_windows.h

@@ -33,7 +33,6 @@ Bold/Italic: Will only work when the font provides a bold/italic typeface
 
 TODO:
 Disable Text Gradient
-Disable Text Shadow
 
 Async (System & Font)
 */