LibPDF: Resize fonts when the text and line matrices change

Userland/Libraries/LibPDF/Fonts/PDFFont.h

@@ -26,6 +26,7 @@ public:
 
     virtual ~PDFFont() = default;
 
+    virtual void set_font_size(float font_size) = 0;
     virtual PDFErrorOr<Gfx::FloatPoint> draw_string(Gfx::Painter&, Gfx::FloatPoint, DeprecatedString const&, Color const&, float font_size, float character_spacing, float horizontal_scaling) = 0;
 
     virtual Type type() const = 0;

Userland/Libraries/LibPDF/Fonts/TrueTypeFont.cpp

@@ -40,6 +40,11 @@ float TrueTypeFont::get_glyph_width(u8 char_code) const
     return m_font->glyph_width(char_code);
 }
 
+void TrueTypeFont::set_font_size(float font_size)
+{
+    m_font = m_font->with_size((font_size * POINTS_PER_INCH) / DEFAULT_DPI);
+}
+
 void TrueTypeFont::draw_glyph(Gfx::Painter& painter, Gfx::FloatPoint point, float, u8 char_code, Color color)
 {
     // Account for the reversed font baseline

Userland/Libraries/LibPDF/Fonts/TrueTypeFont.h

@@ -15,6 +15,7 @@ namespace PDF {
 class TrueTypeFont : public SimpleFont {
 public:
     float get_glyph_width(u8 char_code) const override;
+    void set_font_size(float font_size) override;
     void draw_glyph(Gfx::Painter&, Gfx::FloatPoint, float, u8, Color) override;
     Type type() const override { return PDFFont::Type::TrueType; }
 

Userland/Libraries/LibPDF/Fonts/Type0Font.cpp

@@ -87,6 +87,10 @@ float Type0Font::get_char_width(u16 char_code) const
     return static_cast<float>(width) / 1000.0f;
 }
 
+void Type0Font::set_font_size(float)
+{
+}
+
 PDFErrorOr<Gfx::FloatPoint> Type0Font::draw_string(Gfx::Painter&, Gfx::FloatPoint, DeprecatedString const&, Color const&, float, float, float)
 {
     return Error::rendering_unsupported_error("Type0 font not implemented yet");

Userland/Libraries/LibPDF/Fonts/Type0Font.h

@@ -19,6 +19,7 @@ struct CIDSystemInfo {
 
 class Type0Font : public PDFFont {
 public:
+    void set_font_size(float font_size) override;
     PDFErrorOr<Gfx::FloatPoint> draw_string(Gfx::Painter&, Gfx::FloatPoint pos, DeprecatedString const&, Color const&, float, float, float) override;
     Type type() const override { return PDFFont::Type::Type0; }
 

Userland/Libraries/LibPDF/Fonts/Type1Font.cpp

@@ -54,6 +54,12 @@ float Type1Font::get_glyph_width(u8 char_code) const
     return m_font->glyph_width(char_code);
 }
 
+void Type1Font::set_font_size(float font_size)
+{
+    if (m_font)
+        m_font = m_font->with_size((font_size * POINTS_PER_INCH) / DEFAULT_DPI);
+}
+
 void Type1Font::draw_glyph(Gfx::Painter& painter, Gfx::FloatPoint point, float width, u8 char_code, Color color)
 {
     if (!m_font_program) {

Userland/Libraries/LibPDF/Fonts/Type1Font.h

@@ -15,6 +15,7 @@ namespace PDF {
 class Type1Font : public SimpleFont {
 public:
     float get_glyph_width(u8 char_code) const override;
+    void set_font_size(float font_size) override;
     void draw_glyph(Gfx::Painter& painter, Gfx::FloatPoint point, float width, u8 char_code, Color color) override;
     Type type() const override { return PDFFont::Type::Type1; }
 

Userland/Libraries/LibPDF/Renderer.cpp

@@ -458,6 +458,13 @@ RENDERER_HANDLER(text_set_matrix_and_line_matrix)
     m_text_line_matrix = new_transform;
     m_text_matrix = new_transform;
     m_text_rendering_matrix_is_dirty = true;
+
+    // Settings the text/line matrix retroactively affects fonts
+    if (text_state().font) {
+        auto new_text_rendering_matrix = calculate_text_rendering_matrix();
+        text_state().font->set_font_size(text_state().font_size * new_text_rendering_matrix.x_scale());
+    }
+
     return {};
 }