From 448eaa29661e50c6b1b971cdee6010dba1ff5d07 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Sun, 25 Feb 2024 13:19:43 -0500
Subject: [PATCH] LibPDF: Let Type1Font use TrueTypePainter for standard fonts

...and for fallback fonts too.

We use Liberation Sans (a truetype font) for standard and fallback
fonts. So we should use the standard PDF algorithm for mapping bytes
to truetype glyphs. TrueTypePainter knows how to do this.

Makes the "fi" ligature in the title on page 1 of 5014.CIDFont_Spec.pdf
or the dotless-i in the title of page 2 of ThinkingInPostScript.pdf
show up. They use Helvetica and TImes, and Helvetica and Symbol
respecitively (with -Bold variants).
---
 Userland/Libraries/LibPDF/Fonts/Type1Font.cpp | 34 ++++++++-----------
 Userland/Libraries/LibPDF/Fonts/Type1Font.h   |  3 +-
 2 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp b/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
index 5c1890ea22..671047d449 100644
--- a/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
+++ b/Userland/Libraries/LibPDF/Fonts/Type1Font.cpp
@@ -49,43 +49,39 @@ PDFErrorOr<void> Type1Font::initialize(Document* document, NonnullRefPtr<DictObj
         return Error::parse_error("Type1 fonts must not be CID-keyed"sv);
 
     if (!m_font_program) {
-        m_font = TRY(replacement_for(base_font_name().to_lowercase(), font_size));
+        // NOTE: We use this both for the 14 built-in fonts and for replacement fonts.
+        // We should probably separate these two cases.
+        auto font = TRY(replacement_for(base_font_name().to_lowercase(), font_size));
+
+        auto effective_encoding = encoding();
+        if (!effective_encoding)
+            effective_encoding = Encoding::standard_encoding();
+        m_fallback_font_painter = TrueTypePainter::create(document, dict, *this, *font, *effective_encoding);
     }
 
-    VERIFY(m_font_program || m_font);
+    VERIFY(m_font_program || m_fallback_font_painter);
     return {};
 }
 
 Optional<float> Type1Font::get_glyph_width(u8 char_code) const
 {
-    if (m_font)
-        return m_font->glyph_width(char_code);
+    if (m_fallback_font_painter)
+        return m_fallback_font_painter->get_glyph_width(char_code);
     return OptionalNone {};
 }
 
 void Type1Font::set_font_size(float font_size)
 {
-    if (m_font)
-        m_font = m_font->with_size((font_size * POINTS_PER_INCH) / DEFAULT_DPI);
+    if (m_fallback_font_painter)
+        m_fallback_font_painter->set_font_size(font_size);
 }
 
 PDFErrorOr<void> Type1Font::draw_glyph(Gfx::Painter& painter, Gfx::FloatPoint point, float width, u8 char_code, Renderer const& renderer)
 {
     auto style = renderer.state().paint_style;
 
-    if (!m_font_program) {
-        // Undo shift in Glyf::Glyph::append_simple_path() via OpenType::Font::rasterize_glyph().
-        auto position = point.translated(0, -m_font->pixel_metrics().ascent);
-        // FIXME: Bounding box and sample point look to be pretty wrong
-        if (style.has<Color>()) {
-            painter.draw_glyph(position, char_code, *m_font, style.get<Color>());
-        } else {
-            style.get<NonnullRefPtr<Gfx::PaintStyle>>()->paint(Gfx::IntRect(position.x(), position.y(), width, 0), [&](auto sample) {
-                painter.draw_glyph(position, char_code, *m_font, sample(Gfx::IntPoint(position.x(), position.y())));
-            });
-        }
-        return {};
-    }
+    if (!m_font_program)
+        return m_fallback_font_painter->draw_glyph(painter, point, width, char_code, renderer);
 
     auto effective_encoding = encoding();
     if (!effective_encoding)
diff --git a/Userland/Libraries/LibPDF/Fonts/Type1Font.h b/Userland/Libraries/LibPDF/Fonts/Type1Font.h
index 454905e22d..d327f96a00 100644
--- a/Userland/Libraries/LibPDF/Fonts/Type1Font.h
+++ b/Userland/Libraries/LibPDF/Fonts/Type1Font.h
@@ -8,6 +8,7 @@
 
 #include <LibGfx/Font/ScaledFont.h>
 #include <LibPDF/Fonts/SimpleFont.h>
+#include <LibPDF/Fonts/TrueTypeFont.h>
 #include <LibPDF/Fonts/Type1FontProgram.h>
 
 namespace PDF {
@@ -34,7 +35,7 @@ protected:
 private:
     DeprecatedFlyString m_base_font_name;
     RefPtr<Type1FontProgram> m_font_program;
-    RefPtr<Gfx::Font> m_font;
+    OwnPtr<TrueTypePainter> m_fallback_font_painter;
     HashMap<Type1GlyphCacheKey, RefPtr<Gfx::Bitmap>> m_glyph_cache;
 };