LibGfx: Return 0 width for non-printable ASCII characters

Non-printable characters should always have a width of 0. This is not
true for some characters like tab, but those can be exempted as the need
arises. Doing this here saves us from a bunch of checks in any place
that needs to figure out glyph widths for text which can contain
non-printable characters.

Userland/Libraries/LibGfx/BitmapFont.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/CharacterTypes.h>
 #include <AK/MappedFile.h>
 #include <AK/RefCounted.h>
 #include <AK/RefPtr.h>
@@ -45,7 +46,13 @@ class BitmapFont final : public Font {
  Glyph glyph(u32 code_point) const override;
  bool contains_glyph(u32 code_point) const override { return code_point < (u32)glyph_count() && m_glyph_widths[code_point] > 0; }
 
- u8 glyph_width(size_t ch) const override { return m_fixed_width ? m_glyph_width : m_glyph_widths[ch]; }
+ u8 glyph_width(size_t ch) const override
+ {
+ if (is_ascii(ch) && !is_ascii_printable(ch))
+ return 0;
+
+ return m_fixed_width ? m_glyph_width : m_glyph_widths[ch];
+ }
  ALWAYS_INLINE int glyph_or_emoji_width(u32 code_point) const override
  {
  if (m_fixed_width)