[Git][freetype/freetype][master] 2 commits: [truetype] Limit INSTCTRL ap

Alexei Podtelezhnikov pushed to branch master at FreeType / FreeType

Commits:

a35b081e

by Alexei Podtelezhnikov at 2021-12-11T22:12:25-05:00

[truetype] Limit INSTCTRL appication within specs.

* src/truetype/ttinterp.c (Ins_INSTCTRL): Limit its global effects
to the CVT program and local effects to the glyph program.

This also fixes an Infinality buglet. The `ignore_x_mode` should be
locally unset by the glyph program.

7809007a

by Alexei Podtelezhnikov at 2021-12-11T22:22:57-05:00

[truetype] Relocate subpixel flag setting.

`TT_RunIns` is too busy to deal with subpixel flags. It is better
to set them in `tt_loader_init`, which is executed before each
glyph program.

* src/truetype/ttinterp.c (TT_RunIns): Move the flag setting from
here...
* src/truetype/ttgload.c (tt_loader_init): ... to here.

2 changed files:

src/truetype/ttgload.c
src/truetype/ttinterp.c

Changes:

src/truetype/ttgload.c

@@ -2719,8 +2719,35 @@
        /* note that this flag can also be modified in a glyph's bytecode */
        if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 &&
             exec->GS.instruct_control & 4                            )
 -        exec->ignore_x_mode = 0;
 -#endif
 +        exec->ignore_x_mode = FALSE;
++
 +      exec->iup_called = FALSE;
 +#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
++
 +#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
 +      /*
 +       * Toggle backward compatibility according to what font wants, except
 +       * when
 +       *
 +       * 1) we have a `tricky' font that heavily relies on the interpreter to
 +       *    render glyphs correctly, for example DFKai-SB, or
 +       * 2) FT_RENDER_MODE_MONO (i.e, monochome rendering) is requested.
 +       *
 +       * In those cases, backward compatibility needs to be turned off to get
 +       * correct rendering.  The rendering is then completely up to the
 +       * font's programming.
 +       *
 +       */
 +      if ( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
 +           subpixel_hinting_lean                                    &&
 +           !FT_IS_TRICKY( glyph->face )                             )
 +        exec->backward_compatibility = !( exec->GS.instruct_control & 4 );
 +      else
 +        exec->backward_compatibility = FALSE;
++
 +      exec->iupx_called = FALSE;
 +      exec->iupy_called = FALSE;
 +#endif /* TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL */
        exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
        loader->exec = exec;

src/truetype/ttinterp.c

@@ -5260,16 +5260,21 @@
+       }
+     }
 -    exc->GS.instruct_control &= ~(FT_Byte)Kf;
 -    exc->GS.instruct_control |= (FT_Byte)L;
 +    /* INSTCTRL should only be used in the CVT program */
 +    if ( exc->iniRange == tt_coderange_cvt )
 +    {
 +      exc->GS.instruct_control &= ~(FT_Byte)Kf;
 +      exc->GS.instruct_control |= (FT_Byte)L;
 +    }
 -    if ( K == 3 )
 +    /* except to change the subpixel flags temporarily */
 +    else if ( exc->iniRange == tt_coderange_glyph && K == 3 )
+     {
  #ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
        /* INSTCTRL modifying flag 3 also has an effect */
        /* outside of the CVT program                   */
        if ( SUBPIXEL_HINTING_INFINALITY )
 -        exc->ignore_x_mode = FT_BOOL( L == 4 );
 +        exc->ignore_x_mode = !FT_BOOL( L == 4 );
  #endif
  #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
@@ -5280,6 +5285,8 @@
          exc->backward_compatibility = !FT_BOOL( L == 4 );
  #endif
+     }
 +    else if ( exc->pedantic_hinting )
 +      exc->error = FT_THROW( Invalid_Reference );
+   }
@@ -7755,35 +7762,6 @@
  #endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
 -#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
 -    exc->iup_called = FALSE;
 -#endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
+-
 -#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
 -    /*
 -     * Toggle backward compatibility according to what font wants, except
 -     * when
 -     *
 -     * 1) we have a `tricky' font that heavily relies on the interpreter to
 -     *    render glyphs correctly, for example DFKai-SB, or
 -     * 2) FT_RENDER_MODE_MONO (i.e, monochome rendering) is requested.
 -     *
 -     * In those cases, backward compatibility needs to be turned off to get
 -     * correct rendering.  The rendering is then completely up to the
 -     * font's programming.
 -     *
 -     */
 -    if ( SUBPIXEL_HINTING_MINIMAL          &&
 -         exc->subpixel_hinting_lean        &&
 -         !FT_IS_TRICKY( &exc->face->root ) )
 -      exc->backward_compatibility = !( exc->GS.instruct_control & 4 );
 -    else
 -      exc->backward_compatibility = FALSE;
+-
 -    exc->iupx_called = FALSE;
 -    exc->iupy_called = FALSE;
 -#endif
+-
      /* We restrict the number of twilight points to a reasonable,     */
      /* heuristic value to avoid slow execution of malformed bytecode. */
      num_twilight_points = FT_MAX( 30,

From:	Alexei Podtelezhnikov (@apodtele)
Subject:	[Git][freetype/freetype][master] 2 commits: [truetype] Limit INSTCTRL appication within specs.
Date:	Sun, 12 Dec 2021 03:30:36 +0000