From: Aric Stewart <aric@codeweavers.com>
Subject: Re: [PATCH 4/5] usp10: Iterate in visual order in GPOS_apply_feature().
Message-Id: <495a0409-d42e-24fb-c1ea-711288ada687@codeweavers.com>
Date: Tue, 21 Feb 2017 07:05:29 -0600
In-Reply-To: <1487524599-13189-4-git-send-email-hverbeet@codeweavers.com>
References: <1487524599-13189-4-git-send-email-hverbeet@codeweavers.com>

Signed-off-by: Aric Stewart <aric@codeweavers.com>

On 2/19/17 11:16 AM, Henri Verbeet wrote:
> In particular, cursive attachment application depends on previous visual order
> glyph offsets. Affects e.g. wordpad with Nastaliq fonts.
> 
> Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
> ---
>  dlls/usp10/shape.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/dlls/usp10/shape.c b/dlls/usp10/shape.c
> index bf333b2..fae4288 100644
> --- a/dlls/usp10/shape.c
> +++ b/dlls/usp10/shape.c
> @@ -882,14 +882,17 @@ static int apply_GSUB_feature(HDC hdc, SCRIPT_ANALYSIS *psa, ScriptCache* psc, W
>  
>  static VOID GPOS_apply_feature(ScriptCache *psc, LPOUTLINETEXTMETRICW lpotm, LPLOGFONTW lplogfont, const SCRIPT_ANALYSIS *analysis, INT* piAdvance, LoadedFeature *feature, const WORD *glyphs, INT glyph_count, GOFFSET *pGoffset)
>  {
> -    int i;
> +    int dir = analysis->fLogicalOrder && analysis->fRTL ? -1 : 1;
> +    unsigned int start_idx, i, j;
>  
>      TRACE("%i lookups\n", feature->lookup_count);
> +
> +    start_idx = dir < 0 ? glyph_count - 1 : 0;
>      for (i = 0; i < feature->lookup_count; i++)
>      {
> -        int j;
>          for (j = 0; j < glyph_count; )
> -            j = OpenType_apply_GPOS_lookup(psc, lpotm, lplogfont, analysis, piAdvance, feature->lookups[i], glyphs, j, glyph_count, pGoffset);
> +            j = OpenType_apply_GPOS_lookup(psc, lpotm, lplogfont, analysis, piAdvance,
> +                    feature->lookups[i], glyphs, start_idx + dir * j, glyph_count, pGoffset);
>      }
>  }
>  
>