Re: [PATCH 1/2] gdi32: Support the subpixel rendering for FreeType >= 2.8.1 .

[Nikolay Sivov]

On 10/04/2018 03:17 PM, Byeongsik Jeon wrote:
> FreeType >= 2.8.1 support LCD-optimized rendering without LCD filters.
> It works regardless of FT_Err_Unimplemented_Feature check.
> Signed-off-by: Byeongsik Jeon
>
> dlls/gdi32/freetype.c | 25 ++++++++++++++-----------
>   1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/dlls/gdi32/freetype.c b/dlls/gdi32/freetype.c
> index b7e2413753..468c1951b6 100644
> --- a/dlls/gdi32/freetype.c
> +++ b/dlls/gdi32/freetype.c
> @@ -993,18 +993,22 @@ static BOOL is_hinting_enabled(void)
>
> static BOOL is_subpixel_rendering_enabled( void )
>   {
> -#ifdef FT_LCD_FILTER_H
>       static int enabled = -1;
>       if (enabled == -1)
>       {
> -
>    enabled = (pFT_Library_SetLcdFilter &&
> -
>               pFT_Library_SetLcdFilter( NULL, 0 ) != FT_Err_Unimplemented_Feature);
> -
>    /* FreeType >= 2.8.1 offers LCD-optimezed rendering without lcd filters. */
> -
>    if ( FT_SimpleVersion >= ((2 << 16) | (8 << 8) | (1 << 0)))
> -
>        enabled = TRUE;
>
> +#ifdef FT_LCD_FILTER_H
> -
>    else if ( pFT_Library_SetLcdFilter &&
> -
>              pFT_Library_SetLcdFilter( NULL, 0 ) != FT_Err_Unimplemented_Feature )
> -
>        enabled = TRUE;
>
> +#endif
> -
>    else enabled = FALSE;
> -
>     TRACE("subpixel rendering is %senabled\n", enabled ? "" : "NOT ");
> }
> return enabled;
>
> -#else
> - return FALSE;
>
> -#endif
>   }

Could you explain why does this make a difference? I'd expect 
FT_Library_SetLcdFilter to be still functional in 2.8.1+, also how is 
this new rendering mode is enabled?
> @@ -7274,7 +7278,6 @@ static DWORD get_glyph_outline(GdiFont *incoming_font, UINT glyph, UINT format,
>       case WINE_GGO_HBGR_BITMAP:
>       case WINE_GGO_VRGB_BITMAP:
>       case WINE_GGO_VBGR_BITMAP:
> -#ifdef FT_LCD_FILTER_H
>         {
>           switch (ft_face->glyph->format)
>           {
> @@ -7360,8 +7363,11 @@ static DWORD get_glyph_outline(GdiFont *incoming_font, UINT glyph, UINT format,
>               if ( needsTransform )
>                   pFT_Outline_Transform (&ft_face->glyph->outline, &transMatTategaki);
> -
>        if ( pFT_Library_SetLcdFilter )
>
> +#ifdef FT_LCD_FILTER_H
> -
>        if ( FT_SimpleVersion < ((2 << 16) | (8 << 8) | (1 << 0)) &&
> -
>             pFT_Library_SetLcdFilter )
>             pFT_Library_SetLcdFilter( library, FT_LCD_FILTER_DEFAULT );
>
> +#endif
>               pFT_Render_Glyph (ft_face->glyph, render_mode);
>           src = ft_face->glyph->bitmap.buffer;
>
> @@ -7442,9 +7448,6 @@ static DWORD get_glyph_outline(GdiFont *incoming_font, UINT glyph, UINT format,
>       break;
>     }
>
> -#else
> -
>  return GDI_ERROR;
>
> -#endif
>   case GGO_NATIVE:
>     {