[PATCH 3/4] d3dx9: Implement clipping of glyphs in ID3DXFont_DrawText.

[Matteo Bruni]

On Tue, Nov 17, 2020 at 3:34 PM Sven Baars <sbaars at codeweavers.com> wrote:
>
> Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=49546
> Signed-off-by: Sven Baars <sbaars at codeweavers.com>
> ---
>  dlls/d3dx9_36/font.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/dlls/d3dx9_36/font.c b/dlls/d3dx9_36/font.c
> index 235ae11072b..f5775384da3 100644
> --- a/dlls/d3dx9_36/font.c
> +++ b/dlls/d3dx9_36/font.c
> @@ -583,7 +583,6 @@ static const WCHAR *read_line(HDC hdc, const WCHAR *str, unsigned int *count,
>          }
>          else if (format & DT_SINGLELINE)
>          {
> -            *dest_len = num_fit;
>              *count = 0;
>          }
>      }

IIUC this is to allow drawing partial glyphs in the DT_SINGLELINE
case, is that right?

> @@ -768,6 +767,21 @@ static INT WINAPI ID3DXFontImpl_DrawTextW(ID3DXFont *iface, ID3DXSprite *sprite,
>              pos.y = cell_inc.y + y;
>              pos.z = 0;
>
> +            if (!(format & DT_NOCLIP))
> +            {
> +                if (pos.x > rect->right)
> +                {
> +                    IDirect3DTexture9_Release(texture);
> +                    continue;
> +                }
> +
> +                if (pos.x + black_box.right - black_box.left > rect->right)
> +                    black_box.right = black_box.left + rect->right - pos.x;
> +
> +                if (pos.y + black_box.bottom - black_box.top > rect->bottom)
> +                    black_box.bottom = black_box.top + rect->bottom - pos.y;
> +            }
> +
>              ID3DXSprite_Draw(target, texture, &black_box, NULL, &pos, color);
>              IDirect3DTexture9_Release(texture);
>          }

This certainly looks correct. I'm curious how this fixes bug 49546
though. I'm not questioning that it does, just wondering how not
clipping to the rect makes the text disappear altogether...