[cairo] Font matrix difference between 1.0.4 & 1.2.0

[Behdad Esfahbod]

On Thu, 2006-07-13 at 17:01 -0400, Jan Slupski wrote:
> Hi list,
> 
> I found the change in Cairo's behavior between 1.0.4 and 1.2.0 related
> to text handling.
> 
> Basically I'm trying to use the matrix to setup text rotation.
> 
> I use following code:
>    cairo_move_to()
>    cairo_matrix_init_identity(&matrix);
> 
>    //rotate around text center
>    cairo_matrix_translate(&matrix, size.width/2, -size.height/2);
>    cairo_matrix_rotate(&matrix, 90/180.*3.1415926);
>    cairo_matrix_translate(&matrix, -size.width/2, size.height/2);
> 
>    cairo_matrix_scale(&matrix, fontsize, fontsize);
>    cairo_set_font_matrix(cr, &matrix);
> 
>    cairo_show_text (cr, string);
> 
> 
> While this code used to work with cairo 1.0.4, it does not in 1.2.0
> anymore. Seems like the rotation(?) translation(?) is applied to 
> every letter separately.
> 
> Is this intentional?

Yes and no.  The font matrix should not be used to create a rotated-text
effect.  For that, the ctm should be used (normal cairo_rotate).
However, the output you have attached doesn't look good.  I'm
investigating.

behdad

> Samples and the example code attached.
> 
> Thanks,
> Jan Slupski
> 
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>     | |_| |\ |  S L U P S K I             jslupski at juljas.net
>   |_| | | | \|                             http://juljas.net/
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behdad
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