wrong pixel extents retrieved from PangoLayout of arabic text

[Parth Kanungo <kanungoparth gmail com>]

Hello,

I am facing an issue related to the pixel extents of PangoLayout.

Here is what I have done.

I am rendering Arabic Text.

         gunichar2 text[] = {  0x0644, 0x0627, 0x0020, 0x064A, 0x0648, 0x062C, 0x062F, 0x0020, 0x0645, 0x0644, 0x0641, 0x0020, 0x0641, 0x064A, 0x062F, 0x064A, 0x0648, 0x0020, 0x0645, 0x062A, 0x0627, 0x062D, 0x0020, 0x062D, 0x0627, 0x0644, 0x064A, 0x064B, 0x0627, 0x002E, 0 };

char* inputStr = g_utf16_to_utf8(text, 28, &itemsRead, &itemsWritten, &error);

pango_layout_set_text(layout, (const char*)inputStr, -1);

I have set the height, width and other parameters of PangoLayout.

pango_layout_set_height(layout,100*PANGO_SCALE);

pango_layout_set_width(layout,215*PANGO_SCALE);

pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);

pango_layout_set_wrap(layout, PANGO_WRAP_CHAR);

On output, it appeared to me as if the left-most portion of the text was getting clipped. Hence, I printed the pixel-extents of the PangoLayout.   

(Output image:  https://sites.google.com/site/fontengine/issue)

This is what I got:

logical_rect:

x: -6

y:  0

w:  227

h:  72

ink_rect

x: -5

y:  8

w: 226

h:  64

I don't understand how can I get a negitive x OR, a width greater than the width that I have manually set on PangoLayout

Moreover, I found that this issue occurs only in case of arabic text. 

Is this a known bug? OR, have I done some mistake here?

My source code (test.cpp) has been shared here:  https://sites.google.com/site/fontengine/issue/

Thanks a lot.

--

Parth