PDFlib - controlling background and opacity of text color, text background and text stroke - pdflib

Question

I'm trying to set separate values of background and opacity of text color, text background and text stroke (outline).
Code below
$p->save();
$p->setfont($font, 240);
$p->set_gstate($p->create_gstate('opacityfill=1 opacitystroke=1')); // Both fill and stroke are opaque
$p->set_graphics_option('fillcolor={rgb 0.075 0.973 0.024} strokecolor={rgb 0 0 1}');
$p->fit_textline('QfjIL', 30, 30, 'matchbox={boxheight={88% 24.5%} borderwidth=0 round=0 fillcolor={rgb 1 1 0}} charspacing=0 textrendering=2 strokewidth=10 position={left top}');
$p->restore();
results in:
Yellow background, blue letter stroke and green letter fill are opaque - as expected.
Adding opacity for fill and stroke to gstate as:
$p->save();
$p->setfont($font, 240);
$p->set_gstate($p->create_gstate('opacityfill=0.3 opacitystroke=0.3'));
$p->set_graphics_option('fillcolor={rgb 0.075 0.973 0.024} strokecolor={rgb 0 0 1}');
$p->fit_textline('QfjIL', 30, 30, 'matchbox={boxheight={88% 24.5%} borderwidth=0 round=0 fillcolor={rgb 1 1 0}} charspacing=0 textrendering=2 strokewidth=10 position={left top}');
$p->restore();
results in ALL OF background, fill and stroke using the same opacity:
Question:
How can I control separately text background opacity (yellow), letter stroke opacity (blue) and letter fill opacity (green)?

Answer 1

this is the expected result, as you specify the graphics state for all fill and stroke content.
You should set the opacity gstate only for the text, and a solid gstate for the matchbox.
$p->save();
$gstate_solid = $p->create_gstate('opacityfill=1 opacitystroke=1');
$gstate = $p->create_gstate('opacityfill=0.3 opacitystroke=0.3');
$p->fit_textline('QfjIL', 30, 30,
'fontname=NotoSerif-Regular encoding=unicode fontsize=240 ' .
'matchbox={boxheight={88% 24.5%} borderwidth=0 round=0 fillcolor={rgb 1 1 0} gstate=' . $gstate_solid . '} '
'charspacing=0 textrendering=2 strokewidth=10 position={left top} gstate=' . $gstate . 'fillcolor={rgb 0.075 0.973 0.024} strokecolor={rgb 0 0 1}');
$p->restore();
this give the following result, I guess this is the expected result.
you find within the PDFlib 9.2 API reference, chapter 6.2 "Matchboxes" all details about the matchbox options.