[metapost] MPlib: some observations on the mp_gr_copy_object(MP mp, mp_graphic_object*p) function

[Graham Douglas]

Hi All

I'm working with MPlib (version 1.801, compiled under Windows 7, 64 bit
) and using mp_gr_copy_object(MP mp,mp_graphic_object*p) to create a way
to cache graphics produced by MPlib (which is now working well, after
the "fixes" below.).  I noticed that the mp_gr_copy_object(MP
mp,mp_graphic_object*p) function (in psout.c) was not copying a number
of key values into the new object --- such as ljoin, lcap colour
information etc. My apologies if this has been fixed or, of course,
there are good reasons that these values are not copied (or it is some
other error on my part). Anyway, I thought I'd make a note of this just
in case. I have highlighted the changes I made within psout.c

Warm wishes
Graham

mp_graphic_object* mp_gr_copy_object(MP mp,mp_graphic_object*p)
{

.....

switch(gr_type(p)){
case mp_fill_code:
tf= (mp_fill_object*)mp_new_graphic_object(mp,mp_fill_code);
gr_pre_script(tf)= mp_xstrdup(mp,gr_pre_script((mp_fill_object*)p));
gr_post_script(tf)= mp_xstrdup(mp,gr_post_script((mp_fill_object*)p));
gr_path_p(tf)= mp_gr_copy_path(mp,gr_path_p((mp_fill_object*)p));
gr_htap_p(tf)= mp_gr_copy_path(mp,gr_htap_p(p));
gr_pen_p(tf)= mp_gr_copy_path(mp,gr_pen_p((mp_fill_object*)p));

//=============================================
//GMD Graham fixes --------------------------------->
tf->ljoin = ((mp_fill_object*)p)->ljoin;
tf->miterlim = ((mp_fill_object*)p)->miterlim;
tf->color_model = ((mp_fill_object*)p)->color_model;
tf->color.a_val = ((mp_fill_object*)p)->color.a_val;
tf->color.b_val = ((mp_fill_object*)p)->color.b_val;
tf->color.c_val = ((mp_fill_object*)p)->color.c_val;
tf->color.d_val = ((mp_fill_object*)p)->color.d_val;
//<-----------------------------------------------------------------
//=============================================
q= (mp_graphic_object*)tf;
break;
case mp_stroked_code:
ts= (mp_stroked_object*)mp_new_graphic_object(mp,mp_stroked_code);
gr_pre_script(ts)= mp_xstrdup(mp,gr_pre_script((mp_stroked_object*)p));
gr_post_script(ts)= mp_xstrdup(mp,gr_post_script((mp_stroked_object*)p));
gr_path_p(ts)= mp_gr_copy_path(mp,gr_path_p((mp_stroked_object*)p));
gr_pen_p(ts)= mp_gr_copy_path(mp,gr_pen_p((mp_stroked_object*)p));
gr_dash_p(ts)= mp_gr_copy_dashes(mp,gr_dash_p(p));

//=============================================
//GMD Graham fixes --------------------------------->
ts->ljoin = ((mp_stroked_object*)p)->ljoin;
ts->color_model = ((mp_stroked_object*)p)->color_model;
ts->miterlim = ((mp_stroked_object*)p)->miterlim;
ts->lcap = ((mp_stroked_object*)p)->lcap;
ts->color_model = ((mp_stroked_object*)p)->color_model;
ts->color.a_val = ((mp_stroked_object*)p)->color.a_val;
ts->color.b_val = ((mp_stroked_object*)p)->color.b_val;
ts->color.c_val = ((mp_stroked_object*)p)->color.c_val;
ts->color.d_val = ((mp_stroked_object*)p)->color.d_val;
//<-----------------------------------------------------------------
//=============================================
q= (mp_graphic_object*)ts;