> To add Chord and Pie to the path handling you should add
> PATH_Chord/Pie to graphics/path.c, which will probably call PATH_Arc
> or something. Treat the path stuff as if it were another graphics
> driver (cf enhmetafiledrv) - in fact I almost converted to one, but
> there are some annoying problems in doing so. I don't understand what
> you mean about coordinate calculation.
take for instance a pie and an open path, we could call PATH_Arc and two
times PATH_LineTo. but where do we get the coordinates for these
PATH_LineTo's ? the helper function X11DRV_DrawArc calculates these because
it must be able to draw pies. we can calculate them again in graphics/path.c
or something, but wouldn't it be nicer to calculate these just once, and not
in the graphics driver ? here's part of the X11DRV_DrawArc helper function
that calculates the coordinates of the endpoints:
start_angle=(double)istart_angle*PI/64./180.;
end_angle=(double)(istart_angle+idiff_angle)*PI/64./180.;
/* calculate the endpoints and round correctly */
points[0].x = (int) floor(dc->w.DCOrgX + (right+left)/2.0 +
cos(start_angle) * (right-left-width*2+2) / 2. + 0.5);
points[0].y = (int) floor(dc->w.DCOrgY + (top+bottom)/2.0 -
sin(start_angle) * (bottom-top-width*2+2) / 2. + 0.5);
points[1].x = (int) floor(dc->w.DCOrgX + (right+left)/2.0 +
cos(end_angle) * (right-left-width*2+2) / 2. + 0.5);
points[1].y = (int) floor(dc->w.DCOrgY + (top+bottom)/2.0 -
sin(end_angle) * (bottom-top-width*2+2) / 2. + 0.5);
by the way, I don't think PATH_Chord/Pie functions are necessary. if chords
and pies are drawn using using Arc() and LineTo(), they indirectly use
PATH_Arc and PATH_LineTo and the right stuff is added to an open path. the
same for PATH_AngleArc.. or am I missing something ?
--
Mark Dufour <[EMAIL PROTECTED]>
Kascade <[EMAIL PROTECTED]>
