I can't find any performance benefit to using the GL path and the code
renders this trapezoid incorrectly:
top: FIXED 29.50
bottom: FIXED 30.00
left top: POINT 0.00, 29.50
left bottom: POINT 0.00, 30.50
right top: POINT -127.50, 29.50
right bottom: POINT 52.50, 30.00
This should render a solid line from 0,30 to 52,30 but draws nothing.
The code also uses an area computation for trapezoid coverage which
does not conform to the Render specification which requires a specific
point sampling technique.
Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>