The lack of this pair of parens triggered a compiler warning, which
turned into an error at -Werror. Oops - I thought I'd folded that fix
in before pushing Franklin's series.
This adds a portable, scanline-based polygon filling algorithm, which
fills a polygon by drawing a collection of adjacent horizontal lines.
This change is motivated by the Rockbox port's current lack of a true
polygon fill capability. Until now, it attempted to approximate a
polygon fill by performing a series of triangle fills, but this worked
reliably only for convex polygons. I originally considered making this
new rasterizer part of the Rockbox front end itself, but I ultimately
decided that it made more sense to include it here, in the Puzzles
distribution, where other platforms may benefit from it in the future.
No in-tree front ends use this new function quite yet, but I plan to
follow this commit with a compile-time option to force front ends to
use it for testing.
This new polygon drawing code also comes with its own standalone
driver code to test it out in isolation. This code currently relies on
SDL 2.0 to present a GUI window to the user, which unfortunately adds
a build-time dependency. To lessen the impact of this change, this
program is gated behind a CMake build option. To use it, run:
$ cmake -DBUILD_SDL_PROGRAMS=true
