surface: Add useful selectors.
authorDavid Thompson <dthompson2@worcester.edu>
Sun, 20 Dec 2015 21:03:03 +0000 (16:03 -0500)
committerDavid Thompson <dthompson2@worcester.edu>
Sun, 20 Dec 2015 21:03:03 +0000 (16:03 -0500)
commitdb3dea0c6ab3a2a8407035b44a1aaa4e8cdbdd86
treee809716d96dc8594c4f0e20a107b38fa27a3b62c
parentdd73061d9a20fb5da9e4a6fe0a0d55ea3bfcdd62
surface: Add useful selectors.

* sdl2/surface.scm (pointer-int-ref, surface-width, surface-height)
(surface-pitch, surface-pixels): New procedures.
(%int-size, %pointer-size, %width-offset, %height-offset, %pitch-offset)
(%pixels-offset): New variables.
sdl2/surface.scm