Hello,
I've written a bit of code to shuffle between IMAGO images and SDL surfaces. It should be fast enough to do manipulations on small sprites in real-time on a reasonably fast machine. It only works on RGB(A) images, since I found the overhead for extracting/packing channels is too high. Blitting versions forthcoming when I need them and figure out a good interface for specifying rectangles (for some reason SDL's don't seem all that good to me).
(large-ish) screenshot: http://members.shaw.ca/vsedach/imago_sdl_screen.png
Vladimir
PS - I think my version of with-surface-lock is more correct than the one that comes with cl-sdl right now (sdl:with-locked-surface).
Here are the goodies:
(declaim (optimize (speed 3) (safety 0)))
(defmacro with-surface-lock (surface &body body) (let ((surf (gensym "surface-lock-"))) `(let ((,surf ,surface)) (when (/= 0 (sdl:lock-surface ,surf)) (error "Couldn't lock SDL surface ~A" ,surf)) (unwind-protect (progn ,@body) (sdl:unlock-surface ,surf)))))
(defun convert-to-image (surface) "Given a 24 or 32-bit depth SDL surface, returns an IMAGO RGB image of the same width and height and RGB pixel contents." (assert (or (= 24 (sdl:pixel-format-bits-per-pixel (sdl:surface-format surface))) (= 32 (sdl:pixel-format-bits-per-pixel (sdl:surface-format surface))))) (let* ((width (sdl:surface-w surface)) (height (sdl:surface-h surface)) (image (make-instance 'imago:rgb-image :width width :height height)) (image-array (imago:image-pixels image))) ;; Note that on 32 bit machines, width and height are 32 bit ints (declare (type fixnum width height) (type (simple-array (unsigned-byte 32) (* *)) image-array)) (with-surface-lock surface (dotimes (y height) (declare (type fixnum y)) (dotimes (x width) (declare (type fixnum x)) (setf (aref image-array y x) (sdl:get-pixel surface x y))))) image))
(defmethod convert-to-surface ((image imago:rgb-image) &optional (depth 24)) "Given an IMAGO RGB image, returns an SDL surface of <depth> bit color depth and the same width and height." (let* ((width (imago:image-width image)) (height (imago:image-height image)) (image-array (imago:image-pixels image)) (surface (sdl:create-rgb-surface sdl:+swsurface+ width height depth 0 0 0 0))) (declare (type fixnum width height) (type (simple-array (unsigned-byte 32) (* *)) image-array)) (with-surface-lock surface (dotimes (y height) (declare (type fixnum y)) (dotimes (x width) (declare (type fixnum x)) (sdl:faster-draw-pixel surface x y (aref image-array y x))))) surface))