Update of /project/movitz/cvsroot/movitz/losp/x86-pc In directory clnet:/tmp/cvs-serv17914
Modified Files: vga.lisp Log Message: Patch from M. Bealby.
--- /project/movitz/cvsroot/movitz/losp/x86-pc/vga.lisp 2007/03/21 21:49:11 1.11 +++ /project/movitz/cvsroot/movitz/losp/x86-pc/vga.lisp 2007/03/26 18:04:04 1.12 @@ -10,7 +10,7 @@ ;;;; Author: Frode Vatvedt Fjeld frodef@acm.org ;;;; Created at: Tue Sep 25 14:08:20 2001 ;;;; -;;;; $Id: vga.lisp,v 1.11 2007/03/21 21:49:11 ffjeld Exp $ +;;;; $Id: vga.lisp,v 1.12 2007/03/26 18:04:04 ffjeld Exp $ ;;;; ;;;;------------------------------------------------------------------
@@ -237,6 +237,7 @@ (defvar *vga-page-count* 0) (defvar *vga-width* 0) (defvar *vga-height* 0) +(defvar *vga-viewport* '(0 0 0 0))
(defconstant +vga-misc-read+ #x0c) (defconstant +vga-misc-write+ #x02) @@ -1117,18 +1118,45 @@ (g-clear)) (values))
+;; read a pixel from the DISPLAYED page +(defun pixel (x y) + (memref-int (vga-memory-map) + :index (+ (* (truncate *vga-width* 4) y) + (truncate x y) + (* (truncate *vga-width* 2) + *vga-height* + (mod (1+ *vga-current-page*) + *vga-page-count*))) + :type :unsigned-byte8)) + ;; set a pixel to a colour of our choice -;; always writing to the next page +;; write to the NEXT page (defun (setf pixel) (col x y) - (set-plane (logand x 3)) - (setf (memref-int (vga-memory-map) - :index (+ (* (truncate *vga-width* 4) y) ; pixel - (truncate x 4) - (* (truncate *vga-width* 2) ; page - *vga-height* - *vga-current-page*)) - :type :unsigned-byte8) - col)) + (cond ((< x (nth 0 (viewport))) (return-from pixel nil)) + ((> x (nth 1 (viewport))) (return-from pixel nil)) + ((< y (nth 2 (viewport))) (return-from pixel nil)) + ((> y (nth 3 (viewport))) (return-from pixel nil)) + (t (set-plane (logand x 3)) + (setf (memref-int (vga-memory-map) + :index (+ (* (truncate *vga-width* 4) y) ; pixel + (truncate x 4) + (* (truncate *vga-width* 2) ; page + *vga-height* + *vga-current-page*)) + :type :unsigned-byte8) + col)))) + + +; return the current viewport as a list +(defun viewport () + *vga-viewport*) + + +; sets the viewport +; rectangle is a list of left-bound, right-bound, top-bound, bottom-bound +(defun (setf viewport) (rectangle) + (setf *vga-viewport* rectangle)) +
;; clear the screen (defun g-clear () @@ -1176,6 +1204,7 @@ (mod (1+ *vga-current-page*) *vga-page-count*)))
+ ;; easy way to get into graphics mode (defun g-start () (setf (vga-state) +vga-state-320x200x256-modex+) @@ -1183,6 +1212,7 @@ (setf *vga-height* 200) (setf *vga-page-count* 2) (setf *vga-current-page* 0) ; writing page + (setf (viewport) `(0 ,(1- *vga-width*) 0 ,(1- *vga-height*))) (unchain-video-mode) (g-clear) (page-flip))
-
ffjeld