emacs-framebuffer

commit 3e88d3fe5168adef96bf95c722a7129ff7dbea0c
parent f4ce24c1f53f4483ed4fa19e27e6710fbbbd9872
Author: Tomas Hlavaty <tom@logand.com>
Date:   Thu, 18 Jun 2020 23:05:54 +0200

added framebuffer-draw-test

Diffstat:
M
emacs-framebuffer.el
 | 
42
++++++++++++++++++++++++++++++++++++++++++

1 file changed, 42 insertions(+), 0 deletions(-)
diff --git a/emacs-framebuffer.el b/emacs-framebuffer.el
@@ -50,6 +50,19 @@
 
 (defvar framebuffer-size nil)
 
+(defun framebuffer-virtual-size ()
+  (with-temp-buffer
+    ;; TODO which framebuffer if more than one?
+    (insert-file-contents "/sys/class/graphics/fb0/virtual_size")
+    (search-forward-regexp "\\([0-9]+\\),\\([0-9]+\\)")
+    (cons (read (match-string 1)) (read (match-string 2)))))
+
+(defun framebuffer-bits-per-pixel ()
+  (with-temp-buffer
+    ;; TODO which framebuffer if more than one?
+    (insert-file-contents "/sys/class/graphics/fb0/bits_per_pixel")
+    (read (current-buffer))))
+
 (defun framebuffer-size ()
   (if (and framebuffer-width framebuffer-height)
       (cons framebuffer-width framebuffer-height)
@@ -304,4 +317,33 @@
     (define-key dired-mode-map "N" 'framebuffer-image-file-dired-next)
     (define-key dired-mode-map "P" 'framebuffer-image-file-dired-previous)))
 
+(defun framebuffer-draw-test ()
+  (interactive)
+  (destructuring-bind (fbw &rest fbh) (framebuffer-size)
+    (destructuring-bind (vw &rest vh) (framebuffer-virtual-size)
+      (destructuring-bind (x1 y1 x2 y2) (window-edges (get-buffer-window) t)
+        (let* ((fw (frame-width))
+               (fh (frame-height))
+               (cw (floor fbw fw))
+               (ch (floor fbh fh))
+               (wx (* x1 cw))
+               (wy (* y1 ch))
+               (ww (* (- x2 x1) cw))
+               (wh (* (- y2 y1) ch)))
+          (with-temp-buffer
+            (set-buffer-multibyte nil)
+            (insert-file-contents-literally "/dev/fb0")
+            (ecase (framebuffer-bits-per-pixel)
+              (32
+               (dotimes (y wh)
+                 (goto-char (+ (point-min) (* 4 vw (+ y wy)) (* 4 wx)))
+                 (dotimes (x ww)
+                   (delete-char 4)
+                   (insert (mod x 256))
+                   (insert (mod y 256))
+                   (insert (random 256))
+                   (insert 0)))))
+            (let ((coding-system-for-write 'raw-text-unix))
+              (write-region (point-min) (point-max) "/dev/fb0"))))))))
+
 (provide 'framebuffer)