1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
| | ;;; canvas.el --- Canvas support for GNU Emacs
;; Copyright (C) 2020 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;; These are several utlity functions for canvas operations that can
;;; be implemented in Lisp code.
\f
;;; Code:
(defun canvas-fill-pixel (canvas x y color opacity)
"Set the pixel at X, Y inside CANVAS to COLOR, with the opacity OPACITY."
(canvas-rectangle canvas x y 1 1 color opacity))
(defun canvas-from-image (image &optional width height)
"Create a canvas from IMAGE.
The canvas will be no wider than WIDTH (if specified),
and no taller than HEIGHT (if specified)."
(let ((canvas (make-canvas (or width (car (image-size image t)))
(or height (cdr (image-size image t))))))
(prog1 canvas (canvas-draw-image canvas image 0 0))))
(defun canvas-width (canvas)
"Return the width of CANVAS."
(car (canvas-dimensions canvas)))
(defun canvas-height (canvas)
"Return the height of CANVAS."
(cdr (canvas-dimensions canvas)))
(provide 'canvas)
;;; canvas.el ends here
|