;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix 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 Guix 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 Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu build svg)
  #:use-module (rsvg)
  #:use-module (cairo)
  #:use-module (srfi srfi-11)
  #:export (svg->png))

(define* (downscaled-surface surface
                             #:key
                             source-width source-height
                             width height)
  "Return a new rendering context where SURFACE is scaled to WIDTH x HEIGHT."
  (let ((cr (cairo-create (cairo-image-surface-create 'argb32
                                                      width height))))
    (cairo-scale cr (/ width source-width) (/ height source-height))
    (cairo-set-source-surface cr surface 0 0)
    (cairo-pattern-set-filter (cairo-get-source cr) 'best)
    (cairo-rectangle cr 0 0 source-width source-height)
    (cairo-fill cr)
    cr))

(define* (svg->png in-svg out-png
                   #:key width height)
  "Render the file at IN-SVG as a PNG file in OUT-PNG.  When WIDTH and HEIGHT
are provided, use them as the dimensions of OUT-PNG; otherwise preserve the
dimensions of IN-SVG."
  (define svg
    (rsvg-handle-new-from-file in-svg))

  (let-values (((origin-width origin-height em ex)
                (rsvg-handle-get-dimensions svg)))
    (let* ((surf (cairo-image-surface-create 'argb32
                                             origin-width origin-height))
           (cr   (cairo-create surf)))
      (rsvg-handle-render-cairo svg cr)
      (cairo-surface-flush surf)
      (let ((cr (if (and width height
                         (not (= width origin-width))
                         (not (= height origin-height)))
                    (downscaled-surface surf
                                        #:source-width origin-width
                                        #:source-height origin-height
                                        #:width width
                                        #:height height)
                    cr)))
        (cairo-surface-write-to-png (cairo-get-target cr) out-png)))))

;;; svg.scm ends here
1aa501a'>gnu: Simplify package inputs.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-07-14 15:57:40 +0200'>2021-07-14</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=731b714e92920039fa63b8229d90c1816ec3910c'>libelf: Update configure script and config.guess and config.sub.</a><span class='msg-avail'>...</span></td><td>Maxime Devos</td></tr>
<tr><td><span title='2021-05-09 23:43:31 +0200'>2021-05-09</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=84943cc9f2d06f7876ffc2bc4ebc0f28a9af9815'>gnu: elfutils: Omit static libraries.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-05-09 23:43:31 +0200'>2021-05-09</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=1d807513963995584364d01be83de67e6bc8f3bf'>gnu: elfutils: Update to 0.183.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-03-23 23:19:57 -0700'>2021-03-23</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=b50f42680352213beb64c248c1af2f9dcc1612fc'>gnu: libelf: Fix compilation for powerpc64le-linux.</a><span class='msg-avail'>...</span></td><td>Leo Le Bouter</td></tr>
<tr><td><span title='2021-01-25 15:40:55 -0500'>2021-01-25</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=68dd78e2e47248b3e1e7ba1807a92a8374b39097'>Merge branch 'master' into staging</a></td><td>Leo Famulari</td></tr>
<tr><td><span title='2021-01-19 17:12:14 -0600'>2021-01-19</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=13f5f3a2516b211766b33b97875c018a6e1e2388'>gnu: libabigail: Update to 1.8.</a><span class='msg-avail'>...</span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2020-12-13 21:44:12 +0100'>2020-12-13</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=17c6b81a67aca90ea13fce2d2a1695a9b5d3be3b'>gnu: elfutils: Update to 0.182.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-07-22 01:39:22 +0200'>2020-07-22</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=337333c2567bdf767fdc8e04520c4bc0c8b33784'>gnu: patchelf: Update to 0.11.</a><span class='msg-avail'>...</span></td><td>Michael Rohleder</td></tr>
<tr><td><span title='2020-06-02 23:41:36 +0200'>2020-06-02</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=c45431a2838644bae90613690b023019b8bce456'>gnu: libabigail: Update to 1.7.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-05-17 20:23:18 +0300'>2020-05-17</span></td><td><a href='/guix/commit/gnu/packages/elf.scm?id=03f4c9414b0c165c856d236ee0024fdf8d54862f'>gnu: elfutils: Skip tests on powerpc.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>