;;; 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
oia.scm?id=85d80283b6d14b19dacdd687590eba494da4864f'>gnu: pep-engine: Update to 2.1.34.</a><span class='msg-avail'>...</span></td><td>Hartmut Goebel</td></tr>
<tr><td><span title='2021-05-23 17:49:56 +0200'>2021-05-23</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=dbcf2b61b1f48cbe84d51873f4e4de60897b914c'>gnu: Fix erroneous uses of 'package/inherit'.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-05-04 09:44:14 +0200'>2021-05-04</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=ec4012c5820fb139d07dee492f8b0d492ec1c042'>gnu: sequoia: Update to 1.1.0.</a><span class='msg-avail'>...</span></td><td>Hartmut Goebel</td></tr>
<tr><td><span title='2021-03-22 11:20:17 +0200'>2021-03-22</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=ff1c7e40252337cb2c992c2d41e0ed4cefe56df0'>gnu: sequoia4pEp: Adjust inputs.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-03-22 09:54:19 +0200'>2021-03-22</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=4d0fe40f65e096a4d07f4cc8c95139a4dda96c53'>gnu: sequoia4pEp: Move to sequoia.scm.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2021-01-30 15:34:41 +0100'>2021-01-30</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=880e6334b7aeda04ad8572f9c68a9055de15aeb8'>gnu: rust-dirs-2: Drop minor version from name.</a><span class='msg-avail'>...</span></td><td>Nicolas Goaziou</td></tr>
<tr><td><span title='2021-01-08 10:33:12 +0100'>2021-01-08</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=a240686cc34454a3221c31f3c546985c2c90bf2c'>gnu: sequoia: Update to 1.0.0.</a><span class='msg-avail'>...</span></td><td>Hartmut Goebel</td></tr>
<tr><td><span title='2021-01-03 20:55:47 +0200'>2021-01-03</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=d76f073aba307bcf0b277290c161a8c054c1c549'>gnu: rust-anyhow-1: Drop minor version from name.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2020-12-02 21:53:44 +0100'>2020-12-02</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=6f9edf40b83782d81f4c1c91d97aa11d042506e0'>gnu: sequoia: Update to 0.20.0.</a><span class='msg-avail'>...</span></td><td>Hartmut Goebel</td></tr>
<tr><td><span title='2020-10-12 11:41:40 +0530'>2020-10-12</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=93922eecc9f8dec90dca8fdf1df163db42c196e5'>gnu: rust-flate2-1.0: Remove minor version from variable name.</a><span class='msg-avail'>...</span></td><td>Arun Isaac</td></tr>
<tr><td><span title='2020-10-12 11:41:39 +0530'>2020-10-12</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=2cc9d2a7cf27a45cf4927fa8a5cdc6d36b05ea09'>gnu: rust-percent-encoding-2.1: Remove minor version from variable name.</a><span class='msg-avail'>...</span></td><td>Arun Isaac</td></tr>
<tr><td><span title='2020-10-12 11:41:39 +0530'>2020-10-12</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=ff4d0937c71318b42ee6d86487df72aae49da6f8'>gnu: rust-url-2.1: Remove minor version from variable name.</a><span class='msg-avail'>...</span></td><td>Arun Isaac</td></tr>
<tr><td><span title='2020-10-12 11:41:38 +0530'>2020-10-12</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=262e40d095dd6851577540fd9bb4023c4565e53e'>gnu: rust-thiserror-1.0: Remove minor version from variable name.</a><span class='msg-avail'>...</span></td><td>Arun Isaac</td></tr>
<tr><td><span title='2020-08-04 15:57:33 +0200'>2020-08-04</span></td><td><a href='/guix/commit/gnu/packages/sequoia.scm?id=0a568bbcdef6b1a5c83e6ea993639e3d6ca3c0cc'>gnu: rust-proc-macro2: Don't include minor version in variable name.</a><span class='msg-avail'>...</span></td><td>Jakub Kądziołka</td></tr>