;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2016, 2017, 2018 Ludovic Courtès ;;; Copyright © 2015 Andy Wingo ;;; ;;; 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 . (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 nce.scm?id=892f1b7273d57b25940700877a02618fe826cc08'>services: Accept <inferior-package>s in lieu of <package>s....Tobias Geerinckx-Rice 2020-12-09services: science.scm: Add missing copyright headers....Efraim Flashner 2020-06-28services: Add rshiny service....Efraim Flashner