Improve SVG support by allowing control of density/DPI

Switch pre-built libs from Imagemagick to Graphicsmagick

test/fixtures/Wikimedia-logo.svg

@@ -1,17 +0,0 @@
-<?xml version="1.0" standalone="yes"?>
-<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
-
-<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1"
-   id="Wikimedia logo"
-   viewBox="-599 -599 1198 1198" width="1024" height="1024">
-<defs>
-  <clipPath id="mask">
-    <path d="M 47.5,-87.5 v 425 h -95 v -425 l -552,-552 v 1250 h 1199 v -1250 z" />
-  </clipPath>
-</defs>
-<g clip-path="url(#mask)">
-  <circle id="green parts" fill="#396" r="336.5"/>
-  <circle id="blue arc" fill="none" stroke="#069" r="480.25" stroke-width="135.5" />
-</g>
-<circle fill="#900" cy="-379.5" r="184.5" id="red circle"/>
-</svg>

test/fixtures/check.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+      <path d="M30,76q6-14,13-26q6-12,14-23q8-12,13-17q3-4,6-6q1-1,5-2q8-1,12-1q1,0,1,1q0,1-1,2q-13,11-27,33q-14,21-24,44q-4,9-5,11q-1,2-9,2q-5,0-6-1q-1-1-5-6q-5-8-12-15q-3-4-3-6q0-2,4-5q3-2,6-2q3,0,8,3q5,4,10,14z" fill="green" />
+</svg>

test/fixtures/index.js

@@ -84,7 +84,7 @@ module.exports = {
   inputWebPWithTransparency: getPath('5_webp_a.webp'), // http://www.gstatic.com/webp/gallery3/5_webp_a.webp
   inputTiff: getPath('G31D.TIF'), // http://www.fileformat.info/format/tiff/sample/e6c9a6e5253348f4aef6d17b534360ab/index.htm
   inputGif: getPath('Crash_test.gif'), // http://upload.wikimedia.org/wikipedia/commons/e/e3/Crash_test.gif
-  inputSvg: getPath('Wikimedia-logo.svg'), // http://commons.wikimedia.org/wiki/File:Wikimedia-logo.svg
+  inputSvg: getPath('check.svg'), // http://dev.w3.org/SVG/tools/svgweb/samples/svg-files/check.svg
   inputPsd: getPath('free-gearhead-pack.psd'), // https://dribbble.com/shots/1624241-Free-Gearhead-Vector-Pack
 
   inputSvs: getPath('CMU-1-Small-Region.svs'), // http://openslide.cs.cmu.edu/download/openslide-testdata/Aperio/CMU-1-Small-Region.svs

test/unit/io.js

@@ -634,20 +634,37 @@ describe('Input/output', function() {
   });
 
   if (sharp.format.magick.input.file) {
-    it('Convert SVG, if supported, to PNG', function(done) {
+    it('Convert SVG to PNG at default 72DPI', function(done) {
       sharp(fixtures.inputSvg)
-        .resize(100, 100)
+        .resize(1024)
+        .extract({left: 290, top: 760, width: 40, height: 40})
         .toFormat('png')
         .toBuffer(function(err, data, info) {
           if (err) {
             assert.strictEqual(0, err.message.indexOf('Input file is missing or of an unsupported image format'));
             done();
           } else {
-            assert.strictEqual(true, info.size > 0);
             assert.strictEqual('png', info.format);
-            assert.strictEqual(100, info.width);
-            assert.strictEqual(100, info.height);
-            fixtures.assertSimilar(fixtures.expected('svg.png'), data, done);
+            assert.strictEqual(40, info.width);
+            assert.strictEqual(40, info.height);
+            fixtures.assertSimilar(fixtures.expected('svg72.png'), data, done);
+          }
+        });
+    });
+    it('Convert SVG to PNG at 300DPI', function(done) {
+      sharp(fixtures.inputSvg, { density: 1200 })
+        .resize(1024)
+        .extract({left: 290, top: 760, width: 40, height: 40})
+        .toFormat('png')
+        .toBuffer(function(err, data, info) {
+          if (err) {
+            assert.strictEqual(0, err.message.indexOf('Input file is missing or of an unsupported image format'));
+            done();
+          } else {
+            assert.strictEqual('png', info.format);
+            assert.strictEqual(40, info.width);
+            assert.strictEqual(40, info.height);
+            fixtures.assertSimilar(fixtures.expected('svg1200.png'), data, done);
           }
         });
     });
@@ -824,6 +841,27 @@ describe('Input/output', function() {
 
   });
 
+  describe('Input options', function() {
+    it('Non-Object options fails', function() {
+      assert.throws(function() {
+        sharp(null, 'zoinks');
+      });
+    });
+    it('Invalid density: string', function() {
+      assert.throws(function() {
+        sharp(null, { density: 'zoinks' } );
+      });
+    });
+    it('Invalid density: float', function() {
+      assert.throws(function() {
+        sharp(null, { density: 0.5 } );
+      });
+    });
+    it('Ignore unknown attribute', function() {
+      sharp(null, { unknown: true } );
+    });
+  });
+
   it('Queue length change events', function(done) {
     var eventCounter = 0;
     var queueListener = function(queueLength) {