Profile: Composite profile using imagemagick

by spawning an external process. Very slow but it works.

util/compositing.js

@@ -0,0 +1,42 @@
+const { spawn } = require('child_process');
+const crypto = require('crypto');
+const fs = require('fs');
+const { Card } = require('../models');
+
+//TODO: Handle missing images
+module.exports = {
+    name: "Compositing",
+    renderProfile: async function(profile, svgTemplate, renderedCards) {
+        let hash = crypto.createHash('md5').update(JSON.stringify(profile)).digest('hex');
+
+        let outFile = `/app/assets/image_cache/profiles/${hash}.gif`;
+        console.log('Rendering profile to ' + outFile);
+
+        //composite {overlay} {background} [{mask}] [-compose {method}]   {result}
+        let args =  ['svg:-', 'null:',
+                        '\(', `${renderedCards[0]}`, '-coalesce', '\)',
+                        '-geometry', '+25+85', '-compose', 'over', '-layers', 'composite', 
+                        'null:', '\(', `${renderedCards[1]}`, '-coalesce', '-resize', '170x283', '\)',
+                        '-geometry', '+350+300', '-compose', 'over', '-layers', 'composite',
+                        'null:', '\(', `${renderedCards[2]}`, '-coalesce', '-resize', '170x283', '\)',
+                        '-geometry', '+535+300', '-compose', 'over', '-layers', 'composite',
+                        'null:', '\(', `${renderedCards[3]}`, '-coalesce', '-resize', '170x283', '\)',
+                        '-geometry', '+720+300', '-compose', 'over', '-layers', 'composite',
+                        '-layers', 'optimize', outFile];
+
+        console.log('GM Args: ' + args);
+
+        const composite = spawn('convert', args);
+        composite.stdin.write(svgTemplate);
+        composite.stdin.end();
+        
+        composite.stderr.on('data', (data) => {
+            console.log(`stdout: ${data}`);
+        });
+        const exitCode = await new Promise( (resolve, reject) => {
+            composite.on('close', resolve);
+        })
+        
+        return outFile;
+    }
+}