implement Canvas::registerFont(ttf)

this is implemented differently depending on the operating system. for
MacOS, CTFontManagerRegisterFontsForURL is the call to add a temporary
font. for Linux we use FontConfig, and for Windows use
AddFontResourceEx. all have been tested successfully

also updated examples/font.js

Author: chearon

binding.gyp

@@ -53,6 +53,7 @@
         'src/color.cc',
         'src/Image.cc',
         'src/ImageData.cc',
+        'src/register_font.cc',
         'src/init.cc'
       ],
       'conditions': [

examples/font.js

@@ -4,42 +4,32 @@
  */
 
 var Canvas = require('../lib/canvas')
-  , canvas = new Canvas(320, 320)
-  , Font = Canvas.Font
-  , ctx = canvas.getContext('2d')
   , fs = require('fs')
   , path = require("path");
 
-if (!Font) {
-	throw new Error('Need to compile with font support');
-}
-
 function fontFile(name) {
   return path.join(__dirname, '/pfennigFont/', name);
 }
 
-var pfennigFont = new Font('pfennigFont', fontFile('Pfennig.ttf'));
-pfennigFont.addFace(fontFile('PfennigBold.ttf'),   'bold');
-pfennigFont.addFace(fontFile('PfennigItalic.ttf'), 'normal', 'italic');
-pfennigFont.addFace(fontFile('PfennigBoldItalic.ttf'), 'bold', 'italic');
-
-var canvas = new Canvas(320, 320)
-var ctx = canvas.getContext('2d')
+Canvas.registerFont(fontFile('Pfennig.ttf'));
+Canvas.registerFont(fontFile('PfennigBold.ttf'));
+Canvas.registerFont(fontFile('PfennigItalic.ttf'));
+Canvas.registerFont(fontFile('PfennigBoldItalic.ttf'));
 
-// Tell the ctx to use the font.
-ctx.addFont(pfennigFont);
+var canvas = new Canvas(320, 320);
+var ctx = canvas.getContext('2d');
 
 ctx.font = 'normal normal 50px Helvetica';
 
 ctx.fillText('Quo Vaids?', 0, 70);
 
-ctx.font = 'bold 50px pfennigFont';
+ctx.font = 'bold 50px Pfennig';
 ctx.fillText('Quo Vaids?', 0, 140);
 
-ctx.font = 'italic 50px pfennigFont';
+ctx.font = 'italic 50px Pfennig';
 ctx.fillText('Quo Vaids?', 0, 210);
 
-ctx.font = 'bold italic 50px pfennigFont';
+ctx.font = 'bold italic 50px Pfennig';
 ctx.fillText('Quo Vaids?', 0, 280);
 
 var out = fs.createWriteStream(__dirname + '/font.png');

lib/canvas.js

@@ -13,6 +13,7 @@ var canvas = require('./bindings')
   , Canvas = canvas.Canvas
   , Image = canvas.Image
   , cairoVersion = canvas.cairoVersion
+  , registerFont = canvas.registerFont
   , Context2d = require('./context2d')
   , PNGStream = require('./pngstream')
   , JPEGStream = require('./jpegstream')
@@ -33,6 +34,12 @@ var Canvas = exports = module.exports = Canvas;
 
 exports.version = packageJson.version;
 
+/**
+ * Register custom font
+ */
+
+exports.registerFont = registerFont;
+
 /**
  * Cairo version.
  */

src/init.cc

@@ -12,12 +12,27 @@
 #include "CanvasGradient.h"
 #include "CanvasPattern.h"
 #include "CanvasRenderingContext2d.h"
+#include "register_font.h"
 
 // Compatibility with Visual Studio versions prior to VS2015
 #if defined(_MSC_VER) && _MSC_VER < 1900
 #define snprintf _snprintf
 #endif
 
+NAN_METHOD(register_font_js) {
+  if (!info[0]->IsString()) {
+    return Nan::ThrowError("Wrong argument type");
+  }
+
+  String::Utf8Value filePath(info[0]);
+
+  if (!register_font((unsigned char*) *filePath)) {
+    Nan::ThrowError("Could not load font to the system's font host");
+  } else {
+    printf("registered %s ok\n", *filePath);
+  }
+}
+
 NAN_MODULE_INIT(init) {
   Canvas::Initialize(target);
   Image::Initialize(target);
@@ -26,6 +41,8 @@ NAN_MODULE_INIT(init) {
   Gradient::Initialize(target);
   Pattern::Initialize(target);
 
+  Nan::SetMethod(target, "registerFont", register_font_js);
+
   target->Set(Nan::New<String>("cairoVersion").ToLocalChecked(), Nan::New<String>(cairo_version_string()).ToLocalChecked());
 #ifdef HAVE_JPEG
 

src/register_font.cc

@@ -0,0 +1,21 @@
+#ifdef __APPLE__
+#include <CoreFoundation/CoreFoundation.h>
+#include <CoreText/CoreText.h>
+#elif defined(_WIN32)
+#include <windows.h>
+#else
+#include <fontconfig/fontconfig.h>
+#endif
+
+bool
+register_font(unsigned char *filepath) {
+  #ifdef __APPLE__
+  CFURLRef filepathUrl = CFURLCreateFromFileSystemRepresentation(NULL, filepath, strlen((char*)filepath), false);
+  return CTFontManagerRegisterFontsForURL(filepathUrl, kCTFontManagerScopeProcess, NULL);
+  #elif defined(_WIN32)
+  return AddFontResourceEx((LPCSTR)filepath, FR_PRIVATE, 0) != 0;
+  #else
+  return FcConfigAppFontAddFile(FcConfigGetCurrent(), (FcChar8 *)(filepath));
+  #endif
+}
+

src/register_font.h

@@ -0,0 +1,2 @@
+bool register_font(unsigned char *filepath);
+