CanvasRenderingContext2d#filter

Like patternQuality, but applies to transformations effecting more than just
patternsi (i.e. the implicitly created pattern).

See
http://cairographics.org/manual/cairo-cairo-pattern-t.html#cairo-pattern-set-filter
for more information.

Readme.md

@@ -155,6 +155,16 @@ Defaults to _path_.
 
 This property is tracked as part of the canvas state in save/restore.
 
+### CanvasRenderingContext2d#filter
+
+Like `patternQuality`, but applies to transformations effecting more than just patterns. Defaults to _good_.
+
+  - fast
+  - good
+  - best
+  - nearest
+  - bilinear
+
 ### Global Composite Operations
 
 In addition to those specified and commonly implemented by browsers, the following have been added:

src/CanvasRenderingContext2d.cc

@@ -141,6 +141,7 @@ Context2d::Initialize(Handle<Object> target) {
   proto->SetAccessor(String::NewSymbol("shadowBlur"), GetShadowBlur, SetShadowBlur);
   proto->SetAccessor(String::NewSymbol("antialias"), GetAntiAlias, SetAntiAlias);
   proto->SetAccessor(String::NewSymbol("textDrawingMode"), GetTextDrawingMode, SetTextDrawingMode);
+  proto->SetAccessor(String::NewSymbol("filter"), GetFilter, SetFilter);
   target->Set(String::NewSymbol("CanvasRenderingContext2d"), constructor->GetFunction());
 }
 
@@ -1015,6 +1016,48 @@ Context2d::SetTextDrawingMode(Local<String> prop, Local<Value> val, const Access
   }
 }
 
+/*
+ * Get filter.
+ */
+
+Handle<Value>
+Context2d::GetFilter(Local<String> prop, const AccessorInfo &info) {
+  HandleScope scope;
+  Context2d *context = ObjectWrap::Unwrap<Context2d>(info.This());
+  const char *filter;
+  switch (cairo_pattern_get_filter(cairo_get_source(context->context()))) {
+    case CAIRO_FILTER_FAST: filter = "fast"; break;
+    case CAIRO_FILTER_BEST: filter = "best"; break;
+    case CAIRO_FILTER_NEAREST: filter = "nearest"; break;
+    case CAIRO_FILTER_BILINEAR: filter = "bilinear"; break;
+    default: filter = "good";
+  }
+  return scope.Close(String::NewSymbol(filter));
+}
+
+/*
+ * Set filter.
+ */
+
+void
+Context2d::SetFilter(Local<String> prop, Local<Value> val, const AccessorInfo &info) {
+  String::AsciiValue str(val->ToString());
+  Context2d *context = ObjectWrap::Unwrap<Context2d>(info.This());
+  cairo_filter_t filter;
+  if (0 == strcmp("fast", *str)) {
+    filter = CAIRO_FILTER_FAST;
+  } else if (0 == strcmp("best", *str)) {
+    filter = CAIRO_FILTER_BEST;
+  } else if (0 == strcmp("nearest", *str)) {
+    filter = CAIRO_FILTER_NEAREST;
+  } else if (0 == strcmp("bilinear", *str)) {
+    filter = CAIRO_FILTER_BILINEAR;
+  } else {
+    filter = CAIRO_FILTER_GOOD;
+  }
+  cairo_pattern_set_filter(cairo_get_source(context->context()), filter);
+}
+
 /*
  * Get miter limit.
  */

src/CanvasRenderingContext2d.h

@@ -126,6 +126,7 @@ class Context2d: public node::ObjectWrap {
     static Handle<Value> GetShadowBlur(Local<String> prop, const AccessorInfo &info);
     static Handle<Value> GetAntiAlias(Local<String> prop, const AccessorInfo &info);
     static Handle<Value> GetTextDrawingMode(Local<String> prop, const AccessorInfo &info);
+    static Handle<Value> GetFilter(Local<String> prop, const AccessorInfo &info);
     static void SetPatternQuality(Local<String> prop, Local<Value> val, const AccessorInfo &info);
     static void SetGlobalCompositeOperation(Local<String> prop, Local<Value> val, const AccessorInfo &info);
     static void SetGlobalAlpha(Local<String> prop, Local<Value> val, const AccessorInfo &info);
@@ -139,6 +140,7 @@ class Context2d: public node::ObjectWrap {
     static void SetShadowBlur(Local<String> prop, Local<Value> val, const AccessorInfo &info);
     static void SetAntiAlias(Local<String> prop, Local<Value> val, const AccessorInfo &info);
     static void SetTextDrawingMode(Local<String> prop, Local<Value> val, const AccessorInfo &info);
+    static void SetFilter(Local<String> prop, Local<Value> val, const AccessorInfo &info);
     inline void setContext(cairo_t *ctx) { _context = ctx; }
     inline cairo_t *context(){ return _context; }
     inline Canvas *canvas(){ return _canvas; }