SkPDF Implement colorfilters on bitmaps

src/pdf/SkPDFDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPDFDevice.h"
 
 #include "SkAnnotation.h"
 #include "SkColor.h"
+#include "SkColorFilter.h"
 #include "SkClipStack.h"
 #include "SkData.h"
 #include "SkDraw.h"
 #include "SkGlyphCache.h"
 #include "SkPaint.h"
 #include "SkPath.h"
 #include "SkPathOps.h"
 #include "SkPDFBitmap.h"
 #include "SkPDFFont.h"
 #include "SkPDFFormXObject.h"
@@ skipping 2173 matching lines @@
         shape.addRect(SkRect::MakeWH(SkIntToScalar(subset.width()),
                                      SkIntToScalar(subset.height())));
         shape.transform(matrix);
         content.setShape(shape);
     }
     if (!content.needSource()) {
         return;
     }
 
     SkBitmap subsetBitmap;
-    // Should extractSubset be done by the SkPDFDevice?
     if (!bitmap->extractSubset(&subsetBitmap, subset)) {
         return;
     }
+    if (SkColorFilter* colorFilter = paint.getColorFilter()) {
+        // TODO(http://skbug.com/4378): implement colorfilter on other
+        // draw calls.  This code here works for all drawBitmap*()
+        // calls amd ImageFilters (which rasterize a layer on this
+        // backend).  Fortuanely, this seems to be how Chromium

[scroggo, 2015/09/24 17:20:26]

nit: Fortunately*

+        // impements most color-filters.
+        SkBitmap tmp;
+        if (subsetBitmap.copyTo(&tmp, kN32_SkColorType)) {
+            SkAutoLockPixels autoLockPixelsTmp(tmp);
+            for (int y = 0; y < tmp.height();  ++y) {
+                SkPMColor* pixels = tmp.getAddr32(0, y);
+                colorFilter->filterSpan(pixels, tmp.width(), pixels);
+            }
+            tmp.setImmutable();
+            subsetBitmap = tmp;
+        }
+    }
     SkAutoTUnref<SkPDFObject> image(SkPDFBitmap::Create(fCanon, subsetBitmap));
     if (!image) {
         return;
     }
 
     SkPDFUtils::DrawFormXObject(this->addXObjectResource(image.get()),
                                 &content.entry()->fContent);
 }