avoid copy of image data by using new, more efficient mapnik::raster …

…constructor - closes #1516
mapnik · Oct 3, 2012 · 4bc6b0c · 4bc6b0c
1 parent f4ead94
commit 4bc6b0c
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Showing 3 changed files with 9 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,8 @@ For a complete change history, see the git log.
 
 ## Future
 
+- Faster rendering of rasters by reducing memory allocation of temporary buffers (#1516)
+
 - Added ability to pass a pre-created collision detector to the cairo renderer (#1444)
 
 - Tolerance parameter is now supported for querying datasources at a given point (#503/#1499)

diff --git a/plugins/input/gdal/gdal_featureset.cpp b/plugins/input/gdal/gdal_featureset.cpp
@@ -223,7 +223,8 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
 
         if (im_width > 0 && im_height > 0)
         {
-            mapnik::image_data_32 image(im_width, im_height);
+            mapnik::raster_ptr raster = boost::make_shared<mapnik::raster>(intersect, im_width, im_height);
+            mapnik::image_data_32 & image = raster->data_;
             image.set(0xffffffff);
 
             MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Image Size=(" << im_width << "," << im_height << ")";
@@ -489,7 +490,7 @@ feature_ptr gdal_featureset::get_feature(mapnik::query const& q)
                                     image.width(), image.height(), GDT_Byte, 4, 4 * image.width());
                 }
 
-                feature->set_raster(boost::make_shared<mapnik::raster>(intersect, image));
+                feature->set_raster(raster);
             }
             return feature;
         }

diff --git a/plugins/input/raster/raster_featureset.cpp b/plugins/input/raster/raster_featureset.cpp
@@ -111,9 +111,10 @@ feature_ptr raster_featureset<LookupPolicy>::next()
                                                             rem.maxy() + y_off + height);
                         intersect = t.backward(feature_raster_extent);
 
-                        image_data_32 image(width,height);
-                        reader->read(x_off, y_off, image);
-                        feature->set_raster(boost::make_shared<raster>(intersect, image,reader->premultiplied_alpha()));
+                        mapnik::raster_ptr raster = boost::make_shared<mapnik::raster>(intersect, width, height);
+                        reader->read(x_off, y_off, raster->data_);
+                        raster->premultiplied_alpha_ = reader->premultiplied_alpha();
+                        feature->set_raster(raster);
                     }
                 }
             }