fix: distribution map did not work when there were no nodes with a tag

1 files changed, 12 insertions, 1 deletions

diff --git a/tagstats/geodistribution.hpp b/tagstats/geodistribution.hpp
index 8b4e43f..d4a080f 100644
--- a/tagstats/geodistribution.hpp
+++ b/tagstats/geodistribution.hpp
@@ -179,7 +179,7 @@ public:
             }
         }
 
-        void *png = gdImagePngPtr(im, size);
+        void* png = gdImagePngPtr(im, size);
         gdImageDestroy(im);
 
         return png;
@@ -192,6 +192,17 @@ public:
         gdFree(png);
     }
 
+    static void* create_empty_png(int* size) {
+        gdImagePtr im = gdImageCreate(c_width, c_height);
+        int bgColor = gdImageColorAllocate(im, 0, 0, 0);
+        gdImageColorTransparent(im, bgColor);
+
+        void* png = gdImagePngPtr(im, size);
+        gdImageDestroy(im);
+
+        return png;
+    }
+
     /**
      * Return the number of cells set.
      */