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tutorials/summed_area/snippets/defineCount.js

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+// where br is the cell we're calculating
+function defineCount(br) {
+    let c = 0;
+
+    // br.x is the column number
+    // br.y is the row number
+    for (y = 0; y <= br.y; y++) { // loop through all rows above br (and the row br is on) 
+        for (x = 0; x <= br.x; x++) { // loop through all columns to the left of br (and br column) 
+            var i = x + n * y; // convert 2d array format to 1d index 
+            if (t[i].s) { // if cell[i].status==true then increase count 
+                c++;
+            }
+        }
+    }
+    return c;
+}