add initial scraper for dashing

tools/lua/scrape_dashing.lua

 function tostr(t)
     local str = ""
     for k, v in next, t do
         if #str > 0 then
             str = str .. ", "
         end
         if type(k) == "number" then
             str = str .. "[" .. k .. "] = "
         else
             str = str .. tostring(k) .. " = "
         end
         if type(v) == "table" then
             str = str .. "{ " .. tostr(v) .. " }"
         else
             str = str .. tostring(v)
         end
     end
     return str
 end
 
-local total = {}    -- accumulate() stores its data in here
+local total_found = {}    -- accumulate() stores its data in here
+local total_total = {}
 local canvas        -- holds the current canvas (from startcanvas())
 
 --[[
     startcanvas() is called at the start of each picture file, passing the
     canvas that we will be drawing into, and the name of the file.
     
     Following this call, there will be some number of calls to accumulate(t)
     where t is a table of parameters that were passed to that draw-op.
     
         t.verb is a string holding the name of the draw-op (e.g. "drawRect")
     
     when a given picture is done, we call endcanvas(canvas, fileName)
 ]]
 function sk_scrape_startcanvas(c, fileName)
     canvas = c
 end
 
 --[[
     Called when the current canvas is done drawing.
 ]]
 function sk_scrape_endcanvas(c, fileName)
     canvas = nil
 end
 
---[[
-    Called with the parameters to each canvas.draw call, where canvas is the
-    current canvas as set by startcanvas()
-]]
+function increment(table, key)
+    table[key] = (table[key] or 0) + 1
+end
+
+
+local drawPointsTable = {}
+local drawPointsTable_direction = {}
+
 function sk_scrape_accumulate(t)
-    local n = total[t.verb] or 0
-    total[t.verb] = n + 1
+    increment(total_total, t.verb)
 
-    if false and t.verb == "drawRect" and t.paint:isAntiAlias() then
-        local r = t.rect;
-        local p = t.paint;
-        local c = p:getColor();
-        print("drawRect ", tostr(r), tostr(c), "\n")
+    local p = t.paint
+    if p then
+        local pe = p:getPathEffect();
+        if pe then
+            increment(total_found, t.verb)
+        end
     end
 
-    if false and t.verb == "drawPath" then
-        local pred, r1, r2, d1, d2 = t.path:isNestedRects()
-        
-        if pred then
-            print("drawRect_Nested", tostr(r1), tostr(r2), d1, d2)
-        else
-            print("drawPath", "isEmpty", tostring(t.path:isEmpty()),
-                    "isRect", tostring(t.path:isRect()), tostr(t.path:getBounds()))
+    if "drawPoints" == t.verb then
+        local points = t.points
+        increment(drawPointsTable, #points)
+        if 2 == #points then
+            if points[1].y == points[2].y then
+                increment(drawPointsTable_direction, "hori")
+            elseif points[1].x == points[2].x then
+                increment(drawPointsTable_direction, "vert")
+            else
+                increment(drawPointsTable_direction, "other")
+            end
         end
     end
 end
 
 --[[
     lua_pictures will call this function after all of the pictures have been
     "accumulated".
 ]]
 function sk_scrape_summarize()
-    io.write("\n{ ", tostr(total), " }\n")
+    for k, v in next, total_found do
+        io.write(k, " = ", v, "/", total_total[k], "\n")
+    end
+    print("histogram of point-counts for all drawPoints calls")
+    print(tostr(drawPointsTable))
+    print(tostr(drawPointsTable_direction))
 end