Add filename to gradient scrape

tools/lua/gradients.lua

-function sk_scrape_startcanvas(c, fileName) end
-function sk_scrape_endcanvas(c, fileName) end
+filename = ""
+
+function sk_scrape_startcanvas(c, fileName)
+    filename = fileName
+end
+
+function sk_scrape_endcanvas(c, fileName)
+
+end
 
 LuaDoubleNearlyZero = 1.0 / bit32.lshift(1.0, 12)
 
 function LuaDoubleNearlyEqual(a, b)
     return math.abs(a-b) <= LuaDoubleNearlyZero
 end
 
 verbs = {}
 gradients = {}
 
 i = 1
 
 function sk_scrape_accumulate(t)
     local p = t.paint
     if p then
         local s = p:getShader()
         if s then
             local g = s:asAGradient()
             if g then
                 if verbs[t.verb] then
                     verbs[t.verb] = verbs[t.verb] + 1
                 else
                     verbs[t.verb] = 1
                 end
 
                 gradients[i] = {}
 
+                gradients[i].filename = filename
+
                 gradients[i].colorCount = g.colorCount
                 gradients[i].type       = g.type
                 gradients[i].tile       = g.tile
 
                 isEvenlySpaced = true
                 for j = 1, g.colorCount, 1 do
                     if not LuaDoubleNearlyEqual(g.positions[j], (j-1)/(g.colorCount-1)) then
                         isEvenlySpaced = false
                     end
                 end
@@ skipping 23 matching lines @@
 function sk_scrape_summarize()
     for k, v in pairs(gradients) do
         local pos = ""
         for j = 1, v.colorCount , 1 do
             pos = pos .. v.positions[j]
             if j ~= v.colorCount then
                 pos = pos .. ","
             end
         end
 
-        io.write(string.format("%d %s %s %d %d %s %s\n",
+        io.write(string.format("%s %d %s %s %d %d %s %s\n",
+                                v.filename,
                                 v.colorCount,
                                 v.type,
                                 v.tile,
                                 tonumber(v.isEvenlySpaced and 1 or 0),
                                 v.numHardStops,
                                 v.verb,
                                 pos))
     end
 end