Add scraper to find paths that fallback to software

tools/lua/paths.lua

+--
+-- Copyright 2014 Google Inc.
+--
+-- Use of this source code is governed by a BSD-style license that can be
+-- found in the LICENSE file.
+--
+
+-- Path scraping script.
+-- This script is designed to count the number of times we fall back to software
+-- rendering for a path in a given SKP. However, this script does not count an exact
+-- number of uploads, since there is some overlap with clipping: e.g. two clipped paths
+-- may cause three uploads to the GPU (set clip 1, set clip 2, unset clip 2/reset clip 1),
+-- but these cases are rare.
+
+draws = 0
+drawPaths = 0
+drawPathsAnti = 0
+drawPathsConvexAnti = 0
+
+clips = 0
+clipPaths = 0
+clipPathsAnti = 0
+clipPathsConvexAnti = 0
+
+usedPath = false
+usedSWPath = false
+
+skpsTotal = 0
+skpsWithPath = 0
+skpsWithSWPath = 0
+
+function sk_scrape_startcanvas(c, fileName)
+   usedPath = false
+   usedSWPath = false
+end
+
+function sk_scrape_endcanvas(c, fileName)
+   skpsTotal = skpsTotal + 1
+   if usedPath then
+      skpsWithPath = skpsWithPath + 1
+      if usedSWPath then
+         skpsWithSWPath = skpsWithSWPath + 1
+      end
+   end
+end
+
+function string.starts(String,Start)
+   return string.sub(String,1,string.len(Start))==Start
+end
+
+function isPathValid(path)
+   if not path then
+      return false
+   end
+
+   if path:isEmpty() then
+      return false
+   end
+
+   if path:isRect() then
+      return false
+   end
+
+   return true
+end
+
+function sk_scrape_accumulate(t)
+   if (string.starts(t.verb, "draw")) then
+      draws = draws + 1
+   end
+
+   if (string.starts(t.verb, "clip")) then
+      clips = clips + 1
+   end
+
+   if t.verb == "clipPath" then
+      local path = t.path
+      if isPathValid(path) then
+         clipPaths = clipPaths + 1
+         usedPath = true
+         if t.aa then
+            clipPathsAnti = clipPathsAnti + 1
+            if path:isConvex() then
+               clipPathsConvexAnti = clipPathsConvexAnti + 1
+            else
+               usedSWPath = true
+            end
+         end
+      end
+   end
+
+   if t.verb == "drawPath" then
+      local path = t.path
+      local paint = t.paint
+      if paint and isPathValid(path) then
+         drawPaths = drawPaths + 1
+         usedPath = true
+         if paint:isAntiAlias() then
+            drawPathsAnti = drawPathsAnti + 1
+            if path:isConvex() then
+               drawPathsConvexAnti = drawPathsConvexAnti + 1
+            else
+               usedSWPath = true
+            end
+         end
+      end
+   end
+end
+
+function sk_scrape_summarize() 
+   local swDrawPaths = drawPathsAnti - drawPathsConvexAnti
+   local swClipPaths = clipPathsAnti - clipPathsConvexAnti
+
+   io.write("clips = clips + ", clips, "\n");
+   io.write("draws = draws + ", draws, "\n");
+   io.write("clipPaths = clipPaths + ", clipPaths, "\n");
+   io.write("drawPaths = drawPaths + ", drawPaths, "\n");
+   io.write("swClipPaths = swClipPaths + ", swClipPaths, "\n");
+   io.write("swDrawPaths = swDrawPaths + ", swDrawPaths, "\n");
+
+   io.write("skpsTotal = skpsTotal + ", skpsTotal, "\n");
+   io.write("skpsWithPath = skpsWithPath + ", skpsWithPath, "\n");
+   io.write("skpsWithSWPath = skpsWithSWPath + ", skpsWithSWPath, "\n");
+end