skpdiff: add ability to write the diff scores in a csv file (one line per pair of diff images, with…

experimental/skpdiff/SkDiffContext.cpp

Index: experimental/skpdiff/SkDiffContext.cpp
===================================================================
--- experimental/skpdiff/SkDiffContext.cpp	(revision 10191)
+++ experimental/skpdiff/SkDiffContext.cpp	(working copy)
@@ -6,6 +6,7 @@
  */
 
 #include "SkBitmap.h"
+#include "SkCommandLineFlags.h"
 #include "SkImageDecoder.h"
 #include "SkOSFile.h"
 #include "SkStream.h"
@@ -14,6 +15,8 @@
 #include "SkImageDiffer.h"
 #include "skpdiff_util.h"
 
+DECLARE_string(csv);
+
 SkDiffContext::SkDiffContext() {
     fRecords = NULL;
     fDiffers = NULL;
@@ -68,6 +71,28 @@
     newRecord->fNext = fRecords;
     fRecords = newRecord;
 
+    FILE* csvFile = NULL;
+    if (!FLAGS_csv.isEmpty()) {
+        csvFile = fopen(FLAGS_csv[0], "a");
+        SkASSERT(csvFile);
+        if (ftell(csvFile) == 0) {
+            fprintf(csvFile, "%s", "skp");
+            for (int differIndex = 0; differIndex < fDifferCount; differIndex++) {
+                SkImageDiffer* differ = fDiffers[differIndex];
+                fprintf(csvFile, ", %s", differ->getName());
+            }
+            fprintf(csvFile, "\n");
+        }
+    }
+
+    if (csvFile) {
+        const char* filename = baselinePath + strlen(baselinePath) - 1;
+        while (filename > baselinePath && *(filename - 1) != '/') {
+            filename--;
+        }
+        fprintf(csvFile, "%s", filename);
+    }
+
     // Perform each diff
     for (int differIndex = 0; differIndex < fDifferCount; differIndex++) {
         SkImageDiffer* differ = fDiffers[differIndex];
@@ -80,6 +105,10 @@
             diffData.fDiffName = differ->getName();
             diffData.fResult = differ->getResult(diffID);
 
+            if (csvFile) {
+                fprintf(csvFile, ", %f", diffData.fResult);
+            }
+
             int poiCount = differ->getPointsOfInterestCount(diffID);
             SkIPoint* poi = differ->getPointsOfInterest(diffID);
             diffData.fPointsOfInterest.append(poiCount, poi);
@@ -87,8 +116,17 @@
             // Because we are doing everything synchronously for now, we are done with the diff
             // after reading it.
             differ->deleteDiff(diffID);
+        } else {
+            if (csvFile) {
+                fprintf(csvFile, ", -1");
+            }
         }
     }
+
+    if (csvFile) {
+        fprintf(csvFile, "\n");
+        fclose(csvFile);
+    }
 }