add point of interest API

experimental/skpdiff/SkPMetric.cpp

 #include <cmath>
 
 #include "SkBitmap.h"
 #include "skpdiff_util.h"
 #include "SkPMetric.h"
 
 struct RGB {
     float r, g, b;
 };
 
@@ skipping 211 matching lines @@
                 }
                 imageL->readPixel(nx, ny, &l);
                 float weight = matrix[xx + radius];
                 lSum += l * weight;
             }
             outImageL->writePixel(x, y, lSum);
         }
     }
 }
 
-float pmetric(const ImageLAB* baselineLAB, const ImageLAB* testLAB) {
+float pmetric(const ImageLAB* baselineLAB, const ImageLAB* testLAB, SkTDArray<SkIPoint>* poi) {
     int width = baselineLAB->width;
     int height = baselineLAB->height;
     int maxLevels = (int)log2(width < height ? width : height);
 
     const float fov = M_PI / 180.0f * 45.0f;
     float contrastSensitivityMax = contrast_sensitivity(3.248f, 100.0f);
     float pixelsPerDegree = width / (2.0f * tanf(fov * 0.5f) * 180.0f / M_PI);
 
     ImageL3D baselineL(width, height, maxLevels);
     ImageL3D testL(width, height, maxLevels);
@@ skipping 117 matching lines @@
                 colorScale *= colorScale;
 
                 if ((contrastA * contrastA + contrastB * contrastB) * colorScale > F)
                 {
                     isFailure = true;
                 }
             }
 
             if (isFailure) {
                 failures++;
+                poi->push()->set(x, y);
             }
         }
     }
 
     SkDELETE_ARRAY(cyclesPerDegree);
     SkDELETE_ARRAY(contrast);
     SkDELETE_ARRAY(thresholdFactorFrequency);
     return (double)failures;
 }
 
 const char* SkPMetric::getName() {
     return "perceptual";
 }
 
 int SkPMetric::queueDiff(SkBitmap* baseline, SkBitmap* test) {
     int diffID = fQueuedDiffs.count();
     double startTime = get_seconds();
-    QueuedDiff* diff = fQueuedDiffs.push();
+    QueuedDiff& diff = fQueuedDiffs.push_back();
+    diff.result = 0.0;
 
     // Ensure the images are comparable
     if (baseline->width() != test->width() || baseline->height() != test->height() ||
                     baseline->width() <= 0 || baseline->height() <= 0) {
-        diff->finished = true;
-        diff->result = 0.0;
+        diff.finished = true;
         return diffID;
     }
 
     ImageLAB baselineLAB(baseline->width(), baseline->height());
     ImageLAB testLAB(baseline->width(), baseline->height());
 
     bitmap_to_cielab(baseline, &baselineLAB);
     bitmap_to_cielab(test, &testLAB);
 
-    diff->result = pmetric(&baselineLAB, &testLAB);
+    diff.result = pmetric(&baselineLAB, &testLAB, &diff.poi);
 
     SkDebugf("Time: %f\n", (get_seconds() - startTime));
 
     return diffID;
 }
 
 
+void SkPMetric::deleteDiff(int id) {
+   fQueuedDiffs[id].poi.reset();
+}
+
 bool SkPMetric::isFinished(int id) {
     return fQueuedDiffs[id].finished;
 }
 
 double SkPMetric::getResult(int id) {
     return fQueuedDiffs[id].result;
 }
+
+int SkPMetric::getPointsOfInterestCount(int id) {
+    return fQueuedDiffs[id].poi.count();
+}
+
+SkIPoint* SkPMetric::getPointsOfInterest(int id) {
+    return fQueuedDiffs[id].poi.begin();
+}