feat: tolerance based color equality (~1%)

src/main/java/com/pavelfatin/typometer/benchmark/BenchmarkImpl.java

@@ -18,6 +18,7 @@
 
 import com.pavelfatin.typometer.ExceptionHandler;
 import com.pavelfatin.typometer.metrics.Metrics;
+import com.pavelfatin.typometer.metrics.ColorUtil;
 import com.pavelfatin.typometer.screen.ScreenAccessor;
 
 import java.awt.*;
@@ -176,7 +177,8 @@ private static void typeSync(ExecutorService executor, Robot robot, ScreenAccess
         int y = point.y;
 
         for (int delay : delays) {
-            if (!accessor.getPixelColor((int) round(x), y).equals(metrics.getBackground())) {
+            if (!ColorUtil.equals(metrics.getBackground(), accessor.getPixelColor((int)round(x), y)))
+            {
                 throw new BenchmarkException("Previously undetected block cursor found.");
             }
 

src/main/java/com/pavelfatin/typometer/benchmark/ChangeDetector.java

@@ -17,6 +17,7 @@
 package com.pavelfatin.typometer.benchmark;
 
 import com.pavelfatin.typometer.screen.ScreenAccessor;
+import com.pavelfatin.typometer.metrics.ColorUtil;
 
 import java.awt.*;
 
@@ -29,8 +30,7 @@ static void waitForChange(ScreenAccessor accessor, int x, int y, Color previousC
 
         do {
             for (int i = 0; i < CHECK_PERIOD; i++) {
-                Color color = accessor.getPixelColor(x, y);
-                if (!previousColor.equals(color)) {
+                if (!ColorUtil.equals(accessor.getPixelColor(x, y), previousColor)) {
                     return;
                 }
             }

src/main/java/com/pavelfatin/typometer/metrics/ColorUtil.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 Francisco Requena, https://frarees.github.io
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pavelfatin.typometer.metrics;
+
+import java.awt.Color;
+
+public class ColorUtil {
+    private ColorUtil() {
+    }
+
+    public static boolean equals(Color c1, Color c2, int tolerance) {
+        return (Math.abs(c1.getRed() - c2.getRed()) <= tolerance) &&
+            (Math.abs(c1.getGreen() - c2.getGreen()) <= tolerance) &&
+            (Math.abs(c1.getBlue() - c2.getBlue()) <= tolerance);
+    }
+
+    public static boolean equals(Color c1, Color c2) {
+        return equals(c1, c2, 3);
+    }
+}

src/main/java/com/pavelfatin/typometer/metrics/MetricsDetector.java

@@ -102,24 +102,26 @@ private static Metrics metricsFrom(List<Rectangle> rectangles, BufferedImage ima
 
         Point point = new Point((int) round(x1), (int) round(y1));
 
-        int background = image2.getRGB((int) round(x2 + step * 2), (int) round(y2));
+        Color background = new Color(image2.getRGB((int) round(x2 + step * 2), (int) round(y2)));
 
-        boolean blockCursor = image2.getRGB((int) round(x2 + step), (int) round(y2)) != background;
+        boolean blockCursor = !ColorUtil.equals(new Color(image2.getRGB((int) round(x2 + step), (int) round(y2))), background);
 
         int availableLength = uniformLengthFrom(image2, new Point(point.x + (int) round(step * offset), point.y), background);
 
         int length = (int) (floor(availableLength / step)) - (blockCursor ? 1 : 0);
 
-        return new Metrics(point, step, length + offset - 1, new Color(background), blockCursor);
+        return new Metrics(point, step, length + offset - 1, background, blockCursor);
     }
 
-    private static int uniformLengthFrom(BufferedImage image, Point point, int color) {
+    private static int uniformLengthFrom(BufferedImage image, Point point, Color color) {
         int width = image.getWidth();
 
         int x;
 
         for (x = point.x; x < width; x++) {
-            if (image.getRGB(x, point.y) != color) break;
+            if (!ColorUtil.equals(new Color(image.getRGB(x, point.y)), color)) {
+                break;
+            }
         }
 
         return x - point.x;

src/test/java/com/pavelfatin/typometer/metrics/MetricsTest.java

@@ -146,14 +146,14 @@ private static void assertPointsPresent(boolean expectation, BufferedImage image
         for (int i = begin; i < end; i++) {
             int ix = (int) round(x);
 
-            Color color = new Color(image.getRGB(ix, p.y));
+            boolean present = ColorUtil.equals(metrics.getBackground(), new Color(image.getRGB(ix, p.y)));
 
             if (expectation) {
                 String message = String.format("Point %d must be present at (%d, %d)", i + 1, ix, p.y);
-                Assert.assertNotEquals(message, metrics.getBackground(), color);
+                Assert.assertFalse(message, present);
             } else {
                 String message = String.format("Point %d must not be present at (%d, %d)", i + 1, ix, p.y);
-                Assert.assertEquals(message, metrics.getBackground(), color);
+                Assert.assertTrue(message, present);
             }
 
             x += metrics.getStep();