[Tradfri] Fix bug in color space conversion

Always cap calculated RGB values to the range 0 to 255. Fixes: #4349 Signed-off-by: Holger Reichert <mail@h0lger.de>
eclipse-archived · Sep 26, 2017 · 0f74e56 · 0f74e56
1 parent bb9f6f9
commit 0f74e56
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Showing 2 changed files with 32 additions and 4 deletions.
diff --git a/...i.test/src/test/java/org/eclipse/smarthome/binding/tradfri/internal/TradfriColorTest.java b/...i.test/src/test/java/org/eclipse/smarthome/binding/tradfri/internal/TradfriColorTest.java
@@ -52,6 +52,22 @@ public void testFromCieKnownGood2() {
         assertEquals(33, color.hsbType.getBrightness().intValue());
     }
 
+    @Test
+    public void testFromCieKnownGood3() {
+        TradfriColor color = TradfriColor.fromCie(11469, 3277, 181);
+        assertNotNull(color);
+        assertEquals(12, (int) color.rgbR); //
+        assertEquals(0, (int) color.rgbG);
+        assertEquals(181, (int) color.rgbB);
+        assertEquals(11469, (int) color.xyX);
+        assertEquals(3277, (int) color.xyY);
+        assertEquals(181, (int) color.brightness);
+        assertNotNull(color.hsbType);
+        assertEquals(245, color.hsbType.getHue().intValue()); //
+        assertEquals(100, color.hsbType.getSaturation().intValue()); //
+        assertEquals(71, color.hsbType.getBrightness().intValue());
+    }
+
     @Test
     public void testFromHSBTypeKnownGood1() {
         TradfriColor color = TradfriColor.fromHSBType(HSBType.RED);

diff --git a/...ng.tradfri/src/main/java/org/eclipse/smarthome/binding/tradfri/internal/TradfriColor.java b/...ng.tradfri/src/main/java/org/eclipse/smarthome/binding/tradfri/internal/TradfriColor.java
@@ -124,9 +124,9 @@ public static TradfriColor fromCie(int xyX, int xyY, int xyBrightness) {
         // green = green <= 0.0031308 ? 12.92 * green : (1.0 + 0.055) * Math.pow(green, (1.0 / 2.4)) - 0.055;
         // blue = blue <= 0.0031308 ? 12.92 * blue : (1.0 + 0.055) * Math.pow(blue, (1.0 / 2.4)) - 0.055;
 
-        int redRounded = (int) Math.round(red * 255.0);
-        int greenRounded = (int) Math.round(green * 255.0);
-        int blueRounded = (int) Math.round(blue * 255.0);
+        int redRounded = ensureRgbRange((int) Math.round(red * 255.0));
+        int greenRounded = ensureRgbRange((int) Math.round(green * 255.0));
+        int blueRounded = ensureRgbRange((int) Math.round(blue * 255.0));
 
         // construct hsbType from RGB values
         // this hsbType has corrected values for RGB based on the hue/saturation/brightness values
@@ -162,7 +162,7 @@ public static TradfriColor fromHSBType(HSBType hsbType) {
         // red = (red > 0.04045) ? Math.pow((red + 0.055) / (1.0 + 0.055), 2.4) : (red / 12.92);
         // green = (green > 0.04045) ? Math.pow((green + 0.055) / (1.0 + 0.055), 2.4) : (green / 12.92);
         // blue = (blue > 0.04045) ? Math.pow((blue + 0.055) / (1.0 + 0.055), 2.4) : (blue / 12.92);
-        
+
         // Wide RGB D65 conversion
         // math inspiration: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
         double X = red * 0.664511 + green * 0.154324 + blue * 0.162028;
@@ -280,4 +280,16 @@ public static PercentType calculateColorTemperature(int xyX, int xyY) {
         return new PercentType((int) Math.round(value * 100.0));
     }
 
+    /**
+     * Ensure that the given value is in the RGB range (0 to 255).
+     * Negative values get capped to 0. Values over 255 get capped to 255.
+     *
+     * @param rgbValue the rgb value
+     * @return capped rgb value
+     */
+    private static int ensureRgbRange(int rgbValue) {
+        // minimum rgb = 0, maximum rgb = 255
+        return Math.min(Math.max(rgbValue, 0), 255);
+    }
+
 }