| /* |
| * Copyright 2017 The Android Open Source Project |
| * |
| * 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.android.server.display; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.assertNotEquals; |
| import static org.junit.Assert.assertNotNull; |
| import static org.junit.Assert.assertNull; |
| import static org.junit.Assert.assertTrue; |
| import static org.mockito.ArgumentMatchers.anyFloat; |
| import static org.mockito.ArgumentMatchers.anyInt; |
| import static org.mockito.Mockito.mock; |
| import static org.mockito.Mockito.when; |
| |
| import android.content.res.Resources; |
| import android.content.res.TypedArray; |
| import android.hardware.display.BrightnessConfiguration; |
| import android.os.PowerManager; |
| import android.util.MathUtils; |
| import android.util.Spline; |
| |
| import androidx.test.filters.SmallTest; |
| import androidx.test.runner.AndroidJUnit4; |
| |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| |
| import java.util.Arrays; |
| |
| @SmallTest |
| @RunWith(AndroidJUnit4.class) |
| public class BrightnessMappingStrategyTest { |
| |
| private static final int[] LUX_LEVELS = { |
| 0, |
| 5, |
| 20, |
| 40, |
| 100, |
| 325, |
| 600, |
| 1250, |
| 2200, |
| 4000, |
| 5000 |
| }; |
| |
| private static final float[] DISPLAY_LEVELS_NITS = { |
| 13.25f, |
| 54.0f, |
| 78.85f, |
| 105.02f, |
| 132.7f, |
| 170.12f, |
| 212.1f, |
| 265.2f, |
| 335.8f, |
| 415.2f, |
| 478.5f, |
| }; |
| |
| private static final int[] DISPLAY_LEVELS_BACKLIGHT = { |
| 9, |
| 30, |
| 45, |
| 62, |
| 78, |
| 96, |
| 119, |
| 146, |
| 178, |
| 221, |
| 255 |
| }; |
| |
| private static final float[] DISPLAY_RANGE_NITS = { 2.685f, 478.5f }; |
| private static final int[] BACKLIGHT_RANGE = { 1, 255 }; |
| |
| private static final float[] EMPTY_FLOAT_ARRAY = new float[0]; |
| private static final int[] EMPTY_INT_ARRAY = new int[0]; |
| |
| private static final float MAXIMUM_GAMMA = 3.0f; |
| private static final int[] GAMMA_CORRECTION_LUX = { |
| 0, |
| 100, |
| 1000, |
| 2500, |
| 4000, |
| 4900, |
| 5000 |
| }; |
| private static final float[] GAMMA_CORRECTION_NITS = { |
| 1.0f, |
| 10.55f, |
| 96.5f, |
| 239.75f, |
| 383.0f, |
| 468.95f, |
| 478.5f, |
| }; |
| private static final Spline GAMMA_CORRECTION_SPLINE = Spline.createSpline( |
| new float[] { 0.0f, 100.0f, 1000.0f, 2500.0f, 4000.0f, 4900.0f, 5000.0f }, |
| new float[] { 0.035f, 0.035f, 0.221f, 0.523f, 0.797f, 0.980f, 1.0f }); |
| |
| @Test |
| public void testSimpleStrategyMappingAtControlPoints() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy simple = BrightnessMappingStrategy.create(res); |
| assertNotNull("BrightnessMappingStrategy should not be null", simple); |
| for (int i = 0; i < LUX_LEVELS.length; i++) { |
| final float expectedLevel = |
| (float) DISPLAY_LEVELS_BACKLIGHT[i] / PowerManager.BRIGHTNESS_ON; |
| assertEquals(expectedLevel, |
| simple.getBrightness(LUX_LEVELS[i]), 0.01f /*tolerance*/); |
| } |
| } |
| |
| @Test |
| public void testSimpleStrategyMappingBetweenControlPoints() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy simple = BrightnessMappingStrategy.create(res); |
| assertNotNull("BrightnessMappingStrategy should not be null", simple); |
| for (int i = 1; i < LUX_LEVELS.length; i++) { |
| final float lux = (LUX_LEVELS[i - 1] + LUX_LEVELS[i]) / 2; |
| final float backlight = simple.getBrightness(lux) * PowerManager.BRIGHTNESS_ON; |
| assertTrue("Desired brightness should be between adjacent control points.", |
| backlight > DISPLAY_LEVELS_BACKLIGHT[i - 1] |
| && backlight < DISPLAY_LEVELS_BACKLIGHT[i]); |
| } |
| } |
| |
| @Test |
| public void testSimpleStrategyIgnoresNewConfiguration() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| |
| final int N = LUX_LEVELS.length; |
| final float[] lux = { 0f, 1f }; |
| final float[] nits = { 0, PowerManager.BRIGHTNESS_ON }; |
| |
| BrightnessConfiguration config = new BrightnessConfiguration.Builder() |
| .setCurve(lux, nits) |
| .build(); |
| strategy.setBrightnessConfiguration(config); |
| assertNotEquals(1.0f, strategy.getBrightness(1f), 0.01 /*tolerance*/); |
| } |
| |
| @Test |
| public void testSimpleStrategyIgnoresNullConfiguration() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| |
| strategy.setBrightnessConfiguration(null); |
| final int N = DISPLAY_LEVELS_BACKLIGHT.length; |
| final float expectedBrightness = |
| (float) DISPLAY_LEVELS_BACKLIGHT[N - 1] / PowerManager.BRIGHTNESS_ON; |
| assertEquals(expectedBrightness, |
| strategy.getBrightness(LUX_LEVELS[N - 1]), 0.01 /*tolerance*/); |
| } |
| |
| @Test |
| public void testPhysicalStrategyMappingAtControlPoints() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy physical = BrightnessMappingStrategy.create(res); |
| assertNotNull("BrightnessMappingStrategy should not be null", physical); |
| for (int i = 0; i < LUX_LEVELS.length; i++) { |
| final float expectedLevel = DISPLAY_LEVELS_NITS[i] / DISPLAY_RANGE_NITS[1]; |
| assertEquals(expectedLevel, |
| physical.getBrightness(LUX_LEVELS[i]), 0.01f /*tolerance*/); |
| } |
| } |
| |
| @Test |
| public void testPhysicalStrategyMappingBetweenControlPoints() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy physical = BrightnessMappingStrategy.create(res); |
| assertNotNull("BrightnessMappingStrategy should not be null", physical); |
| Spline backlightToBrightness = |
| Spline.createSpline(toFloatArray(BACKLIGHT_RANGE), DISPLAY_RANGE_NITS); |
| for (int i = 1; i < LUX_LEVELS.length; i++) { |
| final float lux = (LUX_LEVELS[i - 1] + LUX_LEVELS[i]) / 2; |
| final float backlight = physical.getBrightness(lux) * PowerManager.BRIGHTNESS_ON; |
| final float nits = backlightToBrightness.interpolate(backlight); |
| assertTrue("Desired brightness should be between adjacent control points.", |
| nits > DISPLAY_LEVELS_NITS[i - 1] && nits < DISPLAY_LEVELS_NITS[i]); |
| } |
| } |
| |
| @Test |
| public void testPhysicalStrategyUsesNewConfigurations() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| |
| final float[] lux = { 0f, 1f }; |
| final float[] nits = { |
| DISPLAY_RANGE_NITS[0], |
| DISPLAY_RANGE_NITS[DISPLAY_RANGE_NITS.length - 1] |
| }; |
| |
| BrightnessConfiguration config = new BrightnessConfiguration.Builder() |
| .setCurve(lux, nits) |
| .build(); |
| strategy.setBrightnessConfiguration(config); |
| assertEquals(1.0f, strategy.getBrightness(1f), 0.01 /*tolerance*/); |
| |
| // Check that null returns us to the default configuration. |
| strategy.setBrightnessConfiguration(null); |
| final int N = DISPLAY_LEVELS_NITS.length; |
| final float expectedBrightness = DISPLAY_LEVELS_NITS[N - 1] / DISPLAY_RANGE_NITS[1]; |
| assertEquals(expectedBrightness, |
| strategy.getBrightness(LUX_LEVELS[N - 1]), 0.01f /*tolerance*/); |
| } |
| |
| @Test |
| public void testDefaultStrategyIsPhysical() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT, |
| DISPLAY_LEVELS_NITS, DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| assertTrue(strategy instanceof BrightnessMappingStrategy.PhysicalMappingStrategy); |
| } |
| |
| @Test |
| public void testNonStrictlyIncreasingLuxLevelsFails() { |
| final int[] lux = Arrays.copyOf(LUX_LEVELS, LUX_LEVELS.length); |
| final int idx = lux.length / 2; |
| int tmp = lux[idx]; |
| lux[idx] = lux[idx+1]; |
| lux[idx+1] = tmp; |
| Resources res = createResources(lux, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| |
| // And make sure we get the same result even if it's monotone but not increasing. |
| lux[idx] = lux[idx+1]; |
| res = createResources(lux, DISPLAY_LEVELS_NITS, DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| } |
| |
| @Test |
| public void testDifferentNumberOfControlPointValuesFails() { |
| //Extra lux level |
| final int[] lux = Arrays.copyOf(LUX_LEVELS, LUX_LEVELS.length+1); |
| // Make sure it's strictly increasing so that the only failure is the differing array |
| // lengths |
| lux[lux.length - 1] = lux[lux.length - 2] + 1; |
| Resources res = createResources(lux, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| |
| res = createResources(lux, DISPLAY_LEVELS_BACKLIGHT); |
| strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| |
| // Extra backlight level |
| final int[] backlight = Arrays.copyOf( |
| DISPLAY_LEVELS_BACKLIGHT, DISPLAY_LEVELS_BACKLIGHT.length+1); |
| backlight[backlight.length - 1] = backlight[backlight.length - 2] + 1; |
| res = createResources(LUX_LEVELS, backlight); |
| strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| |
| // Extra nits level |
| final float[] nits = Arrays.copyOf(DISPLAY_RANGE_NITS, DISPLAY_LEVELS_NITS.length+1); |
| nits[nits.length - 1] = nits[nits.length - 2] + 1; |
| res = createResources(LUX_LEVELS, nits, DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| strategy = BrightnessMappingStrategy.create(res); |
| assertNull(strategy); |
| } |
| |
| @Test |
| public void testPhysicalStrategyRequiresNitsMapping() { |
| Resources res = createResources(LUX_LEVELS, EMPTY_INT_ARRAY /*brightnessLevelsBacklight*/, |
| DISPLAY_LEVELS_NITS, EMPTY_FLOAT_ARRAY /*nitsRange*/, BACKLIGHT_RANGE); |
| BrightnessMappingStrategy physical = BrightnessMappingStrategy.create(res); |
| assertNull(physical); |
| |
| res = createResources(LUX_LEVELS, EMPTY_INT_ARRAY /*brightnessLevelsBacklight*/, |
| DISPLAY_LEVELS_NITS, DISPLAY_RANGE_NITS, EMPTY_INT_ARRAY /*backlightRange*/); |
| physical = BrightnessMappingStrategy.create(res); |
| assertNull(physical); |
| |
| res = createResources(LUX_LEVELS, EMPTY_INT_ARRAY /*brightnessLevelsBacklight*/, |
| DISPLAY_LEVELS_NITS, EMPTY_FLOAT_ARRAY /*nitsRange*/, |
| EMPTY_INT_ARRAY /*backlightRange*/); |
| physical = BrightnessMappingStrategy.create(res); |
| assertNull(physical); |
| } |
| |
| @Test |
| public void testStrategiesAdaptToUserDataPoint() { |
| Resources res = createResources(LUX_LEVELS, DISPLAY_LEVELS_NITS, |
| DISPLAY_RANGE_NITS, BACKLIGHT_RANGE); |
| assertStrategyAdaptsToUserDataPoints(BrightnessMappingStrategy.create(res)); |
| res = createResources(LUX_LEVELS, DISPLAY_LEVELS_BACKLIGHT); |
| assertStrategyAdaptsToUserDataPoints(BrightnessMappingStrategy.create(res)); |
| } |
| |
| private static void assertStrategyAdaptsToUserDataPoints(BrightnessMappingStrategy strategy) { |
| // Save out all of the initial brightness data for comparison after reset. |
| float[] initialBrightnessLevels = new float[LUX_LEVELS.length]; |
| for (int i = 0; i < LUX_LEVELS.length; i++) { |
| initialBrightnessLevels[i] = strategy.getBrightness(LUX_LEVELS[i]); |
| } |
| |
| // Add a data point in the middle of the curve where the user has set the brightness max |
| final int idx = LUX_LEVELS.length / 2; |
| strategy.addUserDataPoint(LUX_LEVELS[idx], 1.0f); |
| |
| // Then make sure that all control points after the middle lux level are also set to max... |
| for (int i = idx; i < LUX_LEVELS.length; i++) { |
| assertEquals(strategy.getBrightness(LUX_LEVELS[idx]), 1.0, 0.01 /*tolerance*/); |
| } |
| |
| // ...and that all control points before the middle lux level are strictly less than the |
| // previous one still. |
| float prevBrightness = strategy.getBrightness(LUX_LEVELS[idx]); |
| for (int i = idx - 1; i >= 0; i--) { |
| float brightness = strategy.getBrightness(LUX_LEVELS[i]); |
| assertTrue("Brightness levels must be monotonic after adapting to user data", |
| prevBrightness >= brightness); |
| prevBrightness = brightness; |
| } |
| |
| // Now reset the curve and make sure we go back to the initial brightness levels recorded |
| // before adding the user data point. |
| strategy.clearUserDataPoints(); |
| for (int i = 0; i < LUX_LEVELS.length; i++) { |
| assertEquals(initialBrightnessLevels[i], strategy.getBrightness(LUX_LEVELS[i]), |
| 0.01 /*tolerance*/); |
| } |
| |
| // Now set the middle of the lux range to something just above the minimum. |
| float minBrightness = strategy.getBrightness(LUX_LEVELS[0]); |
| strategy.addUserDataPoint(LUX_LEVELS[idx], minBrightness + 0.01f); |
| |
| // Then make sure the curve is still monotonic. |
| prevBrightness = 0f; |
| for (float lux : LUX_LEVELS) { |
| float brightness = strategy.getBrightness(lux); |
| assertTrue("Brightness levels must be monotonic after adapting to user data", |
| prevBrightness <= brightness); |
| prevBrightness = brightness; |
| } |
| |
| // And that the lowest lux level still gives the absolute minimum brightness. This should |
| // be true assuming that there are more than two lux levels in the curve since we picked a |
| // brightness just barely above the minimum for the middle of the curve. |
| minBrightness = (float) MathUtils.pow(minBrightness, MAXIMUM_GAMMA); // Gamma correction. |
| assertEquals(minBrightness, strategy.getBrightness(LUX_LEVELS[0]), 0.01 /*tolerance*/); |
| } |
| |
| private static float[] toFloatArray(int[] vals) { |
| float[] newVals = new float[vals.length]; |
| for (int i = 0; i < vals.length; i++) { |
| newVals[i] = (float) vals[i]; |
| } |
| return newVals; |
| } |
| |
| private Resources createResources(int[] luxLevels, int[] brightnessLevelsBacklight) { |
| return createResources(luxLevels, brightnessLevelsBacklight, |
| EMPTY_FLOAT_ARRAY /*brightnessLevelsNits*/, EMPTY_FLOAT_ARRAY /*nitsRange*/, |
| EMPTY_INT_ARRAY /*backlightRange*/); |
| } |
| |
| private Resources createResources(int[] luxLevels, float[] brightnessLevelsNits, |
| float[] nitsRange, int[] backlightRange) { |
| return createResources(luxLevels, EMPTY_INT_ARRAY /*brightnessLevelsBacklight*/, |
| brightnessLevelsNits, nitsRange, backlightRange); |
| } |
| |
| private Resources createResources(int[] luxLevels, int[] brightnessLevelsBacklight, |
| float[] brightnessLevelsNits, float[] nitsRange, int[] backlightRange) { |
| Resources mockResources = mock(Resources.class); |
| // For historical reasons, the lux levels resource implicitly defines the first point as 0, |
| // so we need to chop it off of the array the mock resource object returns. |
| int[] luxLevelsResource = Arrays.copyOfRange(luxLevels, 1, luxLevels.length); |
| when(mockResources.getIntArray(com.android.internal.R.array.config_autoBrightnessLevels)) |
| .thenReturn(luxLevelsResource); |
| |
| when(mockResources.getIntArray( |
| com.android.internal.R.array.config_autoBrightnessLcdBacklightValues)) |
| .thenReturn(brightnessLevelsBacklight); |
| |
| TypedArray mockBrightnessLevelNits = createFloatTypedArray(brightnessLevelsNits); |
| when(mockResources.obtainTypedArray( |
| com.android.internal.R.array.config_autoBrightnessDisplayValuesNits)) |
| .thenReturn(mockBrightnessLevelNits); |
| |
| TypedArray mockNitsRange = createFloatTypedArray(nitsRange); |
| when(mockResources.obtainTypedArray( |
| com.android.internal.R.array.config_screenBrightnessNits)) |
| .thenReturn(mockNitsRange); |
| |
| when(mockResources.getIntArray( |
| com.android.internal.R.array.config_screenBrightnessBacklight)) |
| .thenReturn(backlightRange); |
| |
| when(mockResources.getInteger( |
| com.android.internal.R.integer.config_screenBrightnessSettingMinimum)) |
| .thenReturn(1); |
| when(mockResources.getInteger( |
| com.android.internal.R.integer.config_screenBrightnessSettingMaximum)) |
| .thenReturn(255); |
| when(mockResources.getFraction( |
| com.android.internal.R.fraction.config_autoBrightnessAdjustmentMaxGamma, 1, 1)) |
| .thenReturn(MAXIMUM_GAMMA); |
| return mockResources; |
| } |
| |
| private TypedArray createFloatTypedArray(float[] vals) { |
| TypedArray mockArray = mock(TypedArray.class); |
| when(mockArray.length()).thenAnswer(invocation -> { |
| return vals.length; |
| }); |
| when(mockArray.getFloat(anyInt(), anyFloat())).thenAnswer(invocation -> { |
| final float def = (float) invocation.getArguments()[1]; |
| if (vals == null) { |
| return def; |
| } |
| int idx = (int) invocation.getArguments()[0]; |
| if (idx >= 0 && idx < vals.length) { |
| return vals[idx]; |
| } else { |
| return def; |
| } |
| }); |
| return mockArray; |
| } |
| |
| // Gamma correction tests. |
| // x0 = 100 y0 = ~0.01 |
| // x1 = 1000 y1 = ~0.20 |
| // x2 = 2500 y2 = ~0.50 |
| // x3 = 4000 y3 = ~0.80 |
| // x4 = 4900 y4 = ~0.99 |
| |
| @Test |
| public void testGammaCorrectionLowChangeAtCenter() { |
| // If we set a user data point at (x2, y2^0.5), i.e. gamma = 0.5, it should bump the rest |
| // of the spline accordingly. |
| final int x1 = 1000; |
| final int x2 = 2500; |
| final int x3 = 4000; |
| final float y1 = GAMMA_CORRECTION_SPLINE.interpolate(x1); |
| final float y2 = GAMMA_CORRECTION_SPLINE.interpolate(x2); |
| final float y3 = GAMMA_CORRECTION_SPLINE.interpolate(x3); |
| Resources resources = createResources(GAMMA_CORRECTION_LUX, GAMMA_CORRECTION_NITS, |
| DISPLAY_LEVELS_NITS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(resources); |
| // Let's start with a sanity check: |
| assertEquals(y1, strategy.getBrightness(x1), 0.01f /* tolerance */); |
| assertEquals(y2, strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(y3, strategy.getBrightness(x3), 0.01f /* tolerance */); |
| // OK, let's roll: |
| float gamma = 0.5f; |
| strategy.addUserDataPoint(x2, (float) MathUtils.pow(y2, gamma)); |
| assertEquals(MathUtils.pow(y1, gamma), strategy.getBrightness(x1), 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y2, gamma), strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y3, gamma), strategy.getBrightness(x3), 0.01f /* tolerance */); |
| // The adjustment should be +0.63 (manual calculation). |
| assertEquals(+0.63f, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| } |
| |
| @Test |
| public void testGammaCorrectionHighChangeAtCenter() { |
| // This time we set a user data point at (x2, y2^0.25), i.e. gamma = 0.3 (the minimum), |
| // which should bump the rest of the spline accordingly, and further correct x2 to hit |
| // y2^0.25 (not y2^0.3). |
| final int x1 = 1000; |
| final int x2 = 2500; |
| final int x3 = 4000; |
| final float y1 = GAMMA_CORRECTION_SPLINE.interpolate(x1); |
| final float y2 = GAMMA_CORRECTION_SPLINE.interpolate(x2); |
| final float y3 = GAMMA_CORRECTION_SPLINE.interpolate(x3); |
| Resources resources = createResources(GAMMA_CORRECTION_LUX, GAMMA_CORRECTION_NITS, |
| DISPLAY_LEVELS_NITS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(resources); |
| // Sanity check: |
| assertEquals(y1, strategy.getBrightness(x1), 0.01f /* tolerance */); |
| assertEquals(y2, strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(y3, strategy.getBrightness(x3), 0.01f /* tolerance */); |
| // Let's roll: |
| float gamma = 0.25f; |
| final float minGamma = 1.0f / MAXIMUM_GAMMA; |
| strategy.addUserDataPoint(x2, (float) MathUtils.pow(y2, gamma)); |
| assertEquals(MathUtils.pow(y1, minGamma), strategy.getBrightness(x1), |
| 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y2, gamma), strategy.getBrightness(x2), |
| 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y3, minGamma), strategy.getBrightness(x3), |
| 0.01f /* tolerance */); |
| // The adjustment should be +1.0 (maximum adjustment). |
| assertEquals(+1.0f, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| } |
| |
| @Test |
| public void testGammaCorrectionExtremeChangeAtCenter() { |
| // Extreme changes (e.g. setting brightness to 0.0 or 1.0) can't be gamma corrected, so we |
| // just make sure the adjustment reflects the change. |
| Resources resources = createResources(GAMMA_CORRECTION_LUX, GAMMA_CORRECTION_NITS, |
| DISPLAY_LEVELS_NITS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(resources); |
| assertEquals(0.0f, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| strategy.addUserDataPoint(2500, 1.0f); |
| assertEquals(+1.0f, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| strategy.addUserDataPoint(2500, 0.0f); |
| assertEquals(-1.0f, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| } |
| |
| @Test |
| public void testGammaCorrectionChangeAtEdges() { |
| // The algorithm behaves differently at the edges, because gamma correction there tends to |
| // be extreme. If we add a user data point at (x0, y0+0.3), the adjustment should be 0.3, |
| // resulting in a gamma of 3**-0.6 = ~0.52. |
| final int x0 = 100; |
| final int x2 = 2500; |
| final int x4 = 4900; |
| final float y0 = GAMMA_CORRECTION_SPLINE.interpolate(x0); |
| final float y2 = GAMMA_CORRECTION_SPLINE.interpolate(x2); |
| final float y4 = GAMMA_CORRECTION_SPLINE.interpolate(x4); |
| Resources resources = createResources(GAMMA_CORRECTION_LUX, GAMMA_CORRECTION_NITS, |
| DISPLAY_LEVELS_NITS, DISPLAY_LEVELS_BACKLIGHT); |
| BrightnessMappingStrategy strategy = BrightnessMappingStrategy.create(resources); |
| // Sanity, as per tradition: |
| assertEquals(y0, strategy.getBrightness(x0), 0.01f /* tolerance */); |
| assertEquals(y2, strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(y4, strategy.getBrightness(x4), 0.01f /* tolerance */); |
| // Rollin': |
| float adjustment = 0.3f; |
| float gamma = (float) MathUtils.pow(MAXIMUM_GAMMA, -adjustment); |
| strategy.addUserDataPoint(x0, y0 + adjustment); |
| assertEquals(y0 + adjustment, strategy.getBrightness(x0), 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y2, gamma), strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y4, gamma), strategy.getBrightness(x4), 0.01f /* tolerance */); |
| assertEquals(adjustment, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| // Similarly, if we set a user data point at (x4, 1.0), the adjustment should be 1 - y4. |
| adjustment = 1.0f - y4; |
| gamma = (float) MathUtils.pow(MAXIMUM_GAMMA, -adjustment); |
| strategy.addUserDataPoint(x4, 1.0f); |
| assertEquals(MathUtils.pow(y0, gamma), strategy.getBrightness(x0), 0.01f /* tolerance */); |
| assertEquals(MathUtils.pow(y2, gamma), strategy.getBrightness(x2), 0.01f /* tolerance */); |
| assertEquals(1.0f, strategy.getBrightness(x4), 0.01f /* tolerance */); |
| assertEquals(adjustment, strategy.getAutoBrightnessAdjustment(), 0.01f /* tolerance */); |
| } |
| } |