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Convert BrightnessUtils to use brightness as float

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convertGammaToLinear needed to be constrained to 0-12, as sometimes ret
variable was 12.000001.

The first parameter for gammaToLinear_minValue_shouldReturnMin has been
changed - initally it used 1 (MIN_INT) but it should have been using 0
(GAMMA_SPACE_MIN). Since the function rounded the value at the end, the
result ended up the same.

The original functions cannot be removed yet since Car uses these methods.

Bug: 150671605

Test: m -j99 RunSettingsLibRoboTests ROBOTEST_FILTER="com.android.settingslib.display.BrightnessUtilsTest"

Change-Id: I4bba2ca0785f94597590c8f4bb3a7a8a834d6c83
This commit is contained in:
Fiona Campbell
2020-04-21 16:32:21 +01:00
parent 3443ba8dc9
commit 3c6b51a9ec
2 changed files with 30 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
packages/SettingsLib/src/com/android/settingslib/display/BrightnessUtils.java
View File

@@ -67,7 +67,7 @@ public class BrightnessUtils {
/**
* Version of {@link #convertGammaToLinear} that takes and returns float values.
* TODO: brightnessfloat Merge with above method later.
* TODO(flc): refactor Android Auto to use float version
*
* @param val The slider value.
* @param min The minimum acceptable value for the setting.
@@ -83,9 +83,13 @@ public class BrightnessUtils {
ret = MathUtils.exp((normalizedVal - C) / A) + B;
}
// HLG is normalized to the range [0, 12], so we need to re-normalize to the range [0, 1]
// HLG is normalized to the range [0, 12], ensure that value is within that range,
// it shouldn't be out of bounds.
final float normalizedRet = MathUtils.constrain(ret, 0, 12);
// Re-normalize to the range [0, 1]
// in order to derive the correct setting value.
return MathUtils.lerp(min, max, ret / 12);
return MathUtils.lerp(min, max, normalizedRet / 12);
}
/**
@@ -111,16 +115,7 @@ public class BrightnessUtils {
* @return The corresponding slider value
*/
public static final int convertLinearToGamma(int val, int min, int max) {
// For some reason, HLG normalizes to the range [0, 12] rather than [0, 1]
final float normalizedVal = MathUtils.norm(min, max, val) * 12;
final float ret;
if (normalizedVal <= 1f) {
ret = MathUtils.sqrt(normalizedVal) * R;
} else {
ret = A * MathUtils.log(normalizedVal - B) + C;
}
return Math.round(MathUtils.lerp(GAMMA_SPACE_MIN, GAMMA_SPACE_MAX, ret));
return convertLinearToGammaFloat((float) val, (float) min, (float) max);
}
/**

29
packages/SettingsLib/tests/robotests/src/com/android/settingslib/display/BrightnessUtilsTest.java
View File

@@ -17,6 +17,7 @@
package com.android.settingslib.display;
import static com.android.settingslib.display.BrightnessUtils.GAMMA_SPACE_MAX;
import static com.android.settingslib.display.BrightnessUtils.GAMMA_SPACE_MIN;
import static com.google.common.truth.Truth.assertThat;
@@ -27,26 +28,40 @@ import org.robolectric.RobolectricTestRunner;
@RunWith(RobolectricTestRunner.class)
public class BrightnessUtilsTest {
private static final int MIN = 1;
private static final int MAX = 255;
private static final int MIN_INT = 1;
private static final int MAX_INT = 255;
private static final float MIN_FLOAT = 0.0f;
private static final float MAX_FLOAT = 1.0f;
@Test
public void linearToGamma_minValue_shouldReturn0() {
assertThat(BrightnessUtils.convertLinearToGamma(MIN, MIN, MAX)).isEqualTo(0);
public void linearToGamma_minValue_shouldReturnMin() {
assertThat(BrightnessUtils.convertLinearToGamma(MIN_INT, MIN_INT, MAX_INT))
.isEqualTo(GAMMA_SPACE_MIN);
assertThat(BrightnessUtils.convertLinearToGammaFloat(MIN_FLOAT, MIN_FLOAT, MAX_FLOAT))
.isEqualTo(GAMMA_SPACE_MIN);
}
@Test
public void linearToGamma_maxValue_shouldReturnGammaSpaceMax() {
assertThat(BrightnessUtils.convertLinearToGamma(MAX, MIN, MAX)).isEqualTo(GAMMA_SPACE_MAX);
assertThat(BrightnessUtils.convertLinearToGamma(MAX_INT, MIN_INT, MAX_INT))
.isEqualTo(GAMMA_SPACE_MAX);
assertThat(BrightnessUtils.convertLinearToGammaFloat(MAX_FLOAT, MIN_FLOAT, MAX_FLOAT))
.isEqualTo(GAMMA_SPACE_MAX);
}
@Test
public void gammaToLinear_minValue_shouldReturnMin() {
assertThat(BrightnessUtils.convertGammaToLinear(MIN, MIN, MAX)).isEqualTo(MIN);
assertThat(BrightnessUtils.convertGammaToLinear(GAMMA_SPACE_MIN, MIN_INT, MAX_INT))
.isEqualTo(MIN_INT);
assertThat(BrightnessUtils.convertGammaToLinearFloat(GAMMA_SPACE_MIN, MIN_FLOAT, MAX_FLOAT))
.isEqualTo(MIN_FLOAT);
}
@Test
public void gammaToLinear_gammaSpaceValue_shouldReturnMax() {
assertThat(BrightnessUtils.convertGammaToLinear(GAMMA_SPACE_MAX, MIN, MAX)).isEqualTo(MAX);
assertThat(BrightnessUtils.convertGammaToLinear(GAMMA_SPACE_MAX, MIN_INT, MAX_INT))
.isEqualTo(MAX_INT);
assertThat(BrightnessUtils.convertGammaToLinearFloat(GAMMA_SPACE_MAX, MIN_FLOAT, MAX_FLOAT))
.isEqualTo(MAX_FLOAT);
}
}