public static float getModifiedValue(float value, Shade shade) {
if (shade.getValue() == 500) {
return value;
}
float indexFloat = ((float) shade.getValue()) / 100.0f;
int indexFloor = (int) Math.floor(indexFloat);
int indexCeil = (int) Math.ceil(indexFloat);
int max = mValuePercentConversion.length - 1;
int lowerIndex = Math.min(Math.max(indexFloor, 0), max);
int upperIndex = Math.min(Math.max(indexCeil, 0), max);
float lowerPercent = mValuePercentConversion[lowerIndex];
float valuePercent;
if (lowerIndex != upperIndex) {
float upperPercent = mValuePercentConversion[upperIndex];
float deltaPercent = upperPercent - lowerPercent;
float deltaIndex = upperIndex - lowerIndex;
valuePercent = lowerPercent + (deltaPercent / deltaIndex) * (indexFloat - (float) lowerIndex);
} else {
valuePercent = lowerPercent;
}
if (shade.getValue() < 500) {
return value + ((1.0f - value) * valuePercent);
} else {
return value + (value * valuePercent);
}
}
public static float getModifiedHue(float hue, Shade shade) {
float s = (float) shade.getValue();
if (s > 500) {
// Initial calculations are based on hue being in the range [0.0-1.0]
// java has the range [0.0-360.0] so we'll do a little conversion
hue = hue / 360.0f;
float hueAt900 = (1.003f * hue) - 0.016f;
hue = ((hueAt900 - hue) / ((float) 900 - (float) 500)) * (s - (float) 500) + hue;
return hue * 360.0f;
} else {
return hue;
}
}
public static float getModifiedSaturation(float saturation, Shade shade) {
if (shade.getValue() == 500) {
return saturation;
}
if (shade.getValue() < 500) {
// get the saturation target @ 50:
// clamp to 0.0
float f = (0.136f * saturation) - 0.025f;
float satAt50 = Math.max(f, 0.0f);
// lerp shade 500->900
return ((saturation - satAt50) / (500 - 50)) * (shade.getValue() - 50) + satAt50;
} else {
// get the saturation target @ 900:
// quick inaccurate version:
// 110% of the base saturation (clamped to 1.0)
// CGFloat satAt900 = MIN(baseSaturation * 1.10, 1.0);
// expensive(?) accurate version
float satAt900 =
Math.min((-1.019f * saturation * saturation) + (2.283f * saturation) - 0.281f, 1.0f);
// lerp shade 500->900
return ((satAt900 - saturation) / (900 - 500)) * (shade.getValue() - 500) + saturation;
}
}