/// <summary>
/// Linearly interpolates between two color values.
/// </summary>
/// <param name="from">The color value that represents 0 on the lerp number line.</param>
/// <param name="to">The color value that represents 1 on the lerp number line.</param>
/// <param name="frac">A value in the range [0, 1].</param>
/// <remarks>
/// This method does a simple lerp on each color value and on the alpha channel. It does
/// not properly take into account the alpha channel's effect on color blending.
/// </remarks>
public static ColorBgra Lerp(ColorBgra from, ColorBgra to, double frac)
{
return FromBgraClamped(
(((double)@from.B).Lerp(to.B, frac)),
(((double)@from.G).Lerp(to.G, frac)),
(((double)@from.R).Lerp(to.R, frac)),
(((double)@from.A).Lerp(to.A, frac)));
}
private static SaveFormats.LinearColor BgraToLinearColor(ColorBgra bgra)
{
return new SaveFormats.LinearColor(
(float)bgra.R / 255,
(float)bgra.G / 255,
(float)bgra.B / 255,
(float)bgra.A / 255);
}
/// <summary>
/// Blends the colors based on the given weight values.
/// </summary>
/// <param name="c">The array of color values.</param>
/// <param name="w">The array of weight values.</param>
/// <returns>
/// Each color will be blended in proportionally to its weight value respective to
/// the total summation of the weight values.
/// </returns>
/// <remarks>
/// "WAIP" stands for "weights, floating-point"</remarks>
public static ColorBgra BlendColors(ColorBgra[] c, double[] w)
{
if (c.Length != w.Length)
{
throw new ArgumentException("c.Length != w.Length");
}
if (c.Length == 0)
{
return Transparent;
}
double wsum = 0;
double asum = 0;
for (int i = 0; i < w.Length; ++i)
{
wsum += w[i];
asum += c[i].A * w[i];
}
double a = asum / wsum;
double aMultWsum = a * wsum;
double b;
double g;
double r;
if (Equals(asum, 0.0) == true)
{
b = 0;
g = 0;
r = 0;
}
else
{
b = 0;
g = 0;
r = 0;
for (int i = 0; i < c.Length; ++i)
{
b += (double)c[i].A * c[i].B * w[i];
g += (double)c[i].A * c[i].G * w[i];
r += (double)c[i].A * c[i].R * w[i];
}
b /= aMultWsum;
g /= aMultWsum;
r /= aMultWsum;
}
return FromBgra((byte)b, (byte)g, (byte)r, (byte)a);
}
/// <summary>
/// Blends the colors based on the given weight values.
/// </summary>
/// <param name="c">The array of color values.</param>
/// <param name="w">The array of weight values.</param>
/// <returns>
/// The weights should be fixed point numbers.
/// The total summation of the weight values will be treated as "1.0".
/// Each color will be blended in proportionally to its weight value respective to
/// the total summation of the weight values.
/// </returns>
/// <remarks>
/// "WAIP" stands for "weights, arbitrary integer precision"</remarks>
public static ColorBgra BlendColors(ColorBgra[] c, uint[] w)
{
if (c.Length != w.Length)
{
throw new ArgumentException("c.Length != w.Length");
}
if (c.Length == 0)
{
return FromUInt32(0);
}
long wsum = 0;
long asum = 0;
for (int i = 0; i < w.Length; ++i)
{
wsum += w[i];
asum += c[i].A * w[i];
}
var a = (uint)((asum + (wsum >> 1)) / wsum);
long b;
long g;
long r;
if (a == 0)
{
b = 0;
g = 0;
r = 0;
}
else
{
b = 0;
g = 0;
r = 0;
for (int i = 0; i < c.Length; ++i)
{
b += (long)c[i].A * c[i].B * w[i];
g += (long)c[i].A * c[i].G * w[i];
r += (long)c[i].A * c[i].R * w[i];
}
b /= asum;
g /= asum;
r /= asum;
}
return FromUInt32((uint)b + ((uint)g << 8) + ((uint)r << 16) + (a << 24));
}
/// <summary>
/// Blends four colors together based on the given weight values.
/// </summary>
/// <returns>The blended color.</returns>
/// <remarks>
/// The weights should be 16-bit fixed point numbers that add up to 65536 ("1.0").
/// 4W16IP means "4 colors, weights, 16-bit integer precision"
/// </remarks>
public static ColorBgra BlendColors(ColorBgra c1,
uint w1,
ColorBgra c2,
uint w2,
ColorBgra c3,
uint w3,
ColorBgra c4,
uint w4)
{
const uint ww = 32768;
uint af = (c1.A * w1) + (c2.A * w2) + (c3.A * w3) + (c4.A * w4);
uint a = (af + ww) >> 16;
uint b;
uint g;
uint r;
if (a == 0)
{
b = 0;
g = 0;
r = 0;
}
else
{
b =
(uint)
((((long)c1.A * c1.B * w1) + ((long)c2.A * c2.B * w2) + ((long)c3.A * c3.B * w3) +
((long)c4.A * c4.B * w4)) / af);
g =
(uint)
((((long)c1.A * c1.G * w1) + ((long)c2.A * c2.G * w2) + ((long)c3.A * c3.G * w3) +
((long)c4.A * c4.G * w4)) / af);
r =
(uint)
((((long)c1.A * c1.R * w1) + ((long)c2.A * c2.R * w2) + ((long)c3.A * c3.R * w3) +
((long)c4.A * c4.R * w4)) / af);
}
return FromBgra((byte)b, (byte)g, (byte)r, (byte)a);
}
/// <summary>
/// Smoothly blends between two colors.
/// </summary>
public static ColorBgra Blend(ColorBgra ca, ColorBgra cb, byte cbAlpha)
{
uint caA = FastScaleByteByByte((byte)(255 - cbAlpha), ca.A);
uint cbA = FastScaleByteByByte(cbAlpha, cb.A);
uint cbAt = caA + cbA;
uint r;
uint g;
uint b;
if (cbAt == 0)
{
r = 0;
g = 0;
b = 0;
}
else
{
r = ((ca.R * caA) + (cb.R * cbA)) / cbAt;
g = ((ca.G * caA) + (cb.G * cbA)) / cbAt;
b = ((ca.B * caA) + (cb.B * cbA)) / cbAt;
}
return FromBgra((byte)b, (byte)g, (byte)r, (byte)cbAt);
}
private void SyncHsvFromRgb(ColorBgra bgra)
{
ColorHsv hsv = ColorHsv.FromColor(bgra.ToColor());
this.SetColorGradientValuesHsv(hsv.Hue, hsv.Saturation, hsv.Value);
this.SetColorGradientMinMaxColorsHsv(hsv.Hue, hsv.Saturation, hsv.Value);
colorWheel1.Color = hsv;
}
