static int _DilateColor(this IBitmapSampler target, IBitmapSampler mask, float alphaThreshold = 0)
{
int count = 0;
var rows = new Dictionary <int, Vector4[]>();
for (int y = 0; y < mask.Height; ++y)
{
var row = rows[y] = new Vector4[mask.Width];
for (int x = 0; x < mask.Width; ++x)
{
row[x] = mask._GetDilatedTexel(x, y, alphaThreshold);
}
foreach (var k in rows.Keys.Where(item => (y - item) > 2).ToList())
{
count += target._ApplyRow(k, rows[k], true);
mask._ApplyRow(k, rows[k], false);
rows.Remove(k);
}
}
// apply remaining rows
foreach (var k in rows.Keys.ToList())
{
count += target._ApplyRow(k, rows[k], true);
mask._ApplyRow(k, rows[k], false);
rows.Remove(k);
}
return(count);
}
private static void _ApplyAlphaPremultiply(this IBitmapSampler source)
{
for (int y = 0; y < source.Height; ++y)
{
for (int x = 0; x < source.Width; ++x)
{
source[x, y] = source[x, y].Premultiply();
}
}
}
private static void _FillRGB(this IBitmapSampler source, Vector4 rgba)
{
for (int y = 0; y < source.Height; ++y)
{
for (int x = 0; x < source.Width; ++x)
{
rgba.W = source[x, y].W;
source[x, y] = rgba;
}
}
}
public _PixelTextureSampler(IBitmapSampler source, bool normalizedUV)
{
_Source = source;
if (normalizedUV)
{
_Size = new SizeF(1, 1);
_Scale = new Vector2(_Source.Width, source.Height);
}
else
{
_Size = new SizeF(_Source.Width, _Source.Height);
_Scale = Vector2.One;
}
_Offset = -Vector2.One / 2;
}
private static int _ApplyRow(this IBitmapSampler target, int y, Vector4[] row, bool ignoreAlpha)
{
int count = 0;
for (int x = 0; x < row.Length; ++x)
{
var c = row[x]; if (c.W == 0)
{
continue;
}
if (ignoreAlpha)
{
c.W = 0;
}
target[x, y] = c;
++count;
}
return(count);
}
public static bool Contains(this IBitmapSampler image, Point p)
{
return(image.Contains(p.X, p.Y));
}
public static bool Contains(this IBitmapSampler texture, int x, int y)
{
return(texture.Bounds().Contains(x, y));
}
public static Rectangle Bounds(this IBitmapSampler tex)
{
return(new Rectangle(0, 0, tex.Width, tex.Height));
}
/// <summary>
/// Gets a sampling of the 9 neighbour pixels
/// </summary>
/// <param name="texture"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="alphaThreshold"></param>
/// <returns>
/// If the central pixel is not transparent, returns the pixel itself, else it returns a sampling.
/// </returns>
static Vector4 _GetDilatedTexel(this IBitmapSampler texture, int x, int y, float alphaThreshold = 0)
{
if (texture[x, y].W > alphaThreshold)
{
return(Vector4.Zero);
}
var t1 = texture[x + 1, y];
var t2 = texture[x - 1, y];
var t3 = texture[x, y + 1];
var t4 = texture[x, y - 1];
if (t1.W <= alphaThreshold &&
t2.W <= alphaThreshold &&
t3.W <= alphaThreshold &&
t4.W <= alphaThreshold
)
{
return(Vector4.Zero);
}
var t5 = texture[x - 1, y - 1];
var t6 = texture[x + 1, y - 1];
var t7 = texture[x - 1, y + 1];
var t8 = texture[x + 1, y + 1];
var c = Vector4.Zero;
if (t1.W > alphaThreshold)
{
c += t1.WithW(1);
}
if (t2.W > alphaThreshold)
{
c += t2.WithW(1);
}
if (t3.W > alphaThreshold)
{
c += t3.WithW(1);
}
if (t4.W > alphaThreshold)
{
c += t4.WithW(1);
}
if (t5.W > alphaThreshold)
{
c += t5.WithW(1);
}
if (t6.W > alphaThreshold)
{
c += t6.WithW(1);
}
if (t7.W > alphaThreshold)
{
c += t7.WithW(1);
}
if (t8.W > alphaThreshold)
{
c += t8.WithW(1);
}
if (c.W > 0)
{
c /= c.W; c = c.Saturate();
}
return(c);
}
public static ITextureSampler <Vector4> ToTextureSampler(this IBitmapSampler sampler, bool normalizedUV)
{
return(new _PixelTextureSampler(sampler, normalizedUV));
}