void TextureCoordinateShader(BrushShader shader, Point[] points, int index, int count, Rect rect)
{
float uPerUnit;
float vPerUnit;
switch (Stretch)
{
case Stretch.None:
uPerUnit = 1f / ImageSource.Width;
vPerUnit = 1f / ImageSource.Height;
break;
case Stretch.Fill:
uPerUnit = 1f / rect.Width;
vPerUnit = 1f / rect.Height;
break;
default:
{
float ratio = (float)ImageSource.Width / (float)ImageSource.Height;
Vector vSize = new Vector(ImageSource.Width, ImageSource.Height);
Vector hSize = vSize;
vSize.X = rect.Width;
vSize.Y = rect.Width / ratio;
hSize.Y = rect.Height;
hSize.X = ratio * hSize.Y;
Vector max;
Vector min;
Vector interest;
if (vSize.LengthSquare > hSize.LengthSquare)
{
max = vSize;
min = hSize;
}
else
{
min = vSize;
max = hSize;
}
if (Stretch == Stretch.UniformToFill)
interest = max;
else
interest = min;
uPerUnit = 1f / interest.X;
vPerUnit = 1f / interest.Y;
}
break;
}
for (int i = index; i < index + count; i++)
{
Point point = points[i];
shader.TextureCoordinates[i] = new TextureCoordinate(point.X * uPerUnit, point.Y * vPerUnit);
}
}
protected override BrushShader GetShader(Geometry geometry)
{
BrushShader ret = new BrushShader();
ret.ImageSource = ImageSource;
ret.TextureCoordinates = new TextureCoordinate[geometry.Points.Length];
if (Target == BrushTarget.Geometry)
{
TextureCoordinateShader(ret, geometry.Points, 0, geometry.Points.Length, geometry.BoundingBox);
}
else
{
for (int i = 0; i < geometry.Points.Length; i += geometry.VerticesPerPrimitive)
{
TextureCoordinateShader(ret, geometry.Points, i, geometry.VerticesPerPrimitive, Rect.GetBoundingBox(geometry.Points, i, geometry.VerticesPerPrimitive));
}
}
return ret;
}
protected override BrushShader GetShader(Geometry geometry)
{
BrushShader ret = new BrushShader();
ret.Color = myColor;
return ret;
}