internal bool TryConvertNamedDirectionToAngle(string token, out double angle)
{
var reader = new CssReader(token, ' ');
if (reader.CanRead && reader.Read() == "to")
{
var defaultVector = Vector2.Down; // By default gradient is drawn top-down
var directionVector = Vector2.Zero;
reader.MoveNext();
while (reader.CanRead)
{
directionVector.SetNamedDirection(reader.Read());
reader.MoveNext();
}
angle = Vector2.Angle(ref defaultVector, ref directionVector);
// We start rotation from Vector(0, -1) clockwise
// If gradient ends in I or II quarter of coordinate system
// we use angle to calculate actual rotation
if (directionVector.X > 0)
{
angle = 360 - angle;
}
return(true);
}
angle = 0;
return(false);
}
private (bool, Size) GeRadius(CssReader reader, RadialGradientShape shape, ref RadialGradientFlags flags)
{
if (reader.CanRead)
{
var size = Dimensions.Zero;
if (shape == RadialGradientShape.Circle)
{
var radiusToken = reader.Read();
var isRadius = OffsetConverter.TryExtractOffset(radiusToken, out var radius);
if (isRadius)
{
size = new Dimensions(radius, radius);
reader.MoveNext();
}
}
if (shape == RadialGradientShape.Ellipse)
{
var radiusHToken = reader.Read();
var radiusVToken = reader.ReadNext();
var isRadiusH = OffsetConverter.TryExtractOffset(radiusHToken, out var radiusH);
var isRadiusV = OffsetConverter.TryExtractOffset(radiusVToken, out var radiusV);
if (isRadiusH && isRadiusV)
{
size = new Dimensions(radiusH, radiusV);
reader.MoveNext();
}
else
{
// Revert radiusVToken
reader.Rollback();
}
}
if (size != Dimensions.Zero)
{
if (size.Width.Type == OffsetType.Proportional)
{
FlagsHelper.Set(ref flags, WidthProportional);
}
if (size.Height.Type == OffsetType.Proportional)
{
FlagsHelper.Set(ref flags, HeightProportional);
}
return(true, new Size(size.Width.Value, size.Height.Value));
}
}
// Value -1 means undefined for RadialGradientShader
return(false, new Size(-1, -1));
}
private (bool, Dimensions) GeRadius(CssReader reader, RadialGradientShape shape)
{
if (reader.CanRead)
{
var size = Dimensions.Zero;
if (shape == RadialGradientShape.Circle)
{
var radiusToken = reader.Read();
var isRadius = Offset.TryParseWithUnit(radiusToken, out var radius);
if (isRadius)
{
size = new Dimensions(radius, radius);
reader.MoveNext();
}
}
if (shape == RadialGradientShape.Ellipse)
{
var radiusHToken = reader.Read();
var radiusVToken = reader.ReadNext();
var isRadiusH = Offset.TryParseWithUnit(radiusHToken, out var radiusH);
var isRadiusV = Offset.TryParseWithUnit(radiusVToken, out var radiusV);
if (isRadiusH && isRadiusV)
{
size = new Dimensions(radiusH, radiusV);
reader.MoveNext();
}
else
{
// Revert radiusVToken
reader.Rollback();
}
}
if (size != Dimensions.Zero)
{
return(true, size);
}
}
return(false, Dimensions.Zero);
}
private RadialGradientSize GetShapeSize(CssReader reader)
{
if (reader.CanRead)
{
var token = reader.Read().Replace("-", "").Trim();
if (Enum.TryParse <RadialGradientSize>(token, true, out var shapeSize))
{
reader.MoveNext();
return(shapeSize);
}
}
return(RadialGradientSize.FarthestCorner);
}
private RadialGradientShape GetShape(CssReader reader)
{
if (reader.CanRead)
{
var token = reader.Read().Trim();
if (Enum.TryParse <RadialGradientShape>(token, true, out var shape))
{
reader.MoveNext();
return(shape);
}
}
return(RadialGradientShape.Ellipse);
}
private (bool, RadialGradientStretch) GetStretch(CssReader reader)
{
if (reader.CanRead)
{
var token = reader.Read().Replace("-", "").Trim();
if (Enum.TryParse <RadialGradientStretch>(token, true, out var stretch))
{
reader.MoveNext();
return(true, stretch);
}
}
return(false, RadialGradientStretch.FarthestCorner);
}
