public static double Solve_Object_Axis_Position(CssValue Pos, double ObjectArea, double ObjectSize)
{/* https://www.w3.org/TR/css-backgrounds-3/#the-background-position */
if (Pos is null)
{
throw new ArgumentNullException(nameof(Pos));
}
if (Pos.Type != ECssValueTypes.PERCENT)
{
throw new ArgumentException("Pos must be a CSS percent-type value!");
}
Contract.EndContractBlock();
var P = Pos.AsDecimal();
return((P * ObjectArea) - (P * ObjectSize));
}
/// <summary>
/// The default sizing algorithm is a set of rules commonly used to find an object's concrete object size.
/// It resolves the simultaneous constraints presented by the object's intrinsic dimensions and either an unconstrained specified size or one consisting of only a definite width and/or height.
/// </summary>
public static Rect2f Default_Sizing_Algorithm(CssPrincipalBox Box, CssValue Specified_Width, CssValue Specified_Height, double Default_Width, double Default_Height)
{/* Docs: https://www.w3.org/TR/css3-images/#default-object-size */
if (Box is null)
{
throw new ArgumentNullException(nameof(Box));
}
if (Specified_Width is null)
{
throw new ArgumentNullException(nameof(Specified_Width));
}
if (Specified_Height is null)
{
throw new ArgumentNullException(nameof(Specified_Height));
}
Contract.EndContractBlock();
/* The default sizing algorithm is defined as follows: */
/* If the specified size is a definite width and height, the concrete object size is given that width and height. */
if (Specified_Width.IsDefinite && Specified_Height.IsDefinite)
{
return(new Rect2f(Specified_Width.AsDecimal(), Specified_Height.AsDecimal()));
}
/*
* If the specified size is only a width or height (but not both) then the concrete object size is given that specified width or height. The other dimension is calculated as follows:
* 1) If the object has an intrinsic aspect ratio, the missing dimension of the concrete object size is calculated using the intrinsic aspect ratio and the present dimension.
* 2) Otherwise, if the missing dimension is present in the object's intrinsic dimensions, the missing dimension is taken from the object's intrinsic dimensions.
* 3) Otherwise, the missing dimension of the concrete object size is taken from the default object size.
*/
if (Specified_Width.HasValue ^ Specified_Height.HasValue)
{
if (Box.Intrinsic_Ratio.HasValue)
{/* 1) If the object has an intrinsic aspect ratio, the missing dimension of the concrete object size is calculated using the intrinsic aspect ratio and the present dimension. */
if (Specified_Width.HasValue)
{
return(new Rect2f(Specified_Width.AsDecimal(), (Specified_Width.AsDecimal() / Box.Intrinsic_Ratio.Value)));
}
else
{
return(new Rect2f((Specified_Height.AsDecimal() * Box.Intrinsic_Ratio.Value), Specified_Height.AsDecimal()));
}
}
/* 2) Otherwise, if the missing dimension is present in the object's intrinsic dimensions, the missing dimension is taken from the object's intrinsic dimensions. */
if (!Specified_Width.HasValue && Box.Intrinsic_Width.HasValue)
{
return(new Rect2f(Box.Intrinsic_Width.Value, Specified_Height.AsDecimal()));
}
else if (!Specified_Height.HasValue && Box.Intrinsic_Height.HasValue)
{
return(new Rect2f(Specified_Width.AsDecimal(), Box.Intrinsic_Height.Value));
}
/* 3) Otherwise, the missing dimension of the concrete object size is taken from the default object size. */
if (Specified_Width.HasValue)
{
return(new Rect2f(Specified_Width.AsDecimal(), Default_Height));
}
else
{
return(new Rect2f(Default_Width, Specified_Height.AsDecimal()));
}
}
/*
* If the specified size has no constraints:
* 1) If the object has an intrinsic height or width, its size is resolved as if its intrinsic size were given as the specified size.
* 2) Otherwise, its size is resolved as a contain constraint against the default object size.
*/
if (Box.Intrinsic_Width.HasValue || Box.Intrinsic_Height.HasValue)
{
if (Box.Intrinsic_Width.HasValue && Box.Intrinsic_Height.HasValue)
{
return(new Rect2f(Box.Intrinsic_Width.Value, Box.Intrinsic_Height.Value));
}
}
else if (Box.Intrinsic_Width.HasValue ^ Box.Intrinsic_Height.HasValue)
{
/* Step 1 */
if (Box.Intrinsic_Ratio.HasValue)
{/* 1) If the object has an intrinsic aspect ratio, the missing dimension of the concrete object size is calculated using the intrinsic aspect ratio and the present dimension. */
if (Box.Intrinsic_Width.HasValue)
{
return(new Rect2f(Box.Intrinsic_Width.Value, (Box.Intrinsic_Width.Value / Box.Intrinsic_Ratio.Value)));
}
else
{
return(new Rect2f((Box.Intrinsic_Height.Value * Box.Intrinsic_Ratio.Value), Box.Intrinsic_Height.Value));
}
}
/* Step 3 */
if (Box.Intrinsic_Width.HasValue)
{
return(new Rect2f(Box.Intrinsic_Width.Value, Default_Height));
}
else
{
return(new Rect2f(Default_Width, Box.Intrinsic_Height.Value));
}
}
/* 2) Otherwise, its size is resolved as a contain constraint against the default object size. */
return(Contain_Constraint_Algorithm(Box, Default_Width, Default_Height));
}
