Enum PdnHalftonePattern

Namespace

PaintDotNet.Effects.Gpu

Assembly

PaintDotNet.Effects.Gpu.dll

Specifies the shape that the Halftone effect lays down in each cell of its screen. Every pattern is amplitude modulated: the cells are always the same size and sit on the same grid, and it is the amount of the cell that gets inked which carries the tone.

public enum PdnHalftonePattern

Fields

Dots = 0

A circular dot at the centre of each cell, growing outward as the cell's ink coverage rises. The classic amplitude-modulated screen used for print and comics.

Diamond = 1

The Euclidean spot, known to PostScript as PSSquare: a disc in the highlights that swells into a diamond at the midtone and then recedes as a disc of white in the shadows. The diamond is reached at exactly fifty percent, where the inked and uninked areas are congruent, and the second half of the range is the first half inverted, so tone moves through the midtone at a constant rate - where Dots stays circular, so its corners of white close abruptly once the dots touch at a coverage of pi/4.

Ellipse = 2

An elliptical dot, elongated along the screen's own axis; the workhorse of commercial offset printing. Where a round dot meets all four neighbours at once, an ellipse meets them along its long axis first and its short axis later, splitting the single abrupt join into two smaller ones - between which the dots visibly chain into lines.

Square = 3

A square dot, growing until it fills its cell exactly. The only shape here whose inked area is exact at every tone rather than fitted, because a square inside a square cell is never clipped.

Crosshatch = 4

Two line screens at right angles to each other, each thinned so that their union still reproduces the requested tone rather than doubling it.

Lines = 5

A single straight line through each cell, growing thicker as the cell's ink coverage rises. Cells along the line are inked independently, so it swells and narrows along its length.