In addition to its color and style, a brush can have a brush stipple bitmap. Painting with a stipple brush is similar to calling draw-bitmap with the stipple bitmap in the filled region.
As an alternative to a color, style, and stipple, a brush can have a gradient that is a linear-gradient% or radial-gradient%. When a brush has a gradient and the target for drawing is not monochrome, then other brush settings are ignored. With a gradient, for each point in a drawing destination, the gradient associates a color to the point based on starting and ending colors and starting and ending lines (for a linear gradient) or circles (for a radial gradient); a gradient-assigned color is applied for each point that is touched when drawing with the brush. By default, coordinates in the gradient are transformed by the drawing context’s transformation when the brush is used, but a brush can have its own gradient transformation that is used, instead. A gradient transformation has the same representation and meaning as for get-transformation in dc<%>.
A brush style is one of the following (but is ignored if the brush has a gradient and the target is not monochrome):
Draws using the brush’s color. If a monochrome brush stipple is installed into the brush, black pixels from the stipple are transferred to the destination using the brush’s color, and white pixels from the stipple are not transferred.
The same as 'solid for a color brush stipple. For a monochrome stipple, white pixels from the stipple are transferred to the destination using the destination’s background color.
The following modes correspond to built-in brush stipples drawn in 'solid mode:
However, when a specific brush stipple is installed into the brush, the above modes are ignored and 'solid is used, instead.
(new brush% [ [color color] [style style] [stipple stipple] [gradient gradient]] [transformation transformation]) → (is-a?/c brush%) color : (or/c string? (is-a?/c color%)) = "black"
(one-of/c 'transparent 'solid 'opaque 'xor 'hilite 'panel 'bdiagonal-hatch 'crossdiag-hatch 'fdiagonal-hatch 'cross-hatch 'horizontal-hatch 'vertical-hatch) = 'solid stipple : (or/c #f (is-a?/c bitmap%)) = #f
(or/c #f (is-a?/c linear-gradient%) (is-a?/c radial-gradient%)) = #f
(or/c #f (vector/c (vector/c real? real? real? real? real? real?) real? real? real? real? real?))
If a brush with a gradient also has a transformation, then the transformation applies to the gradient’s coordinates instead of the target drawing context’s transformation; otherwise, the target drawing context’s transformation applies to gradient coordinates.
(send a-brush set-color color) → void? color : (is-a?/c color%) (send a-brush set-color color-name) → void? color-name : string? (send a-brush set-color red green blue) → void? red : (integer-in 0 255) green : (integer-in 0 255) blue : (integer-in 0 255)
For the case that the color is specified using a string, see color-database<%> for information about color names.
If bitmap is modified while is associated with a brush, the effect on the brush is unspecified. A brush cannot be modified if it was obtained from a brush-list% or while it is selected into a drawing context.