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 a stipple or gradient are transformed by the drawing context’s transformation when the brush is used, but a brush can have its own brush transformation that is used, instead. A brush 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):
'transparent —
Draws with no effect (on the interior of the drawn shape). 'solid —
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. 'opaque —
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. 'xor —
The same as 'solid, accepted only for partial backward compatibility. 'panel —
The same as 'solid, accepted only for partial backward compatibility. 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.
To draw outline shapes (such as unfilled boxes and ellipses), use the 'transparent brush style.
To avoid creating multiple brushes with the same characteristics, use the global brush-list% object the-brush-list, or provide a color and style to set-brush in dc<%>.
See also make-brush.
constructor
(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"
style :
(or/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
gradient :
(or/c #f (is-a?/c linear-gradient%) (is-a?/c radial-gradient%)) = #f
transformation :
(or/c #f (vector/c (vector/c real? real? real? real? real? real?) real? real? real? real? real?)) = #f
method
(send a-brush get-gradient) →
(or/c (is-a?/c linear-gradient%) (is-a?/c radial-gradient%) #f)
method
(send a-brush get-handle) → (or/c cpointer? #f)
method
(send a-brush get-stipple) → (or/c (is-a?/c bitmap%) #f)
method
→
(or/c 'transparent 'solid 'opaque 'xor 'hilite 'panel 'bdiagonal-hatch 'crossdiag-hatch 'fdiagonal-hatch 'cross-hatch 'horizontal-hatch 'vertical-hatch)
method
(send a-brush get-transformation)
→
(or/c #f (vector/c (vector/c real? real? real? real? real? real?) real? real? real? real? real?))
If a brush with a stipple or gradient also has a transformation, then the transformation applies to the stipple or gradient’s coordinates instead of the target drawing context’s transformation; otherwise, the target drawing context’s transformation applies to stipple and gradient coordinates.
method
(send a-brush is-immutable?) → boolean?
method
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.
method
(send a-brush set-stipple bitmap [ transformation]) → void? bitmap : (or/c (is-a?/c bitmap%) #f)
transformation :
(or/c #f (vector/c (vector/c real? real? real? real? real? real?) real? real? real? real? real?)) = #f
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.
method
style :
(or/c 'transparent 'solid 'opaque 'xor 'hilite 'panel 'bdiagonal-hatch 'crossdiag-hatch 'fdiagonal-hatch 'cross-hatch 'horizontal-hatch 'vertical-hatch)