RhPicture Plugin GDI Brush objects

SummaryA description of the GDI Brush objects as exposed through the RhPicture plugin

GDI+ Brush objects

GDI+ Brush objects are used to draw contents (fills) of geometry. There are a number of distinct Brush types available in GDI+, some of which are exposed in the RhPicture plugin:

Solid
Hatch
Texture
Linear Gradient

Brush types not available in the RhPicture plugin:

Path Gradient

Note that you do not need a Brush object to draw fills in the RhPicture plugin. Every method that takes a Brush object is overloaded and can be called with a colour instead, in which case you get a simple solid fill:

 Dim RhPicture : Set RhPicture = Rhin.GetPluginObject("RhPicture")
 Call RhPicture.CreateImage(80, 50, vbWhite)
 Call RhPicture.FillCircle(Array(40,25), 20, vbRed)

If you want to draw non-solid fills, you'll have to use an RhPicture Brush object. You can obtain a Brush object by calling one of the Brush creation methods on RhPicture:

 Dim RhPicture : Set RhPicture = Rhin.GetPluginObject("RhPicture")
 Call RhPicture.CreateImage(80, 50, vbWhite)


 Dim BrushObj : Set BrushObj = RhPicture.CreateGradientBrush(Array(0, 0), Array(50,0), vbRed, vbBlack)
 Call RhPicture.FillCircle(Array(40,25), 20, BrushObj)

Note that you can store any number of Brush objects in your script and you can reuse them as often as you like. Brush objects are not bound to the RhPicture instance that created them and you can use them on any RhPicture object. There are several Brush creation methods available, one for each type of Brush:

 RhPicture.CreateSolidBrush(Color As GDIColor) As GDIBrush
 RhPicture.CreateHatchBrush(HatchStyle As Integer, Foreground As GDIColor, Optional Background As GDIColor) As GDIBrush
 RhPicture.CreateTextureBrush(Texture As String, Optional WrapMode As Integer) As GDIBrush
 RhPicture.CreateGradientBrush(From As GDIPoint, To As GDIPoint, Color1 As GDIColor, Color2 As GDIColor) As GDIBrush

Parameter	Type	Description
Color	GDIColor	A GDIColor instance used for the solid fill.
HatchStyle	Integer	A Hatch style enumeration. See table below for valid values.
Foreground	GDIColor	The color to assign to the hatch pattern.
Background	GDIColor	The color to assign to the background of the hatch pattern. If omitted, the hatch is drawn with a transparant background.
Texture	String	The path of an existing image file to use as texture.
WrapMode	Integer	The wrapping style enumeration controlling how the texture is tiled. See table below for valid values.
From	GDIPoint	A 2D coordinate that defines the start of the gradient.
To	GDIPoint	A 2D coordinate that defines the end of the gradient.
Color1	GDIColor	The colour at the start of the gradient.
Color2	GDIColor	The colour at the end of the gradient.

Enumerations explained:

HatchBrush style enumeration constants. GDI+ defines 53 different hatch styles. The zip-file contains all of these.
HatchBrush Constants
Hatch = 0	Hatch = 1	Hatch = 2	Hatch = 3	Hatch = 4
Hatch = 5	Hatch = 6	Hatch = 7	Hatch = 8	Hatch = 9
Hatch = 10	Hatch = 11	Hatch = 12	Hatch = 13	Hatch = 14
Hatch = 15	Hatch = 16	Hatch = 17	Hatch = 18	Hatch = 19
Hatch = 20	Hatch = 21	Hatch = 22	Hatch = 23	Hatch = 24
Hatch = 25	Hatch = 26	Hatch = 27	Hatch = 28	Hatch = 29
Hatch = 30	Hatch = 31	Hatch = 32	Hatch = 33	Hatch = 34
Hatch = 35	Hatch = 36	Hatch = 37	Hatch = 38	Hatch = 39
Hatch = 40	Hatch = 41	Hatch = 42	Hatch = 43	Hatch = 44
Hatch = 45	Hatch = 46	Hatch = 47	Hatch = 48	Hatch = 49
Hatch = 50	Hatch = 51	Hatch = 52

TextureBrush tile constants.
Repeat x & y	Mirror x	Mirror y	Mirror x & y	Single tile

Tile = 0	Tile = 1	Tile = 2	Tile = 3	Tile = 4

Linear Gradients explained:

Be careful when using Linear Gradient brushes. The coordinates that define the start and end points of the gradient may be subject to noise. Since gradients are stacked rather than mirrored it is possible you get bleeding colours if you've defined your gradient to fit exactly within your drawing region. It is usually best to make the gradient extend one pixel in each direction: