Action
Enable or disable writing of color components.
Syntax
ColorMask r, g ,b ,a
Remarks
r |
Enable or disable the red channel update of the FT800 color buffer. The initial value is 1 and means enable |
g |
Enable or disable the green channel update of the FT800 color buffer. The initial value is 1 and means enable |
b |
Enable or disable the blue channel update of the FT800 color buffer. The initial value is 1 and means enable |
a |
Enable or disable the alpha channel update of the FT800 color buffer. The initial value is 1 and means enable |
The color mask controls whether the color values of a pixel are updated. Sometimes it is used to selectively update only the
red, green, blue or alpha channels of the image. More often, it is used to completely disable color updates while updating the
tag and stencil buffers.
See also
Example
' Pseudocode
'Draw a '8' digit in the middle of the screen. Then paint an invisible 40-pixel circular
'touch area into the tag buffer
Begin_G BITMAPS
Vertex2II 68, 40, 31, &H38
PointSize 40 * 16
ColorMask 0, 0, 0, 0
Begin_G FTPOINTS
Tag &H38
Vertex2II 80, 60, 0, 0
