**ShowPlay Reference Manual, Chapter 3 (ControlVariables): sk_params**
===== Sketch parameters -- Control interactive drawing options =====
The "sketch" parameters are used to enable interactive drawing during a Showplay paradigm.

The Sketch parameters are:\\
sk_flag - main control flag
  * 1 - sketching features are activated
  * 2 - draw at cursor
  * 4 - transform cursor position by SK_AFFINE matrix
  * 8 - flip the X cursor coordinate
  * 16 - flip the Y cursor coordinate
  * 32 - beep if drawing in SK_IMAGE 0 region (with flag 64+128)
  * 64 - check cursor positions within SK_IMAGE
  * 128 - save SK_IMAGE value at cursor as SK_VAL
  * 256 - draw with SK_OFFCOLOR if SK_VAL is 0
sk_tmin - minimum elapsed time before recording new cursor position\\
sk_dmin - minimum cursor displacement (pixels) before recording new cursor position\\
sk_dmax - maximum cursor displacement (pixels) for connected points; greater than this starts a new vector list\\
sk_wid - \\
sk_hgt - \\
sk_imagename - background template image file name\\
sk_rect - rectangle to constrain drawing\\
sk_beep - name of beep sound
sk_dbeep - minimum time between beeps (ms)

All sketching operations are implemented in the real-time program module "rt_response".  Copy the original and modify it in your task folder if you want to customize sketching features.
 
Note: Sketch data are recorded within the "pdigm" output file, and are also saved in a "drawing.txt" file.

**See Also:**\\

[[jvs:cigal|CIGAL Home]], 
[[jvs:cigal:manual|CIGAL Manual]], 
[[jvs:cigal:showplay|ShowPlay Home]], 
[[jvs:cigal:showplay:manual|ShowPlay Manual]], 
[[jvs:cigal:showplay:manual:chapter3|InputParameters List]], 
[[jvs:cigal:showplay:manual:help|Manual Help]]