Tone Fill Routines: Explanation of Subroutines
Sets the value of the tone level used by uetone
by the minimum & maximum values and step size, or by the number of levels.
- Explanation of Parameters
| xmin, xmax
||The minimum and maximum values of the tone levels. The levels do not
necessarily need to have conveniently rounded numbers.
When dx<0, uses dx as the step size.
When dx=0, inquires
'NLEV' and generates approximately nlev tone levels.
When dx>0, generates approximately INT(ABS(DX))
- This routine uses the same algorithm as UDGCLA (see Section 8.2.3)
to generate the level values. To unify the algorithm, the same internal
variables as 'NLEV' and 'ICYCLE' used in UDPACK are provided
in UEPACK. When these variables are changed in the UDPACK, they must also be
changed in the UEPACK.
Must be xmin != xmax.
- The tone level is set as the step size specified by DX
multiplied by an integer factor.
- The difference in the values of color indices specified by the internal
variables 'ICOLOR1' and 'ICOLOR2' (the initial values are 15
and 94, respectively) is divided by the number of tone levels to obtain the
color index for each level. The pattern index 'ITPAT' (initial
value is 999: solid fill) is added to the color index to generate the
tone pattern index. for the level.