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cmd_shade |
Function (ROM Call 0x38A) |
Executes TI-Basic 'Shade' command.
cmd_shade displays the Graph Screen, graphs two expressions on the screen as
functions using "x" as the independent variable, and shades the areas in
which the first expression is less than the second one (see TI-Basic manual
for more info). This function expects one of the following layouts on the
expression stack:
END_TAG expression_2 expression_1 |
END_TAG x_low expression_2 expression_1 |
END_TAG x_high x_low expression_2 expression_1 |
END_TAG pattern x_high x_low expression_2 expression_1 |
END_TAG pat_res pattern x_high x_low expression_2 expression_1 |
Additionally, each of the entries x_low, x_high, pattern,
and pat_res may be omitted and replaced with
NOTHING_TAG. The parameter Args
should point to the tag of the last item (i.e. expression_1).
x_low and x_high, if included, must be floating point or
integer items. They specify the left and right boundaries for the shading
process. Valid values are all real values between the values of TI-Basic
system variables "xmin" and "xmax". Also, "xmin" and "xmax" are defaults for
x_low and x_high if they are omitted.
pattern and pat_res, if included, must be integer items.
pattern specifies one of the following four shading patterns:
1 | Vertical shading [DEFAULT] |
2 | Horizontal shading |
3 | Negative-slope (45 degree) shading |
4 | Positive-slope (45 degree) shading |
pat_res specifies the resolution of the shading patterns:
1 | Solid shading |
2 | 1 pixel spacing [DEFAULT] |
3 | 2 pixel spacing |
4 | 3 pixel spacing |
5 | 4 pixel spacing |
6 | 5 pixel spacing |
7 | 6 pixel spacing |
8 | 7 pixel spacing |
9 | 8 pixel spacing |
10 | 9 pixel spacing |
Note that the drawn graph is not part of the smart graph feature (see the
TI-Basic manual for more info), and that regraphing will erase all drawn
items.
Uses: ER_catch, ER_success, ER_throwVar, GetValue, next_expression_index, push_expression, push_Float, push_quantum, top_estack, gr_active, OSCheckBreak, is_transfinite, ForceFloat, GraphActivate, GrLineFlt, QSkipGraphErr, XCvtPtoF, YCvtFtoWin, MakeWinRect, WinAttr, WinLine, _bcd_math
See also: cmd_drawfunc, cmd_drawparm, cmd_drawpol