PRESET

The PRESET graphic SCREEN statement turns a pixel at a coordinate to the background color or a designated color attribute.

Syntax

PRESET [STEP](column%, row%)[, colorAttribute]

Parameters:

Can use STEP when relative graphics coordinates are required.
column and row coordinates can be literal ot variable INTEGER values which can be offscreen.
If the colorAttribute is omitted, PRESET will use the current destination page's _BACKGROUNDCOLOR.

Usage:

Color attributes are limited to those available in the SCREEN mode used. PSET can be used to adopt previously used colors.
Any color value other than 0 will be white in monochrome SCREEN modes 2 and 11 where the COLOR statement cannot be used.
PRESET can invisibly locate other graphics objects like CIRCLEs and add color to subsequent graphic objects and DRAW when used.
The PRESET action can be used in a graphics PUT to produce a color inverted image on any background. See Example 2.
The graphic cursor is set to the center of the program window on program start for STEP relative coordinates.
PRESET can be used in any graphic screen mode, but cannot be used in the default screen mode 0 as it is text only!

Example 1: Using PRESET to locate a DRAW statement that draws a box that is bright red.

SCREEN 12
PRESET(100, 100)
DRAW "C12 U20 R20 D20 L20"

Explanation: The DRAW string required a color designation as PRESET defaulted to the black background color.

Example 2: Displays the flags of countries that use simple horizontal or vertical color blocks with a highlighted arrow key menu.

DIM SHARED c$(21), x$(21), gg%(477)

ARRAY
SETUP
SELECTION
TERMINATE

END

SUB ARRAY
c$(1) = "Armenia H040914"
c$(2) = "Austria H041504"
c$(3) = "Belgium V001404"
c$(4) = "Bulgaria H150204"
c$(5) = "Chad V011404"
c$(6) = "C“te D'Ivoire V061502"
c$(7) = "Estonia H090015"
c$(8) = "France V011504"
c$(9) = "Germany H000414"
c$(10) = "Hungary H041502"
c$(11) = "Ireland V021506"
c$(12) = "Italy V021504"
c$(13) = "Lithuania H140204"
c$(14) = "Luxembourg H041509"
c$(15) = "Mali V021404"
c$(16) = "Netherlands H041501"
c$(17) = "Nigeria V021502"
c$(18) = "Romania V091404"
c$(19) = "Russia H150104"
c$(20) = "Sierra Leone H021509"
c$(21) = "Yemen H041500"
END SUB

SUB DISPLAY.FLAG (calc%)
f% = VAL(MID$(x$(calc%), 2, 2))
s% = VAL(MID$(x$(calc%), 4, 2))
t% = VAL(MID$(x$(calc%), 6, 2))

IF LEFT$(x$(calc%), 1) = "V" THEN
  LINE (120, 225)-(253, 465), f%, BF
  LINE (254, 225)-(385, 465), s%, BF
  LINE (386, 225)-(519, 465), t%, BF
END IF

IF LEFT$(x$(calc%), 1) = "H" THEN
  LINE (120, 225)-(519, 305), f%, BF
  LINE (120, 306)-(519, 386), s%, BF
  LINE (120, 387)-(519, 465), t%, BF
END IF
END SUB

SUB SELECTION 'menu selection using arrow keys
x% = 2: y% = 4

DO
  WHILE (x% <> prevx% OR y% <> prevy%) AND k$ <> CHR$(27)
    k$ = INKEY$
    x% = x% + (k$ = (CHR$(0) + "K") AND x% > 1) + ABS(k$ = (CHR$(0) + "M") AND x% < 3)
    y% = y% + (k$ = (CHR$(0) + "H") AND y% > 1) + ABS(k$ = (CHR$(0) + "P") AND y% < 7)
    calc% = (x% - 1) * 7 + y%: LOCATE 14, 18: PRINT c$(calc%); SPACE$(10)
    x1% = 140 + (x% - 1) * 128
    x2% = x1% + LEN(c$(calc%)) * 8 + 7
    y1% = 48 + y% * 16
    IF x1% <> prevx1% OR y1% <> prevy1% THEN
      IF g% THEN PUT(prevx1%, prevy1%), gg%(), PSET
      GET(x1%, y1%)-(x2%, y1% + 16), gg%(): g% = 1
      PUT(x1%, y1%), gg%(), PRESET
      prevx1% = x1%: prevx2% = x2%: prevy1% = y1%
      DISPLAY.FLAG calc%
    END IF
  WEND
LOOP UNTIL k$ = CHR$(27)
END SUB

SUB SETUP
SCREEN 12
COLOR 6
c% = 1

FOR x% = 11 TO 50 STEP 16
  FOR y% = 1 TO 7
    x$(c%) = RIGHT$(c$(c%), 7)
    c$(c%) = RTRIM$(LEFT$(c$(c%), LEN(c$(c%)) - 7))
    LOCATE y% + 4, x% + 8: PRINT c$(c%)
    c% = c% + 1
NEXT y%, x%

COLOR 11: LOCATE 3, 20: PRINT "Use the Cursor Keys to Select a Country:"
LINE (119, 224)-(520, 466), 7, B
END SUB

SUB TERMINATE
FOR c% = 1 TO 219
  LINE (116 + c%, 29 + c%)-(523 - c%, 469 - c%), 0, B
NEXT
END SUB

Code by AlGoreIthm

Explanation: Using the PUT PRESET action highlights the menu selection in graphic screen modes by returning a negative image.

PRESET

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Syntax

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PRESET

Syntax

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