LINE - mkilgore/QB64pe GitHub Wiki

The LINE statement is used in graphic SCREEN modes to create lines or boxes.

LINE [STEP] [(column1,]-[STEP] (column2, row2), color[,]

• The STEP keyword make column and row coordinates relative to the previously coordinates set by any graphic statement.
• The optional parameters (column1, row1) set the line's starting point.
• The dash and second coordinate parameters (column2, row2) must be designated to complete the line or box.
• The INTEGER color attribute or LONG _RGB32 32 bit color value sets the drawing color. If omitted, the current destination page's _DEFAULTCOLOR is used.
• Optional B keyword creates a rectangle (box) using the start and end coordinates as diagonal corners. BF creates a box filled.
• The style% signed INTEGER value sets a dotted pattern to draw the line or rectangle outline.

• Creates a colored line between the given coordinates. Can be drawn partially off screen.
• B creates a box outline with each side parallel to the program screen sides. BF creates a filled box.
• style% can be used to create a dotted pattern to draw the line.
  • B can be used with a style% to draw the rectangle outline using the desired pattern.
  • BF ignores the style% parameter. See examples 2, 3 and 4 below.
• The graphic cursor is set to the center of the program window on program start. Using the STEP keyword makes the coordinates relative to the current graphic cursor.
• LINE 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: Following one line with another by omitting the second line's first coordinate parameter bracket entirely:

LINE (100, 100)-(200, 200), 10    'creates a line
LINE -(400, 200), 12              'creates a second line from end of first

END '' ''

Explanation: The full equivalent LINE statement would be: LINE(200, 200)-(400, 200), 12

LINE (100, 100)-(300, 300), 10, , 63    'creates a styled line
LINE (100, 100)-(300, 300), 12, B, 255  'creates styled box shape

END '' ''

Explanation: The first diagonal dashed green line bisects the red dashed square from Top Left to Bottom Right Corners.

SCREEN 13
_FULLSCREEN 'required in QB64 only
_DELAY 5
FOR...NEXT i% = 1 TO 2 ^ 15 'use exponential value instead of -32768
    COLOR 15:LOCATE 10, 5: PRINT i%;
    LINE (10, 60)-(300, 60), 0 'erase previous lines
    LINE (10, 60)-(300, 60), 12, , i%
    tmp$ = ""
    FOR...NEXT b% = 15 TO 0 STEP -1 'create binary text value showing bits on as <span style="color:red;">█</span>, off as space
        IF...THEN i% AND 2 ^ b% THEN tmp$ = tmp$ + CHR$(219) ELSE tmp$ = tmp$ + SPACE$(1)
    NEXT
    COLOR 12:LOCATE 10, 20: PRINT tmp$;
    IF...THEN INKEY$ <> "" THEN EXIT FOR...NEXT 'any key exit
    _DELAY .001 'set delay time as required
NEXT '' ''

Explanation: The style value's Most Significant Bit (MSB) is set to the left with LSB on right as 16 text blocks are set on or off.

LINE (100, 100)-(300, 100), 10, , &B0000111100001111 '16-bits
LINE (100, 110)-(300, 110), 11, , &B0011001100110011
LINE (100, 120)-(300, 120), 12, , &B0101010101010101
LINE (100, 130)-(300, 130), 13, , &B1000100010001000

Explanation: The binary pattern created with 0s and 1s using the &B number prefix define the pattern to draw the colored lines.

• SCREEN, COLOR
• DRAW, CIRCLE, STEP
• PSET, PRESET
• AND, OR (logical operators)