Paintkeyword

Fills an area delimited by a border of a specified color

Syntax

Paint [target,] [STEP] (x, y)[, [paint][, [border_color]]]

Parameters

Name		Description
`target`		specifies buffer to draw on. `STEP` indicates that coordinates are relative `(x, y)` coordinates of the pixel on which to start the flood fill (paint)
`paint`		the color attribute or fill pattern a numeric value indicates a color, while a string indicates a fill pattern
`border_color`		boundary color for the fill

Description

Graphics command to fill an area delimited by a border of specified color. Also known as 'flood-fill' or 'paint bucket'.

Paint can operate on the current work page as set by the ScreenSet statement or on the target Get/Put buffer, if specified.

Filling starts at specified (x,y) coordinates; if STEP is specified, these are relative to the last graphics cursor position. Coordinates are also affected by custom coordinates system set up by Window and/or View (Graphics) statements; clipping set by View also applies.

If the paint argument is a number, it is assumed a color in the same format used by the Color statement, and the region is flood-filled using that color. If paint is a String, the region will be filled using a pattern; the pattern is always 8*8 pixels, and the passed string must hold pixels data in a format dependent on the current color depth. The string holds pattern pixels row by row, and its size should be as follows:

For color depths 1, 2, 4 and 8:
size = 8 * 8 = 64
For color depths 15 and 16:
size = (8 * 8) * 2 = 128
For color depths 24 and 32:
size = (8 * 8) * 4 = 256

If the passed string is smaller, missing pixels will be 0. If the paint argument is omitted, normal filling is performed using the current foreground color set by Color. Flood-filling continues until pixels of the specified border color are found; if border_color is omitted, the current background color is assumed.

Warning: If the border is drawn with a transparent color (in conjunction with the GFX_ALPHA_PRIMITIVES option flag) and some pixels are overdrawn on it, the resultant (blended) color of these overdrawn pixels can cause a leak point through which the fill color escapes outside the border. So drawing a border with a transparent color is not recommended.

Remarks

Differences from QB

target is new to FreeBASIC
In QB, the fill pattern was always 8-bits wide, and the height was the length of the string (up to 64). In FreeBASIC, the fill pattern is 8 pixels wide, independent of the color depth, and the height is always 8
The background color parameter supported by QB is not supported by the FreeBASIC version

Example

' draws a white circle painted blue inside

Screen 13

Circle (160, 100), 30, 15

Paint (160, 100), 1, 15

Sleep

' draws a circle and fills it with a checkered pattern



'' choose the bit depth for the Screen

'' try setting this to other values: 8, 16 or 32



Const bit_depth = 8



'' function for returning a pixel color, represented as a string

'' returns a the string in the appropriate format for the current bit depth

Function paint_pixel( ByVal c As ULong, ByVal bit_depth_ As Integer ) As String

    

    If bit_depth_ <= 8 Then '' 8-bit:

        Function =  Chr( CUByte(c) )

        

    ElseIf bit_depth_ <= 16 Then '' 16-bit:

        Function = MKShort( c Shr 3 And &h1f Or _

                            c Shr 5 And &h7e0 Or _

                            c Shr 8 And &hf800 )

        

    ElseIf bit_depth_ <= 32 Then '' 32-bit:

        Function = MKL(c)

        

    End If

    

End Function





'' open a graphics window at the chosen bit depth

ScreenRes 320, 200, bit_depth



'' declare variables for holding colors

Dim As ULong c, c1, c2, cb



'' declare string variable for holding the pattern used in Paint

Dim As String paint_pattern = ""



'' set colors

If bit_depth <= 8 Then

    c1 = 7  ''pattern color 1

    c2 = 8  ''pattern color 2

    cb = 15 ''border color

Else

    c1 = RGB(192, 192, 192) '' pattern color 1

    c2 = RGB(128, 128, 128) '' pattern color 2

    cb = RGB(255, 255, 255) '' border color

End If



'' make the pattern to be used in Paint

For y As UInteger = 0 To 7

    For x As UInteger = 0 To 7

        

        '' choose the color of the pixel (c)

        If (x \ 4 + y \ 4) Mod 2 > 0 Then

            c = c1

        Else

            c = c2

        End If

        

        '' add the pixel to the pattern

        paint_pattern = paint_pattern + paint_pixel(c, bit_depth)

        

        '' the following line can be used if you want to draw the 

        '' pattern tile in the top left hand corner of the screen:

        

        ' pset (x, y), c

        

    Next x

Next y



'' draw a circle with the border color

Circle (160, 100), 50, cb, , , 1.0



'' paint the circle region with paint_pattern, stopping at the border color

Paint (160, 100), paint_pattern, cb



'' pause before ending the program

Sleep

Reference

Documented in KeyPgPaint.html