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qb64/internal/help/ThirtyTwoBit-SUB.md

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** ThirtyTwoBit Screen Shot SUB for QB64 Screen and Image Handles**
## Syntax
> ThirtyTwoBit left_column%, top_row%, right_column%, bottom_row%, handle&, new_filename$
* Copies portions or all of a Screen or image using the handle value to a new bitmap. [SAVEIMAGE](SAVEIMAGE) does full screen only!
* Make sure the maximum coordinates used are one less than the **screen** image's size or an [ERROR Codes](ERROR-Codes) will occur!
* A handle value of 0 will copy the present portion of the main program screen while the screen's handle may hold a previous image.
* Can be used with 4, 8 or 24/32 bit colors. 4 BPP = 16 colors, 8 BPP = 256 colors and 24/32 BPP has 16 million colors.
```vb
' ************************************** DEMO CODE **********************************
'
_TITLE "Demo of ThirtyTwoBit SUB by Ted Weissgerber 2010"
dst& = _NEWIMAGE(800, 600, 32) 'for console bitmap
SCREEN dst&
PAINT (799, 599), _RGB(180, 180, 180)
LINE (7, 15)-(648, 496), _RGB(0, 0, 80), BF
INPUT "Enter an image filename: ", filename$
bmp& = _LOADIMAGE(filename$, 256)
IF bmp& = -1 THEN BEEP: SYSTEM
bitmap& = _NEWIMAGE(_WIDTH(bmp&), _HEIGHT(bmp&), 256)
_COPYPALETTE bmp&, bitmap& 'adopt image color settings
_PUTIMAGE , bmp&, bitmap& 'place bitmap in screen page
_DEST 0:
_PUTIMAGE (8, 16), bitmap& 'place screen page in console
'SAVEIMAGE 0, "Savedimage.bmp" ' get full screen image with Galleon's SAVEIMAGE SUB
x2% = (_WIDTH(bmp&) - 1)
y2% = (_HEIGHT(bmp&) - 1)
ThirtyTwoBit 0, 0, x2%, y2%, bmp&, "BobSave.bmp" ' save actual image as BMP
' ********************** END DEMO *********************************
```
```text
'****************************** Freeware by Bob Seguin *******************************
' Adapted for QB64 by Ted Weissgerber in 2010
'*************************************************************************************
SUB ThirtyTwoBit (x1%, y1%, x2%, y2%, image&, Filename$)
DIM Colors8%(255)
IF x1% > x2% THEN SWAP x1%, x2%
IF y1% > y2% THEN SWAP y1%, y2%
_SOURCE image&
pixelbytes& = _PIXELSIZE(image&)
IF pixelbytes& = 0 THEN BEEP: EXIT SUB 'no text screens
FileType$ = "BM"
QB64$ = "QB64" 'free advertiising in reserved bytes
IF pixelbytes& = 1 THEN OffsetBITS& = 1078 ELSE OffsetBITS& = 54 'no palette in 24/32 bit
InfoHEADER& = 40
PictureWidth& = (x2% - x1%) + 1
PictureDepth& = (y2% - y1%) + 1
NumPLANES% = 1
IF pixelbytes& = 1 THEN BPP% = 8 ELSE BPP% = 24
Compression& = 0
WidthPELS& = 3780
DepthPELS& = 3780
IF pixelbytes& = 1 THEN 'byte padder prevents image skewing
NumColors& = 256 'set 256 colors even if they are not used by the screen mode
IF (PictureWidth& MOD 4) THEN ZeroPad$ = SPACE$(4 - (PictureWidth& MOD 4))
ELSE '24/32 bit images use 3 bytes for RGB pixel values
NumColors& = 0 '24/32 bit say zero
IF ((PictureWidth& * 3) MOD 4) THEN ZeroPad$ = SPACE$((4 - ((PictureWidth& * 3) MOD 4)))
END IF
ImageSize& = (PictureWidth& + LEN(ZeroPad$)) * PictureDepth&
FileSize& = ImageSize& + OffsetBITS&
f = FREEFILE
OPEN Filename$ FOR BINARY AS #f
PUT #f, , FileType$
PUT #f, , FileSize&
PUT #f, , QB64$
PUT #f, , OffsetBITS&
PUT #f, , InfoHEADER&
PUT #f, , PictureWidth&
PUT #f, , PictureDepth&
PUT #f, , NumPLANES%
PUT #f, , BPP%
PUT #f, , Compression&
PUT #f, , ImageSize&
PUT #f, , WidthPELS&
PUT #f, , DepthPELS&
PUT #f, , NumColors&
PUT #f, , SigColors& '51 offset
IF pixelbytes& = 1 THEN '4 or 8 BPP use 256 color Palette
u$ = CHR$(0)
FOR c& = 0 TO 255 'PUT as BGR order colors
cv& = _PALETTECOLOR(c&, image&)
Colr$ = CHR$(_BLUE32(cv&))
PUT #f, , Colr$
Colr$ = CHR$(_GREEN32(cv&))
PUT #f, , Colr$
Colr$ = CHR$(_RED32(cv&))
PUT #f, , Colr$
PUT #f, , u$ 'Unused byte
NEXT
END IF
FOR y% = y2% TO y1% STEP -1 'place bottom up
FOR x% = x1% TO x2%
c& = POINT(x%, y%)
IF pixelbytes& = 1 THEN
a$ = CHR$(c&)
Colors8%(c&) = 1
ELSE: a$ = LEFT$(MKL$(c&), 3)
END IF
PUT #f, , a$
NEXT
PUT #f, , ZeroPad$
NEXT
FOR n = 0 TO 255
IF Colors8%(n) = 1 THEN SigColors& = SigColors& + 1
NEXT n
PUT #f, 51, SigColors&
CLOSE #f
END SUB
```
**This SUB procedure can also be [$INCLUDE]($INCLUDE) in a program!**
## See Also
* [_LOADIMAGE](_LOADIMAGE)
* [SAVEIMAGE](SAVEIMAGE) (Full image bitmaps)
* [Program ScreenShots](Program-ScreenShots)
* [ThirtyTwoBit MEM SUB](ThirtyTwoBit-MEM-SUB)
* [Bitmaps](Bitmaps)