DECLARE FUNCTION SAVEBMP% (bmpfilename$)
DECLARE FUNCTION loadbmp% (bmpfilename$)

TYPE BMPFileHeader
	FileType AS STRING * 2
	Size AS LONG
	Reserved1 AS INTEGER
	Reserved2 AS INTEGER
	OffBits AS LONG
END TYPE
 
TYPE BMPInfoHeader
	Size AS LONG
	Imagewidth AS LONG
	Imageheight AS LONG
	Planes AS INTEGER
	bitcount AS INTEGER
	Compression AS LONG
	SizeImage AS LONG
	XPelsPerMeter AS LONG
	YPelsPerMeter AS LONG
	ClrUsed AS LONG
	ClrImportant AS LONG
END TYPE
'

SCREEN 12

'draw something
RANDOMIZE TIMER
FOR i% = 0 TO 15
 READ c&
 PALETTE i%, c&
NEXT
DATA &h5,&h10,&h20,&h30
DATA &h500,&h1000,&h2000,&h3000
DATA &h50000,&h100000,&h200000,&h300000
DATA &h50505,&h101010,&h202020,&h303030 
FOR k% = 1 TO 20
	x% = RND * 640 + 1
	y% = RND * 480
	r% = RND * 80 + (80 \ 8)
	clr% = INT(RND * 4) * 3
	a = RND * 3.141592
	b = RND * 3.141592 / 1.5
	x1% = CINT(COS(a) * SIN(b) * 100)
	y1% = CINT(SIN(a) * SIN(b) * 100)
	z1% = CINT(COS(b) * 100)
	FOR i% = -r% TO r%
		i1% = i% * 100 / CSNG(r%)
		FOR j% = -SQR(r% * r% - i% * i%) TO SQR(r% * r% - i% * i%)
			j1% = j% * 100 / CSNG(r%)
			k1% = SQR(11000 - i1% * i1% - j1% * j1%)
			c! = 3 * (x1% * i1% + j1% * y1% + k1% * z1%) / 10000
			ccc% = 1 + clr% + INT(c!) + (RND > (c! - INT(c!)))
			PSET (x% + i%, y% + j%), ccc%
	 NEXT j%, i%
NEXT

PRINT "Saving.."
t! = TIMER
dummy = SAVEBMP("balls.bmp")
PRINT dummy, TIMER - t!
SLEEP 5
CLS

PRINT "Loading..."
dummy = loadbmp("balls.bmp")
PRINT dummy


SLEEP

'
'------------------------------------------------------------------
FUNCTION loadbmp% (bmpfilename$)
'returns 0 for success, 1 for file does not exist, 2 for file is not a saved Screen 12
	DIM fh AS BMPFileHeader
	DIM ih AS BMPInfoHeader
	
	f = FREEFILE
	OPEN bmpfilename$ FOR BINARY AS f
	IF LOF(f) = 0 THEN CLOSE #1: KILL bmpfilename$: loadbmp% = 1: EXIT FUNCTION
			 
	GET #f, , fh
	GET #f, , ih

IF (ih.Imagewidth <> 640) OR (ih.Imageheight <> 480) OR (ih.bitcount) <> 4 THEN
	loadbmp% = 2: CLOSE f: EXIT FUNCTION
END IF

	Buffer$ = SPACE$(64)

	GET #f, , Buffer$
	DEF SEG = VARSEG(Buffer$)
	offs& = SADD(Buffer$)
	OUT &H3C8, 0
	FOR i% = 0 TO 15
		OUT &H3C9, PEEK(offs& + 2) \ 4
		OUT &H3C9, PEEK(offs& + 1) \ 4
		OUT &H3C9, PEEK(offs&) \ 4
		offs& = offs& + 4
	NEXT
	
	'Get image
	Buffer$ = SPACE$(320 * 48)
	DEF SEG = VARSEG(Buffer$)
	FOR k% = 9 TO 0 STEP -1
	 GET #f, , Buffer$
	 offs& = SADD(Buffer$)
	FOR i% = 48 * (k% + 1) - 1 TO 48 * k% STEP -1
		FOR j% = 0 TO 639 STEP 2
			PSET (j%, i%), PEEK(offs&) \ 16
			PSET (j% + 1, i%), PEEK(offs&) AND 15
			offs& = offs& + 1
		NEXT j%, i%
	NEXT k%
	CLOSE f
END FUNCTION

'
'------------------------------------------------------------------
FUNCTION SAVEBMP% (bmpfilename$)
'returns 0 for success, 1 for file already exists
	DIM FileHeader AS BMPFileHeader
	DIM InfoHeader AS BMPInfoHeader
	
	' BITMAPFILEHEADER
	FileHeader.FileType = "BM"'BMP format marker
	FileHeader.Size = 640& * 480 \ 2 + 118
	FileHeader.OffBits = 118
	InfoHeader.Size = 40
	InfoHeader.Imagewidth = 640
	InfoHeader.Imageheight = 480
	InfoHeader.Planes = 1
	InfoHeader.bitcount = 4
	InfoHeader.SizeImage = 640& * 480 \ 2' Image size in bytes
	InfoHeader.ClrUsed = 16' Colors used in picture
	
		f = FREEFILE
	OPEN bmpfilename$ FOR BINARY AS f
	IF LOF(f) <> 0 THEN CLOSE f: KILL bmpfilename$: SAVEBMP = 1: EXIT FUNCTION
	
	PUT #f, , FileHeader
	PUT #f, , InfoHeader
	
	'Save palette data
	Buffer$ = SPACE$(64)
		OUT &H3C7, 0
		FOR i% = 0 TO 15
		Red% = INP(&H3C9)
		Green% = INP(&H3C9)
		blue% = INP(&H3C9)
		MID$(Buffer$, 4 * i% + 1) = CHR$(blue% * 4) + CHR$(Green% * 4) + CHR$(Red% * 4) + CHR$(0)
	NEXT i%
	PUT #f, , Buffer$
	
	'Save image data-use poke for speed
	Buffer$ = SPACE$(320 * 48)
	DEF SEG = VARSEG(Buffer$)
	FOR k% = 9 TO 0 STEP -1
	offs& = SADD(Buffer$)
	FOR i% = 48 * (k% + 1) - 1 TO 48 * k% STEP -1
		FOR j% = 0 TO 639 STEP 2
			POKE offs&, 16 * POINT(j%, i%) + POINT(j% + 1, i%)
			offs& = offs& + 1
		NEXT j%, i%
		PUT #f, , Buffer$
	NEXT k%
	CLOSE f
END FUNCTION