'Design of a windows 3.1 bitmap - Taken from bmp.txt on the
'x2ftp.oulu.fi ftp site under /pub/msdos/programming/formats
'Specifications for a Windows 3.1 bitmap. (.BMP)
'Email any questions/responses to me at zabudsk@ecf.utoronto.ca
'or post to alt.lang.basic or comp.lang.basic.misc.
'SHOWBM10 - Flexible BMP file loader
'Version 1.00* - Apr.23,1997
'*modified by Toshi for speed and options
'*further optimizations: integer divides, precalcs.
'Get the most recent version at http://www.ecf.utoronto.ca/~zabudsk
'initialize
DEFINT A-Z: 'comment out if errors occur
RANDOMIZE TIMER
DIM xstart, xsiz, ystart, ysiz AS INTEGER
CONST xmax = 320, ymax = 200
CONST va = &H3C8, vd = &H3C9
DEF SEG = 0
'settings (0=false or 1=true)
dither = 0
grey = 0 'My dithering algorithm needs work, beware.
slowpal = 0
FILES "*.bmp"
INPUT "Bitmap filename to load: ", filename$
PRINT
PRINT "The Program will read in the source file and display it on the screen."
PRINT
PRINT "Source file: "; filename$
PRINT
CLS
IF INSTR(filename$, ".") = 0 THEN filename$ = filename$ + ".BMP"
OPEN filename$ FOR BINARY AS #1
IF LOF(1) = 0 THEN
CLOSE #1
PRINT "Empty File. Deleting"
KILL filename$
END
END IF
header$ = SPACE$(14)
sizing$ = SPACE$(4)
GET #1, 1, header$
IF LEN(header$) = 0 THEN PRINT "Not a valid Bitmap file.": CLOSE : END
IF MID$(header$, 1, 2) <> "BM" THEN PRINT "Not a valid Bitmap file.": CLOSE : END
GET #1, 15, sizing$
bmpinfosize = CVI(sizing$)
IF bmpinfosize = 12 THEN
infoheader$ = SPACE$(12)
GET #1, 15, infoheader$
nbits = CVI(MID$(infoheader$, 15, 4))
IF nbits = 1 THEN
palet$ = SPACE$(6)
GET #1, bmpinfosize + 15, palet$
ELSEIF nbits = 4 THEN
palet$ = SPACE$(48)
GET #1, bmpinfosize + 15, palet$
ELSEIF nbits = 8 THEN
palet$ = SPACE$(768)
GET #1, bmpinfosize + 15, palet$
END IF
ELSEIF bmpinfosize = 40 THEN
infoheader$ = SPACE$(40)
GET #1, 15, infoheader$
nbits = CVI(MID$(infoheader$, 15, 4))
IF nbits = 1 THEN
palet$ = SPACE$(8)
GET #1, bmpinfosize + 15, palet$
ELSEIF nbits = 4 THEN
palet$ = SPACE$(64)
GET #1, bmpinfosize + 15, palet$
ELSEIF nbits = 8 THEN
palet$ = SPACE$(1024)
GET #1, bmpinfosize + 15, palet$
END IF
END IF
ft$ = MID$(header$, 1, 2)
PRINT "Type of file (Should be BM): "; ft$
filesize& = CVL(MID$(header$, 3, 4))
PRINT "Size of file: "; filesize&
r1 = CVI(MID$(header$, 7, 2))
PRINT "Reserved 1: "; r1
r2 = CVI(MID$(header$, 9, 2))
PRINT "Reserved 2: "; r2
offset& = CVL(MID$(header$, 11, 4))
PRINT "Number of bytes offset from beginning: "; offset&
PRINT
headersize& = CVL(MID$(infoheader$, 1, 4))
PRINT "Size of header: "; headersize&
picwidth = CVL(MID$(infoheader$, 5, 4))
PRINT "Width: "; picwidth
picheight = CVL(MID$(infoheader$, 9, 4))
PRINT "Height: "; picheight
nplanes = CVI(MID$(infoheader$, 13, 4))
PRINT "Planes: "; nplanes
PRINT "Bits per plane: "; nbits
PRINT
IF headersize& = 40 THEN
PRINT "Compression: ";
comptype = CVL(MID$(infoheader$, 17, 4))
IF comptype = 0 THEN PRINT "None"
IF comptype = 1 THEN PRINT "Run Length - 8 Bits"
IF comptype = 2 THEN PRINT "Run Length - 4 Bits"
imagesize& = CVL(MID$(infoheader$, 21, 4))
PRINT "Image Size (bytes): "; imagesize&
xsize = CVL(MID$(infoheader$, 25, 4))
PRINT "X size (pixels per metre): "; xsize
ysize = CVL(MID$(infoheader$, 29, 4))
PRINT "Y size (pixels per metre): "; ysize
colorsused = CVL(MID$(infoheader$, 33, 4))
PRINT "Number of colours used: "; colorsused
neededcolours = CVL(MID$(infoheader$, 37, 4))
PRINT "Number of important colours: "; neededcolours
IF colorsused <> 0 THEN
palet$ = SPACE$(4 * colorsused)
GET #1, bmpinfosize + 15, palet$
END IF
END IF
PRINT
PRINT "Press Any key to continue."
WHILE INKEY$ = ""
WEND
'display picture -------------------------------------------------
IF nbits = 1 THEN
SCREEN 11
xres = 640
yres = 480
nc = 2
ELSEIF nbits = 4 THEN
SCREEN 12
xres = 640
yres = 480
nc = 16
ELSEIF nbits = 8 OR nbits = 24 THEN
SCREEN 13
xres = 320
yres = 200
nc = 256
END IF
IF bmpinfosize = 40 THEN ngroups = 4
IF bmpinfosize = 12 THEN ngroups = 3
IF nbits = 24 THEN
IF grey = 1 THEN
IF ngroups = 3 THEN
FOR c = 0 TO 63
d = c * 4
palet$ = palet$ + CHR$(d) + CHR$(d) + CHR$(d)
palet$ = palet$ + CHR$(d) + CHR$(d) + CHR$(d + 1)
palet$ = palet$ + CHR$(d) + CHR$(d + 1) + CHR$(d)
palet$ = palet$ + CHR$(d + 1) + CHR$(d) + CHR$(d)
NEXT c
ELSEIF ngroups = 4 THEN
FOR c = 0 TO 63
d = c * 4
palet$ = palet$ + CHR$(d) + CHR$(d) + CHR$(d) + CHR$(0)
palet$ = palet$ + CHR$(d) + CHR$(d) + CHR$(d + 1) + CHR$(0)
palet$ = palet$ + CHR$(d) + CHR$(d + 1) + CHR$(d) + CHR$(0)
palet$ = palet$ + CHR$(d + 1) + CHR$(d) + CHR$(d) + CHR$(0)
NEXT c
END IF
ELSE
FOR t = 0 TO 5
FOR u = 0 TO 5
FOR v = 0 TO 5
palet$ = palet$ + CHR$(INT(v * (256 / 6)))
palet$ = palet$ + CHR$(INT(u * (256 / 6)))
palet$ = palet$ + CHR$(INT(t * (256 / 6)))
IF ngroups = 4 THEN palet$ = palet$ + CHR$(0)
NEXT v
NEXT u
NEXT t
FOR count = 0 TO 31
palet$ = palet$ + CHR$(count * 8) + CHR$(count * 8) + CHR$(count * 8)
IF ngroups = 4 THEN palet$ = palet$ + CHR$(0)
NEXT count
palet$ = palet$ + CHR$(255) + CHR$(255) + CHR$(255)
END IF
END IF
IF slowpal = 1 THEN
FOR x = 1 TO LEN(palet$) STEP ngroups
zb# = INT((ASC(MID$(palet$, x, 1))) / 4)
zg# = INT((ASC(MID$(palet$, x + 1, 1))) / 4)
zr# = INT((ASC(MID$(palet$, x + 2, 1))) / 4)
zc# = zb# * 65536# + zg# * 256# + zr#
' cres = ASC(MID$(palet$, x + 3, 1))
PALETTE ((x - 1) / ngroups), zc#
NEXT x
ELSE 'Use VGA Palette I/O Registers to set palette values - Faster
OUT va, 0
FOR x = 1 TO LEN(palet$) STEP ngroups
zb = INT((ASC(MID$(palet$, x, 1))) / 4)
zg = INT((ASC(MID$(palet$, x + 1, 1))) / 4)
zr = INT((ASC(MID$(palet$, x + 2, 1))) / 4)
' zc# = zb# * 65536# + zg# * 256# + zr#
' cres = ASC(MID$(palet$, x + 3, 1))
OUT vd, zr
OUT vd, zg
OUT vd, zb
'PALETTE ((x - 1) / ngroups), zc#
NEXT x
END IF
IF comptype = 0 THEN
'No Compression
IF nbits = 24 THEN
y = picheight - 1
x = 0
Lin$ = SPACE$((INT((3 * picwidth - 1) / 4) + 1) * 4)
WHILE y >= 0
GET 1, , Lin$
IF grey = 0 THEN
'WHILE x < picwidth
WHILE x < xmax AND y < ymax
b = ASC(MID$(Lin$, x * 3 + 1, 1))
g = ASC(MID$(Lin$, x * 3 + 2, 1))
r = ASC(MID$(Lin$, x * 3 + 3, 1))
IF b = g AND g = r THEN
p1 = INT(b / 8) + 216
IF b = 255 THEN p1 = 247
ELSE
r = INT(r * (6 / 256))
g = INT(g * (6 / 256))
b = INT(b * (6 / 256))
IF dither THEN
qa = INT(RND(1) * (r + 1)) * .4
qb = INT(RND(1) * (g + 1)) * .4
qc = INT(RND(1) * (b + 1)) * .4
r = INT(r + qa - (r * .2))
g = INT(g + qg - (g * .2))
b = INT(b + qb - (b * .2))
IF r > 5 THEN r = 5
IF r < 0 THEN r = 0
IF g > 5 THEN g = 5
IF g < 0 THEN g = 0
IF b > 5 THEN b = 5
IF b < 0 THEN b = 0
END IF
p1 = r * 36 + g * 6 + b
END IF
PSET (x, y), p1
x = x + 1
WEND
ELSE
'WHILE x < picwidth
WHILE x < xmax AND y < ymax
p1 = INT((ASC(MID$(Lin$, x * 3 + 1, 1)) + ASC(MID$(Lin$, x * 3 + 2, 1)) + ASC(MID$(Lin$, x * 3 + 3, 1))) / 3)
PSET (x, y), p1
x = x + 1
WEND
END IF
y = y - 1
x = 0
WEND
ELSEIF nbits = 8 THEN
y = picheight - 1
x = 0
Lin$ = SPACE$((INT((picwidth - 1) / 4) + 1) * 4)
WHILE y >= 0
GET #1, , Lin$
WHILE x < picwidth
PSET (x, y), ASC(MID$(Lin$, x + 1, 1))
x = x + 1
WEND
y = y - 1
x = 0
WEND
ELSEIF nbits = 4 THEN
y = picheight - 1
x = 0
Lin$ = SPACE$((INT((picwidth - 1) / 8) + 1) * 4)
WHILE y >= 0
GET 1, , Lin$
WHILE x < picwidth
p2 = ASC(MID$(Lin$, INT(x / 2) + 1, 1)) AND 15
p1 = (ASC(MID$(Lin$, INT(x / 2) + 1, 1)) AND 240) / 16
PSET (x, y), p1
IF x + 1 < picwidth THEN PSET (x + 1, y), p2
x = x + 2
WEND
y = y - 1
x = 0
WEND
ELSEIF nbits = 1 THEN
y = picheight - 1
x = 0
Lin$ = SPACE$((INT((picwidth - 1) / 32) + 1) * 4)
WHILE y >= 0
GET 1, , Lin$
WHILE x < picwidth
p8 = ASC(MID$(Lin$, INT(x / 8) + 1, 1))
FOR b = 0 TO 7
IF x + (7 - b) < picwidth THEN PSET (x + (7 - b), y), (p8 AND 2 ^ b) / 2 ^ b
NEXT b
x = x + 8
WEND
y = y - 1
x = 0
WEND
END IF
ELSEIF comptype = 1 THEN
'Compression Essentials
'[a][b] a>0, repeat b a-times
'[0][0] End of line
'[0][1] End of bitmap
'[0][2][h][v] Move current position h to the right and v down
'PRINT "Wow! RLE-8 Compression."
a$ = " "
x = 0
y = 0
ef = 0
WHILE ef = 0
GET #1, , a$
c = ASC(a$)
IF c > 0 THEN
GET #1, , a$
b = ASC(a$)
FOR count = 1 TO c
PSET (picwidth - x - 1, picheight - y - 1), b
x = x + 1
'if x>=picwidth then x=0:y=y+1
NEXT count
ELSE
GET #1, , a$
c = ASC(a$)
IF c = 0 THEN
x = 0
y = y + 1
ELSEIF c = 1 THEN
ef = 1
ELSEIF c = 2 THEN
GET #1, , a$
h = ASC(a$)
GET #1, , a$
v = ASC(a$)
x = x + h
y = y + v
ELSE
FOR count = 1 TO c
GET #1, , a$
p1 = ASC(a$)
PSET (picwidth - x - 1, picheight - y - 1), p1
x = x + 1
'if x>=picwidth then x=0:y=y+1
NEXT count
IF c MOD 2 = 1 THEN GET #1, , a$
END IF
IF (y = picheight - 1 AND x >= picwidth) OR y >= picheight THEN ef = 1
END IF
IF EOF(1) THEN ef = 1
WEND
ELSEIF comptype = 2 THEN
'Compression Essentials
'[a][b1|b0] a>0, repeat b1|b0 a/2-times e.g. a=5 -> b1 b0 b1 b0 b1
'[0][0] End of line
'[0][1] End of bitmap
'[0][2][h][v] Move current position h to the right and v down
'PRINT "Wow! RLE-4 Compression."
a$ = " "
x = 0
y = 0
ef = 0
WHILE ef = 0
GET #1, , a$
c = ASC(a$)
IF c > 0 THEN
GET #1, , a$
b = ASC(a$)
FOR count = 1 TO c
IF (count MOD 2) = 0 THEN
PSET (picwidth - x - 1, picheight - y - 1), b AND 15
ELSE
PSET (picwidth - x - 1, picheight - y - 1), (b AND 240) / 16
END IF
x = x + 1
'if x>=picwidth then x=0:y=y+1
NEXT count
ELSE
GET #1, , a$
c = ASC(a$)
IF c = 0 THEN
x = 0
y = y + 1
ELSEIF c = 1 THEN
ef = 1
ELSEIF c = 2 THEN
GET #1, , a$
h = ASC(a$)
GET #1, , a$
v = ASC(a$)
x = x + h
y = y + v
ELSE
FOR count = 1 TO INT(c / 2)
GET #1, , a$
p1 = ASC(a$)
PSET (picwidth - x - 1, picheight - y - 1), (p1 AND 240) / 16
x = x + 1
PSET (picwidth - x - 1, picheight - y - 1), p1 AND 15
x = x + 1
'if x>=picwidth then x=0:y=y+1
NEXT count
br = INT(c / 2)
IF (c MOD 2) = 1 THEN
GET #1, , a$
PSET (picwidth - x - 1, picheight - y - 1), (p1 AND 240) / 16
x = x + 1
br = br + 1
END IF
IF br MOD 2 = 1 THEN GET #1, , a$
END IF
IF (y = picheight - 1 AND x >= picwidth) OR y >= picheight THEN ef = 1
END IF
IF EOF(1) THEN ef = 1
WEND
END IF
CLOSE
END
DEFSNG A-Z
SUB info
'bmpinfosize - Is the size of the information header for the bitmap.
' Different bitmap versions have variations in filetypes.
' 40 is a standard windows 3.1 bitmap.
' 12 is for OS/2 bitmaps
'The next routine reads in the appropriate headers and colour tables.
'nbits is the number of bits per pixel - i.e. number of colours
'1 bit = 2 colours, 4 bits = 16 colours, 8 bits = 256 colours, etc.
'the 24 bit mode does not have a palette, its colours are expressed as
'image data
'Design of a windows 3.1 bitmap - Taken from bmp.txt on the
'x2ftp.oulu.fi ftp site under /pub/msdos/programming/formats
'Specifications for a Windows 3.1 bitmap. (.BMP)
'Email any questions/responses to me at zabudsk@ecf.utoronto.ca
'or post to alt.lang.basic or comp.lang.basic.misc.
' | # of |
'Offset | bytes | Function (value)
'-------+--------+--- General Picture information starts here---------
' 0 | 2 | (BM) - Tells us that the picture is in bmp format
' 2 | 4 | Size of the file (without header?)
' 6 | 2 | (0) Reserved1 - Must be zero
' 8 | 2 | (0) Reserved2 - Must be zero
' 10 | 4 | Number of bytes offset of the picture data
'-------+--------+--- Information Header starts here -----------------
' 14 | 4 | (40/12) Size of information header (Win3.1/OS2)
' 18 | 4 | Picture width in pixels
' 22 | 4 | Picture Height in pixels
' 26 | 2 | (1) Number of planes, must be 1
' 28 | 2 | Number of bits per pixel (bpp), must be 1,4,8 or 24
' 30 | 4 | (0) Compression - 0 means no compression, 1,2 are RLEs
' 34 | 4 | Image size in bytes
' 38 | 4 | picture width in pels per metre
' 42 | 4 | picture height in pels per metre
' 46 | 4 | (0) Number of colours used in the picture, 0 means all
' 50 | 4 | (0) Number of important colours, 0 means all
'-------+--------+--- Palette data starts here -----------------------
' 54 | 1 | (b) - blue intensity component, color 0 - range 0 to 255
' 55 | 1 | (g) - green intensity component, color 0 - range 0 to 255
' 56 | 1 | (r) - red intensity component, color 0 - range 0 to 255
' 57 | 1 | (0) - unused
' 58 | 1 | (b) - blue intensity component, color 0 - range 0 to 255
' ... | ... |
' 54 | 4*2^bpp| total range of palette
'-------+--------+--- Image data starts here -------------------------
'54+ | width* | Bitmap data starting at lower left portion of the
'(4*2^n)| height*| image moving from left towards right. Moving up 1
' | (8/bpp)| pixel when at the right hand side of the image, starting
' | | from the left side again, until the top right of the
' | | image is reached
'Note that this format is slightly different for a OS/2 Bitmap.
'The header is the same up to (but not including) bit 30-
'The palette colour values follow at bit 30, with the form...
'1 byte blue intensity
'1 byte green intensity
'1 byte red intensity
'For each colour of the picture.
'Bitmapped image data follows the colour tables
'Special note: When storing 1 bit (2 colour) pictures.
'8 horizontal pixels are packed into 1 byte. Each bit determines
'the colour of one pixel (colour 0 or colour 1)
'4 bit pictures (16 colours) use 2 nibbles (4 bits) for each pixel
'thus there are 2 pixels for each byte of image data.
'8 bit pictures use 1 byte per pixel. Each byte of image data
'represents one of 256 colours.
'24 bit pictures express colour values by using 3 bytes and each has a
'value between 0 and 255. The first byte is for red, the second is for
'green and the third is for blue. Thus (256)^3 or 2^24 of 16777216 different
'colours.
'Even more special note:
'each line of bitmap images have a long word integer boundary;
'this means that at the end of each line, there may be extra "padding"
'bytes to ensure that the actual amount of data encoded with each line
'is encoded to be a multiple of 4 bytes (the size of a long word).
END SUB
taken from one of the links from this site (most links are dead):
https://www.tek-tips.com/viewthread.cfm?qid=559294 (https://www.tek-tips.com/viewthread.cfm?qid=559294)