weber@brand.UUCP (Allan G. Weber) (09/13/86)
I have seen some requests go by for information on the format of MacDraw data files. I deciphered some of the format while in the process of writing a MacDraw to Impress program for printing MacDraw pictures on Imagen printers. The following is a files of notes I made on the format. If anybody can fill in the holes or find mistakes I would appreciate hearing about it. Allan Weber Weber%Brand@USC-ECL ...sdcrdcf!usc-oberon!brand!weber ----------------------------- MacDraw data file information Allan Weber (Weber@USC-ECLC) USC Signal and Image Processing Institute Last edit: 16-Dec-85 This file contains a description of the data records produced by "Macdraw Version 1.7 3/18/85". Some of the information in the data records has not yet been deciphered and is indicated below by question marks. Note: Many of the data structures for points and rectangles use 4-byte "fixed-point numbers" instead of the normal 2-byte integers. Fixed-point numbers are described in "Inside Macintosh", page MI-11. They are similar to integers with the addition of a 2-byte fractional part, thus yielding a number with the same range but greater precision. A MacDraw file starts with a 512 byte header. There does not appear to be any information in the header required for recreating the image on a device like a laser printer. File header (512 bytes) Offset 0..213 ? 214..229 Enclosing rectangle for entire drawing (Fixed-point) 230..511 ? After the file header is a sequence of data records, one for each object in the image. Each object data record starts with an 8-byte record header, followed in most cases by varible-length object-dependent data. The first byte in each of the record headers indicates the type of object. At the end of the file is a terminator (type 0) record. Record header (8 bytes) Offset 0 code 0 = terminator 1 = text 2 = right angle vector 3 = sloped vector 4 = rectangle 5 = round rectangle 6 = ellipse 7 = arc 8 = curve 9 = polygon 10= group 11 = PICT data (from MacPaint) 1 lock 0 = unlocked, 1 = locked 2 ? 3 ? 4 line width code: 1 = 0 pixels, 2 = 1 pixel, 3 = 2 pixels, 4 = 4 pixels, 5 = 6 pixels 5 pen pattern number: 1..36 6 fill pattern number: 1..36 7 special for vectors, the arrow type 0 = ------, 1 = ----->, 2 = <-----, 3 = <-----> for round rectangles, the corner radius: 1 = 0", 2 = 1/8, 3 = 3/16, 4 = 1/4, 5 = 5/16, 6 = 3/8 8.. An object-specific record (if any) follows after the header Object Specific Data (follows record header) 0: Terminator record (0 bytes) A terminator record is used to mark the end of the list of objects or the end of a set of objects that have been grouped together. 1: Text record (20 bytes + length of string) 0..3 ? 4 style 0 = plain, 1 = bold, 2 = italic, 4 = underline, 8 = hollow, 16 = shadow 5 font 1 = Chicago, 2 = Geneva, 3 = New York, 4 = Monaco, 5 = Venice, 6 = London, 7 = Athens 6 size 1 = 9 pt, 2 = 10 pt, 3 = 12 pt, 4 = 14 pt, 5 = 18 pt, etc. 7 spacing 1 = single, 2 = three halves, 3 = double 8 align 1 = left, 2 = center, 3 = right 9 angle 0 = normal 4 = flip horizontal 1 = rotate right 5 = flip vertical 2 = upsidedown 6 = rotate right and flip horizontal 3 = rotate left 7 = rotate left and flip horizontal 10:11 Number of characters in text string 12:19 Rectangle enclosing text (Integer) (Note: the rectangle gives the location of the text BEFORE doing any rotating and/or flipping according to byte 9.) 20 Start of text string (not terminated with null) 2,3: Vector record (16 bytes) 0:7 Start point (Fixed-point) 8:15 End point (Fixed-point) 4,5,6: Rectangles and Ellipse record (16 bytes) 0:15 Rectangle enclosing object (Fixed-point) 7: Arc record (20 bytes) 0:15 Rectangle enclosing ellipse used to generate arc (Fixed-point) 16:17 Start angle (degrees) 18:19 Extent of arc (degrees) 8: Curve record (32 bytes + 2 bytes/point) 0..1 ? 2:3 Number of bytes in rest of record 4:5 Number of points in curve including start point and ending null point 6:21 Rectangle enclosing curve (Fixed-point) 22 1 = make closed (add final point same as first point) 23 ? 24:31 Start point (Fixed-point) 32 Start of X,Y increment pairs (2 bytes/pair), 2's complement, terminated by a pair of zero bytes. 9: Polygon record (24 bytes + 8 bytes/point) 0..1 ? 2:3 Number of bytes in rest of record 4:5 Number of points in polygon 6:21 Rectangle enclosing curve (Fixed-point) 22 1 = make closed (add final point same as first point) 2 = smoothed polygon 23 ? 24 Start of list of points in the polygon (Fixed-point), 8 bytes/pnt 10: Group record (32 bytes) A group record is used to indicate the beginning of a collection of objects that have been grouped together using the Group command under the Arrange menu. The group contains all the following objects until a terminator record is encountered. 0:15 Rectangle enclosing all members in the group (Fixed-point) 16..31 ? 11: PICT record (42+) 0..3 ? 4:11 ? Rectangle (Integer) 12:27 Rectangle enclosing picture (Fixed-point) 28..31 ? 32:33 Width of picture in bytes 34:41 ? Rectangle (Integer) 42.. Bitmap -------------------------------------