[Sketch Section]

Sketch Section

This section contains the description of a picture. Its actual data is found in the embedded «Paint Data Section».

Offset Size Normal Object

0000 W X size as displayed

0002 W Y size as displayed

0004 W X offset of picture within displayed area

0006 W Y offset of picture within displayed area

0008 W X offset within form (0000 for non-objects)

000A W Y offset within form (oo00 for non-objects)

000C W X size of form (0000 for non-objects)

000E W Y size of form (0000 for non-objects)

0010 W Always 00 00?

«Paint Data Section»

W X magnification

W Y magnification

L Left cut

L Right cut

L Top cut

L Bottom cut

A picture is a rectangle which should be displayed. The proper picture is within this rectangle, surrounded by empty space. To keep down the file size, we put a (smaller) rectangle around the picture, and only encode the pixel data within this smaller rectangle. The (larger) rectangle is in its turn put on a (rectangular) form. So we have three rectangles within each other, from large to small: the form, the picture as displayed, and the pixel data.

The first eight words encode the locations and sizes of these rectangles in pixel units. The last four words may all be set to zero, to indicate no form rectangle is used. All sizes are given without taking any magnification and cropping into account.

The magnification factors determine whether the picture should be compressed or expanded. 03E8 (1000 decimal) is normal size; lower numbers compress, higher numbers expand. So 01F4 would mean halfsize. They just tell how the picture should be displayed, and changing the magnification factor will not change any of the other values. Note that the Sketch program does not read these values; they are only used for sketch objects.

The cuts determine whether a portion of the picture should be hidden, on one of its four sides. Cuts are in fractions of C*Size. So 0000 means do no cut, and 0600 would hide half of a picture 0100 dots large. The displayed size (offset 0 and 2) is taken as a basis for this. Note that the Sketch program does not read these values; they are only used for sketch objects.