- HUNGLv 71 十年前最愛解答
.GEM File Extension
Ventura Publisher Vector Graphic
Vector graphic created by Ventura Publisher or GEM Draw
Program(s) that open gem files
MacLink Plus (converts to PICT)
Corel Paint Shop Pro
你要用 Corel Paint Shop Pro 去開啟。
有關 Gem 的 file format 資料如下：
Format of GEM metafile (.GEM)
The GEM metafile is a stored sequence of GEM drawing instructions. Its normal uses are:
The native file format of GEM Draw, a vector drawing program;
GEM Paint always produces a minimal .GEM file to accompany the .IMG files it saves.
The standard method used for printing in GEM. Because GEM is small enough to run in 512k of RAM, there is usually not enough room in memory for a large program and a printer driver. Therefore the program generates a metafile, and then runs OUTPUT.APP to send that metafile to the printer.
Judging by the code in GEM Output, .GMP files created by Desktop Publisher use the same or a very similar format.
All word values are 16-bit, signed and little-endian (at least in Intel GEM). In this listing, "DW" (define word) is used to indicate such a word.
All GEM metafiles start with a header:
DW magic ;Magic number. DW length ;Header length DW version ;GEM version required to interpret this file. DW coords ;Coordinate type DW Xmin,Ymin,Xmax,Ymax DW Xpage,Ypage DW Xminc,Yminc,Xmaxc,Ymaxc DW flags
Most GEM metafiles have a 24-word header; the remaining header words being reserved.
is always -1 (0xFFFF)
is the number of words in the header; in most metafiles, this will be 24 (0x18). Some metafiles (those generated by Deskpress) have been seen with headers 71 words long; words nos. 23-70 being a text description with one character per word.
is the GEM version needed to play back this file, encoded as a decimal number. Common versions are:
0 (ie, any GEM)
Metafile EVENTS.GEM in the Programmers' Toolkit
101 (ie, GEM 1.01)
Metafiles produced by GEM Paint and GEM Draw
310 (ie, GEM 3.10)
Metafiles produced by Deskpress.
400 (ie, GEM 4.00)
Metafiles produced by Artline.
is the coordinate system in use. This is either 0 (Normalised Device Coordinates) or 2 (Raster Coordinates).
NDC files have their origin in the bottom left hand corner of the page, and coordinates are given as 32767 * fraction of the page size (so 16383 means halfway across the page).
RC files have their origin at the top left hand corner of the page, and coordinates are given in pixels.
Nearly always, files will be in raster coordinates.
The maximum and minimum coordinates used by the image.
The size of the page, in tenths of millimetres. Can be zero.
The bottom left and top right corners of the coordinate system. In the case of GEM Paint images, this is the maximum size that the bitmap could have been (in pixels). These values can be zero, in which case the coordinate system is assumed to go from (0,0) to (32767,32767).
Bit 0 is set if the metafile is a wrapper for a bitmap image (eg: those files written by GEM Paint).