Print Graphics Image

Dialog Box: Print Graphics Image [ File menu]

--- Windows

only---This command is for normal printer output through the printer driver (see below). If you have a PostScript printer, you should probably use the PostScript command in the File menu rather than this one for non-3D images; that command sends PostScript language commands directly to the printer, bypassing the printer driver. The PostScript language has a few capabilities which are missing from the system routines. Using

Direct PostScript output may give somewhat different, and usually more correct colors, than using the Print option (although color inaccuracies may possibly be fixed by changing the settings of the printer driver in the Page Setup command).

In the case of 3D images (that is printing while in the 3D Display mode), ATOMS does not send drawing commands to the printer - rather the entire drawing (or sections

thereof) must be imaged in memory, and this raster or bitmap image is sent to the printer.

--- Macintosh only

---Three different Print Modes may be used, depending on the settings in this dialog and the ATOMS display mode - 1) Standard or QuickDraw, 2) Direct PostScript or 3) Bitmap.

Option 1) sends standard QuickDraw graphics commands (the same as those used for the screen) to a printer driver, which may be supplied by Apple or the printer manufacturer.

The printer then makes the image in its own memory. You select the printer or printer driver in the Chooser option in the Apple menu (OS 8/9) or in the Print Center (OS X).

This option sometimes results in poor quality output, with too-thick or irregular lines, patterns at a scale of 72 dpi instead of the true printer resolution, or incorrect colors. If this happens try one of the other options.

If you have a PostScript printer, for non-3D output you should probably select the Direct PostScript option - this causes ATOMS to send PostScript language commands to the printer instead of the QuickDraw drawing commands, although these commands are transmitted through the currently-selected printer driver. Some printer drivers, especially the standard LaserWriter drivers, may not print at the maximum resolution of the printer without this option. Note that direct PostScript printer output is only supported through this option, not through the PostScript item in the File menu. The Pattern Series selection is ignored - patterns are determined by the Printer.

Option 3) forms the image in memory, then sends it as a bitmap to the printer. This option is always used for 3D Display modes. This method may be very slow, but often gives higher quality than option 1).

--- End Macintosh/Windows only

---If the Standard printer dialog on OK box is checked, the Print dialog supplied by the operating system or the printer driver comes up after you click OK. Use that dialog to set the number of copies or in some cases the resolution. The orientation (portrait or landscape) can also be set in the Page Setup dialog in the File menu.

If you have a color printer, you may need to make a choice between color and black-and-white printing in one of the printer dialogs as well as with the Color printing checkbox in this dialog. This choice may be an option in the standard printer dialog above, or you may need to set it in the Page Setup option in the File menu. Background applies only to color printing; for black-and-white printing the background is always white (although you could print on black paper).

See Frames for details of the frame and frame units.

In this print option, for non-3D images, ATOMS sends standard graphics commands to the operating system, which passes them on to the printer driver, a piece of software which is normally written by the printer manufacturer (but sometimes by Microsoft in the case of Windows). For color printing, it is standard to send RGB values to specify colors for lines and files, and for black-and-white printing, it is standard to send gray-scale values (actually, RGB values with all three components equal). The printer driver interprets these values in terms solid areas and/or dot patterns of ink on the paper. No color printer can print all colors as solid areas; traditional printing uses as few as three or four colors, most commonly cyan, magenta, yellow and black, intermixed or dithered in dot-patterns to produce a full range of colors. Microcomputer printers may use more colors, but the principle is the same, and dot density is typically lower than in traditional printing, so it may be important to select colors which are as simple as possible in terms of red, green and blue or cyan, magenta and yellow (see Colors, Palettes and DotPatterns ).

Use ATOMS b/w patterns - Pattern Series. Black-and-white printer drivers must interpret the gray values for fills as dot patterns of varying density. The patterns supplied by the printer driver may or may not be satisfactory for the ATOMS user. Rather than send gray-scale values for fills, ATOMS can also send its own dot patterns, which have been carefully designed for its purposes. The Fine series is appropriate for small drawings which will not be reproduced photographically. The Coarse series simulates halftone screening and is appropriate for photographic reproduction. To be precise, at a printer resolution of 300 dots per inch, most of the patterns have a screen density of 53 lines per inch, at 45 degrees; this is about half the density of typical standard printing, so a reduction of about a factor of two is generallly satisfactory. Of course, different printer resolution would dictate different reduction factors. Note that this coarse/fine setting is the same as that in the Raster and Metafile or PICT files dialogs in the File menu.

--- Macintosh only

---ATOMS patterns are always used for b/w printing, but they may be rescaled or otherwise changed by the printer driver.

--- End Macintosh/Windows only

---Actually, different printer drivers may interpret the standard gray-scale commands in terms of patterns which are similar either to the fine or coarse series supplied by ATOMS.

Some may convert the ATOMS patterns to their own patterns, and some may not accept the ATOMS patterns at all. Some may offer their own choice of pattern types or

densities (typically in the printer dialog above or the Page Setup dialog in the File menu). Thus some experimentation may be necessary to find the best choice for patterns (i.e. printer-driver patterns, fine ATOMS patterns; or coarse ATOMS patterns). Gray lines of greater than one-dot width are always drawn by filling an outline with one of the ATOMS patterns - gray-scale values are not used because many printers will not print

gray lines. Thus the coarse/fine setting is always used for wide b/w lines.

Maximum memory. This is used only when printing in bitmap mode, which is always used for the 3D display mode. Operating system support for printing in 3D mode is incomplete, and ATOMS itself must therefore draw raster or bitmap images and send these to the printer, rather than relying on the printer driver. Memory considerations similar to those involved in Raster Files therefore come into play.

Both Macintosh and Windows operating systems use virtual memory, which means that they pretend that a hard disk can be used in place of actual hardware memory chips. For some purposes this is useful, but when writing raster files it usually results in "disk thrashing", or constant reading and writing of data to the hard disk.

ATOMS is capable of imaging and writing raster files in segments or bands to avoid this problem. This requires repeating the entire drawing process for each band, but this usually is much faster than the reading/writing to disk involved in using virtual memory.

To do this requires knowing how much actual chip memory is available. Unfortunately, at present the operating systems do not provide this information in a useful way. Thus the user may need to determine this by trial and error using the Maximum memory parameter. This is the same parameter which is set in the Raster Files dialog.

When the Maximum memory parameter is set to zero, ATOMS will simply ask the system for a block of memory large enough to image the entire drawing at once. If this amount of memory is greater than the amount of chip memory which is made available by the system (and this may be considerably less than the actual amount of chip memory in the computer), the operating system will use virtual memory, which is typically

manifested by disk thrashing. If you change the Maximum memory to some amount less than that require for the image (say half), ATOMS will only request this amount of memory from the system, and virtual memory may not come into play. A Maximum memory setting should be good for a given session, regardless of the size of the raster file; larger files will use more bands. However, the amount of memory available may depend on whether other applications are active.

The amount of virtual memory is determined by the available space on the hard disk. If this is insufficient, ATOMS will automatically use bands, but since virtual memory is being used, it may still be advantageous to use a Maximum memory value which will increase the number of bands.

3.2.1.10 Page Setup

The Page Setup dialog box in the File Menu of the Graphics Window is identical to the Page Setup dialog in the File Menu of the Startup Window