The PostScript Driver

  The GRAPE PostScript driver is capable of black&white or color pictures, intersecting patches, different paper sizes, etc. The default values may not work with your special problem, so you have to configure it for your needs. E. g. geometries with many patches but without intersections take a lot of time -- hours in worst case -- to be written out because the driver checks for intersection lines and for intersections. If you switch off these checkings the upper mentioned process may only take a few seconds but intersecting patches look ugly.

Advanced PostScript users will find lots of options in the output file's header as well, of course the ability to switch on the drawing of patch bounds depends on patch bounds having been written.

 
Figure 4.20: PostScript Layer and Its Gamma Curve Editor

Decide if the image can be rotated on the paper by 90 degree to get a bigger size.

Decide if the image can be isometrically stretched to the size of the paper. This may be unwanted if .eps-files are created.

Input field for the filename. When is pressed more than once a number is appended.

As a difference to other filename requestors you do not have to enter the extension, the correct one .ps or .eps is automatically added.

Browse through the filesystem to select a filename or a path to edit in the input .

This Checkbox decides if the output files are marked as .eps-file.

Open a layer to edit the size of the paper in 1/72 inches.

 
Figure 4.21: Paper Size Layer

Height.

Width.

Size of the border on al sides of the paper. The image will be centered within the left over space.

Reset the values to A4 with border 1 inch (2.51 cm).

Close the layer.

Color or black and white output?

Invert all colors?

If GraphicDevice is in grid-mode and is off: draw everything black.

Open a layer with spline-editors for gamma-curves. In black and white mode only the grey spline is used, otherwise the three color splines.

In black and white mode: weight factor for red color components.

In black and white mode: weight factor for green color components.

In black and white mode: weight factor for blue color components.

Input the linewidth in points (1/72 inch) here.

Draw the bounds of patches. That is: draw grid and patch at one time. Sometimes the grid part will have holes, there is no solution for this problem except two scenes, the grid one being a bit before the patch one.

Calculate and draw an intersection line if two patches intersect.

Switch off intersection test and intersection lines. If they aren't needed this can speed up the output by an enormous degree.

Correction factor for shinyness value from the surface properties. If the highlight's size is different from the real one try to adjust this number.

Write the PostScript file. You can create numbered sequences of PostScript-files if you more then once without closing the layer between.

Close the PostScript driver configuration editing layer and its sublayers. The values are stored in memory but never written to a file.

For OOP purposes the device writes some useless state information at the top of the layer, just ignore it.

The configuration for the GraphicPs can be set using the ResourceDev. The resource entry in the resource files totally replaces the old ps.opt files. The info block for the GraphicPs simply looks like

  GraphicPs = {
   tag = value;
    . 
    . 
   tag;
    .
    .
  }

The possible tags for the GraphicPs are:

help

Print all available tags, their type and current settings.

use_colors

int
Create a colored or a gray scale postscript file. If the tag is given without a value color mode will be enabled, default value is 0.

patch_bounds

int
Show the bounds of the patches additionally as lines. This is useful to show the single patches of an solid model. If the tag is given without a value patch bounds will be enabled, default value is 1.

optimal_rotate

int
Rotate the picture to get a maximum sized picture for the given paper size. Useful together with the optimal_stretch tag. Tag alone will enable the optimal rotation, default value is 1.

optimal_stretch

int
Scale the picture to get a maximum picture size. Also enabled giving only the tag without a value, default value is 1.

paper_height

paper_width

paper_margin

int
Paper size and margins in 1/72 inches. Default values are height 843, width 596 and margins 72. These are the values for a DIN A4 paper in portrait format. If the optimal_rotation is enabled. The landscape or portrait values can be used equivalent.

draw_cutting_lines

int
Draw the lines, where patches are cutted from other patches. This is only useful and necessary if your geometries are self intersecting or intersected one by another. If the cutting_check is disabled, the value will be ignored. Default value is 1.

eps

int
Create an Encapsulated PostScript file instead of a normal one. If only the tag is given eps will be enabled, default value is 0.

specular_correction

double
Correction for the shinyness value. This option is used, if size of the highlight on your surface differs from the one in your graphic window. Default value is 1.0.

linewidth

double
Configure the linewidth of the lines. Default value is 0.400000.

invert_colors

int
Invert the colors. This is useful if you don't want to adapt your surface properties and line color, but simply want to create a picture from your graphic on a white background. If the tag is given without a value, colors will be inverted, default value is 0.

black_lines

int
If the grid mode is configured and this flag is enabled all lines will be drawn in black, even if they were colored or gray. Tag alone means enable black lines, default value is 1.

huge_patch_outline_mode

int
default value 0

no_cutting_check

int
Do not make an intersection check. This can speed up your output time dramatically, but can only be used, if you know, that your surfaces do not intersect. Also intersections between two different object are not resolved. Intersection check is also disabled, giving the tag without a value. Default value is 0.

gouraud

int
Enable the PostScript gourand shading. This will result in very smooth and pretty pictures, but will increase the printing time. This shading is done inside the printer, so use it only if your printer is rather fast. This shading is not visible using a ghostview, but could be seen using a ghostscript to render it into a bitmap and view this bitmap. If the tag is given without a value gourand shading will be enabled, default value is 0.

obscure

int
If this flag is enabled, patches, which are obsscured will removed in front of creating the file. This will encrease the time used to create the postscriptfile, but may improve the printout time on the printer. Use this option if the file should be printed in a very high solution or if your printer is much slower than computer. Be aware, that the PostScript file is created once, but may be preinted a several times. Only the tag given will be interpreted as obscure check enable, default value is 0.

square_bndbox

int
Using this flag a file with a squared bounding box is created. This bounding represent exactl the border of the graphic window. Using this option the graphic will have the same margin as in the graphic window. It is very usefull if you want to print several different graphic output together in the same page. If the tag is given without a value the squared bounding box will be enabled, default value is 0.

raw_clipping

int
Normally the patches are cutted at the clipping box. Use this flag to remove all patches which have at least one vertex outside the clipping box. With that option an inside view of an object through a cutting hole will look much more like a technical picture. Also with this tag the tag alone enables the option and the default value is 0.

depthsort_tolerance_factor

double
Correction factor for the depthsorting algorithm. Use it if you have problems with the depthsorting of patches. Teh default value is 1.0.

rgb_to_gray

VEC3
The weight factors for the RGB to gray calculation. Only used, if the color output is disabled. Default values are: 0.30, 0.59, 0.11.

filename

string
Filename for the Postscript file. A .ps or an .eps will be appended depending on the Encapsulate mode off or on. The default name is grape.