G'MIC GIMP Help: Samj's Annular Steiner Chain Round Tiles (Annular_Steiner_Chain_Round_Tile_en) - GreycLab/gmic-community GitHub Wiki

Overview

A Steiner Chain, as explained on Wikipedia, creates a series of circles, around a central circle, whose edges all touch, but do not overlap. These circle's edges also touch, but do not overlap, a second circle which contains all of the previous circles, including the first.

This filter performs a simple version of the Steiner Chain calculation, and assumes that the outer circle has the same origin point as the inner circle, and therefore draws a ring of circles around an origin circle, all of the same size.

The contents of the inner circle are drawn from the layer upon which the filter is executed on.

"Sample execution."

The Controls

"Picture of script option controls."

Dimensions pixels -- Since the resultant layer/image is square, this value determines both the width and the height of the output.
Default: 800
Range: 256 - 1920
Delete layer source -- A flag indicating whether or not the original layer should be deleted upon creation of the script generated image.
Default: Checked (Yes delete layer)
Position x origin (%) -- (Possibly subject to change. I am waiting to hear from samj) This appears to function as a zoom of the origin point, causing the sampled size of the main image to increase, thus also affecting the output material in the smaller circles.
Position y origin (%) -- This effects the Y coordinate of the origin point, and offsets it downward by a percentage of the diameter of the base sample.
Default: 0.00
Range: 0.00 - 100.00
Dimensions (%) -- This effects a zoom factor of the source material, with 100% (the default) being fully zoomed out, thus lower values increase the magnification.
Default: -- 100.00
Range: 0.00 - 100.00
Angle image contour -- Each smaller circle is normally projected with it's orientation offset by an angle equal to the angle of it's position. Thus the top circle will be oriented 90 degrees off of horizontal, as it appears at 90 degrees off of horizontal. This value is subtracted from the offset. Thus if a value of 90 is entered here, a top centre circle will have it's contents displayed as if they were horizontal, while a value of 0 will cause the standard vertical appearance in said circle.
Default: 0.00
Range: 0.00 - 360.00
Image Contour Dimensions: -- Each of the smaller circles can have a part of their surface area filled with a sampling from the original image. This setting determines how much of that surface area is filled in. Values below 100.00 result in a "ring" formed around the sampled material, and the sample shown being scaled down to a smaller size.
Default: 100.00
Range: 1.00 - 100.00
Nb circles surrounding -- The number of lesser circles to be placed around the main, inner circle.
Default: 12
Range: 3 - 180
TIP -- Smaller numbers result in larger circles. In fact 3 - 6 results in outer circles being larger than the inner one.
Angle Tilt -- This refers to the placement of the outer circles. A run with an even number of surrounding circles results in the center of the first circle being at the position that the number 3 would occupy on a clock. An odd number places the center between two lesser circles at this same point. The value entered here is added as an offset to this angular position, and causes the circles to "advance on the clock" in their relative positions.
Default: 0.00
Range: 0.00 - 360.00
TIP -- By adjusting this value the circles advance in position, and this in turn will cause the "apparent" spin of the contents of the outer circles to change as well.
Activate colors geometric shapes -- This setting enables and disables some colorizing of the results. The values below this point will explain what each colorization does.
Default: Enabled
Contours -- This is the color value for the filter's contour lines, if they are activated by the next setting. These lines can represent several things, see the next entry for details.
Default: Enabled
Display contours -- This selection field allows You to decide if, and or how, various contour data is rendered.
No: No contour data is displayed in the final output.
A: This option draws a border, in the color selected above, around each circle, including the normally non-visible outer circle.
B: This option draws contours as A does, with the addition of ring which passes through the origin point of each of the outer circles.
C: This option draws contours as B does, with the addition of a ring marking the point of tangency, exact point of contact, between the outer circles.
D: This option is like C, but omits the ring through the outer circles' origin points.
E: This option renders borders around all circles, including the non-visible outer circle, EXCEPT the inner circle. The inner one is rendered without a border.
F: This option renders borders around only the visible circles.
G: This option renders borders around only the visible outer circles.
Circle 1 -- This color choice will create a zone of transparent color around the outer circles, which when counted from 1 being at the three-o'clock position, represent an even number. This zone will have a width equal to 100.00 - "Image contour dimensions". So it is a percentage of the circles diameter.
Circle 2 -- This color choice will create a zone of transparent color around the outer circles, which when counted from 1 being at the three-o'clock position, represent an odd number. This zone will have a width equal to 100.00 - "Image contour dimensions". So it is a percentage of the circles diameter.
Random Colors -- This option overrides the colors defined in "Circle 1" and "Circle 2", and replaces them with pseudo random colors. The colors appear to be a predefined set representing Red, Blue, Green, Yellow, Pink, Purple, Black and White.
Default: Disabled

Input Details

This filter appears to effect only a single input layer regardless of the specified input mode. The second parameter (Defaulting to True) can be used to delete the source layer after the script has been run. If the Output mode is "New Image", then the original image's source layer will remain un altered, but will not be present in the new image if this option is used.

If said option is set to False (unchecked), then the source layer will appear in any new image created.

##Output Details By default this filter modifies the active layer in place. If the "Delete layer source" is unchecked, then a new layer is added at the top of the stack.

##Feature Compatibility / Quirks Layer Groups

This script can be run on a layer in a group, but the output ignores previous grouping and simply adds the resulting layer at the top of the layer stack. (See other notes below)

Quirks

This filter does have a few quirks.

When run with any form of active selection, there are many issues. The Preview is almost totally inaccurate, new layers can be empty, and more. Selections will work if all G"MIC Input/Output settings are left to default values, but the preview will be wrong.

It is best to run this filter using only the following Input/Output options if using a selection:

Active(Default)
In Place (Default)
New Image

Command String

G'MIC-GIMP command lines may not contain any spaces except for the one right after the script name!
-Annular_Steiner_Chain_Round_Tile_en int,int,float,float,float,float,float,int,float,int,int,int,int,int,int,int,int,int,int,int,int,int,int,int representing ...,
-Annular_Steiner_Chain_Round_Tile_en 800,1,20.25,20.25,88.88,4.26,42.6842,12,21.3,1,0,0,0,255,0,255,255,0,127,0,0,255,127,0

General Help Details

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