I want to draw dots on an image that is W by W pixels. The image is stored as a 1-D array of pixels. The pixel (x,y) is at array index x + y * W. I am thinking that I can use a fixed step size, N, and draw a dot at every Nth pixel. What value of N will produce equilateral triangles?
Here is the result using W = 100 and N = 673

As you can see the triangles formed are nearly equilateral. Given W, how can I find "good" values for N, which will form near equilateral triangles?
I doubt if there is a simple answer to this question. Below is a plot of the "goodness" of the 10 triangles that can be formed using the first five points. Goodness is min side length over max side length. W = 100, and the first point is at (50,0). The horizontal axis is N, from 600 to 1200.
You can see there are 10 peaks above 0.9 goodness. These correspond to N = 628, 674, 726, 759, 826, 860, 926, 1026, 1137, 1165. The very last "good" spot is at N = 2850 where the points 0,1,2 form a nearly equilateral triangle. I have a theory that for any W, there will be an nearly equilateral formed when N = 0.2885 * W^2 (approximately).