I'm working with polygon stippling, and it's going ok, except that I'm having trouble defining the stippling pattern. Does anyone know the magic behind the stippling pattern?

bit old but have look here: https://www.codeproject.com/Articles/23444/A-Simple-OpenGL-Stipple-Polygon-Example-EP-OpenGL​

it's got code too ?

Until then ?

I figured it out yeah. What was throwing me off was that their stipple pattern is 64x16 in the code, not 32x32.

Here's the code to convert a .bmp file to a stipple pattern:

#include <iostream>
using namespace std;
 
#include <GL/glew.h>

#include "bmp.h"

int main(void)
{
	BMP input;

	if (false == input.load("input.bmp", true))
	{
		cout << "Could not load input.bmp" << endl;
		return false;
	}

	if (input.width != 32 || input.height != 32)
	{
		cout << "input.bmp is not 32x32" << endl;
		return false;
	}

	const size_t num_channels = 4;

	size_t count = 0;

	for (size_t i = 0; i < 32 * 32 ; i += 8)
	{
		size_t index0 = num_channels * (i + 0);
		size_t index1 = num_channels * (i + 1);
		size_t index2 = num_channels * (i + 2);
		size_t index3 = num_channels * (i + 3);
		size_t index4 = num_channels * (i + 4);
		size_t index5 = num_channels * (i + 4);
		size_t index6 = num_channels * (i + 6);
		size_t index7 = num_channels * (i + 7);
		
		unsigned char c = 0;

		if (input.Pixels[index0] == 255)
			c = c + 128;

		if (input.Pixels[index1] == 255)
			c = c + 64;

		if (input.Pixels[index2] == 255)
			c = c + 32;

		if (input.Pixels[index3] == 255)
			c = c + 16;

		if (input.Pixels[index4] == 255)
			c = c + 8;

		if (input.Pixels[index5] == 255)
			c = c + 4;

		if (input.Pixels[index6] == 255)
			c = c + 2;

		if (input.Pixels[index7] == 255)
			c = c + 1;

		count++;

		if (count < 32 * 32 / 8)
			cout << "0x" << (hex) << int(c) << ',';
		else
			cout << "0x" << (hex) << int(c);

		if(count % 4 == 0)
			cout << endl;
	}

	return 0;
}