Memory Leak

Procedural textures; take two

March 16, 2006 at 10:50 am · Filed under Aldahar

So, Rick and I came up with a new pseudo-random number distribution:


double random_pow(int power)
{
	double num = 2.0 * rand() / RAND_MAX - 1;
	return (copysign(pow(num, power), num) + 1) / 2;
}

I’m using the standard C library versions of rand() and RAND_MAX, so this function generates a random number in [0, 1] biased towards 0.5 using the exponent power. I thought it might be useful in making most of my field green but having a few brown or yellow flecks at the end points, but I’m not sure it worked out correctly. Grass 1 and Grass 2 are my tries using this system. The code for the first one is:


Color lawn_grass(int x, int y)
{
	static color darkGreen(23, 90, 0);
	static color lightGreen(51, 175, 15);
	static color brown(87, 67, 6);
	color green = clint(darkGreen, lightGreen, rand_double());
	return clint(green, brown, rand_double()).convert();
}

For the second one, it’s:


Color lawn_grass(int x, int y)
{
	static color darkGreen(27, 81, 0);
	staric color lightGreen(75, 150, 25);
	static color brown(90, 97, 16);
	color green = clint(darkGreen, lightGreen, rand_double());
	return clint(green, brown, rand_double()).convert();
}

Crap. It occurs to me that neither of my grass functions use my random_pow() function. I’ll have to look around to see if I saved the originals.

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