/* See LICENSE file for copyright and license details. */
#ifndef TYPE
#include "common.h"

USAGE("[-s spirals | t] [-al] -w width -h height")

static int anticlockwise = 0;
static int logarithmic = 0;
static int angle = 0;
static double spirals = 1;
static size_t width = 0;
static size_t height = 0;
static int with_params;
static int with_vector;

#define FILE "blind-spiral-gradient.c"
#include "define-functions.h"

int
main(int argc, char *argv[])
{
	struct stream stream;
	void (*process)(struct stream *stream);

	ARGBEGIN {
	case 'a':
		anticlockwise = 1;
		break;
	case 'l':
		logarithmic = 1;
		break;
	case 's':
		spirals = etolf_flag('s', UARGF());
		if (!spirals)
			eprintf("the value of -s must not be 0");
		break;
	case 't':
		angle = 1;
		break;
	case 'w':
		width = etozu_flag('w', UARGF(), 1, SIZE_MAX);
		break;
	case 'h':
		height = etozu_flag('h', UARGF(), 1, SIZE_MAX);
		break;
	default:
		usage();
	} ARGEND;

	if (!width || !height || argc || (spirals != 1 && angle))
		usage();

	eopen_stream(&stream, NULL);

	SELECT_PROCESS_FUNCTION(&stream);

	if (stream.width > 5 || stream.height > 5 ||
	    stream.width * stream.height < 2 ||
	    stream.width * stream.height > 5)
		eprintf("<stdin>: each frame must contain exactly 2, 3, 4, or 5 pixels\n");

	with_params = (stream.width * stream.height) & 1;
	with_vector = stream.width * stream.height > 3;

	stream.width = width;
	stream.height = height;
	fprint_stream_head(stdout, &stream);
	efflush(stdout, "<stdout>");
	process(&stream);
	return 0;
}

#else

static void
PROCESS(struct stream *stream)
{
	typedef TYPE pixel_t[4];
	pixel_t buf[BUFSIZ / sizeof(pixel_t)];
	TYPE *params, x1, y1, x2, y2, b, r, u, v;
	TYPE x, y, a = 0, e = 1, p = 1, k = 1, ep = 1;
	TYPE x3 = 1, y3 = 0, rd = 1, P, R, Rx, Ry, Pe = 2, Re = 2, PRe = 0.5;
	size_t i, ix, iy, ptr = 0;
	for (;;) {
		while (stream->ptr < stream->frame_size) {
			if (!eread_stream(stream, stream->frame_size - stream->ptr)) {
				ewriteall(STDOUT_FILENO, buf, ptr * sizeof(*buf), "<stdout>");
				return;
			}
		}
		params = (TYPE *)stream->buf;
		x1 = (params)[0];
		y1 = (params)[1];
		x2 = (params)[4];
		y2 = (params)[5];
		if (with_vector) {
			x3 = (params)[8];
			y3 = (params)[9];
			Pe = (params)[12];
			Re = (params)[13];
			rd = (params)[14];
			PRe = 1 / sqrt(Pe * Re);
			b = sqrt(x3 * x3 + y3 * y3);
			x3 /= b;
			y3 /= b;
		}
		if (with_params) {
			a = (params)[with_vector ? 16 : 8];
			e = (params)[with_vector ? 17 : 9];
			p = (params)[with_vector ? 18 : 10];
			k = (params)[with_vector ? 19 : 11];
			ep = 1 / (e * p);
		}
		memmove(stream->buf, stream->buf + stream->frame_size,
			stream->ptr -= stream->frame_size);

		x2 -= x1;
		y2 -= y1;
		u = atan2(y2, x2);
		b = sqrt(x2 * x2 + y2 * y2);
		b *= (TYPE)spirals;
		if (logarithmic)
			b = log(b);
		b /= pow(2 * (TYPE)M_PI, e);

		for (iy = 0; iy < height; iy++) {
			y = (TYPE)iy - y1;
			for (ix = 0; ix < width; ix++) {
				x = (TYPE)ix - x1;
				if (!x && !y) {
					v = 0;
				} else {
					v = atan2(y, x);
					if (anticlockwise)
						v = -v;
					v -= u;
					v += 4 * (TYPE)M_PI;
					v = mod(v, 2 * (TYPE)M_PI);
				}
				if (!with_vector) {
					r = sqrt(x * x + y * y);
				} else {
					P = x * x3 + y * y3;
					Rx = x - P * x3;
					Ry = y - P * y3;
					R = sqrt(Rx * Rx + Ry * Ry) / rd;
					P = pow(abs(P), Pe);
					R = pow(abs(R), Re);
					r = pow(P + R, PRe);
				}
				r -= a;
				if (!logarithmic) {
					r = pow(r / b, ep);
					r = (r - v) / (2 * (TYPE)M_PI);
				} else if (r) {
					r = log(r / k);
					r = pow(r / b, ep);
					r = (r - v) / (2 * (TYPE)M_PI);
				}
				if (angle)
					r = (TYPE)(int)(r + 1) + v / (2 * (TYPE)M_PI); 
				else
					r = mod(r, 1 / (TYPE)spirals) * (TYPE)spirals + r - mod(r, (TYPE)1);
				for (i = 0; i < stream->n_chan; i++)
					buf[ptr][i] = r;
				if (++ptr == ELEMENTSOF(buf)) {
					ewriteall(STDOUT_FILENO, buf, sizeof(buf), "<stdout>");
					ptr = 0;
				}
			}
		}
	}
}

#endif