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

USAGE("[-c]")

static int per_channel = 0;

#define FILE "blind-matrix-reflect.c"
#include "define-functions.h"

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

	ARGBEGIN {
	case 'c':
		per_channel = 1;
		break;
	default:
		usage();
	} ARGEND;

	if (argc)
		usage();

	eopen_stream(&stream, NULL);

	if (stream.width > 2 || stream.height > 2 || stream.width * stream.height != 2)
		eprintf("<stdin>: each frame must contain exactly 2 pixels\n");

	stream.width  = 3;
	stream.height = 3;
	fprint_stream_head(stdout, &stream);
	efflush(stdout, "<stdout>");

	if (stream.encoding == DOUBLE)
		process = process_lf;
	else if (stream.encoding == FLOAT)
		process = process_f;
	else
		eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);

	process(&stream);
	return 0;
}

#else

static void
PROCESS(struct stream *stream)
{
	typedef TYPE pixel_t[4];
	pixel_t matrix[9];
	pixel_t buf[2];
	TYPE x2, y2, norm2;
	size_t i;

	for (i = 0; i < stream->n_chan; i++) {
		matrix[0][i] = 1, matrix[1][i] = 0, matrix[2][i] = 0;
		matrix[3][i] = 0, matrix[4][i] = 1, matrix[5][i] = 0;
		matrix[6][i] = 0, matrix[7][i] = 0, matrix[8][i] = 1;
	}

	while (eread_frame(stream, buf)) {
		if (per_channel) {
			for (i = 0; i < stream->n_chan; i++) {
				x2 = buf[0][i] * buf[0][i];
				y2 = buf[1][i] * buf[1][i];
				norm2 = x2 + y2;
				matrix[4][i] = -(matrix[0][i] = (x2 - y2) / norm2);
				matrix[3][i] = matrix[1][i] = 2 * buf[0][i] * buf[1][i] / norm2;
			}
		} else {
			buf[0][1] *= buf[0][3];
			buf[1][1] *= buf[1][3];
			x2 = buf[0][1] * buf[0][1];
			y2 = buf[1][1] * buf[1][1];
			norm2 = x2 + y2;
			matrix[4][0] = -(matrix[0][0] = (x2 - y2) / norm2);
			matrix[3][0] = matrix[1][0] = 2 * buf[0][1] * buf[1][1] / norm2;
			for (i = 1; i < stream->n_chan; i++) {
				matrix[0][i] = matrix[0][0];
				matrix[1][i] = matrix[1][0];
				matrix[3][i] = matrix[3][0];
				matrix[4][i] = matrix[4][0];
			}
		}
		ewriteall(STDOUT_FILENO, matrix, sizeof(matrix), "<stdout>");
	}
}

#endif