/*
 * Copyright (c) 2008-2020 Stefan Krah. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */


#include "mpdecimal.h"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>


static void
err_exit(const char *msg)
{
    fprintf(stderr, "%s\n", msg);
    exit(1);
}

static mpd_t *
new_mpd(void)
{
    mpd_t *x = mpd_qnew();
    if (x == NULL) {
        err_exit("out of memory");
    }

    return x;
}

/*
 * Example from: http://en.wikipedia.org/wiki/Mandelbrot_set
 *
 * Escape time algorithm for drawing the set:
 *
 * Point x0, y0 is deemed to be in the Mandelbrot set if the return
 * value is maxiter. Lower return values indicate how quickly points
 * escaped and can be used for coloring.
 */
static int
color_point(const mpd_t *x0, const mpd_t *y0, const long maxiter, mpd_context_t *ctx)
{
    mpd_t *x, *y, *sq_x, *sq_y;
    mpd_t *two, *four, *c;
    long i;

    x = new_mpd();
    y = new_mpd();
    mpd_set_u32(x, 0, ctx);
    mpd_set_u32(y, 0, ctx);

    sq_x = new_mpd();
    sq_y = new_mpd();
    mpd_set_u32(sq_x, 0, ctx);
    mpd_set_u32(sq_y, 0, ctx);

    two = new_mpd();
    four = new_mpd();
    mpd_set_u32(two, 2, ctx);
    mpd_set_u32(four, 4, ctx);

    c = new_mpd();
    mpd_set_u32(c, 0, ctx);

    for (i = 0; i < maxiter && mpd_cmp(c, four, ctx) <= 0; i++) {
        mpd_mul(y, x, y, ctx);
        mpd_mul(y, y, two, ctx);
        mpd_add(y, y, y0, ctx);

        mpd_sub(x, sq_x, sq_y, ctx);
        mpd_add(x, x, x0, ctx);

        mpd_mul(sq_x, x, x, ctx);
        mpd_mul(sq_y, y, y, ctx);
        mpd_add(c, sq_x, sq_y, ctx);
    }

    mpd_del(c);
    mpd_del(four);
    mpd_del(two);
    mpd_del(sq_y);
    mpd_del(sq_x);
    mpd_del(y);
    mpd_del(x);

    return i;
}

int
main(int argc, char **argv)
{
    mpd_context_t ctx;
    mpd_t *x0, *y0;
    mpd_t *sqrt_2, *xstep, *ystep;
    mpd_ssize_t prec = 19;

    long iter = 1000;
    int points[40][80];
    int i, j;
    clock_t start_clock, end_clock;


    if (argc != 3) {
        fprintf(stderr, "usage: ./bench prec iter\n");
        exit(1);
    }
    prec = strtoll(argv[1], NULL, 10);
    iter = strtol(argv[2], NULL, 10);

    mpd_init(&ctx, prec);
    /* no more MPD_MINALLOC changes after here */

    sqrt_2 = new_mpd();
    xstep = new_mpd();
    ystep = new_mpd();
    x0 = new_mpd();
    y0 = new_mpd();

    mpd_set_u32(sqrt_2, 2, &ctx);
    mpd_sqrt(sqrt_2, sqrt_2, &ctx);
    mpd_div_u32(xstep, sqrt_2, 40, &ctx);
    mpd_div_u32(ystep, sqrt_2, 20, &ctx);

    start_clock = clock();
    mpd_copy(y0, sqrt_2, &ctx);
    for (i = 0; i < 40; i++) {
        mpd_copy(x0, sqrt_2, &ctx);
        mpd_set_negative(x0);
        for (j = 0; j < 80; j++) {
            points[i][j] = color_point(x0, y0, iter, &ctx);
            mpd_add(x0, x0, xstep, &ctx);
        }
        mpd_sub(y0, y0, ystep, &ctx);
    }
    end_clock = clock();

#ifdef BENCH_VERBOSE
    for (i = 0; i < 40; i++) {
        for (j = 0; j < 80; j++) {
            if (points[i][j] == iter) {
                putchar('*');
            }
            else if (points[i][j] >= 10) {
                putchar('+');
            }
            else if (points[i][j] >= 5) {
                putchar('.');
            }
            else {
                putchar(' ');
            }
        }
        putchar('\n');
    }
    putchar('\n');
#else
    (void)points; /* suppress gcc warning */
#endif

    printf("time: %f\n\n", (double)(end_clock-start_clock)/(double)CLOCKS_PER_SEC);

    mpd_del(y0);
    mpd_del(x0);
    mpd_del(ystep);
    mpd_del(xstep);
    mpd_del(sqrt_2);

    return 0;
}