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/* Copyright (C) 2018 June McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <complex.h>
#include <err.h>
#include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include "gfx/gfx.h"
static double absSq(double complex z) {
return creal(z) * creal(z) + cimag(z) * cimag(z);
}
static uint32_t depth = 50;
static uint32_t mandelbrot(double complex c) {
double complex z = 0;
for (uint32_t i = 0; i < depth; ++i) {
if (absSq(z) > 4.0) return i;
z = z * z + c;
}
return 0;
}
static double complex origin = -0.75 + 0.0 * I;
static double complex scale = 3.5 + 2.0 * I;
static double complex rotate = 1;
void draw(uint32_t *buf, size_t width, size_t height) {
for (size_t y = 0; y < height; ++y) {
double complex zy = ((double)y / (double)height - 0.5) * cimag(scale) * I;
for (size_t x = 0; x < width; ++x) {
double complex zx = ((double)x / (double)width - 0.5) * creal(scale);
uint64_t n = mandelbrot(origin + (zx + zy) * rotate);
uint32_t g = (double)n / (double)depth * 255.0;
buf[y * width + x] = g << 16 | g << 8 | g;
}
}
}
bool input(char in) {
const double PI = acos(-1.0);
double complex realTrans = 0.01 * creal(scale) * rotate;
double complex imagTrans = 0.01 * cimag(scale) * I * rotate;
double complex rotation = cexp(0.01 * PI * I);
switch (in) {
case 'q': return false;
case '.': depth++; break;
case ',': if (depth) depth--; break;
case '+': scale *= 0.9; break;
case '-': scale *= 1.1; break;
case 'l': origin += realTrans; break;
case 'h': origin -= realTrans; break;
case 'j': origin += imagTrans; break;
case 'k': origin -= imagTrans; break;
case 'u': rotate *= rotation; break;
case 'i': rotate /= rotation; break;
}
return true;
}
const char *status(void) {
static char buf[256];
snprintf(
buf, sizeof(buf),
"%u %g+%gi %g+%gi %g+%gi",
depth,
creal(origin), cimag(origin),
creal(scale), cimag(scale),
creal(rotate), cimag(rotate)
);
return buf;
}
int init(int argc, char *argv[]) {
(void)argc;
(void)argv;
return EX_OK;
}
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