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/* Copyright (C) 2018 Curtis 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 uint32_t color(uint32_t n) {
uint32_t gray = (double)n / (double)depth * 255.0;
return gray << 16 | gray << 8 | gray;
}
static double complex translate = -0.75;
static double complex rotate = 1.0;
static double scale = 2.5;
void draw(uint32_t *buf, size_t width, size_t height) {
double yRatio = (height > width) ? (double)height / (double)width : 1.0;
double xRatio = (width > height) ? (double)width / (double)height : 1.0;
for (size_t y = 0; y < height; ++y) {
for (size_t x = 0; x < width; ++x) {
double zx = ((double)x / (double)width - 0.5) * xRatio;
double zy = ((double)y / (double)height - 0.5) * yRatio;
uint32_t n = mandelbrot((zx + zy * I) * scale * rotate + translate);
buf[y * width + x] = color(n);
}
}
}
static uint32_t depthDelta = 1;
static double translateDelta = 0.01;
static double rotateDelta = 0.01;
static double scaleFactor = 1.1;
bool input(char in) {
const double PI = acos(-1.0);
switch (in) {
case 'q': return false;
case '.': depth += depthDelta; break;
case ',': if (depth > depthDelta) depth -= depthDelta; break;
case 'l': translate += translateDelta * scale * rotate; break;
case 'h': translate -= translateDelta * scale * rotate; break;
case 'j': translate += translateDelta * I * scale * rotate; break;
case 'k': translate -= translateDelta * I * scale * rotate; break;
case 'u': rotate *= cexp(rotateDelta * PI * I); break;
case 'i': rotate /= cexp(rotateDelta * PI * I); break;
case '+': scale /= scaleFactor; break;
case '-': scale *= scaleFactor; break;
}
return true;
}
const char *status(void) {
static char buf[256];
snprintf(
buf, sizeof(buf),
"-d %u -t %g+%gi -r %g+%gi -z %g",
depth,
creal(translate), cimag(translate),
creal(rotate), cimag(rotate),
scale
);
return buf;
}
int init(int argc, char *argv[]) {
(void)argc;
(void)argv;
return EX_OK;
}
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