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/* Copyright (C) 2018 C. 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 <string.h>
#include <sysexits.h>
#include <time.h>
#include <unistd.h>
#include "gfx.h"
static uint32_t rgb(uint8_t r, uint8_t g, uint8_t b) {
return (uint32_t)r << 16 | (uint32_t)g << 8 | (uint32_t)b;
}
static uint32_t gray(uint8_t n) {
return rgb(n, n, n);
}
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 translate = -0.75;
static double complex transform = 2.5;
static uint32_t samples = 1;
static void sample(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;
memset(buf, 0, 4 * width * height);
size_t superWidth = width * samples;
size_t superHeight = height * samples;
for (size_t y = 0; y < superHeight; ++y) {
for (size_t x = 0; x < superWidth; ++x) {
double zx = (((double)x + 0.5) / (double)superWidth - 0.5) * xRatio;
double zy = (((double)y + 0.5) / (double)superHeight - 0.5) * yRatio;
uint32_t n = mandelbrot((zx + zy * I) * transform + translate);
buf[(y / samples) * width + (x / samples)] += n;
}
}
}
static void color(uint32_t *buf, size_t width, size_t height) {
for (size_t i = 0; i < width * height; ++i) {
buf[i] = gray(255 * buf[i] / samples / samples / depth);
}
}
static double frameTime;
void draw(uint32_t *buf, size_t width, size_t height) {
clock_t t0 = clock();
sample(buf, width, height);
color(buf, width, height);
frameTime = (double)(clock() - t0) / (double)CLOCKS_PER_SEC;
}
static double translateStep = 1.0 / 128.0;
static double rotateStep = 1.0 / 128.0;
static double scaleStep = 1.0 / 32.0;
bool input(char in) {
const double PI = acos(-1.0);
switch (in) {
break; case 'q': return false;
break; case '.': depth++;
break; case ',': if (depth > 1) depth--;
break; case 'l': translate += translateStep * transform;
break; case 'h': translate -= translateStep * transform;
break; case 'j': translate += translateStep * I * transform;
break; case 'k': translate -= translateStep * I * transform;
break; case 'u': transform *= cexp(rotateStep * PI * I);
break; case 'i': transform /= cexp(rotateStep * PI * I);
break; case '+': transform *= 1.0 - scaleStep;
break; case '-': transform /= 1.0 - scaleStep;
break; case '0': translate = -0.75; transform = 2.5;
break; case ']': samples++;
break; case '[': if (samples > 1) samples--;
}
return true;
}
const char *status(void) {
static char buf[256];
snprintf(
buf, sizeof(buf),
"brot -s %u -i %u -t %g%+gi -f %g%+gi # %.6f",
samples, depth,
creal(translate), cimag(translate),
creal(transform), cimag(transform),
frameTime
);
return buf;
}
static double complex parseComplex(const char *str) {
double real = 0.0, imag = 0.0;
real = strtod(str, (char **)&str);
if (str[0] == 'i') {
imag = real;
real = 0.0;
} else if (str[0]) {
imag = strtod(str, NULL);
}
return real + imag * I;
}
int init(int argc, char *argv[]) {
int opt;
while (0 < (opt = getopt(argc, argv, "f:i:s:t:"))) {
switch (opt) {
break; case 'f': transform = parseComplex(optarg);
break; case 'i': depth = strtoul(optarg, NULL, 0);
break; case 's': samples = strtoul(optarg, NULL, 0);
break; case 't': translate = parseComplex(optarg);
break; default: return EX_USAGE;
}
}
return EX_OK;
}
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