From f9b559f3a0c969e45b0baaf29e4bf1d5612397a4 Mon Sep 17 00:00:00 2001 From: Anton Lydike Date: Sun, 15 Mar 2020 14:48:16 +0100 Subject: [PATCH] drew my first mandelbrot today --- complex.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ main.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 108 insertions(+), 1 deletion(-) create mode 100644 complex.c diff --git a/complex.c b/complex.c new file mode 100644 index 0000000..1b71c8b --- /dev/null +++ b/complex.c @@ -0,0 +1,54 @@ +#include + + +typedef struct _mycomplex { + float re; + float im; +} Complex; + + +inline Complex complex_new(float re, float im) __attribute__ ((always_inline)); +inline Complex complex_add(Complex c1, Complex c2) __attribute__ ((always_inline)); +inline Complex complex_mult(Complex c1, Complex c2) __attribute__ ((always_inline)); +inline double complex_abs(Complex c) __attribute__ ((always_inline)); + +inline Complex complex_new(float re, float im) +{ + Complex c; + c.re = re; + c.im = im; + return c; +} + +inline Complex complex_mult(Complex c1, Complex c2) +{ + Complex ret; + ret.re = c1.re * c2.re - c1.im * c2.im; + ret.im = c1.re * c2.im + c1.im * c2.re; + return ret; +} + +inline Complex complex_add(Complex c1, Complex c2) +{ + c1.re += c2.re; + c1.im += c2.im; + return c1; +} + +inline Complex complex_conj(Complex c) { + c.im = -c.im; + return c; +} + +inline double complex_abs(Complex c) +{ + double re, im; + re = c.re; + im = c.im; + return sqrt(re * re + im * im); +} + +inline void complex_print(Complex c) { + printf("%.3f + i%.3f", c.re, c.im); +} + diff --git a/main.c b/main.c index e65b5ac..efeae0f 100644 --- a/main.c +++ b/main.c @@ -1,10 +1,63 @@ #include #include +#include #include "images/images.h" +#include "complex.c" - +void draw_mandelbrot(int width, int height, int iterations); +void draw_mandelbrot_auto(int width, int iterations); +int test_mandelbrot(Complex c, int iterations); int main(int argc, char* argv[]) { + int width = 3000; + int iterations = 60; + if (argc > 1) { + width = atoi(argv[1]); + } + if (argc > 2) { + iterations = atoi(argv[2]); + } + + draw_mandelbrot_auto(width, iterations); +} + +void draw_mandelbrot_auto(int width, int iterations) { + draw_mandelbrot(width, 2 * width / 3, iterations); +} + +void draw_mandelbrot(int width, int height, int iterations) { + int center_x = 2 * width / 3; + int center_y = height / 2; + float step = 3.0f / width; + + Image img; + image_new(width, height, &img); + + for (int x = 0; x < width; x++) { + for (int y = 0; y < height; y++) { + Complex c = complex_new( + (x - center_x) * step, + (y - center_y) * step + ); + int ret = test_mandelbrot(c, iterations); + int r = (ret * 160 / iterations); + int g = (ret * 9 / iterations); + int b = (ret * 165 / iterations); + image_set_px(img, x, y, r,g,b); + } + } + + image_save_bmp(img, "mandelbrot.bmp"); + image_destroy(img); +} + +int test_mandelbrot(Complex c, int iterations) { + Complex z = complex_new(0,0); + for (int i = 0; i < iterations; i++) { + z = complex_add(complex_mult(z,z), c); // z^2 + c + if (complex_abs(z) > 2) return i; + } + return 0; }