65 lines
1.5 KiB
C++
65 lines
1.5 KiB
C++
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#include <cstdio>
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#include <cstdlib>
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#include <cmath>
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#include "complex.h"
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using namespace std;
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struct Color {
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unsigned char r, g, b;
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};
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Complex func(Complex z, Complex c) {
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return z * z + c;
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}
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int main(int argc, char** argv) {
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Complex c = {0, 0};
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int n = 20;
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int width = 800, height = 800;
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float x0 = -2.0f, x1 = 2.0f;
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float y0 = -2.0f, y1 = 2.0f;
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if (argc < 4) {
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cout << "usage: julia [re] [im] [n]" << endl
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<< "using default values: 0 + 0i, n = 20 "<< endl;
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}
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else {
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cout << argv[1] << " + " << argv[2] << "i" << endl << "n = " << n << endl;
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sscanf(argv[1], "%f", &c.re);
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sscanf(argv[2], "%f", &c.im);
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sscanf(argv[3], "%d", &n);
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}
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Color* data = (Color*)malloc(sizeof(Color) * width * height);
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for (int j = 0; j < height; j++) {
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for (int i = 0; i < width; i++) {
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Complex z = {x0 + (x1-x0) / width * i, y0 + (y1-y0) / width * j};
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for (int k = 0; k < n; ++k) {
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z = func(z, c);
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}
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float r = abs(z.re);
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float b = abs(z.im);
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if (r > 255) {
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r = 255;
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}
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if (b > 255) {
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b = 255;
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}
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data[i + width * j].r = 255 - r;
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data[i + width * j].g = 0;
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data[i + width * j].b = 255 - b;
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}
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}
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FILE* file = fopen("julia.ppm", "wb");
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fprintf(file, "P6\n%d %d\n255\n", width, height);
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fwrite(data, sizeof(Color), height * width, file);
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fclose(file);
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free(data);
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}
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