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// fractals add-in by davidovski
// Copyright (C) 2021 davidovski
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
#include <gint/gint.h>
#include <gint/display.h>
#include <gint/keyboard.h>
#include <gint/keycodes.h>
typedef struct vec2 {
float x;
float y;
} vec2;
vec2 offset = {0, 0};
vec2 poi = {1.5f, 0.5f};
vec2 screen = {128, 64};
float zoom = 2.0f;
float max = 40.0f;
vec2 add(vec2 a, vec2 b) {
vec2 r = {a.x + b.x, a.y + b.y};
return r;
}
double dot(vec2 a, vec2 b) {
return a.x*b.x + a.y+b.y;
}
vec2 compsquare(vec2 z) {
float temp = z.x;
z.x = z.x*z.x - z.y*z.y;
z.y = 2.0*temp*z.y;
return z;
}
bool mandelbrot(vec2 point) {
vec2 z = {0, 0};
for (float iters = 0.0f; iters < max; ++iters) {
vec2 sq = compsquare(z);
z.x = sq.x + point.x;
z.y = sq.y + point.y;
z.x = sq.x + point.x;
if (dot(z, z) > 4.0) return false;
}
return true;
}
int main(void) {
gint_setrestart(1);
while (true) {
getkey();
dclear(C_WHITE);
for (float x = 0; x < 128; x++) {
for (float y = 0; y < 64; y++) {
vec2 point = {x / screen.x, y / screen.y};
point.x *= screen.x / screen.y;
point.x -= poi.x;
point.y -= poi.y;
point.x *= zoom;
point.y *= zoom;
point.x -= offset.x;
point.y -= offset.y;
if (mandelbrot(point)) {
dpixel(x , y, C_BLACK);
}
dupdate();
}
}
drect(1, 1, 3, 3, C_BLACK);
dupdate();
getkey();
if (keydown(KEY_ADD)) zoom -= zoom * 0.2f;
if (keydown(KEY_SUB)) zoom += zoom * 0.2f;
if (keydown(KEY_UP)) offset.y -= zoom * 0.1f;
if (keydown(KEY_DOWN)) offset.y += zoom * 0.1f;
if (keydown(KEY_RIGHT)) offset.x -= zoom * 0.1f;
if (keydown(KEY_LEFT)) offset.x += zoom * 0.1f;
if (keydown(KEY_EXIT)) gint_osmenu();
}
return 0;
}
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