179 lines
3.4 KiB
C
179 lines
3.4 KiB
C
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/*
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* Julia Fractal Generator
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <syscall.h>
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#include <string.h>
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#include <stdlib.h>
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#include <time.h>
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#include <unistd.h>
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#include "lib/window.h"
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/*
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* Macros make verything easier.
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*/
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#define SPRITE(sprite,x,y) sprite->bitmap[sprite->width * (y) + (x)]
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#define GFX_(xpt, ypt) ((uint32_t *)window->buffer)[DIRECT_OFFSET(xpt,ypt)]
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/* Pointer to graphics memory */
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window_t * window = NULL;
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/* Julia fractals elements */
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float conx = -0.74; /* real part of c */
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float cony = 0.1; /* imag part of c */
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float Maxx = 2; /* X bounds */
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float Minx = -2;
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float Maxy = 1; /* Y bounds */
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float Miny = -1;
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float initer = 1000; /* Iteration levels */
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float pixcorx; /* Internal values */
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float pixcory;
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int newcolor; /* Color we're placing */
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int lastcolor; /* Last color we placed */
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int no_repeat = 0; /* Repeat colors? */
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/*
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* Color table
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* These are orange/red shades from the Ubuntu platte.
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*/
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int colors[] = {
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0xeec73e,
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0xf0a513,
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0xfb8b00,
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0xf44800,
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0xffff99,
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0xffff00,
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0xfdca01,
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0x986601,
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0xf44800,
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0xfd3301,
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0xd40000,
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0x980101,
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};
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void julia(int xpt, int ypt) {
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long double x = xpt * pixcorx + Minx;
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long double y = Maxy - ypt * pixcory;
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long double xnew = 0;
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long double ynew = 0;
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int k = 0;
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for (k = 0; k <= initer; k++) {
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xnew = x * x - y * y + conx;
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ynew = 2 * x * y + cony;
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x = xnew;
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y = ynew;
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if ((x * x + y * y) > 4)
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break;
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}
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int color;
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if (no_repeat) {
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color = 12 * k / initer;
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} else {
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color = k;
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if (color > 11) {
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color = color % 12;
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}
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}
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if (k >= initer) {
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((uint32_t *)window->buffer)[DIRECT_OFFSET(xpt,ypt)] = 0;
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} else {
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((uint32_t *)window->buffer)[DIRECT_OFFSET(xpt,ypt)] = colors[color];
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}
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newcolor = color;
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}
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int main(int argc, char ** argv) {
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if (argc < 5) {
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printf("usage: %s left top width height\n", argv[0]);
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return -1;
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}
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int left = atoi(argv[1]);
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int top = atoi(argv[2]);
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int width = atoi(argv[3]);
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int height = atoi(argv[4]);
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setup_windowing();
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window = window_create(left, top, width, height);
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window_fill(window, rgb(127,127,127));
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#if 0
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graphics_width = syscall_getgraphicswidth();
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graphics_height = syscall_getgraphicsheight();
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graphics_depth = syscall_getgraphicsdepth();
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gfx_mem = (void *)syscall_getgraphicsaddress();
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#endif
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#if 0
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if (argc > 1) {
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/* Read some arguments */
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int index, c;
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while ((c = getopt(argc, argv, "ni:x:X:c:C:")) != -1) {
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switch (c) {
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case 'n':
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no_repeat = 1;
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break;
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case 'i':
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initer = atof(optarg);
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break;
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case 'x':
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Minx = atof(optarg);
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break;
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case 'X':
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Maxx = atof(optarg);
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break;
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case 'c':
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conx = atof(optarg);
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break;
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case 'C':
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cony = atof(optarg);
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break;
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default:
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break;
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}
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}
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}
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#endif
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printf("initer: %f\n", initer);
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printf("X: %f %f\n", Minx, Maxx);
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float _x = Maxx - Minx;
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float _y = _x / width * height;
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Miny = 0 - _y / 2;
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Maxy = _y / 2;
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printf("Y: %f %f\n", Miny, Maxy);
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printf("conx: %f cony: %f\n", conx, cony);
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pixcorx = (Maxx - Minx) / width;
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pixcory = (Maxy - Miny) / height;
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int j = 0;
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do {
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int i = 1;
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do {
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julia(i,j);
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if (lastcolor != newcolor) julia(i-1,j);
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else if (i > 0) GFX_(i-1,j) = colors[lastcolor];
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newcolor = lastcolor;
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i+= 2;
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} while ( i < width );
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++j;
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window_redraw_full(window);
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} while ( j < height );
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while (1) {
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}
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return 0;
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}
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