68 lines
1.4 KiB
C
68 lines
1.4 KiB
C
/*----------------------------------------------------------------------+
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| ascjulia.c -- demonstrate fractal in text / quick and dirty |
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+----------------------------------------------------------------------*/
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// Standard includes
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#include <limits.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <string.h>
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#include <math.h>
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#include <gigatron/console.h>
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#define HEIGHT 15
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#define WIDTH 26
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#define SCALE 1.7
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#define YSTEP 1
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#define XSTEP 1
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#define CX -0.8
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#define CY 0.156
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int julia(float x, float y) {
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float zz;
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float a;
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float b;
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float a2;
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float b2;
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float atemp;
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int i;
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a = x;
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b = y;
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i = 48;
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while (i < 58)
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{
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a2 = a * a;
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b2 = b * b;
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zz = a2 + b2;
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if(zz > 4) break;
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atemp = a2 - b2 + CX;
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b = 2.0 * a * b + CY;
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a = atemp;
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i++;
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}
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return i;
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}
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void main(void) {
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int x, y, data;
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float sx, sy;
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for(y = 0; y < HEIGHT; y = y + YSTEP ) {
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for(x = 0; x < WIDTH; x = x + XSTEP ) {
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sx = (SCALE * (WIDTH/2.0 - x) / (WIDTH/2.0))*(-1);
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sy = (SCALE * (HEIGHT/2.0 - y) / (HEIGHT/2.0))*(-0.75);
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data = julia(sx, sy);
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console_state.cx = x;
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console_state.cy = y;
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console_state.fgbg = (((data-48)*6+1) & 0x3f) << 8;
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console_print((char*)&data, 1);
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}
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}
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}
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