86 lines
2.7 KiB
C
86 lines
2.7 KiB
C
/* Copyright (c) 2010 Jan Lieven
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to
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* deal in the Software without restriction, including without limitation the
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* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include <limits.h>
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#include "../config.h"
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#include "../pixel.h"
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#include "../util.h"
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#include "../random/prng.h"
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#if (UNUMCOLS <= (UCHAR_MAX / 2)) && (UNUMROWS <= (UCHAR_MAX / 2))
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typedef unsigned char coord_t;
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#else
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typedef unsigned int coord_t;
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#endif
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#define P (1u)
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#define NX (UNUM_COLS - 1u)
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#define NY (UNUM_ROWS - 1u)
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static coord_t const xdcomp[] = {0, NX, 0, P};
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static coord_t const ydcomp[] = {P, 0, NY, 0};
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typedef struct ant_s {
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coord_t x, y; /* current postion */
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coord_t ox, oy; /* previous position, used to dim out old pixels */
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unsigned char vector_index; /* index to one of (0,1),(1,0),(0,-1),(-1,0) */
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} ant_t;
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void ltn_ant() {
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clear_screen(0);
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ant_t ant;
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unsigned int cycles = 500;
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/* random start position and direction */
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ant.x = ant.ox = random8() % UNUM_COLS;
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ant.y = ant.oy = random8() % UNUM_ROWS;
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/* make sure we have a valid vector */
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ant.vector_index = random8() % 4u;
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while(cycles--) {
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/* if the pixel is turned off turn it on */
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if(get_pixel((pixel) {ant.x, ant.y}) == 0) {
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setpixel((pixel) {ant.x, ant.y}, NUMPLANE);
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ant.vector_index = (ant.vector_index + 3u) % 4u; // turn left
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/* dim the previous pixel */
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setpixel((pixel){ant.ox, ant.oy}, NUMPLANE - 1);
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/* memorize this position */
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ant.ox = ant.x;
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ant.oy = ant.y;
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/* if the pixel is turned on turn it off */
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} else {
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setpixel((pixel) {ant.x, ant.y}, 0);
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ant.vector_index = (ant.vector_index + 1u) % 4u; // turn right
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}
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/* move to next pixel, playing field is modeled after a torus */
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ant.x = (ant.x + xdcomp[ant.vector_index]) % UNUM_COLS;
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ant.y = (ant.y + ydcomp[ant.vector_index]) % UNUM_ROWS;
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wait(100);
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}
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}
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