55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
#include <math.h> // Floating point math is dog slow on AVR, but I don't care.
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#include <stdint.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 "plasma.h"
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#ifndef __AVR__
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#define FRAME_TICK 80
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#define FRAME_COUNT 750
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#else
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#define FRAME_TICK 1
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#define FRAME_COUNT 600
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#endif
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#define PLASMA_X (1.0 / (NUM_COLS / (2.0 * M_PI)))
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/**
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* calculates the distance between two points
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* @param x1 x coordinate of the first point
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* @param y1 y coordinate of the first point
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* @param x2 x coordinate of the second point
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* @param y2 y coordinate of the second point
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* @return distance between the points
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*/
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static double dist(double x1, double y1, double x2, double y2)
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{
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return sqrt(((x1 - x2) * (x1 - x2)) + ((y1 - y2) * (y1 - y2)));
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}
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/**
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* draws a simple plasma effect
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*/
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void plasma(void)
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{
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for (double t = 0; t < (FRAME_COUNT / 10.0); t = t + 0.1) {
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for (unsigned char x = 0; x < NUM_COLS; ++x)
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{
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for (unsigned char y = 0; y < NUM_ROWS; ++y)
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{
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double nColor1 = sin(x * PLASMA_X + t) + 1;
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double nColor2 = sin(dist(x, y, NUM_COLS * sin(t) + NUM_COLS,
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NUM_ROWS * cos(t) + NUM_ROWS) * PLASMA_X) + 1;
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unsigned char nColor =
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((nColor1 + nColor2) * (NUMPLANE - 1)) / 2;
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setpixel((pixel){x, y}, nColor);
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}
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}
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wait(FRAME_TICK);
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}
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}
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