#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <tice.h>

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <graphx.h>
#include <keypadc.h>
#include <fileioc.h>

#include "gfx/gfx.h"

//while (!os_GetCSC());

float rand_0_1(void);
float randFunc(void);
float interpolate(float pa, float pb, float px);

uint32_t M = 9355500, //M, A, and C are constant members of the Linear Congruential Generator (LCG)
		 A = 311851;

uint16_t W = 320, // width of screen
		 x = 0; //x position along the screen
uint8_t  C = 1,
		 H = 240, //height of screen
		 amp = 100, //amplitude
		 wl = 10; //wavelength
float 	 y, fq, a, b, z;

void main(void)
{
	y = H / 2,
	fq = (float)1 / wl,
	z = rand_0_1() * M;
	a = randFunc(),
	b = randFunc();


	srand(rtc_Time());

	gfx_Begin();

	while(x < W){

		if(x % wl == 0)
		{
			a = b;
			b = randFunc();
			y = H / 2 + a * amp;
		} else {
			y = H / 2 + interpolate(a, b, ((x % wl) / (float)wl)) * amp;
		}
		gfx_SetPixel( x, (uint8_t)y);
		x += 1;
	}

	while (!os_GetCSC());
	gfx_End();
}




float rand_0_1()
{
	return rand()/(float)RAND_MAX;
}

float randFunc()
{
  z = (A * (int)z + C) % M;
  return z / (float)M - 0.5;
}

float interpolate(float pa, float pb, float px){
    float ft = px * M_PI,
		  f = (1 - cos(ft)) * 0.5;

    return pa * (1 - f) + pb * f;
}