Sine curve | z88dk mono graphics https://balloon.gq/categories/z88dk/

## sin.c
/*
 Sine curve | z88dk mono graphics
 Copyright (c) 2019 Keiichi SHIGA (BALLOON a.k.a. Fu-sen.)
 The MIT License (MIT) - https://gist.github.com/fu-sen/7e55ee56a67e07d804db9379178e3cb5

MSX:
zcc +msx -lm -lmsxbios -create-app -bn sin sin.c (Cassette tape image, generate sin.cas)
 --> BLOAD"CAS:",R
zcc +msx -lm -lmsxbios -create-app -subtype=disk -bn sin sin.c (BASIC BLOAD file, generate sin.msx)
 --> BLOAD"SIN.MSX",R
zcc +msx -lm -lmsxbios -create-app -subtype=wav -bn sin sin.c (Cassette tape audio WAV format, generate sin.wav)
zcc +msx -lm -lmsxbios -create-app -subtype=msxdos -bn sin sin.c (MSX-DOS .com executable file, generate sin.com)
zcc +msx -lm -lmsxbios -create-app -subtype=rom -bn sin sin.c (ROM cartridge image, generate sin.rom)

PC-6001:
If you have a problem with the line drawing, try on Night Build 20190708 or later
zcc +pc6001 -lm -create-app -bn sin sin.c (16k, generate sin.cas)
zcc +pc6001 -lm -subtype=32k -create-app -bn sin sin.c (32k, generate sin.cas)
 --> CLOAD
     RUN

PC-8801:
zcc +pc88 -lm -lgfxpc88 -create-app -Cz--audio program.c (160x100, generate sin.t88)
zcc +pc88 -lm -lgfxpc88hr200 -create-app -Cz--audio program.c (640x200, generate sin.t88)
 --> MON
     R
     G8A00

PC-G850V:
zcc +g800 -lm -create-app -bn sin sin.c (generate sin.ihx)
 --> g800 sin.ihx 100 (g800)

TI-83:
zcc +ti83 -lm -create-app -bn sin sin.c (shell=Ion or Ti-Explorer, generate sin.83p)

TI-86:
zcc +ti83 -lm -create-app -startup=2 -bn sin sin.c (shell=ASE, Rascal or emanon, generate sin.86p)

ZX81:
zcc +zx81 -lm -create-app -bn sin sin.c (generate sin.P)

ZX Spectrum:
zcc +zx -lp3 -lm -create-app -bn sin sin.c (generate sin.tap)

It can be built on various other Z80 platforms!
*/

#include <graphics.h>
#include <math.h>
#include <stdio.h>

void main() {
  int x, y;
  clg();

  for (x=0; x<=getmaxx(); x+=2) {
    plot(x, getmaxy() / 2);
  }

  for (x=0; x<=getmaxx(); x++) {
    y = (int)((getmaxy() / 2) * (1.0 - sin(M_PI * 2.0 * x / getmaxx())));
    if (x==0){
      plot(x, y);
    } else {
      drawto(x, y);
    }
  }

  while (getk() < 1){}
}