swarmc/include/screen.hpp

#pragma once

#include "vec.hpp"
#include <cstddef>
#include <cstdlib>
#include <cstdio>

#include <functional>
#include <unistd.h>
#include <termios.h>
#include <vector>

struct Screen {
    /**
     * Unit pixel information struct
     */
    struct Symbol {
	char sym;
	vec<3> color = {0,0,0};
	bool visible = true;

	Symbol &operator=(char c) { sym = c; return *this; };
    };

    /**
     * Function taking screen coords and space coords and returning a Symbol for
     * that position
     */
    using char_shader_t = std::function<Symbol(int, int, float, float)>;

    std::size_t w, h;

    float dx = 0, dy = 0;
    float sx = 1, sy = 1.8;

    void draw();
    void clear();

    Symbol &at(std::size_t n);
    Symbol &at(int x, int y);
    Symbol &at(float x, float y);

    void resize(std::size_t x, std::size_t y);

    void move_to(float x, float y);

    std::pair<float, float> screen_to_xy(int w, int h);
    std::pair<int, int> xy_to_screen(float x, float y);

    Screen(std::size_t x, std::size_t y) : buf(nullptr)
    { resize(x, y); move_to(0, 0); }
    ~Screen() { delete[] buf; }

    std::vector<const vec<2>*> points;
    std::vector<std::pair<const vec<2>*,const vec<2>*>> vecs;
    char_shader_t shader;

    bool draw_vecs = true;

private:
    Symbol *buf;
    Symbol _dummy;

    static inline void gotoxy(int x, int y)
    {
	std::printf("\033[%d;%dH", y, x);
    }
};

using colorizer_t = std::function<vec<3>(float)>;

struct TanhColorizer {
    float scale = 1.0;
    float translate = 0.0;
    vec<3> operator()(float y);

private:
    static vec<3> hsl_to_rgb(float h, float s, float l);
    static float hue_to_rgb(float p, float q, float t);
};


static termios old, current;
static inline void enter_noncanonical_mode(void)
{
    tcgetattr(STDIN_FILENO, &old);
    current = old;
    current.c_lflag &= ~ICANON; /* disable buffered i/o */
    current.c_lflag &= ~ECHO; /* set no echo mode */
    current.c_cc[VMIN] = 0;/* no wait */
    current.c_cc[VTIME] = 0;/* no wait */

    tcsetattr(STDIN_FILENO, TCSANOW, &current);
}
static inline void enter_canonical_mode(void){ tcsetattr(0, TCSANOW, &old); }