roflcat/include/color_printer_true.hpp

/**
	roflcat
	Copyright (C) 2019 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef COLOR_PRINTER_TRUE_HPP
#define COLOR_PRINTER_TRUE_HPP

#ifndef _XOPEN_SOURCE
#define _XOPEN_SOURCE //for wcwidth
#endif
#include <cwchar> //wcwidth

#include "cmd.hpp"
#include "color_printer_base.hpp"
#include <cstdlib> //std::abs
#include <algorithm> //std::min, std::max
#include <cstdio> //wprintf, putwchar

//True color printer. Too many options to enumerate the entire list of possible colors, so we calculate on the fly
class color_printer_true : public color_printer_base<color_printer_true>
{
friend class printer_base<color_printer_true>;
private:
	static constexpr const char* lookup_table[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48", "49", "50", "51", "52", "53", "54", "55", "56", "57", "58", "59", "60", "61", "62", "63", "64", "65", "66", "67", "68", "69", "70", "71", "72", "73", "74", "75", "76", "77", "78", "79", "80", "81", "82", "83", "84", "85", "86", "87", "88", "89", "90", "91", "92", "93", "94", "95", "96", "97", "98", "99", "100", "101", "102", "103", "104", "105", "106", "107", "108", "109", "110", "111", "112", "113", "114", "115", "116", "117", "118", "119", "120", "121", "122", "123", "124", "125", "126", "127", "128", "129", "130", "131", "132", "133", "134", "135", "136", "137", "138", "139", "140", "141", "142", "143", "144", "145", "146", "147", "148", "149", "150", "151", "152", "153", "154", "155", "156", "157", "158", "159", "160", "161", "162", "163", "164", "165", "166", "167", "168", "169", "170", "171", "172", "173", "174", "175", "176", "177", "178", "179", "180", "181", "182", "183", "184", "185", "186", "187", "188", "189", "190", "191", "192", "193", "194", "195", "196", "197", "198", "199", "200", "201", "202", "203", "204", "205", "206", "207", "208", "209", "210", "211", "212", "213", "214", "215", "216", "217", "218", "219", "220", "221", "222", "223", "224", "225", "226", "227", "228", "229", "230", "231", "232", "233", "234", "235", "236", "237", "238", "239", "240", "241", "242", "243", "244", "245", "246", "247", "248", "249", "250", "251", "252", "253", "254", "255"};
	static constexpr long lookup_table_len = sizeof(lookup_table)/sizeof(lookup_table[0]);
	static constexpr int color_min_amount = 20;
	static constexpr int color_max_amount = 255;

	enum class color{
		red, green, blue
	};
	struct color_state{
		int r = color_min_amount, g = color_min_amount, b = color_max_amount;
		color curr = color::red;


		constexpr color_state(void)noexcept = default;
		constexpr color inc(void){
			switch(curr){
			default:
			case color::red:
				return (curr = color::green);
			case color::green:
				return (curr = color::blue);
			case color::blue:
				return (curr = color::red);
			};
		}
		constexpr color dec(void){
			switch(curr){
			default:
			case color::red:
				return (curr = color::blue);
			case color::green:
				return (curr = color::red);
			case color::blue:
				return (curr = color::green);
			};
		}
	}m_line_color = {}, m_color = {};
public:
	constexpr color_printer_true(const cmd_args& args)noexcept:
		color_printer_base<color_printer_true>(args){}

protected:
	color_printer_true& _print(const wchar_t s)noexcept{
		bool updated = false;
		if(s == L'\n'){
			inc_line();
			updated = true;
		}else{
			int width = wcwidth(s);
			if(width > 0)
				updated = inc_color(wcwidth(s));
			else
				updated = inc_color(1);
		}
		if(updated)
			wprintf(L"\033[38;2;%s;%s;%sm", lookup_table[m_color.r], lookup_table[m_color.g], lookup_table[m_color.b]);
		putwchar(s);
		return *this;
	}
	constexpr void inc_line(void){
		int amount = m_spread*(float{color_max_amount}/4);
		_do_inc_color(amount, m_line_color);
		m_color = m_line_color;
	}
	constexpr bool inc_color(int i){
		int amount = i*m_freq*(float{color_max_amount}/4);
		if(amount == 0)
			return false;
		_do_inc_color(amount, m_color);
		return true;
	}
	constexpr static void _do_inc_color(int amount, color_state& c){
		int* curr = nullptr, *next = nullptr, *prev = nullptr;
		color (color_state::*inc)(void) = nullptr;
		if(amount > 0){
			inc = &color_state::inc;
			switch(c.curr){
			default:
			case color::red:
				curr = &c.r;
				prev = &c.b;
				next = &c.g;
				break;
			case color::green:
				curr = &c.g;
				prev = &c.r;
				next = &c.b;
				break;
			case color::blue:
				curr = &c.b;
				prev = &c.g;
				next = &c.r;
				break;
			};
		}else{
			inc = &color_state::dec;
			switch(c.curr){
			default:
			case color::red:
				curr = &c.b;
				prev = &c.r;
				next = &c.g;
				break;
			case color::green:
				curr = &c.r;
				prev = &c.g;
				next = &c.b;
				break;
			case color::blue:
				curr = &c.g;
				prev = &c.b;
				next = &c.r;
				break;
			};
		}
		amount = std::abs(amount);
		while(amount != 0){
			int old = *curr;
			*curr = std::min((*curr)+amount, color_max_amount);
			amount = (old+amount)-(*curr);
			old = *prev;
			*prev = std::max((*prev)-amount, color_min_amount);
			amount = (amount-old)+(*prev);
			if((*prev) == color_min_amount){
				(c.*inc)();
				int* tmp = curr;
				curr = next;next = prev;prev = tmp;
			}
		}
	}
};

#endif