screen.h

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/*
Copyright (c) 2026 MrXie1109
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#pragma once
#include <array>
#include <cmath>
#include <cstdlib>
#include <iostream>
#include <string>
#include <utility>
 
namespace console {
    template <unsigned COLS, unsigned ROWS>
    class Screen {
        static_assert(COLS % 2 == 0, "COLS must be a multiple of 2!");
        static_assert(ROWS % 4 == 0, "ROWS must be a multiple of 4!");
 
        std::array<std::array<unsigned char, COLS / 2>, ROWS / 4>
            masks; 
 
    public:
        Screen() : masks() {}

        void point(unsigned x, unsigned y, bool on = true) {
            if (x >= COLS || y >= ROWS) return; 
            unsigned                   braille_col = x / 2;
            unsigned                   braille_row = y / 4;
            unsigned                   sub_x       = x % 2;
            unsigned                   sub_y       = y % 4;
            static const unsigned char mapping[2][4]
                = {{0, 1, 2, 6}, {3, 4, 5, 7}};
            unsigned char bit = 1 << mapping[sub_x][sub_y];
            if (on)
                masks[braille_row][braille_col] |= bit;
            else
                masks[braille_row][braille_col] &= ~bit;
        }

        void line(int x0, int y0, int x1, int y1, bool on = true) {
            int dx  = std::abs(x1 - x0);
            int dy  = -std::abs(y1 - y0);
            int sx  = x0 < x1 ? 1 : -1;
            int sy  = y0 < y1 ? 1 : -1;
            int err = dx + dy;
            while (true) {
                point(x0, y0, on);
                if (x0 == x1 && y0 == y1) break;
                int e2 = 2 * err;
                if (e2 >= dy) err += dy, x0 += sx;
                if (e2 <= dx) err += dx, y0 += sy;
            }
        }

        void rect(int x0, int y0, int x1, int y1, bool on = true) {
            line(x0, y0, x1, y0, on);
            line(x1, y0, x1, y1, on);
            line(x1, y1, x0, y1, on);
            line(x0, y1, x0, y0, on);
        }

        void fillRect(int x0, int y0, int x1, int y1, bool on = true) {
            if (x0 > x1) std::swap(x0, x1);
            if (y0 > y1) std::swap(y0, y1);
            for (int y = y0; y <= y1; ++y)
                for (int x = x0; x <= x1; ++x) point(x, y, on);
        }

        void circle(int cx, int cy, int r, bool on = true) {
            int x = 0, y = r;
            int d = 3 - 2 * r;
            while (x <= y) {
                point(cx + x, cy + y, on);
                point(cx - x, cy + y, on);
                point(cx + x, cy - y, on);
                point(cx - x, cy - y, on);
                point(cx + y, cy + x, on);
                point(cx - y, cy + x, on);
                point(cx + y, cy - x, on);
                point(cx - y, cy - x, on);
                if (d < 0)
                    d = d + 4 * x + 6;
                else
                    d = d + 4 * (x - y) + 10, y--;
                x++;
            }
        }

        void fillCircle(int cx, int cy, int r, bool on = true) {
            int x = 0, y = r;
            int d = 3 - 2 * r;
            while (x <= y) {
                for (int i = cx - x; i <= cx + x; ++i) {
                    point(i, cy + y, on);
                    point(i, cy - y, on);
                }
                for (int i = cx - y; i <= cx + y; ++i) {
                    point(i, cy + x, on);
                    point(i, cy - x, on);
                }
 
                if (d < 0) {
                    d += 4 * x + 6;
                } else {
                    d += 4 * (x - y) + 10;
                    y--;
                }
                x++;
            }
        }

        void clear() {
            for (auto &row : masks)
                for (auto &cell : row) cell = 0;
        }

        template <class CharT, class Traits = std::char_traits<CharT>>
        void update(std::basic_ostream<CharT, Traits> &os    = std::cout,
            bool                                       clear = false) const {
            if (clear) {
                os << "\033[2J";
            }
            std::string out;
            out.reserve((ROWS / 4) * (COLS / 2 * 3 + 1));
            for (unsigned row = 0; row < ROWS / 4; ++row) {
                for (unsigned col = 0; col < COLS / 2; ++col) {
                    unsigned int code = 0x2800 + masks[row][col];
                    out += static_cast<char>(0xE0 | (code >> 12));
                    out += static_cast<char>(0x80 | ((code >> 6) & 0x3F));
                    out += static_cast<char>(0x80 | (code & 0x3F));
                }
                out += '\n';
            }
            os << "\033[H" << out.c_str() << std::flush;
        }
    };
}