flanterm.c

/* Copyright (C) 2022-2024 mintsuki and contributors.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

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

#include "flanterm.h"

// Tries to implement this standard for terminfo
// https://man7.org/linux/man-pages/man4/console_codes.4.html

static const uint32_t col256[] = {
    0x000000, 0x00005f, 0x000087, 0x0000af, 0x0000d7, 0x0000ff, 0x005f00, 0x005f5f,
    0x005f87, 0x005faf, 0x005fd7, 0x005fff, 0x008700, 0x00875f, 0x008787, 0x0087af,
    0x0087d7, 0x0087ff, 0x00af00, 0x00af5f, 0x00af87, 0x00afaf, 0x00afd7, 0x00afff,
    0x00d700, 0x00d75f, 0x00d787, 0x00d7af, 0x00d7d7, 0x00d7ff, 0x00ff00, 0x00ff5f,
    0x00ff87, 0x00ffaf, 0x00ffd7, 0x00ffff, 0x5f0000, 0x5f005f, 0x5f0087, 0x5f00af,
    0x5f00d7, 0x5f00ff, 0x5f5f00, 0x5f5f5f, 0x5f5f87, 0x5f5faf, 0x5f5fd7, 0x5f5fff,
    0x5f8700, 0x5f875f, 0x5f8787, 0x5f87af, 0x5f87d7, 0x5f87ff, 0x5faf00, 0x5faf5f,
    0x5faf87, 0x5fafaf, 0x5fafd7, 0x5fafff, 0x5fd700, 0x5fd75f, 0x5fd787, 0x5fd7af,
    0x5fd7d7, 0x5fd7ff, 0x5fff00, 0x5fff5f, 0x5fff87, 0x5fffaf, 0x5fffd7, 0x5fffff,
    0x870000, 0x87005f, 0x870087, 0x8700af, 0x8700d7, 0x8700ff, 0x875f00, 0x875f5f,
    0x875f87, 0x875faf, 0x875fd7, 0x875fff, 0x878700, 0x87875f, 0x878787, 0x8787af,
    0x8787d7, 0x8787ff, 0x87af00, 0x87af5f, 0x87af87, 0x87afaf, 0x87afd7, 0x87afff,
    0x87d700, 0x87d75f, 0x87d787, 0x87d7af, 0x87d7d7, 0x87d7ff, 0x87ff00, 0x87ff5f,
    0x87ff87, 0x87ffaf, 0x87ffd7, 0x87ffff, 0xaf0000, 0xaf005f, 0xaf0087, 0xaf00af,
    0xaf00d7, 0xaf00ff, 0xaf5f00, 0xaf5f5f, 0xaf5f87, 0xaf5faf, 0xaf5fd7, 0xaf5fff,
    0xaf8700, 0xaf875f, 0xaf8787, 0xaf87af, 0xaf87d7, 0xaf87ff, 0xafaf00, 0xafaf5f,
    0xafaf87, 0xafafaf, 0xafafd7, 0xafafff, 0xafd700, 0xafd75f, 0xafd787, 0xafd7af,
    0xafd7d7, 0xafd7ff, 0xafff00, 0xafff5f, 0xafff87, 0xafffaf, 0xafffd7, 0xafffff,
    0xd70000, 0xd7005f, 0xd70087, 0xd700af, 0xd700d7, 0xd700ff, 0xd75f00, 0xd75f5f,
    0xd75f87, 0xd75faf, 0xd75fd7, 0xd75fff, 0xd78700, 0xd7875f, 0xd78787, 0xd787af,
    0xd787d7, 0xd787ff, 0xd7af00, 0xd7af5f, 0xd7af87, 0xd7afaf, 0xd7afd7, 0xd7afff,
    0xd7d700, 0xd7d75f, 0xd7d787, 0xd7d7af, 0xd7d7d7, 0xd7d7ff, 0xd7ff00, 0xd7ff5f,
    0xd7ff87, 0xd7ffaf, 0xd7ffd7, 0xd7ffff, 0xff0000, 0xff005f, 0xff0087, 0xff00af,
    0xff00d7, 0xff00ff, 0xff5f00, 0xff5f5f, 0xff5f87, 0xff5faf, 0xff5fd7, 0xff5fff,
    0xff8700, 0xff875f, 0xff8787, 0xff87af, 0xff87d7, 0xff87ff, 0xffaf00, 0xffaf5f,
    0xffaf87, 0xffafaf, 0xffafd7, 0xffafff, 0xffd700, 0xffd75f, 0xffd787, 0xffd7af,
    0xffd7d7, 0xffd7ff, 0xffff00, 0xffff5f, 0xffff87, 0xffffaf, 0xffffd7, 0xffffff,
    0x080808, 0x121212, 0x1c1c1c, 0x262626, 0x303030, 0x3a3a3a, 0x444444, 0x4e4e4e,
    0x585858, 0x626262, 0x6c6c6c, 0x767676, 0x808080, 0x8a8a8a, 0x949494, 0x9e9e9e,
    0xa8a8a8, 0xb2b2b2, 0xbcbcbc, 0xc6c6c6, 0xd0d0d0, 0xdadada, 0xe4e4e4, 0xeeeeee
};

#define CHARSET_DEFAULT 0
#define CHARSET_DEC_SPECIAL 1

void flanterm_context_reinit(struct flanterm_context *ctx) {
    ctx->tab_size = 8;
    ctx->autoflush = true;
    ctx->cursor_enabled = true;
    ctx->scroll_enabled = true;
    ctx->control_sequence = false;
    ctx->escape = false;
    ctx->osc = false;
    ctx->osc_escape = false;
    ctx->rrr = false;
    ctx->discard_next = false;
    ctx->bold = false;
    ctx->bg_bold = false;
    ctx->reverse_video = false;
    ctx->dec_private = false;
    ctx->insert_mode = false;
    ctx->unicode_remaining = 0;
    ctx->g_select = 0;
    ctx->charsets[0] = CHARSET_DEFAULT;
    ctx->charsets[1] = CHARSET_DEC_SPECIAL;
    ctx->current_charset = 0;
    ctx->escape_offset = 0;
    ctx->esc_values_i = 0;
    ctx->saved_cursor_x = 0;
    ctx->saved_cursor_y = 0;
    ctx->current_primary = (size_t)-1;
    ctx->current_bg = (size_t)-1;
    ctx->scroll_top_margin = 0;
    ctx->scroll_bottom_margin = ctx->rows;
    ctx->oob_output = FLANTERM_OOB_OUTPUT_ONLCR;
}

static void flanterm_putchar(struct flanterm_context *ctx, uint8_t c);

void flanterm_write(struct flanterm_context *ctx, const char *buf, size_t count) {
    for (size_t i = 0; i < count; i++) {
        flanterm_putchar(ctx, buf[i]);
    }

    if (ctx->autoflush) {
        ctx->double_buffer_flush(ctx);
    }
}

static void sgr(struct flanterm_context *ctx) {
    size_t i = 0;

    if (!ctx->esc_values_i)
        goto def;

    for (; i < ctx->esc_values_i; i++) {
        size_t offset;

        if (ctx->esc_values[i] == 0) {
def:
            if (ctx->reverse_video) {
                ctx->reverse_video = false;
                ctx->swap_palette(ctx);
            }
            ctx->bold = false;
            ctx->bg_bold = false;
            ctx->current_primary = (size_t)-1;
            ctx->current_bg = (size_t)-1;
            ctx->set_text_bg_default(ctx);
            ctx->set_text_fg_default(ctx);
            continue;
        }

        else if (ctx->esc_values[i] == 1) {
            ctx->bold = true;
            if (ctx->current_primary != (size_t)-1) {
                if (!ctx->reverse_video) {
                    ctx->set_text_fg_bright(ctx, ctx->current_primary);
                } else {
                    ctx->set_text_bg_bright(ctx, ctx->current_primary);
                }
            } else {
                if (!ctx->reverse_video) {
                    ctx->set_text_fg_default_bright(ctx);
                } else {
                    ctx->set_text_bg_default_bright(ctx);
                }
            }
            continue;
        }

        else if (ctx->esc_values[i] == 5) {
            ctx->bg_bold = true;
            if (ctx->current_bg != (size_t)-1) {
                if (!ctx->reverse_video) {
                    ctx->set_text_bg_bright(ctx, ctx->current_bg);
                } else {
                    ctx->set_text_fg_bright(ctx, ctx->current_bg);
                }
            } else {
                if (!ctx->reverse_video) {
                    ctx->set_text_bg_default_bright(ctx);
                } else {
                    ctx->set_text_fg_default_bright(ctx);
                }
            }
            continue;
        }

        else if (ctx->esc_values[i] == 22) {
            ctx->bold = false;
            if (ctx->current_primary != (size_t)-1) {
                if (!ctx->reverse_video) {
                    ctx->set_text_fg(ctx, ctx->current_primary);
                } else {
                    ctx->set_text_bg(ctx, ctx->current_primary);
                }
            } else {
                if (!ctx->reverse_video) {
                    ctx->set_text_fg_default(ctx);
                } else {
                    ctx->set_text_bg_default(ctx);
                }
            }
            continue;
        }

        else if (ctx->esc_values[i] == 25) {
            ctx->bg_bold = false;
            if (ctx->current_bg != (size_t)-1) {
                if (!ctx->reverse_video) {
                    ctx->set_text_bg(ctx, ctx->current_bg);
                } else {
                    ctx->set_text_fg(ctx, ctx->current_bg);
                }
            } else {
                if (!ctx->reverse_video) {
                    ctx->set_text_bg_default(ctx);
                } else {
                    ctx->set_text_fg_default(ctx);
                }
            }
            continue;
        }

        else if (ctx->esc_values[i] >= 30 && ctx->esc_values[i] <= 37) {
            offset = 30;
            ctx->current_primary = ctx->esc_values[i] - offset;

            if (ctx->reverse_video) {
                goto set_bg;
            }

set_fg:
            if ((ctx->bold && !ctx->reverse_video)
             || (ctx->bg_bold && ctx->reverse_video)) {
                ctx->set_text_fg_bright(ctx, ctx->esc_values[i] - offset);
            } else {
                ctx->set_text_fg(ctx, ctx->esc_values[i] - offset);
            }
            continue;
        }

        else if (ctx->esc_values[i] >= 40 && ctx->esc_values[i] <= 47) {
            offset = 40;
            ctx->current_bg = ctx->esc_values[i] - offset;

            if (ctx->reverse_video) {
                goto set_fg;
            }

set_bg:
            if ((ctx->bold && ctx->reverse_video)
             || (ctx->bg_bold && !ctx->reverse_video)) {
                ctx->set_text_bg_bright(ctx, ctx->esc_values[i] - offset);
            } else {
                ctx->set_text_bg(ctx, ctx->esc_values[i] - offset);
            }
            continue;
        }

        else if (ctx->esc_values[i] >= 90 && ctx->esc_values[i] <= 97) {
            offset = 90;
            ctx->current_primary = ctx->esc_values[i] - offset;

            if (ctx->reverse_video) {
                goto set_bg_bright;
            }

set_fg_bright:
            ctx->set_text_fg_bright(ctx, ctx->esc_values[i] - offset);
            continue;
        }

        else if (ctx->esc_values[i] >= 100 && ctx->esc_values[i] <= 107) {
            offset = 100;
            ctx->current_bg = ctx->esc_values[i] - offset;

            if (ctx->reverse_video) {
                goto set_fg_bright;
            }

set_bg_bright:
            ctx->set_text_bg_bright(ctx, ctx->esc_values[i] - offset);
            continue;
        }

        else if (ctx->esc_values[i] == 39) {
            ctx->current_primary = (size_t)-1;

            if (ctx->reverse_video) {
                ctx->swap_palette(ctx);
            }

            if (!ctx->bold) {
                ctx->set_text_fg_default(ctx);
            } else {
                ctx->set_text_fg_default_bright(ctx);
            }

            if (ctx->reverse_video) {
                ctx->swap_palette(ctx);
            }

            continue;
        }

        else if (ctx->esc_values[i] == 49) {
            ctx->current_bg = (size_t)-1;

            if (ctx->reverse_video) {
                ctx->swap_palette(ctx);
            }

            if (!ctx->bg_bold) {
                ctx->set_text_bg_default(ctx);
            } else {
                ctx->set_text_bg_default_bright(ctx);
            }

            if (ctx->reverse_video) {
                ctx->swap_palette(ctx);
            }

            continue;
        }

        else if (ctx->esc_values[i] == 7) {
            if (!ctx->reverse_video) {
                ctx->reverse_video = true;
                ctx->swap_palette(ctx);
            }
            continue;
        }

        else if (ctx->esc_values[i] == 27) {
            if (ctx->reverse_video) {
                ctx->reverse_video = false;
                ctx->swap_palette(ctx);
            }
            continue;
        }

        // 256/RGB
        else if (ctx->esc_values[i] == 38 || ctx->esc_values[i] == 48) {
            bool fg = ctx->esc_values[i] == 38;

            i++;
            if (i >= ctx->esc_values_i) {
                break;
            }

            switch (ctx->esc_values[i]) {
                case 2: { // RGB
                    if (i + 3 >= ctx->esc_values_i) {
                        goto out;
                    }

                    uint32_t rgb_value = 0;

                    rgb_value |= ctx->esc_values[i + 1] << 16;
                    rgb_value |= ctx->esc_values[i + 2] << 8;
                    rgb_value |= ctx->esc_values[i + 3];

                    i += 3;

                    (fg ? ctx->set_text_fg_rgb : ctx->set_text_bg_rgb)(ctx, rgb_value);

                    break;
                }
                case 5: { // 256 colors
                    if (i + 1 >= ctx->esc_values_i) {
                        goto out;
                    }

                    uint32_t col = ctx->esc_values[i + 1];

                    i++;

                    if (col < 8) {
                        (fg ? ctx->set_text_fg : ctx->set_text_bg)(ctx, col);
                    } else if (col < 16) {
                        (fg ? ctx->set_text_fg_bright : ctx->set_text_bg_bright)(ctx, col - 8);
                    } else if (col < 256) {
                        uint32_t rgb_value = col256[col - 16];
                        (fg ? ctx->set_text_fg_rgb : ctx->set_text_bg_rgb)(ctx, rgb_value);
                    }

                    break;
                }
                default: continue;
            }
        }
    }

out:;
}

static void dec_private_parse(struct flanterm_context *ctx, uint8_t c) {
    ctx->dec_private = false;

    if (ctx->esc_values_i == 0) {
        return;
    }

    bool set;

    switch (c) {
        case 'h':
            set = true; break;
        case 'l':
            set = false; break;
        default:
            return;
    }

    switch (ctx->esc_values[0]) {
        case 25: {
            if (set) {
                ctx->cursor_enabled = true;
            } else {
                ctx->cursor_enabled = false;
            }
            return;
        }
    }

    if (ctx->callback != NULL) {
        ctx->callback(ctx, FLANTERM_CB_DEC, ctx->esc_values_i, (uintptr_t)ctx->esc_values, c);
    }
}

static void linux_private_parse(struct flanterm_context *ctx) {
    if (ctx->esc_values_i == 0) {
        return;
    }

    if (ctx->callback != NULL) {
        ctx->callback(ctx, FLANTERM_CB_LINUX, ctx->esc_values_i, (uintptr_t)ctx->esc_values, 0);
    }
}

static void mode_toggle(struct flanterm_context *ctx, uint8_t c) {
    if (ctx->esc_values_i == 0) {
        return;
    }

    bool set;

    switch (c) {
        case 'h':
            set = true; break;
        case 'l':
            set = false; break;
        default:
            return;
    }

    switch (ctx->esc_values[0]) {
        case 4:
            ctx->insert_mode = set; return;
    }

    if (ctx->callback != NULL) {
        ctx->callback(ctx, FLANTERM_CB_MODE, ctx->esc_values_i, (uintptr_t)ctx->esc_values, c);
    }
}

static void osc_parse(struct flanterm_context *ctx, uint8_t c) {
    if (ctx->osc_escape && c == '\\') {
        goto cleanup;
    }

    ctx->osc_escape = false;

    switch (c) {
        case 0x1b:
            ctx->osc_escape = true;
            break;
        case '\a':
            goto cleanup;
    }

    return;

cleanup:
    ctx->osc_escape = false;
    ctx->osc = false;
    ctx->escape = false;
}

static void control_sequence_parse(struct flanterm_context *ctx, uint8_t c) {
    if (ctx->escape_offset == 2) {
        switch (c) {
            case '[':
                ctx->discard_next = true;
                goto cleanup;
            case '?':
                ctx->dec_private = true;
                return;
        }
    }

    if (c >= '0' && c <= '9') {
        if (ctx->esc_values_i == FLANTERM_MAX_ESC_VALUES) {
            return;
        }
        ctx->rrr = true;
        ctx->esc_values[ctx->esc_values_i] *= 10;
        ctx->esc_values[ctx->esc_values_i] += c - '0';
        return;
    }

    if (ctx->rrr == true) {
        ctx->esc_values_i++;
        ctx->rrr = false;
        if (c == ';')
            return;
    } else if (c == ';') {
        if (ctx->esc_values_i == FLANTERM_MAX_ESC_VALUES) {
            return;
        }
        ctx->esc_values[ctx->esc_values_i] = 0;
        ctx->esc_values_i++;
        return;
    }

    size_t esc_default;
    switch (c) {
        case 'J': case 'K': case 'q':
            esc_default = 0; break;
        default:
            esc_default = 1; break;
    }

    for (size_t i = ctx->esc_values_i; i < FLANTERM_MAX_ESC_VALUES; i++) {
        ctx->esc_values[i] = esc_default;
    }

    if (ctx->dec_private == true) {
        dec_private_parse(ctx, c);
        goto cleanup;
    }

    bool r = ctx->scroll_enabled;
    ctx->scroll_enabled = false;
    size_t x, y;
    ctx->get_cursor_pos(ctx, &x, &y);

    switch (c) {
        case 'F':
            x = 0;
            // FALLTHRU
        case 'A': {
            if (ctx->esc_values[0] > y)
                ctx->esc_values[0] = y;
            size_t orig_y = y;
            size_t dest_y = y - ctx->esc_values[0];
            bool will_be_in_scroll_region = false;
            if ((ctx->scroll_top_margin >= dest_y && ctx->scroll_top_margin <= orig_y)
             || (ctx->scroll_bottom_margin >= dest_y && ctx->scroll_bottom_margin <= orig_y)) {
                will_be_in_scroll_region = true;
            }
            if (will_be_in_scroll_region && dest_y < ctx->scroll_top_margin) {
                dest_y = ctx->scroll_top_margin;
            }
            ctx->set_cursor_pos(ctx, x, dest_y);
            break;
        }
        case 'E':
            x = 0;
            // FALLTHRU
        case 'e':
        case 'B': {
            if (y + ctx->esc_values[0] > ctx->rows - 1)
                ctx->esc_values[0] = (ctx->rows - 1) - y;
            size_t orig_y = y;
            size_t dest_y = y + ctx->esc_values[0];
            bool will_be_in_scroll_region = false;
            if ((ctx->scroll_top_margin >= orig_y && ctx->scroll_top_margin <= dest_y)
             || (ctx->scroll_bottom_margin >= orig_y && ctx->scroll_bottom_margin <= dest_y)) {
                will_be_in_scroll_region = true;
            }
            if (will_be_in_scroll_region && dest_y >= ctx->scroll_bottom_margin) {
                dest_y = ctx->scroll_bottom_margin - 1;
            }
            ctx->set_cursor_pos(ctx, x, dest_y);
            break;
        }
        case 'a':
        case 'C':
            if (x + ctx->esc_values[0] > ctx->cols - 1)
                ctx->esc_values[0] = (ctx->cols - 1) - x;
            ctx->set_cursor_pos(ctx, x + ctx->esc_values[0], y);
            break;
        case 'D':
            if (ctx->esc_values[0] > x)
                ctx->esc_values[0] = x;
            ctx->set_cursor_pos(ctx, x - ctx->esc_values[0], y);
            break;
        case 'c':
            if (ctx->callback != NULL) {
                ctx->callback(ctx, FLANTERM_CB_PRIVATE_ID, 0, 0, 0);
            }
            break;
        case 'd':
            ctx->esc_values[0] -= 1;
            if (ctx->esc_values[0] >= ctx->rows)
                ctx->esc_values[0] = ctx->rows - 1;
            ctx->set_cursor_pos(ctx, x, ctx->esc_values[0]);
            break;
        case 'G':
        case '`':
            ctx->esc_values[0] -= 1;
            if (ctx->esc_values[0] >= ctx->cols)
                ctx->esc_values[0] = ctx->cols - 1;
            ctx->set_cursor_pos(ctx, ctx->esc_values[0], y);
            break;
        case 'H':
        case 'f':
            if (ctx->esc_values[0] != 0) {
                ctx->esc_values[0]--;
            }
            if (ctx->esc_values[1] != 0) {
                ctx->esc_values[1]--;
            }
            if (ctx->esc_values[1] >= ctx->cols)
                ctx->esc_values[1] = ctx->cols - 1;
            if (ctx->esc_values[0] >= ctx->rows)
                ctx->esc_values[0] = ctx->rows - 1;
            ctx->set_cursor_pos(ctx, ctx->esc_values[1], ctx->esc_values[0]);
            break;
        case 'M': {
            size_t count = ctx->esc_values[0] > ctx->rows ? ctx->rows : ctx->esc_values[0];
            for (size_t i = 0; i < count; i++) {
                ctx->scroll(ctx);
            }
            break;
        }
        case 'L': {
            size_t old_scroll_top_margin = ctx->scroll_top_margin;
            ctx->scroll_top_margin = y;
            size_t count = ctx->esc_values[0] > ctx->rows ? ctx->rows : ctx->esc_values[0];
            for (size_t i = 0; i < count; i++) {
                ctx->revscroll(ctx);
            }
            ctx->scroll_top_margin = old_scroll_top_margin;
            break;
        }
        case 'n':
            switch (ctx->esc_values[0]) {
                case 5:
                    if (ctx->callback != NULL) {
                        ctx->callback(ctx, FLANTERM_CB_STATUS_REPORT, 0, 0, 0);
                    }
                    break;
                case 6:
                    if (ctx->callback != NULL) {
                        ctx->callback(ctx, FLANTERM_CB_POS_REPORT, x + 1, y + 1, 0);
                    }
                    break;
            }
            break;
        case 'q':
            if (ctx->callback != NULL) {
                ctx->callback(ctx, FLANTERM_CB_KBD_LEDS, ctx->esc_values[0], 0, 0);
            }
            break;
        case 'J':
            switch (ctx->esc_values[0]) {
                case 0: {
                    size_t rows_remaining = ctx->rows - (y + 1);
                    size_t cols_diff = ctx->cols - (x + 1);
                    size_t to_clear = rows_remaining * ctx->cols + cols_diff + 1;
                    for (size_t i = 0; i < to_clear; i++) {
                        ctx->raw_putchar(ctx, ' ');
                    }
                    ctx->set_cursor_pos(ctx, x, y);
                    break;
                }
                case 1: {
                    ctx->set_cursor_pos(ctx, 0, 0);
                    bool b = false;
                    for (size_t yc = 0; yc < ctx->rows; yc++) {
                        for (size_t xc = 0; xc < ctx->cols; xc++) {
                            ctx->raw_putchar(ctx, ' ');
                            if (xc == x && yc == y) {
                                ctx->set_cursor_pos(ctx, x, y);
                                b = true;
                                break;
                            }
                        }
                        if (b == true)
                            break;
                    }
                    break;
                }
                case 2:
                case 3:
                    ctx->clear(ctx, false);
                    break;
            }
            break;
        case '@':
            for (size_t i = ctx->cols - 1; ; i--) {
                ctx->move_character(ctx, i + ctx->esc_values[0], y, i, y);
                ctx->set_cursor_pos(ctx, i, y);
                ctx->raw_putchar(ctx, ' ');
                if (i == x) {
                    break;
                }
            }
            ctx->set_cursor_pos(ctx, x, y);
            break;
        case 'P':
            for (size_t i = x + ctx->esc_values[0]; i < ctx->cols; i++)
                ctx->move_character(ctx, i - ctx->esc_values[0], y, i, y);
            ctx->set_cursor_pos(ctx, ctx->cols - ctx->esc_values[0], y);
            // FALLTHRU
        case 'X': {
            size_t count = ctx->esc_values[0] > ctx->cols ? ctx->cols : ctx->esc_values[0];
            for (size_t i = 0; i < count; i++)
                ctx->raw_putchar(ctx, ' ');
            ctx->set_cursor_pos(ctx, x, y);
            break;
        }
        case 'm':
            sgr(ctx);
            break;
        case 's':
            ctx->get_cursor_pos(ctx, &ctx->saved_cursor_x, &ctx->saved_cursor_y);
            break;
        case 'u':
            ctx->set_cursor_pos(ctx, ctx->saved_cursor_x, ctx->saved_cursor_y);
            break;
        case 'K':
            switch (ctx->esc_values[0]) {
                case 0: {
                    for (size_t i = x; i < ctx->cols; i++)
                        ctx->raw_putchar(ctx, ' ');
                    ctx->set_cursor_pos(ctx, x, y);
                    break;
                }
                case 1: {
                    ctx->set_cursor_pos(ctx, 0, y);
                    for (size_t i = 0; i < x; i++)
                        ctx->raw_putchar(ctx, ' ');
                    break;
                }
                case 2: {
                    ctx->set_cursor_pos(ctx, 0, y);
                    for (size_t i = 0; i < ctx->cols; i++)
                        ctx->raw_putchar(ctx, ' ');
                    ctx->set_cursor_pos(ctx, x, y);
                    break;
                }
            }
            break;
        case 'r':
            if (ctx->esc_values[0] == 0) {
                ctx->esc_values[0] = 1;
            }
            if (ctx->esc_values[1] == 0) {
                ctx->esc_values[1] = 1;
            }
            ctx->scroll_top_margin = 0;
            ctx->scroll_bottom_margin = ctx->rows;
            if (ctx->esc_values_i > 0) {
                ctx->scroll_top_margin = ctx->esc_values[0] - 1;
            }
            if (ctx->esc_values_i > 1) {
                ctx->scroll_bottom_margin = ctx->esc_values[1];
            }
            if (ctx->scroll_top_margin >= ctx->rows
             || ctx->scroll_bottom_margin > ctx->rows
             || ctx->scroll_top_margin >= (ctx->scroll_bottom_margin - 1)) {
                ctx->scroll_top_margin = 0;
                ctx->scroll_bottom_margin = ctx->rows;
            }
            ctx->set_cursor_pos(ctx, 0, 0);
            break;
        case 'l':
        case 'h':
            mode_toggle(ctx, c);
            break;
        case ']':
            linux_private_parse(ctx);
            break;
    }

    ctx->scroll_enabled = r;

cleanup:
    ctx->control_sequence = false;
    ctx->escape = false;
}

static void restore_state(struct flanterm_context *ctx) {
    ctx->bold = ctx->saved_state_bold;
    ctx->bg_bold = ctx->saved_state_bg_bold;
    ctx->reverse_video = ctx->saved_state_reverse_video;
    ctx->current_charset = ctx->saved_state_current_charset;
    ctx->current_primary = ctx->saved_state_current_primary;
    ctx->current_bg = ctx->saved_state_current_bg;

    ctx->restore_state(ctx);
}

static void save_state(struct flanterm_context *ctx) {
    ctx->save_state(ctx);

    ctx->saved_state_bold = ctx->bold;
    ctx->saved_state_bg_bold = ctx->bg_bold;
    ctx->saved_state_reverse_video = ctx->reverse_video;
    ctx->saved_state_current_charset = ctx->current_charset;
    ctx->saved_state_current_primary = ctx->current_primary;
    ctx->saved_state_current_bg = ctx->current_bg;
}

static void escape_parse(struct flanterm_context *ctx, uint8_t c) {
    ctx->escape_offset++;

    if (ctx->osc == true) {
        osc_parse(ctx, c);
        return;
    }

    if (ctx->control_sequence == true) {
        control_sequence_parse(ctx, c);
        return;
    }

    size_t x, y;
    ctx->get_cursor_pos(ctx, &x, &y);

    switch (c) {
        case ']':
            ctx->osc_escape = false;
            ctx->osc = true;
            return;
        case '[':
            for (size_t i = 0; i < FLANTERM_MAX_ESC_VALUES; i++)
                ctx->esc_values[i] = 0;
            ctx->esc_values_i = 0;
            ctx->rrr = false;
            ctx->control_sequence = true;
            return;
        case '7':
            save_state(ctx);
            break;
        case '8':
            restore_state(ctx);
            break;
        case 'c':
            flanterm_context_reinit(ctx);
            ctx->clear(ctx, true);
            break;
        case 'D':
            if (y == ctx->scroll_bottom_margin - 1) {
                ctx->scroll(ctx);
                ctx->set_cursor_pos(ctx, x, y);
            } else {
                ctx->set_cursor_pos(ctx, x, y + 1);
            }
            break;
        case 'E':
            if (y == ctx->scroll_bottom_margin - 1) {
                ctx->scroll(ctx);
                ctx->set_cursor_pos(ctx, 0, y);
            } else {
                ctx->set_cursor_pos(ctx, 0, y + 1);
            }
            break;
        case 'M':
            // "Reverse linefeed"
            if (y == ctx->scroll_top_margin) {
                ctx->revscroll(ctx);
                ctx->set_cursor_pos(ctx, 0, y);
            } else {
                ctx->set_cursor_pos(ctx, 0, y - 1);
            }
            break;
        case 'Z':
            if (ctx->callback != NULL) {
                ctx->callback(ctx, FLANTERM_CB_PRIVATE_ID, 0, 0, 0);
            }
            break;
        case '(':
        case ')':
            ctx->g_select = c - '\'';
            break;
    }

    ctx->escape = false;
}

static bool dec_special_print(struct flanterm_context *ctx, uint8_t c) {
#define FLANTERM_DEC_SPCL_PRN(C) ctx->raw_putchar(ctx, (C)); return true;
    switch (c) {
        case '`': FLANTERM_DEC_SPCL_PRN(0x04)
        case '0': FLANTERM_DEC_SPCL_PRN(0xdb)
        case '-': FLANTERM_DEC_SPCL_PRN(0x18)
        case ',': FLANTERM_DEC_SPCL_PRN(0x1b)
        case '.': FLANTERM_DEC_SPCL_PRN(0x19)
        case 'a': FLANTERM_DEC_SPCL_PRN(0xb1)
        case 'f': FLANTERM_DEC_SPCL_PRN(0xf8)
        case 'g': FLANTERM_DEC_SPCL_PRN(0xf1)
        case 'h': FLANTERM_DEC_SPCL_PRN(0xb0)
        case 'j': FLANTERM_DEC_SPCL_PRN(0xd9)
        case 'k': FLANTERM_DEC_SPCL_PRN(0xbf)
        case 'l': FLANTERM_DEC_SPCL_PRN(0xda)
        case 'm': FLANTERM_DEC_SPCL_PRN(0xc0)
        case 'n': FLANTERM_DEC_SPCL_PRN(0xc5)
        case 'q': FLANTERM_DEC_SPCL_PRN(0xc4)
        case 's': FLANTERM_DEC_SPCL_PRN(0x5f)
        case 't': FLANTERM_DEC_SPCL_PRN(0xc3)
        case 'u': FLANTERM_DEC_SPCL_PRN(0xb4)
        case 'v': FLANTERM_DEC_SPCL_PRN(0xc1)
        case 'w': FLANTERM_DEC_SPCL_PRN(0xc2)
        case 'x': FLANTERM_DEC_SPCL_PRN(0xb3)
        case 'y': FLANTERM_DEC_SPCL_PRN(0xf3)
        case 'z': FLANTERM_DEC_SPCL_PRN(0xf2)
        case '~': FLANTERM_DEC_SPCL_PRN(0xfa)
        case '_': FLANTERM_DEC_SPCL_PRN(0xff)
        case '+': FLANTERM_DEC_SPCL_PRN(0x1a)
        case '{': FLANTERM_DEC_SPCL_PRN(0xe3)
        case '}': FLANTERM_DEC_SPCL_PRN(0x9c)
    }
#undef FLANTERM_DEC_SPCL_PRN

    return false;
}

// Following wcwidth related code inherited from:
// https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c

struct interval {
    uint32_t first;
    uint32_t last;
};

/* auxiliary function for binary search in interval table */
static int bisearch(uint32_t ucs, const struct interval *table, int max) {
  int min = 0;
  int mid;

  if (ucs < table[0].first || ucs > table[max].last)
    return 0;
  while (max >= min) {
    mid = (min + max) / 2;
    if (ucs > table[mid].last)
      min = mid + 1;
    else if (ucs < table[mid].first)
      max = mid - 1;
    else
      return 1;
  }

  return 0;
}

int mk_wcwidth(uint32_t ucs) {
  /* sorted list of non-overlapping intervals of non-spacing characters */
  /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
  static const struct interval combining[] = {
    { 0x0300, 0x036F }, { 0x0483, 0x0486 }, { 0x0488, 0x0489 },
    { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
    { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 },
    { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 },
    { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
    { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
    { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 0x0901, 0x0902 },
    { 0x093C, 0x093C }, { 0x0941, 0x0948 }, { 0x094D, 0x094D },
    { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, { 0x0981, 0x0981 },
    { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD },
    { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C },
    { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D },
    { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, { 0x0ABC, 0x0ABC },
    { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, { 0x0ACD, 0x0ACD },
    { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, { 0x0B3C, 0x0B3C },
    { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, { 0x0B4D, 0x0B4D },
    { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 },
    { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 },
    { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, { 0x0CBC, 0x0CBC },
    { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
    { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
    { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
    { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
    { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
    { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
    { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
    { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
    { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
    { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
    { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x135F, 0x135F },
    { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 },
    { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD },
    { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD },
    { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 },
    { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B },
    { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 },
    { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 },
    { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF },
    { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 },
    { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F },
    { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B },
    { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F },
    { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB },
    { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F },
    { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x1D167, 0x1D169 },
    { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
    { 0x1D242, 0x1D244 }, { 0xE0001, 0xE0001 }, { 0xE0020, 0xE007F },
    { 0xE0100, 0xE01EF }
  };

  /* test for 8-bit control characters */
  if (ucs == 0)
    return 0;
  if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
    return 1;

  /* binary search in table of non-spacing characters */
  if (bisearch(ucs, combining,
	       sizeof(combining) / sizeof(struct interval) - 1))
    return 0;

  /* if we arrive here, ucs is not a combining or C0/C1 control character */

  return 1 +
    (ucs >= 0x1100 &&
     (ucs <= 0x115f ||                    /* Hangul Jamo init. consonants */
      ucs == 0x2329 || ucs == 0x232a ||
      (ucs >= 0x2e80 && ucs <= 0xa4cf &&
       ucs != 0x303f) ||                  /* CJK ... Yi */
      (ucs >= 0xac00 && ucs <= 0xd7a3) || /* Hangul Syllables */
      (ucs >= 0xf900 && ucs <= 0xfaff) || /* CJK Compatibility Ideographs */
      (ucs >= 0xfe10 && ucs <= 0xfe19) || /* Vertical forms */
      (ucs >= 0xfe30 && ucs <= 0xfe6f) || /* CJK Compatibility Forms */
      (ucs >= 0xff00 && ucs <= 0xff60) || /* Fullwidth Forms */
      (ucs >= 0xffe0 && ucs <= 0xffe6) ||
      (ucs >= 0x20000 && ucs <= 0x2fffd) ||
      (ucs >= 0x30000 && ucs <= 0x3fffd)));
}

// End of https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c inherited code

static int unicode_to_cp437(uint64_t code_point) {
    switch (code_point) {
        case 0x263a: return 1;
        case 0x263b: return 2;
        case 0x2665: return 3;
        case 0x2666: return 4;
        case 0x2663: return 5;
        case 0x2660: return 6;
        case 0x2022: return 7;
        case 0x25d8: return 8;
        case 0x25cb: return 9;
        case 0x25d9: return 10;
        case 0x2642: return 11;
        case 0x2640: return 12;
        case 0x266a: return 13;
        case 0x266b: return 14;
        case 0x263c: return 15;
        case 0x25ba: return 16;
        case 0x25c4: return 17;
        case 0x2195: return 18;
        case 0x203c: return 19;
        case 0x00b6: return 20;
        case 0x00a7: return 21;
        case 0x25ac: return 22;
        case 0x21a8: return 23;
        case 0x2191: return 24;
        case 0x2193: return 25;
        case 0x2192: return 26;
        case 0x2190: return 27;
        case 0x221f: return 28;
        case 0x2194: return 29;
        case 0x25b2: return 30;
        case 0x25bc: return 31;

        case 0x2302: return 127;
        case 0x00c7: return 128;
        case 0x00fc: return 129;
        case 0x00e9: return 130;
        case 0x00e2: return 131;
        case 0x00e4: return 132;
        case 0x00e0: return 133;
        case 0x00e5: return 134;
        case 0x00e7: return 135;
        case 0x00ea: return 136;
        case 0x00eb: return 137;
        case 0x00e8: return 138;
        case 0x00ef: return 139;
        case 0x00ee: return 140;
        case 0x00ec: return 141;
        case 0x00c4: return 142;
        case 0x00c5: return 143;
        case 0x00c9: return 144;
        case 0x00e6: return 145;
        case 0x00c6: return 146;
        case 0x00f4: return 147;
        case 0x00f6: return 148;
        case 0x00f2: return 149;
        case 0x00fb: return 150;
        case 0x00f9: return 151;
        case 0x00ff: return 152;
        case 0x00d6: return 153;
        case 0x00dc: return 154;
        case 0x00a2: return 155;
        case 0x00a3: return 156;
        case 0x00a5: return 157;
        case 0x20a7: return 158;
        case 0x0192: return 159;
        case 0x00e1: return 160;
        case 0x00ed: return 161;
        case 0x00f3: return 162;
        case 0x00fa: return 163;
        case 0x00f1: return 164;
        case 0x00d1: return 165;
        case 0x00aa: return 166;
        case 0x00ba: return 167;
        case 0x00bf: return 168;
        case 0x2310: return 169;
        case 0x00ac: return 170;
        case 0x00bd: return 171;
        case 0x00bc: return 172;
        case 0x00a1: return 173;
        case 0x00ab: return 174;
        case 0x00bb: return 175;
        case 0x2591: return 176;
        case 0x2592: return 177;
        case 0x2593: return 178;
        case 0x2502: return 179;
        case 0x2524: return 180;
        case 0x2561: return 181;
        case 0x2562: return 182;
        case 0x2556: return 183;
        case 0x2555: return 184;
        case 0x2563: return 185;
        case 0x2551: return 186;
        case 0x2557: return 187;
        case 0x255d: return 188;
        case 0x255c: return 189;
        case 0x255b: return 190;
        case 0x2510: return 191;
        case 0x2514: return 192;
        case 0x2534: return 193;
        case 0x252c: return 194;
        case 0x251c: return 195;
        case 0x2500: return 196;
        case 0x253c: return 197;
        case 0x255e: return 198;
        case 0x255f: return 199;
        case 0x255a: return 200;
        case 0x2554: return 201;
        case 0x2569: return 202;
        case 0x2566: return 203;
        case 0x2560: return 204;
        case 0x2550: return 205;
        case 0x256c: return 206;
        case 0x2567: return 207;
        case 0x2568: return 208;
        case 0x2564: return 209;
        case 0x2565: return 210;
        case 0x2559: return 211;
        case 0x2558: return 212;
        case 0x2552: return 213;
        case 0x2553: return 214;
        case 0x256b: return 215;
        case 0x256a: return 216;
        case 0x2518: return 217;
        case 0x250c: return 218;
        case 0x2588: return 219;
        case 0x2584: return 220;
        case 0x258c: return 221;
        case 0x2590: return 222;
        case 0x2580: return 223;
        case 0x03b1: return 224;
        case 0x00df: return 225;
        case 0x0393: return 226;
        case 0x03c0: return 227;
        case 0x03a3: return 228;
        case 0x03c3: return 229;
        case 0x00b5: return 230;
        case 0x03c4: return 231;
        case 0x03a6: return 232;
        case 0x0398: return 233;
        case 0x03a9: return 234;
        case 0x03b4: return 235;
        case 0x221e: return 236;
        case 0x03c6: return 237;
        case 0x03b5: return 238;
        case 0x2229: return 239;
        case 0x2261: return 240;
        case 0x00b1: return 241;
        case 0x2265: return 242;
        case 0x2264: return 243;
        case 0x2320: return 244;
        case 0x2321: return 245;
        case 0x00f7: return 246;
        case 0x2248: return 247;
        case 0x00b0: return 248;
        case 0x2219: return 249;
        case 0x00b7: return 250;
        case 0x221a: return 251;
        case 0x207f: return 252;
        case 0x00b2: return 253;
        case 0x25a0: return 254;
    }

    return -1;
}

static void flanterm_putchar(struct flanterm_context *ctx, uint8_t c) {
    if (ctx->discard_next || (c == 0x18 || c == 0x1a)) {
        ctx->discard_next = false;
        ctx->escape = false;
        ctx->control_sequence = false;
        ctx->unicode_remaining = 0;
        ctx->osc = false;
        ctx->osc_escape = false;
        ctx->g_select = 0;
        return;
    }

    if (ctx->unicode_remaining != 0) {
        if ((c & 0xc0) != 0x80) {
            ctx->unicode_remaining = 0;
            goto unicode_error;
        }

        ctx->unicode_remaining--;
        ctx->code_point |= (uint64_t)(c & 0x3f) << (6 * ctx->unicode_remaining);
        if (ctx->unicode_remaining != 0) {
            return;
        }

        int cc = unicode_to_cp437(ctx->code_point);

        if (cc == -1) {
            size_t replacement_width = (size_t)mk_wcwidth(ctx->code_point);
            if (replacement_width > 0) {
                ctx->raw_putchar(ctx, 0xfe);
            }
            for (size_t i = 1; i < replacement_width; i++) {
                ctx->raw_putchar(ctx, ' ');
            }
        } else {
            ctx->raw_putchar(ctx, cc);
        }
        return;
    }

unicode_error:
    if (c >= 0xc0 && c <= 0xf7) {
        if (c >= 0xc0 && c <= 0xdf) {
            ctx->unicode_remaining = 1;
            ctx->code_point = (uint64_t)(c & 0x1f) << 6;
        } else if (c >= 0xe0 && c <= 0xef) {
            ctx->unicode_remaining = 2;
            ctx->code_point = (uint64_t)(c & 0x0f) << (6 * 2);
        } else if (c >= 0xf0 && c <= 0xf7) {
            ctx->unicode_remaining = 3;
            ctx->code_point = (uint64_t)(c & 0x07) << (6 * 3);
        }
        return;
    }

    if (ctx->escape == true) {
        escape_parse(ctx, c);
        return;
    }

    if (ctx->g_select) {
        ctx->g_select--;
        switch (c) {
            case 'B':
                ctx->charsets[ctx->g_select] = CHARSET_DEFAULT; break;
            case '0':
                ctx->charsets[ctx->g_select] = CHARSET_DEC_SPECIAL; break;
        }
        ctx->g_select = 0;
        return;
    }

    size_t x, y;
    ctx->get_cursor_pos(ctx, &x, &y);

    switch (c) {
        case 0x00:
        case 0x7f:
            return;
        case 0x1b:
            ctx->escape_offset = 0;
            ctx->escape = true;
            return;
        case '\t':
            if ((x / ctx->tab_size + 1) >= ctx->cols) {
                ctx->set_cursor_pos(ctx, ctx->cols - 1, y);
                return;
            }
            ctx->set_cursor_pos(ctx, (x / ctx->tab_size + 1) * ctx->tab_size, y);
            return;
        case 0x0b:
        case 0x0c:
        case '\n':
            if (y == ctx->scroll_bottom_margin - 1) {
                ctx->scroll(ctx);
                ctx->set_cursor_pos(ctx, (ctx->oob_output & FLANTERM_OOB_OUTPUT_ONLCR) ? 0 : x, y);
            } else {
                ctx->set_cursor_pos(ctx, (ctx->oob_output & FLANTERM_OOB_OUTPUT_ONLCR) ? 0 : x, y + 1);
            }
            return;
        case '\b':
            ctx->set_cursor_pos(ctx, x - 1, y);
            return;
        case '\r':
            ctx->set_cursor_pos(ctx, 0, y);
            return;
        case '\a':
            // The bell is handled by the kernel
            if (ctx->callback != NULL) {
                ctx->callback(ctx, FLANTERM_CB_BELL, 0, 0, 0);
            }
            return;
        case 14:
            // Move to G1 set
            ctx->current_charset = 1;
            return;
        case 15:
            // Move to G0 set
            ctx->current_charset = 0;
            return;
    }

    if (ctx->insert_mode == true) {
        for (size_t i = ctx->cols - 1; ; i--) {
            ctx->move_character(ctx, i + 1, y, i, y);
            if (i == x) {
                break;
            }
        }
    }

    // Translate character set
    switch (ctx->charsets[ctx->current_charset]) {
        case CHARSET_DEFAULT:
            break;
        case CHARSET_DEC_SPECIAL:
            if (dec_special_print(ctx, c)) {
                return;
            }
            break;
    }

    if (c >= 0x20 && c <= 0x7e) {
        ctx->raw_putchar(ctx, c);
    } else {
        ctx->raw_putchar(ctx, 0xfe);
    }
}