path: root/Terminal/Terminal.cpp

#include "Terminal.h"
#include <AK/AKString.h>
#include <SharedGraphics/Font.h>
#include <SharedGraphics/Painter.h>
#include <AK/StdLibExtras.h>
#include <LibC/stdlib.h>
#include <LibC/unistd.h>
#include <LibC/stdio.h>
#include <LibC/gui.h>

//#define TERMINAL_DEBUG

struct Stopwatch {
public:
    Stopwatch(const char* name)
        : m_name(name)
    {
        read_tsc(&m_start_lsw, &m_start_msw);
    }

    ~Stopwatch()
    {
        dword end_lsw;
        dword end_msw;
        read_tsc(&end_lsw, &end_msw);
        if (m_start_msw != end_msw) {
            dbgprintf("stopwatch: differing msw, no result for %s\n", m_name);
        }
        dword diff = end_lsw - m_start_lsw;
        dbgprintf("Stopwatch(%s): %u ticks\n", m_name, diff);
    }

private:
    const char* m_name { nullptr };
    dword m_start_lsw { 0 };
    dword m_start_msw { 0 };
};


void Terminal::create_window()
{
    m_pixel_width = m_columns * font().glyph_width() + m_inset * 2;
    m_pixel_height = (m_rows * (font().glyph_height() + m_line_spacing)) + (m_inset * 2) - m_line_spacing;

    GUI_WindowParameters params;
    params.rect = { { 300, 300 }, { m_pixel_width, m_pixel_height } };
    params.background_color = 0x000000;
    strcpy(params.title, "Terminal");
    m_window_id = gui_create_window(&params);
    ASSERT(m_window_id > 0);
    if (m_window_id < 0) {
        perror("gui_create_window");
        exit(1);
    }

    // NOTE: We never release the backing store.
    GUI_WindowBackingStoreInfo info;
    int rc = gui_get_window_backing_store(m_window_id, &info);
    if (rc < 0) {
        perror("gui_get_window_backing_store");
        exit(1);
    }

    m_backing = GraphicsBitmap::create_wrapper(info.size, info.pixels);
    dbgprintf("(Terminal:%d) window backing %ux%u @ %p\n", getpid(), info.size.width, info.size.height, info.pixels);

}

Terminal::Terminal()
    : m_font(Font::default_font())
{
    m_line_height = font().glyph_height() + m_line_spacing;

    set_size(80, 25);
    m_horizontal_tabs = static_cast<byte*>(malloc(columns()));
    for (unsigned i = 0; i < columns(); ++i)
        m_horizontal_tabs[i] = (i % 8) == 0;
    // Rightmost column is always last tab on line.
    m_horizontal_tabs[columns() - 1] = 1;

    m_lines = new Line*[rows()];
    for (size_t i = 0; i < rows(); ++i)
        m_lines[i] = new Line(columns());
}

Terminal::Line::Line(word columns)
    : length(columns)
{
    characters = new byte[length];
    attributes = new Attribute[length];
    needs_invalidation = false;
    memset(characters, ' ', length);
}

Terminal::Line::~Line()
{
    delete [] characters;
    delete [] attributes;
}

void Terminal::Line::clear()
{
    dirty = true;
    memset(characters, ' ', length);
    for (word i = 0 ; i < length; ++i)
        attributes[i].reset();
}

Terminal::~Terminal()
{
    for (size_t i = 0; i < m_rows; ++i)
        delete m_lines[i];
    delete [] m_lines;
    free(m_horizontal_tabs);
}

void Terminal::clear()
{
    for (size_t i = 0; i < rows(); ++i)
        line(i).clear();
    set_cursor(0, 0);
}

inline bool is_valid_parameter_character(byte ch)
{
    return ch >= 0x30 && ch <= 0x3f;
}

inline bool is_valid_intermediate_character(byte ch)
{
    return ch >= 0x20 && ch <= 0x2f;
}

inline bool is_valid_final_character(byte ch)
{
    return ch >= 0x40 && ch <= 0x7e;
}

unsigned parseUInt(const String& str, bool& ok)
{
    unsigned value = 0;
    for (size_t i = 0; i < str.length(); ++i) {
        if (str[i] < '0' || str[i] > '9') {
            ok = false;
            return 0;
        }
        value = value * 10;
        value += str[i] - '0';
    }
    ok = true;
    return value;
}

enum ANSIColor : byte {
    Black = 0,
    Red,
    Green,
    Brown,
    Blue,
    Magenta,
    Cyan,
    LightGray,
    DarkGray,
    BrightRed,
    BrightGreen,
    Yellow,
    BrightBlue,
    BrightMagenta,
    BrightCyan,
    White,
};

static inline Color ansi_color(unsigned color)
{
    static const RGBA32 s_ansi_color[16] = {
        make_rgb(0, 0, 0),          // Black
        make_rgb(225, 56, 43),      // Red
        make_rgb(57, 181, 74),      // Green
        make_rgb(255, 199, 6),      // Brown
        make_rgb(0, 111, 184),      // Blue
        make_rgb(118, 38, 113),     // Magenta
        make_rgb(44, 181, 233),     // Cyan
        make_rgb(204, 204, 204),    // LightGray
        make_rgb(128, 128, 128),    // DarkGray
        make_rgb(255, 0, 0),        // BrightRed
        make_rgb(0, 255, 0),        // BrightGreen
        make_rgb(255, 255, 0),      // Yellow
        make_rgb(0, 0, 255),        // BrightBlue
        make_rgb(255, 0, 255),      // BrightMagenta
        make_rgb(0, 255, 255),      // BrightCyan
        make_rgb(255, 255, 255),    // White
    };
    return s_ansi_color[color];
}

void Terminal::escape$m(const Vector<unsigned>& params)
{
    for (auto param : params) {
        switch (param) {
        case 0:
            // Reset
            m_current_attribute.reset();
            break;
        case 1:
            // Bold
            //m_current_attribute.bold = true;
            break;
        case 30:
        case 31:
        case 32:
        case 33:
        case 34:
        case 35:
        case 36:
        case 37:
            // Foreground color
            m_current_attribute.foreground_color = param - 30;
            break;
        case 40:
        case 41:
        case 42:
        case 43:
        case 44:
        case 45:
        case 46:
        case 47:
            // Background color
            m_current_attribute.background_color = param - 30;
            break;
        }
    }
}

void Terminal::escape$s(const Vector<unsigned>&)
{
    m_saved_cursor_row = m_cursor_row;
    m_saved_cursor_column = m_cursor_column;
}

void Terminal::escape$u(const Vector<unsigned>&)
{
    set_cursor(m_saved_cursor_row, m_saved_cursor_column);
}

void Terminal::escape$H(const Vector<unsigned>& params)
{
    unsigned row = 1;
    unsigned col = 1;
    if (params.size() >= 1)
        row = params[0];
    if (params.size() >= 2)
        col = params[1];
    set_cursor(row - 1, col - 1);
}

void Terminal::escape$A(const Vector<unsigned>& params)
{
    int num = 1;
    if (params.size() >= 1)
        num = params[0];
    if (num == 0)
        num = 1;
    int new_row = (int)m_cursor_row - num;
    if (new_row < 0)
        new_row = 0;
    set_cursor(new_row, m_cursor_column);
}

void Terminal::escape$B(const Vector<unsigned>& params)
{
    int num = 1;
    if (params.size() >= 1)
        num = params[0];
    if (num == 0)
        num = 1;
    int new_row = (int)m_cursor_row + num;
    if (new_row >= m_rows)
        new_row = m_rows - 1;
    set_cursor(new_row, m_cursor_column);
}

void Terminal::escape$C(const Vector<unsigned>& params)
{
    int num = 1;
    if (params.size() >= 1)
        num = params[0];
    if (num == 0)
        num = 1;
    int new_column = (int)m_cursor_column + num;
    if (new_column >= m_columns)
        new_column = m_columns - 1;
    set_cursor(m_cursor_row, new_column);
}

void Terminal::escape$D(const Vector<unsigned>& params)
{
    int num = 1;
    if (params.size() >= 1)
        num = params[0];
    if (num == 0)
        num = 1;
    int new_column = (int)m_cursor_column - num;
    if (new_column < 0)
        new_column = 0;
    set_cursor(m_cursor_row, new_column);
}

void Terminal::escape$K(const Vector<unsigned>& params)
{
    int mode = 0;
    if (params.size() >= 1)
        mode = params[0];
    switch (mode) {
    case 0:
        for (int i = m_cursor_column; i < m_columns; ++i) {
            put_character_at(m_cursor_row, i, ' ');
        }
        break;
    case 1:
        // FIXME: Clear from cursor to beginning of screen.
        notImplemented();
        break;
    case 2:
        notImplemented();
        break;
    default:
        notImplemented();
        break;
    }
}

void Terminal::escape$J(const Vector<unsigned>& params)
{
    int mode = 0;
    if (params.size() >= 1)
        mode = params[0];
    switch (mode) {
    case 0:
        // FIXME: Clear from cursor to end of screen.
        notImplemented();
        break;
    case 1:
        // FIXME: Clear from cursor to beginning of screen.
        notImplemented();
        break;
    case 2:
        clear();
        break;
    case 3:
        // FIXME: <esc>[3J should also clear the scrollback buffer.
        clear();
        break;
    default:
        notImplemented();
        break;
    }
}

void Terminal::execute_xterm_command()
{
    bool ok;
    unsigned value = parseUInt(String((const char*)m_xterm_param1.data(), m_xterm_param1.size()), ok);
    if (ok) {
        switch (value) {
        case 0:
            set_window_title(String((const char*)m_xterm_param2.data(), m_xterm_param2.size()));
            break;
        default:
            notImplemented();
            break;
        }
    }
    m_xterm_param1.clear_with_capacity();
    m_xterm_param2.clear_with_capacity();
}

void Terminal::execute_escape_sequence(byte final)
{
    auto paramparts = String((const char*)m_parameters.data(), m_parameters.size()).split(';');
    Vector<unsigned> params;
    for (auto& parampart : paramparts) {
        bool ok;
        unsigned value = parseUInt(parampart, ok);
        if (!ok) {
            // FIXME: Should we do something else?
            return;
        }
        params.append(value);
    }
    switch (final) {
    case 'A': escape$A(params); break;
    case 'B': escape$B(params); break;
    case 'C': escape$C(params); break;
    case 'D': escape$D(params); break;
    case 'H': escape$H(params); break;
    case 'J': escape$J(params); break;
    case 'K': escape$K(params); break;
    case 'm': escape$m(params); break;
    case 's': escape$s(params); break;
    case 'u': escape$u(params); break;
    default:
        dbgprintf("Terminal::execute_escape_sequence: Unhandled final '%c'\n", final);
        break;
    }

    m_parameters.clear();
    m_intermediates.clear();
}

void Terminal::scroll_up()
{
    word new_row = m_cursor_row;
    if (m_cursor_row == (rows() - 1)) {
        // NOTE: We have to invalidate the cursor first.
        invalidate_cursor();
        delete m_lines[0];
        for (word row = 1; row < rows(); ++row)
            m_lines[row - 1] = m_lines[row];
        m_lines[m_rows - 1] = new Line(m_columns);
        ++m_rows_to_scroll_backing_store;
    } else {
        ++new_row;
    }
    set_cursor(new_row, 0);
}

void Terminal::set_cursor(unsigned row, unsigned column)
{
    if (row == m_cursor_row && column == m_cursor_column)
        return;
    ASSERT(row < rows());
    ASSERT(column < columns());
    invalidate_cursor();
    m_cursor_row = row;
    m_cursor_column = column;
    if (column != columns() - 1)
        m_stomp = false;
    invalidate_cursor();
}

void Terminal::put_character_at(unsigned row, unsigned column, byte ch)
{
    ASSERT(row < rows());
    ASSERT(column < columns());
    line(row).characters[column] = ch;
    line(row).attributes[column] = m_current_attribute;
}

void Terminal::on_char(byte ch)
{
#ifdef TERMINAL_DEBUG
    dbgprintf("Terminal::on_char: %b (%c)\n", ch, ch);
#endif
    switch (m_escape_state) {
    case ExpectBracket:
        if (ch == '[')
            m_escape_state = ExpectParameter;
        else if (ch == ']')
            m_escape_state = ExpectXtermParameter1;
        else
            m_escape_state = Normal;
        return;
    case ExpectXtermParameter1:
        if (ch != ';') {
            m_xterm_param1.append(ch);
            return;
        }
        m_escape_state = ExpectXtermParameter2;
        return;
    case ExpectXtermParameter2:
        if (ch != '\007') {
            m_xterm_param2.append(ch);
            return;
        }
        m_escape_state = ExpectXtermFinal;
        // fall through
    case ExpectXtermFinal:
        m_escape_state = Normal;
        if (ch == '\007')
            execute_xterm_command();
        return;

    case ExpectParameter:
        if (is_valid_parameter_character(ch)) {
            m_parameters.append(ch);
            return;
        }
        m_escape_state = ExpectIntermediate;
        // fall through
    case ExpectIntermediate:
        if (is_valid_intermediate_character(ch)) {
            m_intermediates.append(ch);
            return;
        }
        m_escape_state = ExpectFinal;
        // fall through
    case ExpectFinal:
        if (is_valid_final_character(ch)) {
            m_escape_state = Normal;
            execute_escape_sequence(ch);
            return;
        }
        m_escape_state = Normal;
        return;
    case Normal:
        break;
    }

    switch (ch) {
    case '\0':
        return;
    case '\033':
        m_escape_state = ExpectBracket;
        return;
    case 8: // Backspace
        if (m_cursor_column) {
            set_cursor(m_cursor_row, m_cursor_column - 1);
            put_character_at(m_cursor_row, m_cursor_column, ' ');
            return;
        }
        return;
    case '\a':
        // FIXME: Bell!
        return;
    case '\t': {
        for (unsigned i = m_cursor_column; i < columns(); ++i) {
            if (m_horizontal_tabs[i]) {
                set_cursor(m_cursor_row, i);
                return;
            }
        }
        return;
    }
    case '\r':
        set_cursor(m_cursor_row, 0);
        return;
    case '\n':
        scroll_up();
        return;
    }

    auto new_column = m_cursor_column + 1;
    if (new_column < columns()) {
        put_character_at(m_cursor_row, m_cursor_column, ch);
        set_cursor(m_cursor_row, new_column);
    } else {
        if (m_stomp) {
            m_stomp = false;
            scroll_up();
            put_character_at(m_cursor_row, m_cursor_column, ch);
            set_cursor(m_cursor_row, 1);
        } else {
            // Curious: We wait once on the right-hand side
            m_stomp = true;
            put_character_at(m_cursor_row, m_cursor_column, ch);
        }
    }
}

void Terminal::set_size(word columns, word rows)
{
    m_columns = columns;
    m_rows = rows;
}

Rect Terminal::glyph_rect(word row, word column)
{
    int y = row * m_line_height;
    int x = column * font().glyph_width();
    return { x + m_inset, y + m_inset, font().glyph_width(), font().glyph_height() };
}

Rect Terminal::row_rect(word row)
{
    int y = row * m_line_height;
    return { m_inset, y + m_inset, font().glyph_width() * m_columns, font().glyph_height() };
}

inline Terminal::Attribute& Terminal::attribute_at(word row, word column)
{
    ASSERT(row < m_rows);
    ASSERT(column < m_columns);
    return line(row).attributes[column];
}

bool Terminal::Line::has_only_one_background_color() const
{
    if (!length)
        return true;
    // FIXME: Cache this result?
    auto color = attributes[0].background_color;
    for (size_t i = 1; i < length; ++i) {
        if (attributes[i].background_color != color)
            return false;
    }
    return true;
}

void Terminal::paint()
{
    Stopwatch sw("Terminal::paint");
    Rect rect { 0, 0, m_pixel_width, m_pixel_height };
    Painter painter(*m_backing);

    for (size_t i = 0; i < rows(); ++i)
        line(i).needs_invalidation = false;

    if (m_rows_to_scroll_backing_store && m_rows_to_scroll_backing_store < m_rows) {
        int first_scanline = m_inset;
        int second_scanline = m_inset + (m_rows_to_scroll_backing_store * m_line_height);
        int num_rows_to_memcpy = m_rows - m_rows_to_scroll_backing_store;
        int scanlines_to_copy = (num_rows_to_memcpy * m_line_height) - m_line_spacing;
        fast_dword_copy(
            m_backing->scanline(first_scanline),
            m_backing->scanline(second_scanline),
            scanlines_to_copy * m_pixel_width
        );
        m_need_full_invalidation = true;
        line(max(0, m_cursor_row - m_rows_to_scroll_backing_store)).dirty = true;
    }
    m_rows_to_scroll_backing_store = 0;

    for (word row = 0; row < m_rows; ++row) {
        auto& line = this->line(row);
        if (!line.dirty)
            continue;
        line.dirty = false;
        bool has_only_one_background_color = line.has_only_one_background_color();
        if (has_only_one_background_color)
            painter.fill_rect(row_rect(row), line.attributes[0].background_color);
        for (word column = 0; column < m_columns; ++column) {
            auto& attribute = line.attributes[column];
            line.needs_invalidation = true;
            char ch = line.characters[column];
            auto character_rect = glyph_rect(row, column);
            if (!has_only_one_background_color) {
                auto character_background = ansi_color(attribute.background_color);
                painter.fill_rect(character_rect, character_background);
            }
            if (ch == ' ')
                continue;
            painter.draw_glyph(character_rect.location(), ch, ansi_color(attribute.foreground_color));
        }
    }

    auto cursor_rect = glyph_rect(m_cursor_row, m_cursor_column);
    if (m_in_active_window)
        painter.fill_rect(cursor_rect, Color::MidGray);
    else
        painter.draw_rect(cursor_rect, Color::MidGray);

    line(m_cursor_row).needs_invalidation = true;

    if (m_belling) {
        m_need_full_invalidation = true;
        painter.draw_rect(rect, Color::Red);
    }

    if (m_need_full_invalidation) {
        invalidate_window();
        m_need_full_invalidation = false;
        return;
    }

    Rect invalidation_rect;
    for (int i = 0; i < m_rows; ++i) {
        if (line(i).needs_invalidation)
            invalidation_rect = invalidation_rect.united(row_rect(i));
    }
    invalidate_window(invalidation_rect);
}

void Terminal::invalidate_window(const Rect& a_rect)
{
    GUI_Rect rect = a_rect;
    int rc = gui_invalidate_window(m_window_id, a_rect.is_null() ? nullptr : &rect);
    if (rc < 0) {
        perror("gui_invalidate_window");
        exit(1);
    }
}

void Terminal::set_window_title(const String& title)
{
    int rc = gui_set_window_title(m_window_id, title.characters(), title.length());
    if (rc < 0) {
        perror("gui_set_window_title");
        exit(1);
    }
}

void Terminal::set_in_active_window(bool b)
{
    if (m_in_active_window == b)
        return;
    m_in_active_window = b;
    invalidate_cursor();
    paint();
}

void Terminal::invalidate_cursor()
{
    line(m_cursor_row).dirty = true;
}