REPL debugger integrated into LÖVR error handler

repl.lua

local lovr = lovr
local dbg = require'debugger' -- https://codeberg.org/slembcke/debugger.lua - tested against 101cab55a4

dbg.auto_where = 4
dbg.use_color(true)

local DEFAULT_COLOR = {1, 1, 1}
local ANSI_COLORS = {
['0'] = {0.933, 0.867, 0.722},
['97'] = {0.933, 0.867, 0.722},
['30'] = {0.098, 0.090, 0.118},
['31'] = {0.773, 0.267, 0.231},
['32'] = {0.349, 0.482, 0.384},
['33'] = {0.631, 0.373, 0.302},
['34'] = {0.478, 0.537, 0.600},
['35'] = {0.882, 0.420, 0.357},
['36'] = {0.596, 0.678, 0.718},
['37'] = {0.933, 0.867, 0.722},
['90'] = {0.165, 0.122, 0.133},
['91'] = {0.965, 0.714, 0.294},
['92'] = {0.247, 0.161, 0.169},
['93'] = {0.792, 0.525, 0.416},
['94'] = {0.380, 0.231, 0.216},
['95'] = {0.890, 714, 0.553},
['96'] = {0.455, 0.624, 0.455}
}

local ESC = string.char(27)

local output_lines = {} -- list of { type='text'|'newline', chunks={color, string, ...} }
local current_parse_color = DEFAULT_COLOR

local history = {}
local history_index = 0
local temp_line = ""

local function parse_ansi(str)
  local result = {}
  local last_pos = 1

  for start_idx, code, end_idx in str:gmatch("()" .. ESC .. "%[(%d+)m()") do
    if start_idx > last_pos then
      local color = current_parse_color
      if type(color) ~= 'table' then color = DEFAULT_COLOR end
      table.insert(result, color)
      table.insert(result, str:sub(last_pos, start_idx - 1))
    end

    local new_color = ANSI_COLORS[code]
    if new_color then
      current_parse_color = new_color
    elseif code == '0' then
      current_parse_color = ANSI_COLORS['0'] or DEFAULT_COLOR
    end
    last_pos = end_idx
  end

  if last_pos <= #str then
    local color = current_parse_color
    if type(color) ~= 'table' then color = DEFAULT_COLOR end
    table.insert(result, color)
    table.insert(result, str:sub(last_pos))
  end

  return result
end

function dbg.write(str)
  local parts = {}
  local last_idx = 1
  for idx in str:gmatch("()\n") do
    table.insert(parts, str:sub(last_idx, idx - 1))
    table.insert(parts, "\n")
    last_idx = idx + 1
  end
  if last_idx <= #str then
    table.insert(parts, str:sub(last_idx))
  end

  for _, part in ipairs(parts) do
    if part == "\n" then
      table.insert(output_lines, {type='newline'})
    else
      local colored_chunks = parse_ansi(part)
      if #output_lines == 0 or output_lines[#output_lines].type == 'newline' then
        table.insert(output_lines, {type='text', chunks=colored_chunks})
      else
        local last = output_lines[#output_lines]
        for _, chunk in ipairs(colored_chunks) do
          table.insert(last.chunks, chunk)
        end
      end
    end
  end

  while #output_lines > 60 do table.remove(output_lines, 1) end
end

local function get_render_text(line, cursor_pos)
  local full_text_table = {}
  local current_render_color = ANSI_COLORS['0'] or DEFAULT_COLOR

  local function add_chunk(color, text)
    if type(text) ~= 'string' or text == "" then return end

    if type(color) ~= 'table' then color = current_render_color end
    if type(color) ~= 'table' then color = DEFAULT_COLOR end

    current_render_color = color

    local n = #full_text_table
    if n > 1 and full_text_table[n-1] == color then
      full_text_table[n] = full_text_table[n] .. text
    else
      table.insert(full_text_table, {color, text})
    end
  end

  for _, line_obj in ipairs(output_lines) do
    if line_obj.type == 'text' then
      local n = #line_obj.chunks
      for i = 1, n, 2 do
        local c = line_obj.chunks[i]
        local t = line_obj.chunks[i+1]
        add_chunk(c, t)
      end
    elseif line_obj.type == 'newline' then
      add_chunk(current_render_color, "\n")
    end
  end

  local left = line:sub(1, cursor_pos - 1)
  local right = line:sub(cursor_pos)
  add_chunk(ANSI_COLORS['0'] or DEFAULT_COLOR, left)
  add_chunk({1, 1, 0}, "|")
  add_chunk(DEFAULT_COLOR, right)

  return full_text_table
end

local function render_console(line, cursor_pos)
  if lovr.headset and lovr.headset.isActive() then
    lovr.headset.update()
    local pass = lovr.headset.getPass()
    if pass then
      pass:setDepthTest(nil)
      pass:setDepthWrite(false)
      pass:setColor(0.1, 0.1, 0.12, 1.0)
      pass:plane(0, 1.7, -2.01, 2.0, 1.4)
      pass:setColor(1, 1, 1, 1)
      local colored_text = get_render_text(line, cursor_pos)
      pass:text(colored_text, -0.9, 1.1, -2.0, 0.02, 0, 0, 0, 0, 90, 'left', 'bottom')
      lovr.graphics.submit(pass)
      lovr.headset.submit()
    end
  end

  if lovr.system.isWindowOpen() then
    local pass = lovr.graphics.getWindowPass()
    if pass then
      pass:setDepthTest(nil)
      pass:setDepthWrite(false)
      pass:setColor(0.05, 0.05, 0.05)
      local w, h = lovr.system.getWindowDimensions()
      pass:setProjection(1, mat4():orthographic(w, h))
      pass:plane(0, 0, 0.5, w, h)
      pass:setColor(1, 1, 1, 1)
      local colored_text = get_render_text(line, cursor_pos)
      local fontSize = 20
      pass:text(colored_text, 100, h - 100, 0, fontSize, 0, 0, 0, 0, w - 20, 'left', 'bottom')
      lovr.graphics.submit(pass)
      lovr.graphics.present()
    end
  end
end

function dbg.read(prompt)
  dbg.write('\n' .. prompt)
  local line = ""
  local pos = 1
  lovr.system.pollEvents()
  while true do
    if lovr.system then lovr.system.pollEvents() end
    if lovr.headset then lovr.headset.pollEvents() end
    for name, a in lovr.event.poll() do
      local ctrl = lovr.system.isKeyDown('lctrl') or lovr.system.isKeyDown('rctrl')
      if name == 'quit' or lovr.system.isKeyDown('escape') then return 'q'
      elseif name == 'restart' or name == 'filechanged' or (name == 'keypressed' and a == 'f5') then
        lovr.restart()
      elseif name == 'keypressed' then
        if a == 'return' then
          dbg.write(line .. "\n")
          if #line > 0 and line ~= history[#history] then
            table.insert(history, line)
          end
          history_index = 0
          return line
        elseif a == 'backspace' then
          if pos > 1 then
            line = line:sub(1, pos - 2) .. line:sub(pos)
            pos = pos - 1
          end
        elseif a == 'delete' then
          if pos <= #line then
            line = line:sub(1, pos - 1) .. line:sub(pos + 1)
          end
        elseif a == 'left' then
          pos = math.max(1, pos - 1)
        elseif a == 'right' then
          pos = math.min(#line + 1, pos + 1)
        elseif a == 'home' or (a == 'a' and ctrl) then
          pos = 1
        elseif a == 'end' or (a == 'e' and ctrl) then
          pos = #line + 1
        elseif a == 'w' and ctrl then
          local left = line:sub(1, pos - 1)
          local right = line:sub(pos)
          local new_left = left:gsub("%s*[%w_]+%s*$", "")
          line = new_left .. right
          pos = #new_left + 1
        elseif a == 'u' and ctrl then
          line = line:sub(pos)
          pos = 1
        elseif a == 'k' and ctrl then
          line = line:sub(1, pos - 1)
        elseif a == 'up' then
          if history_index < #history then
            if history_index == 0 then temp_line = line end
            history_index = history_index + 1
            line = history[#history - history_index + 1]
            pos = #line + 1
          end
        elseif a == 'down' then
          if history_index > 0 then
            history_index = history_index - 1
            if history_index == 0 then
              line = temp_line
            else
              line = history[#history - history_index + 1]
            end
            pos = #line + 1
          end
        elseif a == 'v' and ctrl then
           if lovr.system.getClipboardText then
             local text = lovr.system.getClipboardText()
             if text then
               line = line:sub(1, pos - 1) .. text .. line:sub(pos)
               pos = pos + #text
             end
           end
        end
      elseif name == 'textinput' then
        line = line:sub(1, pos - 1) .. a .. line:sub(pos)
        pos = pos + #a
      end
    end
    render_console(line, pos)
    lovr.timer.sleep(0.01)
  end
end

function lovr.errhand(msg)
  local trace = debug.traceback(msg, 4)
  print(trace)
  dbg.write(ESC .. "[91m" .. "Error:\n" .. ESC .. "[0m")
  dbg.write(trace .. "\n\n")
  dbg(false, 3, "error")
  lovr.event.push('quit')
end

return dbg