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path: root/tests/modules/timportexcept.nim
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discard """
  line: 9
  errormsg: "undeclared identifier: '%'"
"""

import strutils except `%`

# doesn't work
echo "$1" % "abc"
224' href='#n224'>224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
-- primitives for editing drawings
Drawing = {}
geom = require 'geom'

function Drawing.draw(line, y)
  local pmx,pmy = love.mouse.getX(), love.mouse.getY()
  if pmx < 16+Drawing_width and pmy > line.y and pmy < line.y+Drawing.pixels(line.h) then
    love.graphics.setColor(0.75,0.75,0.75)
    love.graphics.rectangle('line', 16,line.y, Drawing_width,Drawing.pixels(line.h))
    if icon[Current_drawing_mode] then
      icon[Current_drawing_mode](16+Drawing_width-20, line.y+4)
    else
      icon[Previous_drawing_mode](16+Drawing_width-20, line.y+4)
    end

    if love.mouse.isDown('1') and love.keyboard.isDown('h') then
      draw_help_with_mouse_pressed(line)
      return
    end
  end

  if line.show_help then
    draw_help_without_mouse_pressed(line)
    return
  end

  local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-line.y)

  for _,shape in ipairs(line.shapes) do
    assert(shape)
    if geom.on_shape(mx,my, line, shape) then
      love.graphics.setColor(1,0,0)
    else
      love.graphics.setColor(0,0,0)
    end
    Drawing.draw_shape(16,line.y, line, shape)
  end
  for _,p in ipairs(line.points) do
    if p.deleted == nil then
      if Drawing.near(p, mx,my) then
        love.graphics.setColor(1,0,0)
        love.graphics.circle('line', Drawing.pixels(p.x)+16,Drawing.pixels(p.y)+line.y, 4)
      else
        love.graphics.setColor(0,0,0)
        love.graphics.circle('fill', Drawing.pixels(p.x)+16,Drawing.pixels(p.y)+line.y, 2)
      end
    end
  end
  Drawing.draw_pending_shape(16,line.y, line)
end

function Drawing.in_drawing(drawing, x,y)
  return y >= drawing.y and y < drawing.y + Drawing.pixels(drawing.h) and x >= 16 and x < 16+Drawing_width
end

function Drawing.mouse_pressed(drawing, x,y, button)
  if Current_drawing_mode == 'freehand' then
    drawing.pending = {mode=Current_drawing_mode, points={{x=Drawing.coord(x-16), y=Drawing.coord(y-drawing.y)}}}
  elseif Current_drawing_mode == 'line' or Current_drawing_mode == 'manhattan' then
    local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
    drawing.pending = {mode=Current_drawing_mode, p1=j}
  elseif Current_drawing_mode == 'polygon' then
    local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
    drawing.pending = {mode=Current_drawing_mode, vertices={j}}
  elseif Current_drawing_mode == 'circle' then
    local j = Drawing.insert_point(drawing.points, Drawing.coord(x-16), Drawing.coord(y-drawing.y))
    drawing.pending = {mode=Current_drawing_mode, center=j}
  end
  Lines.current = drawing
end

-- a couple of operations on drawings need to constantly check the state of the mouse
function Drawing.update()
  if Lines.current == nil then return end
  local drawing = Lines.current
  assert(drawing.mode == 'drawing')
  local x, y = love.mouse.getX(), love.mouse.getY()
  if love.mouse.isDown('1') then
    if Drawing.in_drawing(drawing, x,y) then
      if drawing.pending.mode == 'freehand' then
        table.insert(drawing.pending.points, {x=Drawing.coord(love.mouse.getX()-16), y=Drawing.coord(love.mouse.getY()-drawing.y)})
      elseif drawing.pending.mode == 'move' then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-drawing.y)
        drawing.pending.target_point.x = mx
        drawing.pending.target_point.y = my
      end
    end
  elseif Current_drawing_mode == 'move' then
    if Drawing.in_drawing(drawing, x, y) then
      local mx,my = Drawing.coord(x-16), Drawing.coord(y-drawing.y)
      drawing.pending.target_point.x = mx
      drawing.pending.target_point.y = my
    end
  end
end

function Drawing.mouse_released(x,y, button)
  if Current_drawing_mode == 'move' then
    Current_drawing_mode = Previous_drawing_mode
    Previous_drawing_mode = nil
  elseif Lines.current then
    if Lines.current.pending then
      if Lines.current.pending.mode == 'freehand' then
        -- the last point added during update is good enough
        table.insert(Lines.current.shapes, Lines.current.pending)
      elseif Lines.current.pending.mode == 'line' then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
        if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
          local j = Drawing.insert_point(Lines.current.points, mx,my)
          Lines.current.pending.p2 = j
          table.insert(Lines.current.shapes, Lines.current.pending)
        end
      elseif Lines.current.pending.mode == 'manhattan' then
        local p1 = Lines.current.points[Lines.current.pending.p1]
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
        if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
          if math.abs(mx-p1.x) > math.abs(my-p1.y) then
            local j = Drawing.insert_point(Lines.current.points, mx, p1.y)
            Lines.current.pending.p2 = j
          else
            local j = Drawing.insert_point(Lines.current.points, p1.x, my)
            Lines.current.pending.p2 = j
          end
          local p2 = Lines.current.points[Lines.current.pending.p2]
          love.mouse.setPosition(16+Drawing.pixels(p2.x), Lines.current.y+Drawing.pixels(p2.y))
          table.insert(Lines.current.shapes, Lines.current.pending)
        end
      elseif Lines.current.pending.mode == 'polygon' then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
        if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
          local j = Drawing.insert_point(Lines.current.points, mx,my)
          table.insert(Lines.current.shapes, Lines.current.pending)
        end
        table.insert(Lines.current.shapes, Lines.current.pending)
      elseif Lines.current.pending.mode == 'circle' then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
        if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
          local center = Lines.current.points[Lines.current.pending.center]
          Lines.current.pending.radius = geom.dist(center.x,center.y, mx,my)
          table.insert(Lines.current.shapes, Lines.current.pending)
        end
      elseif Lines.current.pending.mode == 'arc' then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-Lines.current.y)
        if mx >= 0 and mx < 256 and my >= 0 and my < Lines.current.h then
          local center = Lines.current.points[Lines.current.pending.center]
          Lines.current.pending.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, Lines.current.pending.end_angle)
          table.insert(Lines.current.shapes, Lines.current.pending)
        end
      end
      Lines.current.pending = {}
      Lines.current = nil
    end
  end
  save_to_disk(Lines, Filename)
end

function Drawing.keychord_pressed(chord)
  if chord == 'C-=' then
    Drawing_width = Drawing_width/Zoom
    Zoom = Zoom+0.5
    Drawing_width = Drawing_width*Zoom
  elseif chord == 'C--' then
    Drawing_width = Drawing_width/Zoom
    Zoom = Zoom-0.5
    Drawing_width = Drawing_width*Zoom
  elseif chord == 'C-0' then
    Drawing_width = Drawing_width/Zoom
    Zoom = 1.5
    Drawing_width = Drawing_width*Zoom
  elseif chord == 'C-f' and not love.mouse.isDown('1') then
    Current_drawing_mode = 'freehand'
  elseif chord == 'C-g' and not love.mouse.isDown('1') then
    Current_drawing_mode = 'polygon'
  elseif love.mouse.isDown('1') and chord == 'g' then
    Current_drawing_mode = 'polygon'
    local drawing = Drawing.current_drawing()
    if drawing.pending.mode == 'freehand' then
      drawing.pending.vertices = {Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)}
    elseif drawing.pending.mode == 'line' or drawing.pending.mode == 'manhattan' then
      if drawing.pending.vertices == nil then
        drawing.pending.vertices = {drawing.pending.p1}
      end
    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
      drawing.pending.vertices = {drawing.pending.center}
    end
    drawing.pending.mode = 'polygon'
  elseif love.mouse.isDown('1') and chord == 'p' and Current_drawing_mode == 'polygon' then
    local drawing = Drawing.current_drawing()
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    local j = Drawing.insert_point(drawing.points, mx,my)
    table.insert(drawing.pending.vertices, j)
  elseif chord == 'C-c' and not love.mouse.isDown('1') then
    Current_drawing_mode = 'circle'
  elseif love.mouse.isDown('1') and chord == 'a' and Current_drawing_mode == 'circle' then
    local drawing = Drawing.current_drawing()
    drawing.pending.mode = 'arc'
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    local j = Drawing.insert_point(drawing.points, mx,my)
    local center = drawing.points[drawing.pending.center]
    drawing.pending.radius = geom.dist(center.x,center.y, mx,my)
    drawing.pending.start_angle = geom.angle(center.x,center.y, mx,my)
  elseif love.mouse.isDown('1') and chord == 'c' then
    Current_drawing_mode = 'circle'
    local drawing = Drawing.current_drawing()
    if drawing.pending.mode == 'freehand' then
      drawing.pending.center = Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)
    elseif drawing.pending.mode == 'line' or drawing.pending.mode == 'manhattan' then
      drawing.pending.center = drawing.pending.p1
    elseif drawing.pending.mode == 'polygon' then
      drawing.pending.center = drawing.pending.vertices[1]
    end
    drawing.pending.mode = 'circle'
  elseif love.mouse.isDown('1') and chord == 'l' then
    Current_drawing_mode = 'line'
    local drawing = Drawing.current_drawing()
    if drawing.pending.mode == 'freehand' then
      drawing.pending.p1 = Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)
    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
      drawing.pending.p1 = drawing.pending.center
    elseif drawing.pending.mode == 'polygon' then
      drawing.pending.p1 = drawing.pending.vertices[1]
    end
    drawing.pending.mode = 'line'
  elseif chord == 'C-l' then
    Current_drawing_mode = 'line'
    local drawing,_,shape = Drawing.select_shape_at_mouse()
    if drawing then
      convert_line(drawing, shape)
    end
  elseif love.mouse.isDown('1') and chord == 'm' then
    Current_drawing_mode = 'manhattan'
    local drawing = Drawing.select_drawing_at_mouse()
    if drawing.pending.mode == 'freehand' then
      drawing.pending.p1 = Drawing.insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)
    elseif drawing.pending.mode == 'line' then
      -- do nothing
    elseif drawing.pending.mode == 'polygon' then
      drawing.pending.p1 = drawing.pending.vertices[1]
    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
      drawing.pending.p1 = drawing.pending.center
    end
    drawing.pending.mode = 'manhattan'
  elseif chord == 'C-m' and not love.mouse.isDown('1') then
    Current_drawing_mode = 'manhattan'
    local drawing,_,shape = Drawing.select_shape_at_mouse()
    if drawing then
      convert_horvert(drawing, shape)
    end
  elseif chord == 'C-s' and not love.mouse.isDown('1') then
    local drawing,_,shape = Drawing.select_shape_at_mouse()
    if drawing then
      smoothen(shape)
    end
  elseif chord == 'C-v' and not love.mouse.isDown('1') then
    local drawing,_,p = Drawing.select_point_at_mouse()
    if drawing then
      Previous_drawing_mode = Current_drawing_mode
      Current_drawing_mode = 'move'
      drawing.pending = {mode=Current_drawing_mode, target_point=p}
      Lines.current = drawing
    end
  elseif love.mouse.isDown('1') and chord == 'v' then
    local drawing,_,p = Drawing.select_point_at_mouse()
    if drawing then
      Previous_drawing_mode = Current_drawing_mode
      Current_drawing_mode = 'move'
      drawing.pending = {mode=Current_drawing_mode, target_point=p}
      Lines.current = drawing
    end
  elseif chord == 'C-d' and not love.mouse.isDown('1') then
    local drawing,i,p = Drawing.select_point_at_mouse()
    if drawing then
      for _,shape in ipairs(drawing.shapes) do
        if Drawing.contains_point(shape, i) then
          if shape.mode == 'polygon' then
            local idx = table.find(shape.vertices, i)
            assert(idx)
            table.remove(shape.vertices, idx)
            if #shape.vertices < 3 then
              shape.mode = 'deleted'
            end
          else
            shape.mode = 'deleted'
          end
        end
      end
      drawing.points[i].deleted = true
    end
    local drawing,_,shape = Drawing.select_shape_at_mouse()
    if drawing then
      shape.mode = 'deleted'
    end
  elseif chord == 'C-h' and not love.mouse.isDown('1') then
    local drawing = Drawing.select_drawing_at_mouse()
    if drawing then
      drawing.show_help = true
    end
  elseif chord == 'escape' and not love.mouse.isDown('1') then
    for _,line in ipairs(Lines) do
      if line.mode == 'drawing' then
        line.show_help = false
      end
    end
  end
end

function Drawing.current_drawing()
  local x, y = love.mouse.getX(), love.mouse.getY()
  for _,drawing in ipairs(Lines) do
    if drawing.mode == 'drawing' then
      if Drawing.in_drawing(drawing, x,y) then
        return drawing
      end
    end
  end
  return nil
end

function Drawing.select_shape_at_mouse()
  for _,drawing in ipairs(Lines) do
    if drawing.mode == 'drawing' then
      local x, y = love.mouse.getX(), love.mouse.getY()
      if Drawing.in_drawing(drawing, x,y) then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-drawing.y)
        for i,shape in ipairs(drawing.shapes) do
          assert(shape)
          if geom.on_shape(mx,my, drawing, shape) then
            return drawing,i,shape
          end
        end
      end
    end
  end
end

function Drawing.select_point_at_mouse()
  for _,drawing in ipairs(Lines) do
    if drawing.mode == 'drawing' then
      local x, y = love.mouse.getX(), love.mouse.getY()
      if Drawing.in_drawing(drawing, x,y) then
        local mx,my = Drawing.coord(x-16), Drawing.coord(y-drawing.y)
        for i,point in ipairs(drawing.points) do
          assert(point)
          if Drawing.near(point, mx,my) then
            return drawing,i,point
          end
        end
      end
    end
  end
end

function Drawing.select_drawing_at_mouse()
  for _,drawing in ipairs(Lines) do
    if drawing.mode == 'drawing' then
      local x, y = love.mouse.getX(), love.mouse.getY()
      if Drawing.in_drawing(drawing, x,y) then
        return drawing
      end
    end
  end
end

function Drawing.contains_point(shape, p)
  if shape.mode == 'freehand' then
    -- not supported
  elseif shape.mode == 'line' or shape.mode == 'manhattan' then
    return shape.p1 == p or shape.p2 == p
  elseif shape.mode == 'polygon' then
    return table.find(shape.vertices, p)
  elseif shape.mode == 'circle' then
    return shape.center == p
  elseif shape.mode == 'arc' then
    return shape.center == p
    -- ugh, how to support angles
  elseif shape.mode == 'deleted' then
    -- already done
  else
    print(shape.mode)
    assert(false)
  end
end

function Drawing.convert_line(drawing, shape)
  -- Perhaps we should do a more sophisticated "simple linear regression"
  -- here:
  --   https://en.wikipedia.org/wiki/Linear_regression#Simple_and_multiple_linear_regression
  -- But this works well enough for close-to-linear strokes.
  assert(shape.mode == 'freehand')
  shape.mode = 'line'
  shape.p1 = insert_point(drawing.points, shape.points[1].x, shape.points[1].y)
  local n = #shape.points
  shape.p2 = insert_point(drawing.points, shape.points[n].x, shape.points[n].y)
end

-- turn a line either horizontal or vertical
function Drawing.convert_horvert(drawing, shape)
  if shape.mode == 'freehand' then
    convert_line(shape)
  end
  assert(shape.mode == 'line')
  local p1 = drawing.points[shape.p1]
  local p2 = drawing.points[shape.p2]
  if math.abs(p1.x-p2.x) > math.abs(p1.y-p2.y) then
    p2.y = p1.y
  else
    p2.x = p1.x
  end
end

function Drawing.smoothen(shape)
  assert(shape.mode == 'freehand')
  for _=1,7 do
    for i=2,#shape.points-1 do
      local a = shape.points[i-1]
      local b = shape.points[i]
      local c = shape.points[i+1]
      b.x = (a.x + b.x + c.x)/3
      b.y = (a.y + b.y + c.y)/3
    end
  end
end

function Drawing.insert_point(points, x,y)
  for i,point in ipairs(points) do
    if Drawing.near(point, x,y) then
      return i
    end
  end
  table.insert(points, {x=x, y=y})
  return #points
end

function Drawing.near(point, x,y)
  local px,py = Drawing.pixels(x),Drawing.pixels(y)
  local cx,cy = Drawing.pixels(point.x), Drawing.pixels(point.y)
  return (cx-px)*(cx-px) + (cy-py)*(cy-py) < 16
end

function Drawing.draw_shape(left,top, drawing, shape)
  if shape.mode == 'freehand' then
    local prev = nil
    for _,point in ipairs(shape.points) do
      if prev then
        love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, Drawing.pixels(point.x)+left,Drawing.pixels(point.y)+top)
      end
      prev = point
    end
  elseif shape.mode == 'line' or shape.mode == 'manhattan' then
    local p1 = drawing.points[shape.p1]
    local p2 = drawing.points[shape.p2]
    love.graphics.line(Drawing.pixels(p1.x)+left,Drawing.pixels(p1.y)+top, Drawing.pixels(p2.x)+left,Drawing.pixels(p2.y)+top)
  elseif shape.mode == 'polygon' then
    local prev = nil
    for _,point in ipairs(shape.vertices) do
      local curr = drawing.points[point]
      if prev then
        love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, Drawing.pixels(curr.x)+left,Drawing.pixels(curr.y)+top)
      end
      prev = curr
    end
    -- close the loop
    local curr = drawing.points[shape.vertices[1]]
    love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, Drawing.pixels(curr.x)+left,Drawing.pixels(curr.y)+top)
  elseif shape.mode == 'circle' then
    local center = drawing.points[shape.center]
    love.graphics.circle('line', Drawing.pixels(center.x)+left,Drawing.pixels(center.y)+top, Drawing.pixels(shape.radius))
  elseif shape.mode == 'arc' then
    local center = drawing.points[shape.center]
    love.graphics.arc('line', 'open', Drawing.pixels(center.x)+left,Drawing.pixels(center.y)+top, Drawing.pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
  elseif shape.mode == 'deleted' then
  else
    print(shape.mode)
    assert(false)
  end
end

function Drawing.draw_pending_shape(left,top, drawing)
  local shape = drawing.pending
  if shape.mode == 'freehand' then
    Drawing.draw_shape(left,top, drawing, shape)
  elseif shape.mode == 'line' then
    local p1 = drawing.points[shape.p1]
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
      return
    end
    love.graphics.line(Drawing.pixels(p1.x)+left,Drawing.pixels(p1.y)+top, Drawing.pixels(mx)+left,Drawing.pixels(my)+top)
  elseif shape.mode == 'manhattan' then
    local p1 = drawing.points[shape.p1]
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
      return
    end
    if math.abs(mx-p1.x) > math.abs(my-p1.y) then
      love.graphics.line(Drawing.pixels(p1.x)+left,Drawing.pixels(p1.y)+top, Drawing.pixels(mx)+left,Drawing.pixels(p1.y)+top)
    else
      love.graphics.line(Drawing.pixels(p1.x)+left,Drawing.pixels(p1.y)+top, Drawing.pixels(p1.x)+left,Drawing.pixels(my)+top)
    end
  elseif shape.mode == 'polygon' then
    -- don't close the loop on a pending polygon
    local prev = nil
    for _,point in ipairs(shape.vertices) do
      local curr = drawing.points[point]
      if prev then
        love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, Drawing.pixels(curr.x)+left,Drawing.pixels(curr.y)+top)
      end
      prev = curr
    end
    love.graphics.line(Drawing.pixels(prev.x)+left,Drawing.pixels(prev.y)+top, love.mouse.getX(),love.mouse.getY())
  elseif shape.mode == 'circle' then
    local center = drawing.points[shape.center]
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
      return
    end
    local cx,cy = Drawing.pixels(center.x)+left, Drawing.pixels(center.y)+top
    love.graphics.circle('line', cx,cy, geom.dist(cx,cy, love.mouse.getX(),love.mouse.getY()))
  elseif shape.mode == 'arc' then
    local center = drawing.points[shape.center]
    local mx,my = Drawing.coord(love.mouse.getX()-16), Drawing.coord(love.mouse.getY()-drawing.y)
    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
      return
    end
    shape.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, shape.end_angle)
    local cx,cy = Drawing.pixels(center.x)+left, Drawing.pixels(center.y)+top
    love.graphics.arc('line', 'open', cx,cy, Drawing.pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
  end
end

function Drawing.pixels(n)  -- parts to pixels
  return n*Drawing_width/256
end
function Drawing.coord(n)  -- pixels to parts
  return math.floor(n*256/Drawing_width)
end

function table.find(h, x)
  for k,v in pairs(h) do
    if v == x then
      return k
    end
  end
end

return Drawing