about summary refs log tree commit diff stats
path: root/drawing.lua
diff options
context:
space:
mode:
Diffstat (limited to 'drawing.lua')
-rw-r--r--drawing.lua745
1 files changed, 0 insertions, 745 deletions
diff --git a/drawing.lua b/drawing.lua
deleted file mode 100644
index 0343f85..0000000
--- a/drawing.lua
+++ /dev/null
@@ -1,745 +0,0 @@
--- primitives for editing drawings
-Drawing = {}
-require 'drawing_tests'
-
--- All drawings span 100% of some conceptual 'page width' and divide it up
--- into 256 parts.
-function Drawing.draw(State, line_index, y)
-  local line = State.lines[line_index]
-  local line_cache = State.line_cache[line_index]
-  line_cache.starty = y
-  local pmx,pmy = App.mouse_x(), App.mouse_y()
-  if pmx < State.right and pmy > line_cache.starty and pmy < line_cache.starty+Drawing.pixels(line.h, State.width) then
-    App.color(Icon_color)
-    love.graphics.rectangle('line', State.left,line_cache.starty, State.width,Drawing.pixels(line.h, State.width))
-    if icon[State.current_drawing_mode] then
-      icon[State.current_drawing_mode](State.right-22, line_cache.starty+4)
-    else
-      icon[State.previous_drawing_mode](State.right-22, line_cache.starty+4)
-    end
-
-    if App.mouse_down(1) and love.keyboard.isDown('h') then
-      draw_help_with_mouse_pressed(State, line_index)
-      return
-    end
-  end
-
-  if line.show_help then
-    draw_help_without_mouse_pressed(State, line_index)
-    return
-  end
-
-  local mx = Drawing.coord(pmx-State.left, State.width)
-  local my = Drawing.coord(pmy-line_cache.starty, State.width)
-
-  for _,shape in ipairs(line.shapes) do
-    assert(shape)
-    if geom.on_shape(mx,my, line, shape) then
-      App.color(Focus_stroke_color)
-    else
-      App.color(Stroke_color)
-    end
-    Drawing.draw_shape(line, shape, line_cache.starty, State.left,State.right)
-  end
-
-  local function px(x) return Drawing.pixels(x, State.width)+State.left end
-  local function py(y) return Drawing.pixels(y, State.width)+line_cache.starty end
-  for i,p in ipairs(line.points) do
-    if p.deleted == nil then
-      if Drawing.near(p, mx,my, State.width) then
-        App.color(Focus_stroke_color)
-        love.graphics.circle('line', px(p.x),py(p.y), Same_point_distance)
-      else
-        App.color(Stroke_color)
-        love.graphics.circle('fill', px(p.x),py(p.y), 2)
-      end
-      if p.name then
-        -- TODO: clip
-        local x,y = px(p.x)+5, py(p.y)+5
-        love.graphics.print(p.name, x,y)
-        if State.current_drawing_mode == 'name' and i == line.pending.target_point then
-          -- create a faint red box for the name
-          App.color(Current_name_background_color)
-          local name_text
-          -- TODO: avoid computing name width on every repaint
-          if p.name == '' then
-            name_text = State.em
-          else
-            name_text = App.newText(love.graphics.getFont(), p.name)
-          end
-          love.graphics.rectangle('fill', x,y, App.width(name_text), State.line_height)
-        end
-      end
-    end
-  end
-  App.color(Current_stroke_color)
-  Drawing.draw_pending_shape(line, line_cache.starty, State.left,State.right)
-end
-
-function Drawing.draw_shape(drawing, shape, top, left,right)
-  local width = right-left
-  local function px(x) return Drawing.pixels(x, width)+left end
-  local function py(y) return Drawing.pixels(y, width)+top end
-  if shape.mode == 'freehand' then
-    local prev = nil
-    for _,point in ipairs(shape.points) do
-      if prev then
-        love.graphics.line(px(prev.x),py(prev.y), px(point.x),py(point.y))
-      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(px(p1.x),py(p1.y), px(p2.x),py(p2.y))
-  elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
-    local prev = nil
-    for _,point in ipairs(shape.vertices) do
-      local curr = drawing.points[point]
-      if prev then
-        love.graphics.line(px(prev.x),py(prev.y), px(curr.x),py(curr.y))
-      end
-      prev = curr
-    end
-    -- close the loop
-    local curr = drawing.points[shape.vertices[1]]
-    love.graphics.line(px(prev.x),py(prev.y), px(curr.x),py(curr.y))
-  elseif shape.mode == 'circle' then
-    -- TODO: clip
-    local center = drawing.points[shape.center]
-    love.graphics.circle('line', px(center.x),py(center.y), Drawing.pixels(shape.radius, width))
-  elseif shape.mode == 'arc' then
-    local center = drawing.points[shape.center]
-    love.graphics.arc('line', 'open', px(center.x),py(center.y), Drawing.pixels(shape.radius, width), shape.start_angle, shape.end_angle, 360)
-  elseif shape.mode == 'deleted' then
-    -- ignore
-  else
-    print(shape.mode)
-    assert(false)
-  end
-end
-
-function Drawing.draw_pending_shape(drawing, top, left,right)
-  local width = right-left
-  local pmx,pmy = App.mouse_x(), App.mouse_y()
-  local function px(x) return Drawing.pixels(x, width)+left end
-  local function py(y) return Drawing.pixels(y, width)+top end
-  local mx = Drawing.coord(pmx-left, width)
-  local my = Drawing.coord(pmy-top, width)
-  -- recreate pixels from coords to precisely mimic how the drawing will look
-  -- after mouse_released
-  pmx,pmy = px(mx), py(my)
-  local shape = drawing.pending
-  if shape.mode == nil then
-    -- nothing pending
-  elseif shape.mode == 'freehand' then
-    local shape_copy = deepcopy(shape)
-    Drawing.smoothen(shape_copy)
-    Drawing.draw_shape(drawing, shape_copy, top, left,right)
-  elseif shape.mode == 'line' then
-    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
-      return
-    end
-    local p1 = drawing.points[shape.p1]
-    love.graphics.line(px(p1.x),py(p1.y), pmx,pmy)
-  elseif shape.mode == 'manhattan' then
-    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
-      return
-    end
-    local p1 = drawing.points[shape.p1]
-    if math.abs(mx-p1.x) > math.abs(my-p1.y) then
-      love.graphics.line(px(p1.x),py(p1.y), pmx,     py(p1.y))
-    else
-      love.graphics.line(px(p1.x),py(p1.y), px(p1.x),pmy)
-    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(px(prev.x),py(prev.y), px(curr.x),py(curr.y))
-      end
-      prev = curr
-    end
-    love.graphics.line(px(prev.x),py(prev.y), pmx,pmy)
-  elseif shape.mode == 'rectangle' then
-    local first = drawing.points[shape.vertices[1]]
-    if #shape.vertices == 1 then
-      love.graphics.line(px(first.x),py(first.y), pmx,pmy)
-      return
-    end
-    local second = drawing.points[shape.vertices[2]]
-    local thirdx,thirdy, fourthx,fourthy = Drawing.complete_rectangle(first.x,first.y, second.x,second.y, mx,my)
-    love.graphics.line(px(first.x),py(first.y), px(second.x),py(second.y))
-    love.graphics.line(px(second.x),py(second.y), px(thirdx),py(thirdy))
-    love.graphics.line(px(thirdx),py(thirdy), px(fourthx),py(fourthy))
-    love.graphics.line(px(fourthx),py(fourthy), px(first.x),py(first.y))
-  elseif shape.mode == 'square' then
-    local first = drawing.points[shape.vertices[1]]
-    if #shape.vertices == 1 then
-      love.graphics.line(px(first.x),py(first.y), pmx,pmy)
-      return
-    end
-    local second = drawing.points[shape.vertices[2]]
-    local thirdx,thirdy, fourthx,fourthy = Drawing.complete_square(first.x,first.y, second.x,second.y, mx,my)
-    love.graphics.line(px(first.x),py(first.y), px(second.x),py(second.y))
-    love.graphics.line(px(second.x),py(second.y), px(thirdx),py(thirdy))
-    love.graphics.line(px(thirdx),py(thirdy), px(fourthx),py(fourthy))
-    love.graphics.line(px(fourthx),py(fourthy), px(first.x),py(first.y))
-  elseif shape.mode == 'circle' then
-    local center = drawing.points[shape.center]
-    if mx < 0 or mx >= 256 or my < 0 or my >= drawing.h then
-      return
-    end
-    local cx,cy = px(center.x), py(center.y)
-    love.graphics.circle('line', cx,cy, geom.dist(cx,cy, App.mouse_x(),App.mouse_y()))
-  elseif shape.mode == 'arc' then
-    local center = drawing.points[shape.center]
-    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 = px(center.x), py(center.y)
-    love.graphics.arc('line', 'open', cx,cy, Drawing.pixels(shape.radius, width), shape.start_angle, shape.end_angle, 360)
-  elseif shape.mode == 'move' then
-    -- nothing pending; changes are immediately committed
-  elseif shape.mode == 'name' then
-    -- nothing pending; changes are immediately committed
-  else
-    print(shape.mode)
-    assert(false)
-  end
-end
-
-function Drawing.in_drawing(drawing, line_cache, x,y, left,right)
-  if line_cache.starty == nil then return false end  -- outside current page
-  local width = right-left
-  return y >= line_cache.starty and y < line_cache.starty + Drawing.pixels(drawing.h, width) and x >= left and x < right
-end
-
-function Drawing.mouse_pressed(State, drawing_index, x,y, mouse_button)
-  local drawing = State.lines[drawing_index]
-  local line_cache = State.line_cache[drawing_index]
-  local cx = Drawing.coord(x-State.left, State.width)
-  local cy = Drawing.coord(y-line_cache.starty, State.width)
-  if State.current_drawing_mode == 'freehand' then
-    drawing.pending = {mode=State.current_drawing_mode, points={{x=cx, y=cy}}}
-  elseif State.current_drawing_mode == 'line' or State.current_drawing_mode == 'manhattan' then
-    local j = Drawing.find_or_insert_point(drawing.points, cx, cy, State.width)
-    drawing.pending = {mode=State.current_drawing_mode, p1=j}
-  elseif State.current_drawing_mode == 'polygon' or State.current_drawing_mode == 'rectangle' or State.current_drawing_mode == 'square' then
-    local j = Drawing.find_or_insert_point(drawing.points, cx, cy, State.width)
-    drawing.pending = {mode=State.current_drawing_mode, vertices={j}}
-  elseif State.current_drawing_mode == 'circle' then
-    local j = Drawing.find_or_insert_point(drawing.points, cx, cy, State.width)
-    drawing.pending = {mode=State.current_drawing_mode, center=j}
-  elseif State.current_drawing_mode == 'move' then
-    -- all the action is in mouse_released
-  elseif State.current_drawing_mode == 'name' then
-    -- nothing
-  else
-    print(State.current_drawing_mode)
-    assert(false)
-  end
-end
-
--- a couple of operations on drawings need to constantly check the state of the mouse
-function Drawing.update(State)
-  if State.lines.current_drawing == nil then return end
-  local drawing = State.lines.current_drawing
-  local line_cache = State.line_cache[State.lines.current_drawing_index]
-  assert(drawing.mode == 'drawing')
-  local pmx, pmy = App.mouse_x(), App.mouse_y()
-  local mx = Drawing.coord(pmx-State.left, State.width)
-  local my = Drawing.coord(pmy-line_cache.starty, State.width)
-  if App.mouse_down(1) then
-    if Drawing.in_drawing(drawing, line_cache, pmx,pmy, State.left,State.right) then
-      if drawing.pending.mode == 'freehand' then
-        table.insert(drawing.pending.points, {x=mx, y=my})
-      elseif drawing.pending.mode == 'move' then
-        drawing.pending.target_point.x = mx
-        drawing.pending.target_point.y = my
-        Drawing.relax_constraints(drawing, drawing.pending.target_point_index)
-      end
-    end
-  elseif State.current_drawing_mode == 'move' then
-    if Drawing.in_drawing(drawing, line_cache, pmx, pmy, State.left,State.right) then
-      drawing.pending.target_point.x = mx
-      drawing.pending.target_point.y = my
-      Drawing.relax_constraints(drawing, drawing.pending.target_point_index)
-    end
-  else
-    -- do nothing
-  end
-end
-
-function Drawing.relax_constraints(drawing, p)
-  for _,shape in ipairs(drawing.shapes) do
-    if shape.mode == 'manhattan' then
-      if shape.p1 == p then
-        shape.mode = 'line'
-      elseif shape.p2 == p then
-        shape.mode = 'line'
-      end
-    elseif shape.mode == 'rectangle' or shape.mode == 'square' then
-      for _,v in ipairs(shape.vertices) do
-        if v == p then
-          shape.mode = 'polygon'
-        end
-      end
-    end
-  end
-end
-
-function Drawing.mouse_released(State, x,y, mouse_button)
-  if State.current_drawing_mode == 'move' then
-    State.current_drawing_mode = State.previous_drawing_mode
-    State.previous_drawing_mode = nil
-    if State.lines.current_drawing then
-      State.lines.current_drawing.pending = {}
-      State.lines.current_drawing = nil
-    end
-  elseif State.lines.current_drawing then
-    local drawing = State.lines.current_drawing
-    local line_cache = State.line_cache[State.lines.current_drawing_index]
-    if drawing.pending then
-      if drawing.pending.mode == nil then
-        -- nothing pending
-      elseif drawing.pending.mode == 'freehand' then
-        -- the last point added during update is good enough
-        Drawing.smoothen(drawing.pending)
-        table.insert(drawing.shapes, drawing.pending)
-      elseif drawing.pending.mode == 'line' then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-          drawing.pending.p2 = Drawing.find_or_insert_point(drawing.points, mx,my, State.width)
-          table.insert(drawing.shapes, drawing.pending)
-        end
-      elseif drawing.pending.mode == 'manhattan' then
-        local p1 = drawing.points[drawing.pending.p1]
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-          if math.abs(mx-p1.x) > math.abs(my-p1.y) then
-            drawing.pending.p2 = Drawing.find_or_insert_point(drawing.points, mx, p1.y, State.width)
-          else
-            drawing.pending.p2 = Drawing.find_or_insert_point(drawing.points, p1.x, my, State.width)
-          end
-          local p2 = drawing.points[drawing.pending.p2]
-          App.mouse_move(State.left+Drawing.pixels(p2.x, State.width), line_cache.starty+Drawing.pixels(p2.y, State.width))
-          table.insert(drawing.shapes, drawing.pending)
-        end
-      elseif drawing.pending.mode == 'polygon' then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-          table.insert(drawing.pending.vertices, Drawing.find_or_insert_point(drawing.points, mx,my, State.width))
-          table.insert(drawing.shapes, drawing.pending)
-        end
-      elseif drawing.pending.mode == 'rectangle' then
-        assert(#drawing.pending.vertices <= 2)
-        if #drawing.pending.vertices == 2 then
-          local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-          if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-            local first = drawing.points[drawing.pending.vertices[1]]
-            local second = drawing.points[drawing.pending.vertices[2]]
-            local thirdx,thirdy, fourthx,fourthy = Drawing.complete_rectangle(first.x,first.y, second.x,second.y, mx,my)
-            table.insert(drawing.pending.vertices, Drawing.find_or_insert_point(drawing.points, thirdx,thirdy, State.width))
-            table.insert(drawing.pending.vertices, Drawing.find_or_insert_point(drawing.points, fourthx,fourthy, State.width))
-            table.insert(drawing.shapes, drawing.pending)
-          end
-        else
-          -- too few points; draw nothing
-        end
-      elseif drawing.pending.mode == 'square' then
-        assert(#drawing.pending.vertices <= 2)
-        if #drawing.pending.vertices == 2 then
-          local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-          if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-            local first = drawing.points[drawing.pending.vertices[1]]
-            local second = drawing.points[drawing.pending.vertices[2]]
-            local thirdx,thirdy, fourthx,fourthy = Drawing.complete_square(first.x,first.y, second.x,second.y, mx,my)
-            table.insert(drawing.pending.vertices, Drawing.find_or_insert_point(drawing.points, thirdx,thirdy, State.width))
-            table.insert(drawing.pending.vertices, Drawing.find_or_insert_point(drawing.points, fourthx,fourthy, State.width))
-            table.insert(drawing.shapes, drawing.pending)
-          end
-        end
-      elseif drawing.pending.mode == 'circle' then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-          local center = drawing.points[drawing.pending.center]
-          drawing.pending.radius = round(geom.dist(center.x,center.y, mx,my))
-          table.insert(drawing.shapes, drawing.pending)
-        end
-      elseif drawing.pending.mode == 'arc' then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        if mx >= 0 and mx < 256 and my >= 0 and my < drawing.h then
-          local center = drawing.points[drawing.pending.center]
-          drawing.pending.end_angle = geom.angle_with_hint(center.x,center.y, mx,my, drawing.pending.end_angle)
-          table.insert(drawing.shapes, drawing.pending)
-        end
-      elseif drawing.pending.mode == 'name' then
-        -- drop it
-      else
-        print(drawing.pending.mode)
-        assert(false)
-      end
-      State.lines.current_drawing.pending = {}
-      State.lines.current_drawing = nil
-    end
-  end
-end
-
-function Drawing.keychord_pressed(State, chord)
-  if chord == 'C-p' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'freehand'
-  elseif App.mouse_down(1) and chord == 'l' then
-    State.current_drawing_mode = 'line'
-    local _,drawing = Drawing.current_drawing(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.p1 = Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)
-    elseif drawing.pending.mode == 'polygon' or drawing.pending.mode == 'rectangle' or drawing.pending.mode == 'square' 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 = 'line'
-  elseif chord == 'C-l' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'line'
-  elseif App.mouse_down(1) and chord == 'm' then
-    State.current_drawing_mode = 'manhattan'
-    local drawing = Drawing.select_drawing_at_mouse(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.p1 = Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)
-    elseif drawing.pending.mode == 'line' then
-      -- do nothing
-    elseif drawing.pending.mode == 'polygon' or drawing.pending.mode == 'rectangle' or drawing.pending.mode == 'square' 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 App.mouse_down(1) then
-    State.current_drawing_mode = 'manhattan'
-  elseif chord == 'C-g' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'polygon'
-  elseif App.mouse_down(1) and chord == 'g' then
-    State.current_drawing_mode = 'polygon'
-    local _,drawing = Drawing.current_drawing(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.vertices = {Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)}
-    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 == 'rectangle' or drawing.pending.mode == 'square' then
-      -- reuse existing vertices
-    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
-      drawing.pending.vertices = {drawing.pending.center}
-    end
-    drawing.pending.mode = 'polygon'
-  elseif chord == 'C-r' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'rectangle'
-  elseif App.mouse_down(1) and chord == 'r' then
-    State.current_drawing_mode = 'rectangle'
-    local _,drawing = Drawing.current_drawing(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.vertices = {Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)}
-    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 == 'polygon' or drawing.pending.mode == 'square' then
-      -- reuse existing (1-2) vertices
-    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
-      drawing.pending.vertices = {drawing.pending.center}
-    end
-    drawing.pending.mode = 'rectangle'
-  elseif chord == 'C-s' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'square'
-  elseif App.mouse_down(1) and chord == 's' then
-    State.current_drawing_mode = 'square'
-    local _,drawing = Drawing.current_drawing(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.vertices = {Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)}
-    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 == 'polygon' then
-      while #drawing.pending.vertices > 2 do
-        table.remove(drawing.pending.vertices)
-      end
-    elseif drawing.pending.mode == 'rectangle' then
-      -- reuse existing (1-2) vertices
-    elseif drawing.pending.mode == 'circle' or drawing.pending.mode == 'arc' then
-      drawing.pending.vertices = {drawing.pending.center}
-    end
-    drawing.pending.mode = 'square'
-  elseif App.mouse_down(1) and chord == 'p' and State.current_drawing_mode == 'polygon' then
-    local _,drawing,line_cache = Drawing.current_drawing(State)
-    local mx,my = Drawing.coord(App.mouse_x()-State.left, State.width), Drawing.coord(App.mouse_y()-line_cache.starty, State.width)
-    local j = Drawing.find_or_insert_point(drawing.points, mx,my, State.width)
-    table.insert(drawing.pending.vertices, j)
-  elseif App.mouse_down(1) and chord == 'p' and (State.current_drawing_mode == 'rectangle' or State.current_drawing_mode == 'square') then
-    local _,drawing,line_cache = Drawing.current_drawing(State)
-    local mx,my = Drawing.coord(App.mouse_x()-State.left, State.width), Drawing.coord(App.mouse_y()-line_cache.starty, State.width)
-    local j = Drawing.find_or_insert_point(drawing.points, mx,my, State.width)
-    while #drawing.pending.vertices >= 2 do
-      table.remove(drawing.pending.vertices)
-    end
-    table.insert(drawing.pending.vertices, j)
-  elseif chord == 'C-o' and not App.mouse_down(1) then
-    State.current_drawing_mode = 'circle'
-  elseif App.mouse_down(1) and chord == 'a' and State.current_drawing_mode == 'circle' then
-    local _,drawing,line_cache = Drawing.current_drawing(State)
-    drawing.pending.mode = 'arc'
-    local mx,my = Drawing.coord(App.mouse_x()-State.left, State.width), Drawing.coord(App.mouse_y()-line_cache.starty, State.width)
-    local center = drawing.points[drawing.pending.center]
-    drawing.pending.radius = round(geom.dist(center.x,center.y, mx,my))
-    drawing.pending.start_angle = geom.angle(center.x,center.y, mx,my)
-  elseif App.mouse_down(1) and chord == 'o' then
-    State.current_drawing_mode = 'circle'
-    local _,drawing = Drawing.current_drawing(State)
-    if drawing.pending.mode == 'freehand' then
-      drawing.pending.center = Drawing.find_or_insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y, State.width)
-    elseif drawing.pending.mode == 'line' or drawing.pending.mode == 'manhattan' then
-      drawing.pending.center = drawing.pending.p1
-    elseif drawing.pending.mode == 'polygon' or drawing.pending.mode == 'rectangle' or drawing.pending.mode == 'square' then
-      drawing.pending.center = drawing.pending.vertices[1]
-    end
-    drawing.pending.mode = 'circle'
-  elseif chord == 'C-u' and not App.mouse_down(1) then
-    local drawing_index,drawing,line_cache,i,p = Drawing.select_point_at_mouse(State)
-    if drawing then
-      if State.previous_drawing_mode == nil then
-        State.previous_drawing_mode = State.current_drawing_mode
-      end
-      State.current_drawing_mode = 'move'
-      drawing.pending = {mode=State.current_drawing_mode, target_point=p, target_point_index=i}
-      State.lines.current_drawing_index = drawing_index
-      State.lines.current_drawing = drawing
-    end
-  elseif chord == 'C-n' and not App.mouse_down(1) then
-    local drawing_index,drawing,line_cache,point_index,p = Drawing.select_point_at_mouse(State)
-    if drawing then
-      if State.previous_drawing_mode == nil then
-        -- don't clobber
-        State.previous_drawing_mode = State.current_drawing_mode
-      end
-      State.current_drawing_mode = 'name'
-      p.name = ''
-      drawing.pending = {mode=State.current_drawing_mode, target_point=point_index}
-      State.lines.current_drawing_index = drawing_index
-      State.lines.current_drawing = drawing
-    end
-  elseif chord == 'C-d' and not App.mouse_down(1) then
-    local _,drawing,_,i,p = Drawing.select_point_at_mouse(State)
-    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(State)
-    if drawing then
-      shape.mode = 'deleted'
-    end
-  elseif chord == 'C-h' and not App.mouse_down(1) then
-    local drawing = Drawing.select_drawing_at_mouse(State)
-    if drawing then
-      drawing.show_help = true
-    end
-  elseif chord == 'escape' and App.mouse_down(1) then
-    local _,drawing = Drawing.current_drawing(State)
-    drawing.pending = {}
-  end
-end
-
-function Drawing.complete_rectangle(firstx,firsty, secondx,secondy, x,y)
-  if firstx == secondx then
-    return x,secondy, x,firsty
-  end
-  if firsty == secondy then
-    return secondx,y, firstx,y
-  end
-  local first_slope = (secondy-firsty)/(secondx-firstx)
-  -- slope of second edge:
-  --    -1/first_slope
-  -- equation of line containing the second edge:
-  --    y-secondy = -1/first_slope*(x-secondx)
-  -- => 1/first_slope*x + y + (- secondy - secondx/first_slope) = 0
-  -- now we want to find the point on this line that's closest to the mouse pointer.
-  -- https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line#Line_defined_by_an_equation
-  local a = 1/first_slope
-  local c = -secondy - secondx/first_slope
-  local thirdx = round(((x-a*y) - a*c) / (a*a + 1))
-  local thirdy = round((a*(-x + a*y) - c) / (a*a + 1))
-  -- slope of third edge = first_slope
-  -- equation of line containing third edge:
-  --     y - thirdy = first_slope*(x-thirdx)
-  --  => -first_slope*x + y + (-thirdy + thirdx*first_slope) = 0
-  -- now we want to find the point on this line that's closest to the first point
-  local a = -first_slope
-  local c = -thirdy + thirdx*first_slope
-  local fourthx = round(((firstx-a*firsty) - a*c) / (a*a + 1))
-  local fourthy = round((a*(-firstx + a*firsty) - c) / (a*a + 1))
-  return thirdx,thirdy, fourthx,fourthy
-end
-
-function Drawing.complete_square(firstx,firsty, secondx,secondy, x,y)
-  -- use x,y only to decide which side of the first edge to complete the square on
-  local deltax = secondx-firstx
-  local deltay = secondy-firsty
-  local thirdx = secondx+deltay
-  local thirdy = secondy-deltax
-  if not geom.same_side(firstx,firsty, secondx,secondy, thirdx,thirdy, x,y) then
-    deltax = -deltax
-    deltay = -deltay
-    thirdx = secondx+deltay
-    thirdy = secondy-deltax
-  end
-  local fourthx = firstx+deltay
-  local fourthy = firsty-deltax
-  return thirdx,thirdy, fourthx,fourthy
-end
-
-function Drawing.current_drawing(State)
-  local x, y = App.mouse_x(), App.mouse_y()
-  for drawing_index,drawing in ipairs(State.lines) do
-    if drawing.mode == 'drawing' then
-      local line_cache = State.line_cache[drawing_index]
-      if Drawing.in_drawing(drawing, line_cache, x,y, State.left,State.right) then
-        return drawing_index,drawing,line_cache
-      end
-    end
-  end
-  return nil
-end
-
-function Drawing.select_shape_at_mouse(State)
-  for drawing_index,drawing in ipairs(State.lines) do
-    if drawing.mode == 'drawing' then
-      local x, y = App.mouse_x(), App.mouse_y()
-      local line_cache = State.line_cache[drawing_index]
-      if Drawing.in_drawing(drawing, line_cache, x,y, State.left,State.right) then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        for i,shape in ipairs(drawing.shapes) do
-          assert(shape)
-          if geom.on_shape(mx,my, drawing, shape) then
-            return drawing,line_cache,i,shape
-          end
-        end
-      end
-    end
-  end
-end
-
-function Drawing.select_point_at_mouse(State)
-  for drawing_index,drawing in ipairs(State.lines) do
-    if drawing.mode == 'drawing' then
-      local x, y = App.mouse_x(), App.mouse_y()
-      local line_cache = State.line_cache[drawing_index]
-      if Drawing.in_drawing(drawing, line_cache, x,y, State.left,State.right) then
-        local mx,my = Drawing.coord(x-State.left, State.width), Drawing.coord(y-line_cache.starty, State.width)
-        for i,point in ipairs(drawing.points) do
-          assert(point)
-          if Drawing.near(point, mx,my, State.width) then
-            return drawing_index,drawing,line_cache,i,point
-          end
-        end
-      end
-    end
-  end
-end
-
-function Drawing.select_drawing_at_mouse(State)
-  for drawing_index,drawing in ipairs(State.lines) do
-    if drawing.mode == 'drawing' then
-      local x, y = App.mouse_x(), App.mouse_y()
-      local line_cache = State.line_cache[drawing_index]
-      if Drawing.in_drawing(drawing, line_cache, x,y, State.left,State.right) 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' or shape.mode == 'rectangle' or shape.mode == 'square' 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.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 = round((a.x + b.x + c.x)/3)
-      b.y = round((a.y + b.y + c.y)/3)
-    end
-  end
-end
-
-function round(num)
-  return math.floor(num+.5)
-end
-
-function Drawing.find_or_insert_point(points, x,y, width)
-  -- check if UI would snap the two points together
-  for i,point in ipairs(points) do
-    if Drawing.near(point, x,y, width) then
-      return i
-    end
-  end
-  table.insert(points, {x=x, y=y})
-  return #points
-end
-
-function Drawing.near(point, x,y, width)
-  local px,py = Drawing.pixels(x, width),Drawing.pixels(y, width)
-  local cx,cy = Drawing.pixels(point.x, width), Drawing.pixels(point.y, width)
-  return (cx-px)*(cx-px) + (cy-py)*(cy-py) < Same_point_distance*Same_point_distance
-end
-
-function Drawing.pixels(n, width)  -- parts to pixels
-  return math.floor(n*width/256)
-end
-function Drawing.coord(n, width)  -- pixels to parts
-  return math.floor(n*256/width)
-end
-
-function table.find(h, x)
-  for k,v in pairs(h) do
-    if v == x then
-      return k
-    end
-  end
-end