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|
require 'keychord'
require 'button'
require 'repl'
local utf8 = require 'utf8'
-- lines is an array of lines
-- a line is either:
-- a string containing text
-- or a drawing
-- a drawing is a table with:
-- a (y) coord in pixels,
-- a (h)eight,
-- an array of points, and
-- an array of shapes
-- a shape is a table containing:
-- a mode
-- an array points for mode 'freehand' (raw x,y coords; freehand drawings don't pollute the points array of a drawing)
-- an array vertices for mode 'polygon', 'rectangle', 'square'
-- p1, p2 for mode 'line'
-- p1, p2, arrow-mode for mode 'arrow-line'
-- cx,cy, r for mode 'circle'
-- pc, r for mode 'circle'
-- pc, r, s, e for mode 'arc'
-- Unless otherwise specified, coord fields are normalized; a drawing is always 256 units wide
-- The field names are carefully chosen so that switching modes in midstream
-- remembers previously entered points where that makes sense.
--
-- Open question: how to maintain Sketchpad-style constraints? Answer for now:
-- we don't. Constraints operate only for the duration of a drawing operation.
-- We'll continue to persist them just to keep the option open to continue
-- solving for them. But for now, this is a program to create static drawings
-- once, and read them passively thereafter.
lines = {}
screenw, screenh, screenflags = 0, 0, nil
current_mode = 'line'
previous_mode = nil
-- All drawings span 100% of some conceptual 'page width' and divide it up
-- into 256 parts. `drawingw` describes their width in pixels.
drawingw = 400 -- pixels
function pixels(n) -- parts to pixels
return n*drawingw/256
end
function coord(n) -- pixels to parts
return math.floor(n*256/drawingw)
end
exec_payload = nil
filename = nil
function love.load(arg)
if #arg > 0 then
filename = arg[1]
lines = load_from_disk(filename)
end
table.insert(lines, '')
love.window.setMode(0, 0) -- maximize
screenw, screenh, screenflags = love.window.getMode()
love.keyboard.setTextInput(true) -- bring up keyboard on touch screen
end
function love.draw()
button_handlers = {}
love.graphics.setColor(1, 1, 1)
love.graphics.rectangle('fill', 1, 1, screenw-1, screenh-1)
love.graphics.setColor(0, 0, 0)
local text
local y = 0
for i,line in ipairs(lines) do
y = y+25
text = love.graphics.newText(love.graphics.getFont(), line)
if line == '' then
button('draw', {x=4,y=y+4, w=12,h=12, color={1,1,0},
icon = function(x,y)
love.graphics.setColor(0.7,0.7,0.7)
love.graphics.rectangle('line', x,y, 12,12)
love.graphics.line(4,y+6, 16,y+6)
love.graphics.line(10,y, 10,y+12)
love.graphics.setColor(0, 0, 0)
end,
onpress1 = function()
table.insert(lines, i, {y=y, h=256/2, points={}, shapes={}, pending={}})
end})
elseif type(line) == 'table' then
-- line drawing
line.y = y
y = y+pixels(line.h)
love.graphics.setColor(0.75,0.75,0.75)
love.graphics.rectangle('line', 16,line.y, drawingw,pixels(line.h))
local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-line.y)
for _,shape in ipairs(line.shapes) do
assert(shape)
if on_shape(mx,my, line, shape) then
love.graphics.setColor(1,0,0)
else
love.graphics.setColor(0,0,0)
end
draw_shape(16,line.y, line, shape)
end
for _,p in ipairs(line.points) do
if p.deleted == nil then
if near(p, mx,my) then
love.graphics.setColor(1,0,0)
love.graphics.circle('line', pixels(p.x)+16,pixels(p.y)+line.y, 4)
else
love.graphics.setColor(0,0,0)
love.graphics.circle('fill', pixels(p.x)+16,pixels(p.y)+line.y, 2)
end
end
end
--? print(#line.points)
draw_pending_shape(16,line.y, line)
else
love.graphics.draw(text, 25,y, 0, 1.5)
end
end
-- cursor
love.graphics.print('_', 25+text:getWidth()*1.5, y)
-- display side effect
if exec_payload then
run(exec_payload)
end
end
function love.update(dt)
if love.mouse.isDown('1') then
if lines.current then
local drawing = lines.current
if type(drawing) == 'table' then
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
if drawing.pending.mode == 'freehand' then
table.insert(drawing.pending.points, {x=coord(love.mouse.getX()-16), y=coord(love.mouse.getY()-drawing.y)})
elseif drawing.pending.mode == 'move' then
local mx,my = coord(x-16), coord(y-drawing.y)
drawing.pending.target_point.x = mx
drawing.pending.target_point.y = my
end
end
end
end
elseif current_mode == 'move' then
local drawing = lines.current
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
local mx,my = coord(x-16), coord(y-drawing.y)
drawing.pending.target_point.x = mx
drawing.pending.target_point.y = my
end
end
end
function love.mousepressed(x,y, button)
propagate_to_button_handlers(x,y, button)
propagate_to_drawings(x,y, button)
end
function love.mousereleased(x,y, button)
if current_mode == 'move' then
current_mode = previous_mode
previous_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 = coord(x-16), coord(y-lines.current.y)
if mx >= 0 and mx < 256 and my >= 0 and my < lines.current.h then
local j = 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 = coord(x-16), 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 = insert_point(lines.current.points, mx, p1.y)
lines.current.pending.p2 = j
else
local j = 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+pixels(p2.x), lines.current.y+pixels(p2.y))
table.insert(lines.current.shapes, lines.current.pending)
end
elseif lines.current.pending.mode == 'polygon' then
local mx,my = coord(x-16), coord(y-lines.current.y)
if mx >= 0 and mx < 256 and my >= 0 and my < lines.current.h then
local j = 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 = coord(x-16), 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 = math.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 = coord(x-16), 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 = 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 propagate_to_drawings(x,y, button)
for i,drawing in ipairs(lines) do
if type(drawing) == 'table' then
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
if current_mode == 'freehand' then
drawing.pending = {mode=current_mode, points={{x=coord(x-16), y=coord(y-drawing.y)}}}
elseif current_mode == 'line' or current_mode == 'manhattan' then
local j = insert_point(drawing.points, coord(x-16), coord(y-drawing.y))
drawing.pending = {mode=current_mode, p1=j}
elseif current_mode == 'polygon' then
local j = insert_point(drawing.points, coord(x-16), coord(y-drawing.y))
drawing.pending = {mode=current_mode, vertices={j}}
elseif current_mode == 'circle' then
local j = insert_point(drawing.points, coord(x-16), coord(y-drawing.y))
drawing.pending = {mode=current_mode, center=j}
end
lines.current = drawing
end
end
end
end
function insert_point(points, x,y)
for i,point in ipairs(points) do
if near(point, x,y) then
return i
end
end
table.insert(points, {x=x, y=y})
return #points
end
function near(point, x,y)
local px,py = pixels(x),pixels(y)
local cx,cy = pixels(point.x), pixels(point.y)
return (cx-px)*(cx-px) + (cy-py)*(cy-py) < 16
end
function 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(pixels(prev.x)+left,pixels(prev.y)+top, pixels(point.x)+left,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(pixels(p1.x)+left,pixels(p1.y)+top, pixels(p2.x)+left,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(pixels(prev.x)+left,pixels(prev.y)+top, pixels(curr.x)+left,pixels(curr.y)+top)
end
prev = curr
end
-- close the loop
local curr = drawing.points[shape.vertices[1]]
love.graphics.line(pixels(prev.x)+left,pixels(prev.y)+top, pixels(curr.x)+left,pixels(curr.y)+top)
elseif shape.mode == 'circle' then
local center = drawing.points[shape.center]
love.graphics.circle('line', pixels(center.x)+left,pixels(center.y)+top, pixels(shape.radius))
elseif shape.mode == 'arc' then
local center = drawing.points[shape.center]
love.graphics.arc('line', 'open', pixels(center.x)+left,pixels(center.y)+top, pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
elseif shape.mode == 'deleted' then
else
print(shape.mode)
assert(false)
end
end
function draw_pending_shape(left,top, drawing)
local shape = drawing.pending
if shape.mode == 'freehand' then
draw_shape(left,top, drawing, shape)
elseif shape.mode == 'line' then
local p1 = drawing.points[shape.p1]
local mx,my = coord(love.mouse.getX()-16), 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(pixels(p1.x)+left,pixels(p1.y)+top, pixels(mx)+left,pixels(my)+top)
elseif shape.mode == 'manhattan' then
local p1 = drawing.points[shape.p1]
local mx,my = coord(love.mouse.getX()-16), 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(pixels(p1.x)+left,pixels(p1.y)+top, pixels(mx)+left,pixels(p1.y)+top)
else
love.graphics.line(pixels(p1.x)+left,pixels(p1.y)+top, pixels(p1.x)+left,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(pixels(prev.x)+left,pixels(prev.y)+top, pixels(curr.x)+left,pixels(curr.y)+top)
end
prev = curr
end
love.graphics.line(pixels(prev.x)+left,pixels(prev.y)+top, love.mouse.getX(),love.mouse.getY())
elseif shape.mode == 'circle' then
local center = drawing.points[shape.center]
local mx,my = coord(love.mouse.getX()-16), 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 = pixels(center.x)+left, pixels(center.y)+top
love.graphics.circle('line', cx,cy, math.dist(cx,cy, love.mouse.getX(),love.mouse.getY()))
elseif shape.mode == 'arc' then
local center = drawing.points[shape.center]
local mx,my = coord(love.mouse.getX()-16), 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 = angle_with_hint(center.x,center.y, mx,my, shape.end_angle)
local cx,cy = pixels(center.x)+left, pixels(center.y)+top
love.graphics.arc('line', 'open', cx,cy, pixels(shape.radius), shape.start_angle, shape.end_angle, 360)
end
end
function on_shape(x,y, drawing, shape)
if shape.mode == 'freehand' then
return on_freehand(x,y, drawing, shape)
elseif shape.mode == 'line' then
return on_line(x,y, drawing, shape)
elseif shape.mode == 'manhattan' then
return x == drawing.points[shape.p1].x or y == drawing.points[shape.p1].y
elseif shape.mode == 'polygon' then
return on_polygon(x,y, drawing, shape)
elseif shape.mode == 'circle' then
local center = drawing.points[shape.center]
return math.dist(center.x,center.y, x,y) == shape.radius
elseif shape.mode == 'arc' then
local center = drawing.points[shape.center]
local dist = math.dist(center.x,center.y, x,y)
if dist < shape.radius*0.95 or dist > shape.radius*1.05 then
return false
end
return angle_between(center.x,center.y, x,y, shape.start_angle,shape.end_angle)
elseif shape.mode == 'deleted' then
else
print(shape.mode)
assert(false)
end
end
function on_freehand(x,y, drawing, shape)
local prev
for _,p in ipairs(shape.points) do
if prev then
if on_line(x,y, drawing, {p1=prev, p2=p}) then
return true
end
end
prev = p
end
return false
end
function on_line(x,y, drawing, shape)
local p1,p2
if type(shape.p1) == 'number' then
p1 = drawing.points[shape.p1]
p2 = drawing.points[shape.p2]
else
p1 = shape.p1
p2 = shape.p2
end
if p1.x == p2.x then
if math.abs(p1.x-x) > 5 then
return false
end
local y1,y2 = p1.y,p2.y
if y1 > y2 then
y1,y2 = y2,y1
end
return y >= y1 and y <= y2
end
-- has the right slope and intercept
local m = (p2.y - p1.y) / (p2.x - p1.x)
local yp = p1.y + m*(x-p1.x)
if yp < 0.95*y or yp > 1.05*y then
return false
end
-- between endpoints
local k = (x-p1.x) / (p2.x-p1.x)
return k > -0.05 and k < 1.05
end
function on_polygon(x,y, drawing, shape)
local prev
for _,p in ipairs(shape.vertices) do
if prev then
if on_line(x,y, drawing, {p1=prev, p2=p}) then
return true
end
end
prev = p
end
return on_line(x,y, drawing, {p1=shape.vertices[1], p2=shape.vertices[#shape.vertices]})
end
function angle_between(x1,y1, x2,y2, s,e)
local angle = math.angle(x1,y1, x2,y2)
--? print(s,e, angle-math.pi*2, angle, angle+math.pi*2)
if s > e then
s,e = e,s
end
-- I'm not sure this is right or ideal..
angle = angle-math.pi*2
if s <= angle and angle <= e then
return true
end
angle = angle+math.pi*2
if s <= angle and angle <= e then
return true
end
angle = angle+math.pi*2
return s <= angle and angle <= e
end
function love.textinput(t)
if love.mouse.isDown('1') then return end
if in_drawing() then return end
lines[#lines] = lines[#lines]..t
end
function keychord_pressed(chord)
-- Don't handle any keys here that would trigger love.textinput above.
if chord == 'return' then
table.insert(lines, '')
elseif chord == 'backspace' then
if #lines > 1 and lines[#lines] == '' then
table.remove(lines)
else
local byteoffset = utf8.offset(lines[#lines], -1)
if byteoffset then
lines[#lines] = string.sub(lines[#lines], 1, byteoffset-1)
end
end
elseif chord == 'C-r' then
lines[#lines+1] = eval(lines[#lines])[1]
lines[#lines+1] = ''
elseif chord == 'C-x' then
parse_into_exec_payload(lines[#lines])
elseif chord == 'C-f' and not love.mouse.isDown('1') then
current_mode = 'freehand'
elseif chord == 'C-g' and not love.mouse.isDown('1') then
current_mode = 'polygon'
elseif love.mouse.isDown('1') and chord == 'g' then
current_mode = 'polygon'
local drawing = current_drawing()
if drawing.pending.mode == 'line' then
drawing.pending.vertices = {drawing.pending.p1}
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_mode == 'polygon' then
local drawing = current_drawing()
local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-drawing.y)
local j = insert_point(drawing.points, mx,my)
table.insert(drawing.pending.vertices, j)
elseif chord == 'C-c' and not love.mouse.isDown('1') then
current_mode = 'circle'
elseif love.mouse.isDown('1') and chord == 'a' and current_mode == 'circle' then
local drawing = current_drawing()
drawing.pending.mode = 'arc'
local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-drawing.y)
local j = insert_point(drawing.points, mx,my)
local center = drawing.points[drawing.pending.center]
drawing.pending.radius = math.dist(center.x,center.y, mx,my)
drawing.pending.start_angle = math.angle(center.x,center.y, mx,my)
elseif love.mouse.isDown('1') and chord == 'c' then
current_mode = 'circle'
local drawing = current_drawing()
if drawing.pending.mode == 'line' 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_mode = 'line'
local drawing = current_drawing()
if drawing.pending.mode == 'freehand' then
drawing.pending.p1 = 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
end
drawing.pending.mode = 'line'
elseif chord == 'C-l' then
current_mode = 'line'
local drawing,i,shape = select_shape_at_mouse()
if drawing then
convert_line(drawing, shape)
end
elseif love.mouse.isDown('1') and chord == 'm' then
current_mode = 'manhattan'
local drawing = select_drawing_at_mouse()
if 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_mode = 'manhattan'
local drawing,i,shape = 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,i,shape = select_shape_at_mouse()
if drawing then
smoothen(shape)
end
elseif chord == 'C-v' and not love.mouse.isDown('1') then
local drawing,_,p = select_point_at_mouse()
if drawing then
previous_mode = current_mode
current_mode = 'move'
drawing.pending = {mode=current_mode, target_point=p}
lines.current = drawing
end
elseif love.mouse.isDown('1') and chord == 'v' then
local drawing,_,p = select_point_at_mouse()
if drawing then
previous_mode = current_mode
current_mode = 'move'
drawing.pending = {mode=current_mode, target_point=p}
lines.current = drawing
end
elseif chord == 'C-d' and not love.mouse.isDown('1') then
local drawing,i,p = select_point_at_mouse()
if drawing then
for _,shape in ipairs(drawing.shapes) do
if 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,i,shape = select_shape_at_mouse()
if drawing then
shape.mode = 'deleted'
end
end
end
function in_drawing()
local x, y = love.mouse.getX(), love.mouse.getY()
for _,drawing in ipairs(lines) do
if type(drawing) == 'table' then
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
return true
end
end
end
return false
end
function current_drawing()
local x, y = love.mouse.getX(), love.mouse.getY()
for _,drawing in ipairs(lines) do
if type(drawing) == 'table' then
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
return drawing
end
end
end
return nil
end
function select_shape_at_mouse()
for _,drawing in ipairs(lines) do
if type(drawing) == 'table' then
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-drawing.y)
for i,shape in ipairs(drawing.shapes) do
assert(shape)
if on_shape(mx,my, drawing, shape) then
return drawing,i,shape
end
end
end
end
end
end
function select_point_at_mouse()
for _,drawing in ipairs(lines) do
if type(drawing) == 'table' then
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-drawing.y)
for i,point in ipairs(drawing.points) do
assert(point)
if near(point, mx,my) then
return drawing,i,point
end
end
end
end
end
end
function select_drawing_at_mouse()
for _,drawing in ipairs(lines) do
if type(drawing) == 'table' then
local x, y = love.mouse.getX(), love.mouse.getY()
if y >= drawing.y and y < drawing.y + pixels(drawing.h) and x >= 16 and x < 16+drawingw then
return drawing
end
end
end
end
function contains_point(shape, p)
if shape.mode == 'freehand' then
-- not supported
elseif shape.mode == 'line' 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
assert(false)
end
end
function 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 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 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 love.keyreleased(key, scancode)
end
function table.find(h, x)
for k,v in pairs(h) do
if v == x then
return k
end
end
end
function angle_with_hint(x1, y1, x2, y2, hint)
local result = math.angle(x1,y1, x2,y2)
if hint then
-- Smooth the discontinuity where angle goes from positive to negative.
-- The hint is a memory of which way we drew it last time.
while result > hint+math.pi/10 do
result = result-math.pi*2
end
while result < hint-math.pi/10 do
result = result+math.pi*2
end
end
return result
end
-- result is from -π/2 to 3π/2, approximately adding math.atan2 from Lua 5.3
-- (LÖVE is Lua 5.1)
function math.angle(x1,y1, x2,y2)
local result = math.atan((y2-y1)/(x2-x1))
if x2 < x1 then
result = result+math.pi
end
return result
end
function math.dist(x1,y1, x2,y2) return ((x2-x1)^2+(y2-y1)^2)^0.5 end
function load_from_disk(filename)
local result = {}
local infile = io.open(filename)
if infile then
while true do
local line = infile:read()
if line == nil then break end
if line == '```lines' then -- inflexible with whitespace since these files are always autogenerated
table.insert(result, load_drawing(infile))
else
table.insert(result, line)
end
end
end
return result
end
function save_to_disk(lines, filename)
local outfile = io.open(filename, 'w')
for _,line in ipairs(lines) do
if type(line) == 'table' then
store_drawing(outfile, line)
else
outfile:write(line..'\n')
end
end
outfile:close()
end
json = require 'json'
function load_drawing(infile)
local drawing = {h=256/2, points={}, shapes={}, pending={}}
while true do
local line = infile:read()
assert(line)
if line == '```' then break end
local shape = json.decode(line)
if shape.mode == 'line' or shape.mode == 'manhattan' then
shape.p1 = insert_point(drawing.points, shape.p1.x, shape.p1.y)
shape.p2 = insert_point(drawing.points, shape.p2.x, shape.p2.y)
elseif shape.mode == 'polygon' then
for i,p in ipairs(shape.vertices) do
shape.vertices[i] = insert_point(drawing.points, p.x,p.y)
end
elseif shape.mode == 'circle' or shape.mode == 'arc' then
shape.center = insert_point(drawing.points, shape.center.x,shape.center.y)
end
table.insert(drawing.shapes, shape)
end
return drawing
end
function store_drawing(outfile, drawing)
outfile:write('```lines\n')
for _,shape in ipairs(drawing.shapes) do
if shape.mode == 'freehand' then
outfile:write(json.encode(shape)..'\n')
elseif shape.mode == 'line' or shape.mode == 'manhattan' then
local line = json.encode({mode=shape.mode, p1=drawing.points[shape.p1], p2=drawing.points[shape.p2]})
outfile:write(line..'\n')
elseif shape.mode == 'polygon' then
local obj = {mode=shape.mode, vertices={}}
for _,p in ipairs(shape.vertices) do
table.insert(obj.vertices, drawing.points[p])
end
local line = json.encode(obj)
outfile:write(line..'\n')
elseif shape.mode == 'circle' then
outfile:write(json.encode({mode=shape.mode, center=drawing.points[shape.center], radius=shape.radius})..'\n')
elseif shape.mode == 'arc' then
outfile:write(json.encode({mode=shape.mode, center=drawing.points[shape.center], radius=shape.radius, start_angle=shape.start_angle, end_angle=shape.end_angle})..'\n')
end
end
outfile:write('```\n')
end
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