add a level of indirection to vertices of shapes
This is like Sketchpad.
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parent
ece73b6683
commit
7d5a70379f
105
main.lua
105
main.lua
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@ -75,7 +75,7 @@ function love.draw()
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love.graphics.setColor(0, 0, 0)
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end,
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onpress1 = function()
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table.insert(lines, i, {y=y, h=256/2, shapes={}, pending={}})
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table.insert(lines, i, {y=y, h=256/2, points={}, shapes={}, pending={}})
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end})
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elseif type(line) == 'table' then
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-- line drawing
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@ -87,14 +87,22 @@ function love.draw()
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local mx,my = coord(love.mouse.getX()-16), coord(love.mouse.getY()-line.y)
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for _,shape in ipairs(line.shapes) do
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if on_shape(mx,my, shape) then
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if on_shape(mx,my, line, shape) then
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love.graphics.setColor(1,0,0)
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else
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love.graphics.setColor(0,0,0)
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end
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draw_shape(16,line.y, shape)
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draw_shape(16,line.y, line, shape)
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end
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draw_pending_shape(16,line.y, line.pending)
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for _,p in ipairs(line.points) do
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if p.x == mx and p.y == my then
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love.graphics.setColor(1,0,0)
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else
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love.graphics.setColor(0,0,0)
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end
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love.graphics.circle('line', pixels(p.x)+16,pixels(p.y)+line.y, 4)
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end
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draw_pending_shape(16,line.y, line)
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else
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love.graphics.draw(text, 25,y, 0, 1.5)
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end
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@ -135,8 +143,8 @@ function love.mousereleased(x,y, button)
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if lines.current.pending.mode == 'freehand' then
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-- the last point added during update is good enough
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elseif lines.current.pending.mode == 'line' then
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lines.current.pending.x2 = coord(x-16)
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lines.current.pending.y2 = coord(y-lines.current.y)
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local j = insert_point(lines.current.points, coord(x-16), coord(y-lines.current.y))
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lines.current.pending.p2 = j
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end
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table.insert(lines.current.shapes, lines.current.pending)
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lines.current.pending = {}
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@ -153,7 +161,8 @@ function propagate_to_drawings(x,y, button)
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if current_mode == 'freehand' then
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drawing.pending = {mode='freehand', points={x=coord(x-16), y=coord(y-drawing.y)}}
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elseif current_mode == 'line' then
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drawing.pending = {mode='line', x1=coord(x-16), y1=coord(y-drawing.y)}
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local j = insert_point(drawing.points, coord(x-16), coord(y-drawing.y))
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drawing.pending = {mode='line', p1=j}
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end
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lines.current = drawing
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end
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@ -161,7 +170,17 @@ function propagate_to_drawings(x,y, button)
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end
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end
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function draw_shape(left,top, shape)
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function insert_point(points, x,y)
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for i,point in ipairs(points) do
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if point.x == x and point.y == y then
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return i
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end
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end
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table.insert(points, {x=x, y=y})
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return #points
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end
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function draw_shape(left,top, drawing, shape)
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if shape.mode == 'freehand' then
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local prev = nil
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for _,point in ipairs(shape.points) do
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@ -171,33 +190,37 @@ function draw_shape(left,top, shape)
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prev = point
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end
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elseif shape.mode == 'line' then
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love.graphics.line(pixels(shape.x1)+left,pixels(shape.y1)+top, pixels(shape.x2)+left,pixels(shape.y2)+top)
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local p1 = drawing.points[shape.p1]
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local p2 = drawing.points[shape.p2]
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love.graphics.line(pixels(p1.x)+left,pixels(p1.y)+top, pixels(p2.x)+left,pixels(p2.y)+top)
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end
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end
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function draw_pending_shape(left,top, shape)
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function draw_pending_shape(left,top, drawing)
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local shape = drawing.pending
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if shape.mode == 'freehand' then
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draw_shape(left,top, shape)
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draw_shape(left,top, drawing, shape)
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elseif shape.mode == 'line' then
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love.graphics.line(pixels(shape.x1)+left,pixels(shape.y1)+top, love.mouse.getX(),love.mouse.getY())
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local p1 = drawing.points[shape.p1]
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love.graphics.line(pixels(p1.x)+left,pixels(p1.y)+top, love.mouse.getX(),love.mouse.getY())
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end
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end
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function on_shape(x,y, shape)
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function on_shape(x,y, drawing, shape)
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if shape.mode == 'freehand' then
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return on_freehand(x,y, shape)
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return on_freehand(x,y, drawing, shape)
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elseif shape.mode == 'line' then
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return on_line(x,y, shape)
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return on_line(x,y, drawing, shape)
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else
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assert(false)
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end
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end
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function on_freehand(x,y, shape)
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function on_freehand(x,y, drawing, shape)
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local prev
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for _,p in ipairs(shape.points) do
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if prev then
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if on_line(x,y, {x1=prev.x,y1=prev.y, x2=p.x,y2=p.y}) then
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if on_line(x,y, drawing, {p1=prev, p2=p}) then
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return true
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end
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end
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@ -206,25 +229,33 @@ function on_freehand(x,y, shape)
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return false
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end
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function on_line(x,y, shape)
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if shape.x1 == shape.x2 then
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if math.abs(shape.x1-x) > 5 then
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function on_line(x,y, drawing, shape)
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local p1,p2
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if type(shape.p1) == 'number' then
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p1 = drawing.points[shape.p1]
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p2 = drawing.points[shape.p2]
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else
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p1 = shape.p1
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p2 = shape.p2
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end
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if p1.x == p2.x then
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if math.abs(p1.x-x) > 5 then
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return false
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end
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local y1,y2 = shape.y1,shape.y2
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local y1,y2 = p1.y,p2.y
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if y1 > y2 then
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y1,y2 = y2,y1
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end
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return y >= y1 and y <= y2
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end
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-- has the right slope and intercept
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local m = (shape.y2 - shape.y1) / (shape.x2 - shape.x1)
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local yp = shape.y1 + m*(x-shape.x1)
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local m = (p2.y - p1.y) / (p2.x - p1.x)
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local yp = p1.y + m*(x-p1.x)
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if yp < 0.95*y or yp > 1.05*y then
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return false
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end
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-- between endpoints
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local k = (x-shape.x1) / (shape.x2-shape.x1)
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local k = (x-p1.x) / (p2.x-p1.x)
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return k > -0.05 and k < 1.05
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end
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@ -259,18 +290,17 @@ function keychord_pressed(chord)
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local drawing = current_drawing()
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assert(drawing.pending.mode == 'freehand')
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drawing.pending.mode = 'line'
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drawing.pending.x1 = drawing.pending.points[1].x
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drawing.pending.y1 = drawing.pending.points[1].y
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drawing.pending.p1 = insert_point(drawing.points, drawing.pending.points[1].x, drawing.pending.points[1].y)
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elseif chord == 'C-l' then
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current_mode = 'line'
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local drawing,i,shape = select_shape_at_mouse()
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if drawing then
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convert_line(shape)
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convert_line(drawing, shape)
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end
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elseif chord == 'C-m' then
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local drawing,i,shape = select_shape_at_mouse()
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if drawing then
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convert_horvert(shape)
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convert_horvert(drawing, shape)
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end
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elseif chord == 'C-s' then
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local drawing,i,shape = select_shape_at_mouse()
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@ -320,29 +350,30 @@ function select_shape_at_mouse()
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end
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end
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function convert_line(shape)
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function convert_line(drawing, shape)
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-- Perhaps we should do a more sophisticated "simple linear regression"
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-- here:
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-- https://en.wikipedia.org/wiki/Linear_regression#Simple_and_multiple_linear_regression
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-- But this works well enough for close-to-linear strokes.
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assert(shape.mode == 'freehand')
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shape.mode = 'line'
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shape.x1 = shape.points[1].x
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shape.y1 = shape.points[1].y
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shape.x2 = shape.points[#shape.points].x
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shape.y2 = shape.points[#shape.points].y
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shape.p1 = insert_point(drawing.points, shape.points[1].x, shape.points[1].y)
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local n = #shape.points
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shape.p2 = insert_point(drawing.points, shape.points[n].x, shape.points[n].y)
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end
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-- turn a line either horizontal or vertical
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function convert_horvert(shape)
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function convert_horvert(drawing, shape)
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if shape.mode == 'freehand' then
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convert_line(shape)
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end
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assert(shape.mode == 'line')
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if math.abs(shape.x1-shape.x2) > math.abs(shape.y1-shape.y2) then
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shape.y2 = shape.y1
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local p1 = drawing.points[shape.p1]
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local p2 = drawing.points[shape.p2]
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if math.abs(p1.x-p2.x) > math.abs(p1.y-p2.y) then
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p2.y = p1.y
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else
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shape.x2 = shape.x1
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p2.x = p1.x
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end
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end
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