2022-05-18 05:18:17 +01:00
|
|
|
local geom = {}
|
|
|
|
|
|
|
|
function geom.on_shape(x,y, drawing, shape)
|
|
|
|
if shape.mode == 'freehand' then
|
|
|
|
return geom.on_freehand(x,y, drawing, shape)
|
|
|
|
elseif shape.mode == 'line' then
|
|
|
|
return geom.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
|
2022-05-18 23:29:18 +01:00
|
|
|
elseif shape.mode == 'polygon' or shape.mode == 'rectangle' or shape.mode == 'square' then
|
2022-05-18 05:18:17 +01:00
|
|
|
return geom.on_polygon(x,y, drawing, shape)
|
|
|
|
elseif shape.mode == 'circle' then
|
|
|
|
local center = drawing.points[shape.center]
|
2022-05-18 06:36:10 +01:00
|
|
|
return geom.dist(center.x,center.y, x,y) == shape.radius
|
2022-05-18 05:18:17 +01:00
|
|
|
elseif shape.mode == 'arc' then
|
|
|
|
local center = drawing.points[shape.center]
|
2022-05-18 06:36:10 +01:00
|
|
|
local dist = geom.dist(center.x,center.y, x,y)
|
2022-05-18 05:18:17 +01:00
|
|
|
if dist < shape.radius*0.95 or dist > shape.radius*1.05 then
|
|
|
|
return false
|
|
|
|
end
|
|
|
|
return geom.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 geom.on_freehand(x,y, drawing, shape)
|
|
|
|
local prev
|
|
|
|
for _,p in ipairs(shape.points) do
|
|
|
|
if prev then
|
|
|
|
if geom.on_line(x,y, drawing, {p1=prev, p2=p}) then
|
|
|
|
return true
|
|
|
|
end
|
|
|
|
end
|
|
|
|
prev = p
|
|
|
|
end
|
|
|
|
return false
|
|
|
|
end
|
|
|
|
|
|
|
|
function geom.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 geom.on_polygon(x,y, drawing, shape)
|
|
|
|
local prev
|
|
|
|
for _,p in ipairs(shape.vertices) do
|
|
|
|
if prev then
|
|
|
|
if geom.on_line(x,y, drawing, {p1=prev, p2=p}) then
|
|
|
|
return true
|
|
|
|
end
|
|
|
|
end
|
|
|
|
prev = p
|
|
|
|
end
|
|
|
|
return geom.on_line(x,y, drawing, {p1=shape.vertices[1], p2=shape.vertices[#shape.vertices]})
|
|
|
|
end
|
|
|
|
|
2022-05-18 23:29:18 +01:00
|
|
|
-- are (x3,y3) and (x4,y4) on the same side of the line between (x1,y1) and (x2,y2)
|
|
|
|
function geom.same_side(x1,y1, x2,y2, x3,y3, x4,y4)
|
|
|
|
if x1 == x2 then
|
|
|
|
return math.sign(x3-x1) == math.sign(x4-x1)
|
|
|
|
end
|
|
|
|
if y1 == y2 then
|
|
|
|
return math.sign(y3-y1) == math.sign(y4-y1)
|
|
|
|
end
|
|
|
|
local m = (y2-y1)/(x2-x1)
|
|
|
|
return math.sign(m*(x3-x1) + y1-y3) == math.sign(m*(x4-x1) + y1-y4)
|
|
|
|
end
|
|
|
|
|
|
|
|
function math.sign(x)
|
|
|
|
if x > 0 then
|
|
|
|
return 1
|
|
|
|
elseif x == 0 then
|
|
|
|
return 0
|
|
|
|
elseif x < 0 then
|
|
|
|
return -1
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
2022-05-18 05:18:17 +01:00
|
|
|
function geom.angle_with_hint(x1, y1, x2, y2, hint)
|
|
|
|
local result = geom.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 geom.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
|
|
|
|
|
|
|
|
-- is the line between x,y and cx,cy at an angle between s and e?
|
|
|
|
function geom.angle_between(ox,oy, x,y, s,e)
|
2022-05-18 06:36:10 +01:00
|
|
|
local angle = geom.angle(ox,oy, x,y)
|
2022-05-18 05:18:17 +01:00
|
|
|
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 geom.dist(x1,y1, x2,y2) return ((x2-x1)^2+(y2-y1)^2)^0.5 end
|
|
|
|
|
|
|
|
return geom
|