joining

3 files changed, 224 insertions, 185 deletions

diff --git a/catenary.lua b/catenary.lua
new file mode 100644
index 0000000..abe18e1
--- /dev/null
+++ b/catenary.lua
@@ -0,0 +1,133 @@
+local G = love.graphics
+
+local function atanh(x)
+	return (1/2) * math.log((1+x)/(1-x))
+end
+
+local function solve_for_A(r)
+	local A
+	if r < 3 then
+		A = math.sqrt(6 * (r-1))
+	else
+		A = math.log(2*r) + math.log(math.log(2*r))
+	end
+	for i=1,5 do
+		A = A - (math.sinh(A) - r*A)/(math.cosh(A)-r)
+	end
+	return A
+end
+
+local function plot(f,x0,xn)
+	local n = 30
+	x0 = x0 or G.inverseTransformPoint(0,0)
+	xn = xn or G.inverseTransformPoint(G.getDimensions(),0)
+
+	if xn < x0 then
+		xn,x0 = x0,xn
+	end
+
+	local h = (xn-x0)/n
+	local ps = {}
+	for i=0,n do
+		local x = x0 + i*h
+		local y = f(x)
+		table.insert(ps,x)
+		table.insert(ps,y)
+	end
+	return ps
+end
+
+local function catenary0(x1,y1,x2,y2, L)
+	-- https://math.stackexchange.com/a/3557768
+	y1 = -y1
+	y2 = -y2
+	local dx = x2-x1
+	local dy = y2-y1
+	local mx = (x1+x2)/2
+	local my = (y1+y2)/2
+
+	local D = math.sqrt(dx^2+dy^2)
+	L = L or D+(1/(D+0.3))
+
+	local r = math.sqrt(L^2 - dy^2)/dx
+	local A = solve_for_A(r)
+
+	local a = dx/(2*A)
+	local b = mx - a*atanh(dy/L)
+	local c = my - L/(2*math.tanh(A))
+
+	return function(x) return -(a * math.cosh((x-b)/a) + c) end
+end
+
+
+local function catenary(x1,y1, x2,y2, L)
+	local D = math.sqrt((x2-x1)^2 + (y2-y1)^2)
+	-- L = L or D+(1/(D+0.3))
+	L = L or D+(0.1/(D+0.1))
+	-- L = D + 0.1
+
+	if x2 < x1 then
+		x1,x2 = x2,x1
+		y1,y2 = y2,y1
+	end
+
+	local f = catenary0(x1,y1,x2,y2,L)
+	return plot(f, x1,x2)
+end
+
+return {
+	catenary = catenary
+}
+
+
+--[[
+local Ps = {{-1,1}, {1,1}}
+
+function love.update(dt)
+	for b = 1,2 do
+		if love.mouse.isDown(b) then
+			Ps[b] = {G.inverseTransformPoint(love.mouse.getPosition())}
+		end
+	end
+end
+
+
+function love.draw()
+	local W,H = G.getDimensions()
+	G.clear(1,1,1)
+	G.setColor(0,0,0)
+	G.origin()
+	local dx = Ps[1][1] - Ps[2][1]
+	local dy = Ps[1][2] - Ps[2][2]
+	local D = math.sqrt(dx^2+dy^2)
+	local L = D+(1/(D+0.3))
+	-- local L = D+1
+	G.print(("%.2f\n%.2f\n%.2f"):format(L,D,L-D),10,10)
+	G.setLineWidth(0.01)
+	G.translate(W/2,H/2)
+	G.scale(50)
+
+	G.setColor(0.8,0.8,0.8)
+	for i=-10,10 do
+		G.line(-10,i,10,i)
+		G.line(i,-10,i,10)
+	end
+
+	G.circle('line',0,0,1)
+
+	-- G.setColor(0,0,0)
+	-- -- plot(function(x) return x^2 end)
+	-- plot(math.tanh)
+	-- G.setColor(0,1,0)
+	-- plot(atanh)
+
+	G.setColor(0,0,0)
+	G.line(catenary(Ps[1][1],Ps[1][2], Ps[2][1], Ps[2][2]))
+
+	G.setColor(1,0,0)
+	G.circle('fill',Ps[1][1],Ps[1][2],0.05)
+	G.setColor(0,0,1)
+	G.circle('fill',Ps[2][1],Ps[2][2],0.05)
+end
+--]]
+
diff --git a/main.lua b/main.lua
index 7b0a7c0..d1a84a8 100644
--- a/main.lua
+++ b/main.lua
@@ -1,131 +1,123 @@
+local class = require 'class'
+local hsluv = require 'hsluv'
+local catenary = require 'catenary'
+
+local tau = 2*math.pi
+local ZOOM = 200
 local G = love.graphics
 
-local function atanh(x)
-	return (1/2) * math.log((1+x)/(1-x))
+local function write_at(text,x,y)
+	G.push()
+	G.translate(x,y)
+	G.scale(1/ZOOM)
+	G.print(text,0,0)
+	G.pop()
 end
 
-local function solve_for_A(r)
-	local A
-	if r < 3 then
-		A = math.sqrt(6 * (r-1))
-	else
-		A = math.log(2*r) + math.log(math.log(2*r))
-	end
-	for i=1,5 do
-		A = A - (math.sinh(A) - r*A)/(math.cosh(A)-r)
-	end
-	return A
+local Port = class()
+Port.R = 0.1
+function Port.make(cls, x,y, num)
+	return setmetatable({x=x,y=y,n=num,wires={}},cls)
 end
-
-local function plot(f,x0,xn)
-	local n = 30
-	x0 = x0 or G.inverseTransformPoint(0,0)
-	xn = xn or G.inverseTransformPoint(G.getDimensions(),0)
-
-	if xn < x0 then
-		xn,x0 = x0,xn
-	end
-
-	local h = (xn-x0)/n
-	local ps = {}
-	for i=0,n do
-		local x = x0 + i*h
-		local y = f(x)
-		table.insert(ps,x)
-		table.insert(ps,y)
+function Port.draw(self, istate)
+	local c = {0,0,0}
+	if istate == 'hover' then
+		c[1] = 1
+	elseif istate == 'selected' then
+		c[2] = 1
 	end
-	return ps
+	love.graphics.setColor(c)
+	G.circle('line',self.x,self.y,self.R)
+	write_at(self.n, self.x, self.y)
+end
+function Port.contains(self, px,py)
+	local d = math.sqrt((self.x - px)^2 + (self.y - py)^2)
+	return d <= self.R
 end
 
-local function catenary0(x1,y1,x2,y2, L)
-	-- https://math.stackexchange.com/a/3557768
-	y1 = -y1
-	y2 = -y2
-	local dx = x2-x1
-	local dy = y2-y1
-	local mx = (x1+x2)/2
-	local my = (y1+y2)/2
-
-	local D = math.sqrt(dx^2+dy^2)
-	L = L or D+(1/(D+0.3))
-
-	local r = math.sqrt(L^2 - dy^2)/dx
-	local A = solve_for_A(r)
+local ports = {}
+local n = 10
+for i = 1,n do
+	local theta = tau * i/n
+	table.insert(ports, Port:make(math.cos(theta), math.sin(theta), i))
+end
+ports[3].wires = {ports[6]}
+ports[5].wires = {ports[7],ports[2]}
 
-	local a = dx/(2*A)
-	local b = mx - a*atanh(dy/L)
-	local c = my - L/(2*math.tanh(A))
 
-	return function(x) return -(a * math.cosh((x-b)/a) + c) end
+local function wire_color(n)
+	local phi = (1+math.sqrt(5))/2
+	local h = (360*phi*n)%360
+	return hsluv.hsluv_to_rgb({h, 80, 60})
 end
 
+local state = 'normal'
+local selected = nil
 
-local function catenary(x1,y1, x2,y2, L)
-	local D = math.sqrt((x2-x1)^2 + (y2-y1)^2)
-	L = L or D+(1/(D+0.3))
-
-	if x2 < x1 then
-		x1,x2 = x2,x1
-		y1,y2 = y2,y1
+local function hovering_port(mx,my)
+	for i,p in ipairs(ports) do
+		if p:contains(mx,my) then
+			return p
+		end
 	end
-
-	local f = catenary0(x1,y1,x2,y2,L)
-	return plot(f, x1,x2)
+	return nil
 end
 
-return {
-	catenary = catenary
-}
-
-
---[[
-local Ps = {{-1,1}, {1,1}}
-
-function love.update(dt)
-	for b = 1,2 do
-		if love.mouse.isDown(b) then
-			Ps[b] = {G.inverseTransformPoint(love.mouse.getPosition())}
+function love.mousepressed(x,y,b)
+	if b == 2 then
+		state = 'normal'
+		selected = nil
+		return
+	end
+	local mx,my = G.inverseTransformPoint(x,y)
+	local p = hovering_port(mx,my)
+	if p then
+		if state == 'normal' then
+			state = 'joining'
+			selected = p.n
+		elseif state == 'joining' then
+			table.insert(ports[selected].wires, p)
+			state = 'normal'
+			selected = nil
 		end
 	end
 end
 
 
+
+local L = 2
+function love.wheelmoved(x,y)
+	L = L + (y/15)
+end
+
 function love.draw()
 	local W,H = G.getDimensions()
 	G.clear(1,1,1)
 	G.setColor(0,0,0)
 	G.origin()
-	local dx = Ps[1][1] - Ps[2][1]
-	local dy = Ps[1][2] - Ps[2][2]
-	local D = math.sqrt(dx^2+dy^2)
-	local L = D+(1/(D+0.3))
-	-- local L = D+1
-	G.print(("%.2f\n%.2f\n%.2f"):format(L,D,L-D),10,10)
+	G.print(L,10,10)
 	G.setLineWidth(0.01)
 	G.translate(W/2,H/2)
-	G.scale(50)
-
-	G.setColor(0.8,0.8,0.8)
-	for i=-10,10 do
-		G.line(-10,i,10,i)
-		G.line(i,-10,i,10)
+	G.scale(ZOOM)
+
+	local mx,my = G.inverseTransformPoint(love.mouse.getPosition())
+	local wn = 0
+	for i,p in ipairs(ports) do
+		local istate = 'normal'
+		if p:contains(mx,my) then istate = 'hover' end
+		if state ~= 'normal' and selected == i then istate = 'selected' end
+		p:draw(istate)
+		for _,q in ipairs(p.wires) do
+			G.setColor(wire_color(wn))
+			wn = wn + 1
+			G.line(catenary.catenary(p.x,p.y,q.x,q.y))
+		end
 	end
 
-	G.circle('line',0,0,1)
-
-	-- G.setColor(0,0,0)
-	-- -- plot(function(x) return x^2 end)
-	-- plot(math.tanh)
-	-- G.setColor(0,1,0)
-	-- plot(atanh)
-
-	G.setColor(0,0,0)
-	G.line(catenary(Ps[1][1],Ps[1][2], Ps[2][1], Ps[2][2]))
-
-	G.setColor(1,0,0)
-	G.circle('fill',Ps[1][1],Ps[1][2],0.05)
-	G.setColor(0,0,1)
-	G.circle('fill',Ps[2][1],Ps[2][2],0.05)
+	if state == 'joining' then
+		G.setColor(wire_color(wn))
+		local p = ports[selected]
+		G.line(catenary.catenary(p.x,p.y,mx,my))
+	end
 end
---]]
 
diff --git a/main_old.lua b/main_old.lua
deleted file mode 100644
index 160a0d7..0000000
--- a/main_old.lua
+++ /dev/null
@@ -1,86 +0,0 @@
-local class = require 'class'
-local hsluv = require 'hsluv'
-
-local tau = 2*math.pi
-local ZOOM = 200
-local G = love.graphics
-
-local function write_at(text,x,y)
-	G.push()
-	G.translate(x,y)
-	G.scale(1/ZOOM)
-	G.print(text,0,0)
-	G.pop()
-end
-
-local Port = class()
-Port.R = 0.1
-function Port.make(cls, x,y, num)
-	return setmetatable({x=x,y=y,n=num,wires={}},cls)
-end
-function Port.draw(self, istate)
-	local c = {0,0,0}
-	if istate == 'hover' then
-		c[1] = 1
-	end
-	love.graphics.setColor(c)
-	G.circle('line',self.x,self.y,self.R)
-	write_at(self.n, self.x, self.y)
-end
-function Port.contains(self, px,py)
-	local d = math.sqrt((self.x - px)^2 + (self.y - py)^2)
-	return d <= self.R
-end
-
-local ports = {}
-local n = 10
-for i = 1,n do
-	local theta = tau * i/n
-	table.insert(ports, Port:make(math.cos(theta), math.sin(theta), i))
-end
-ports[3].wires = {ports[6]}
-ports[5].wires = {ports[7],ports[2]}
-for i = 1,15 do
-	local r1,r2 = math.random(10), math.random(10)
-	if r1 ~= r2 then
-		table.insert(ports[r1].wires, ports[r2])
-	end
-end
-
-
-local function catenary(x1,y1,x2,y2)
-	-- https://math.stackexchange.com/questions/3557767/how-to-construct-a-catenary-of-a-specified-length-through-two-specified-points
-
-end
-
-local function wire_color(n)
-	local phi = (1+math.sqrt(5))/2
-	local h = (360*phi*n)%360
-	return hsluv.hsluv_to_rgb({h, 80, 60})
-end
-
-local state = 'normal'
-
-
-function love.draw()
-	local W,H = G.getDimensions()
-	G.clear(1,1,1)
-	G.setColor(0,0,0)
-	G.origin()
-	G.setLineWidth(0.01)
-	G.translate(W/2,H/2)
-	G.scale(ZOOM)
-
-	local mx,my = G.inverseTransformPoint(love.mouse.getPosition())
-	local wn = 0
-	for i,p in ipairs(ports) do
-		local istate = p:contains(mx,my) and 'hover' or 'normal'
-		p:draw(istate)
-		for _,q in ipairs(p.wires) do
-			G.setColor(wire_color(wn))
-			wn = wn + 1
-			catenary(p.x,p.y,q.x,q.y)
-		end
-	end
-end
-