From: Clifton James Palmer <clifton.palmer@gmail.com>
Date: Sat, 8 Dec 2018 18:23:11 +0000 (-0600)
Subject: Added collision detection and pause on crash
X-Git-Url: http://git.purplebirdman.com/lightcycles-love.git/commitdiff_plain/7f2cb3d1095471a2c4881249e0d6239f34f2a3b8?ds=sidebyside

Added collision detection and pause on crash
---

diff --git a/main.lua b/main.lua
index a0d0ca7..69591dd 100644
--- a/main.lua
+++ b/main.lua
@@ -14,7 +14,9 @@ function love.update(dt)
     if love.keyboard.isDown('escape') then
         love.event.quit()
     end
-    scene:update(dt)
+    if not scene.paused then
+        scene:update(dt)
+    end
 end
 
 function love.quit()
diff --git a/scene.lua b/scene.lua
index 73164e3..84c4473 100644
--- a/scene.lua
+++ b/scene.lua
@@ -5,6 +5,7 @@ require 'player'
 
 
 scene = {}
+scene.paused = false
 scene.width = love.graphics.getWidth()
 scene.height = love.graphics.getHeight()
 scene.players = {}
@@ -16,7 +17,7 @@ scene.grid.delta = 50
 -- load
 function scene:load()
     table.insert(scene.players, require('players/1'))
-    table.insert(scene.players, require('players/2'))
+    --table.insert(scene.players, require('players/2'))
 end
 
 -- draw
@@ -41,6 +42,12 @@ end
 function scene:draw()
     self:drawGrid()
     self:drawPlayers()
+
+    -- draw intersection if it's there
+    if self.intersection then
+        love.graphics.setColor(0, 255, 0)
+        love.graphics.line(self.intersection)
+    end
 end
 
 -- update
@@ -50,10 +57,53 @@ function scene:updatePlayers(dt)
     end
 end
 
+function doLinesIntersect(x1, y1, x2, y2, x3, y3, x4, y4)
+    if x1 == x2 and x3 == x4
+    or y1 == y2 and y3 == y4
+    then
+        -- if lines are parallel, no intersection!
+        return false
+    else
+        -- if lines are not parallel, they must intersect
+        -- do segments overlap?
+        if
+            x1 <= x3 and x3 <= x2
+        and y1 <= y3 and y3 <= y2
+        or
+            x3 <= x1 and x1 <= x4
+        and y3 <= y1 and y1 <= y4
+        then
+            scene.paused = true
+            scene.intersection = {x1, y1, x2, y2, x3, y3, x4, y4}
+            return true
+        end
+    end
+end
+
 function doesLineIntersectPlayerPaths(path, x1, y1, x2, y2)
+    local stash = {}
+    -- for every line in path,
+    -- check intersection with player line
+    for k,v in pairs(path) do
+        if #stash == 4 then
+            if doLinesIntersect(x1, y1, x2, y2, stash[4], stash[3], stash[2], stash[1]) then
+                return true
+            end
+            stash = {}
+        else
+            table.insert(stash,v)
+        end
+    end
     return false
 end
 
+-- love collision handler
+function collision(player)
+    print('Player '..tostring(player)..' crashed!')
+    --love.event.quit()
+end
+love.handlers.collision = collision
+
 function scene:handleCollisions()
     -- calculate the last line for each player from current position
     -- check if line intersects any other path line