basic water render and physics

1 files changed, 48 insertions, 5 deletions

diff --git a/player.lua b/player.lua
index 7995cc6..b6bc4b5 100644
--- a/player.lua
+++ b/player.lua
@@ -5,7 +5,8 @@ local Player = {}
 Player.__index = Player
 setmetatable(Player, { __index = Entity })
 
-local MOVE_SPEED = 70
+local MOVE_SPEED = 65
+local SWIM_SPEED = 15
 local JUMP_FORCE = -200
 local GROUND_LAYER = "ground"
 
@@ -57,6 +58,9 @@ function Player.new(world, spawnX, spawnY)
   self.vy = 0
   
   self.grounded = false
+  self.isInLiquid = false
+  self.wasInLiquid = false
+  self.waterSurfaceContact = false
   return self
 end
 
@@ -98,6 +102,7 @@ function Player:update(dt)
   
   local c = self.contact or { floor = 0, wall = 0, ceiling = 0 }
   local onFloor = c.floor == 1
+  local onWaterSurface = self.waterSurfaceContact
   local prevOnFloor = self.wasOnFloor
   local prevState = self.state
 
@@ -105,7 +110,35 @@ function Player:update(dt)
   if love.keyboard.isDown("left", "a") then move = move - 1 end
   if love.keyboard.isDown("right", "d") then move = move + 1 end
 
-  if onFloor then
+  if self.isInLiquid then
+    local vx, vy = self.body:getLinearVelocity()
+    local mass = self.body:getMass()
+    local gx, gy = self.body:getWorld():getGravity()
+
+    if not self.wasInLiquid then
+      vx = vx * 0.4
+      vy = math.min(vy, 60)
+      self.body:setLinearVelocity(vx, vy)
+    end
+
+    self.body:setLinearDamping(6)
+
+    local buoyancy = 0.9
+    self.body:applyForce(0, -gy * mass * buoyancy)
+
+    local moveY = 0
+    if love.keyboard.isDown("up", "w") then moveY = moveY - 1 end
+    if love.keyboard.isDown("down", "s") then moveY = moveY + 1 end
+
+    local inputLen = math.sqrt(move * move + moveY * moveY)
+    if inputLen > 1 then
+      move = move / inputLen
+      moveY = moveY / inputLen
+    end
+
+    self.body:applyForce(move * SWIM_SPEED, moveY * SWIM_SPEED)
+  elseif onFloor or onWaterSurface then
+    self.body:setLinearDamping(0)
     self.availableJumps = 1
     if move ~= 0 then
       self.lastFacing = move
@@ -114,18 +147,23 @@ function Player:update(dt)
       self.body:setLinearVelocity(0, vy)
     end
   else
+    self.body:setLinearDamping(0)
     if move ~= 0 then self.lastFacing = move end
     self.body:setLinearVelocity(move * MOVE_SPEED * 0.7, vy)
   end
 
   local desiredState
-  if onFloor then
+  if self.isInLiquid then
+    desiredState = "swimming"
+  elseif onFloor then
     desiredState = (move ~= 0) and "running" or "idle"
   else
     desiredState = (vy < 0) and "jumping" or "falling"
   end
 
-  if self.state == "ground_hit" or self.state == "stop_running" then
+  if self.isInLiquid then
+    self.state = desiredState
+  elseif self.state == "ground_hit" or self.state == "stop_running" then
     if not onFloor or self.currentAnim:isFinished() then
       self.state = desiredState
     end
@@ -143,12 +181,14 @@ function Player:update(dt)
   end
 
   self.wasOnFloor = onFloor
+  self.wasInLiquid = self.isInLiquid
 
   local animMap = {
     idle         = self.animations.idle,
     running      = self.animations.running,
     jumping      = self.animations.going_up,
     falling      = self.animations.going_down,
+    swimming     = self.animations.going_down,
     stop_running = self.animations.stop_running,
     ground_hit   = self.animations.ground_hit,
   }
@@ -158,7 +198,10 @@ end
 
 function Player:jump()
   local c = self.contact or { floor = 0, wall = 0, ceiling = 0 }
-  local canJump = (c.floor == 1 or c.wall == 1) and (self.availableJumps or 0) > 0
+  local onWaterSurface = self.waterSurfaceContact
+  local canJump = (c.floor == 1 or c.wall == 1 or onWaterSurface) and (self.availableJumps or 0) > 0
+  if not canJump then return false end
+  if self.isInLiquid and not onWaterSurface then return false end
   if canJump then
     self.body:setLinearVelocity(self.body:getLinearVelocity(), JUMP_FORCE)
     self.state = "jumping"