smooth camera

code/camera.lua

@@ -1,36 +1,38 @@
 Camera = {
-	pos = {x = 0, y = 0},
+   pos = Point:new(0, 0),
    width = 0,
-	height = 0
+   height = 0,
+   speed = 4,
 }
 
 function Camera:followPlayer(player)
-	local pos = player.pos
+	-- make sure we have the Point metatable	self:moveTowards(pos)
+	local pos = Point.copy(player.pos)
 	local room = player:getCollidingAt(pos.x,pos.y,LoadedObjects.Rooms)
 
-	self:positionCenterAt(pos.x, pos.y)
-
-	self:confineTo(room)
+	self:moveTowards(self:confineTo(room, pos))
 end
 
-function Camera:confineTo(box)
+function Camera:confineTo(box, pos)
 	if box == nil then
 		--frameDebug("not in a room")
-		return
+		return pos
 	end
 	--frameDebug("in a room")
 
 	local w = self.width/game.scale
 	local h = self.height/game.scale
+	local npos = pos - self:centerOffset()
 
 	-- bottom edge
-	self.pos.y = math.min(self.pos.y+h, box.to.y)-h
+	npos.y = math.min(npos.y+h, box.to.y)-h
 	-- right edge
-	self.pos.x = math.min(self.pos.x+w, box.to.x)-w
+	npos.x = math.min(npos.x+w, box.to.x)-w
 	-- top edge
-	self.pos.y = math.max(self.pos.y, box.from.y)
+	npos.y = math.max(npos.y, box.from.y)
 	-- left edge
-	self.pos.x = math.max(self.pos.x, box.from.x)
+	npos.x = math.max(npos.x, box.from.x)
+	return npos + self:centerOffset()
 end
 
 function Camera:confineToLevel()
@@ -38,6 +40,32 @@ function Camera:confineToLevel()
 	self.pos.y = math.max(0,math.min(self.pos.y,LevelData.Height-self.height/game.scale))
 end
 
+function Camera:moveTowards(pt)
+   --local pt = Point:new(x,y)
+   local diff = pt - self:center()
+   local dist = diff:abs()
+   local npos
+   if dist < self.speed then
+	  npos = pt
+   else
+	   frameDebug("camera at speed limit")
+	   npos = self:center() + diff * (self.speed/dist)
+	   frameDebug("dist = "..dist..", npos = "..tostring(npos))
+   end
+   self:positionCenterAt(npos.x, npos.y)
+end
+
+function Camera:size()
+	return Point:new(self.width, self.height)
+end
+
+function Camera:centerOffset()
+	return self:size()/game.scale/2
+end
+
+function Camera:center()
+	return self.pos + self:centerOffset()
+end
 function Camera:positionCenterAt(x,y)
 	self.pos.x = x-self.width/game.scale/2
 	self.pos.y = y-self.height/game.scale/2
@@ -48,3 +76,4 @@ function Camera:positionAt(x,y)
 	self.pos.x = math.floor((x/self.width)*self.width)
 	self.pos.y = math.floor((y/self.height)*self.height)
 end
+

code/point.lua

@@ -2,7 +2,7 @@ Point = {}
 Point.__index = Point
 
 function Point:new(x, y)
-   local o = { x = x, y = y }
+   local o = { x = x or 0, y = y or 0 }
    setmetatable(o, self)
    return o
 end