modules/world: add a way to change speed to collision normal

gamecore/modules/world/actors/actor2D.lua

@@ -64,6 +64,8 @@ function Actor2D:initPhysics(x, y, w, h, isSolid)
   self.xfrc   = 0
   self.yfrc   = 0
 
+  self.bounceFactor   = 0
+
   self.isSolid = isSolid or false
 
   self:setFilter()
@@ -120,8 +122,11 @@ function Actor2D:autoMove(dt)
 end
 
 function Actor2D:solveAllCollisions(cols)
-  for i,v in ipairs(cols) do
+  for i, col in ipairs(cols) do
     self:collisionResponse(v)
+    if (col.type == "touch") or (col.type == "bounce") or (col.type == "slide") then
+      self:changeSpeedToCollisionNormal(col.normal.x, col.normal.y)
+    end
   end
 end
 
@@ -129,6 +134,20 @@ function Actor2D:collisionResponse(collision)
   -- here come the response to the collision
 end
 
+function Actor2D:changeSpeedToCollisionNormal(nx, ny)
+  local xsp, ysp = self.xsp, self.ysp
+
+  if (nx < 0 and xsp > 0) or (nx > 0 and xsp < 0) then
+    xsp = -xsp * self.bounceFactor
+  end
+
+  if (ny < 0 and ysp > 0) or (ny > 0 and ysp < 0) then
+    ysp = -ysp * self.bounceFactor
+  end
+
+  self.xsp, self.ysp = xsp, ysp
+end
+
 function Actor2D:move(dx, dy)
   local cols, colNumber
   self.x, self.y, cols, colNumber = self.world:moveActor(self, dx, dy, self.filter)