diff options
Diffstat (limited to 'obj.lua')
| -rw-r--r-- | obj.lua | 52 |
1 files changed, 35 insertions, 17 deletions
@@ -1,4 +1,5 @@ local world = require "world" +local util = require "util" local pi = math.pi local obj = {} @@ -122,15 +123,35 @@ function obj:tick(...) local ox, oy = unpack(o.data.pos) local dx, dy = ox - x, oy - y if dx*dx + dy*dy < dist*dist then + -- local ke = self:energy() + o:energy() + self:collision(o) + o:collision(self) + local angle = math.atan2(dy, dx) - self:collision(o, angle) - o:collision(self, pi - angle) + -- reposition self outside of collided object self:set_pos( self.data.pos[1] - math.cos(angle) * dist + dx, self.data.pos[2] - math.sin(angle) * dist + dy) - self:collision_exit(o, angle) - o:collision_exit(self, pi - angle) + + local av1, av2 = self.data.avel, o.data.avel + -- transfer angular velocity conserving energy + local avel = math.sqrt((av1*av1 + av2*av2) / 2) + self.data.avel = avel * (av1 > av2 and 1 or -1) + o.data.avel = avel * (av1 > av2 and -1 or 1) + + local vx, vy = unpack(self.data.vel) + local ovx, ovy = unpack(o.data.vel) + -- exchange the components of the velocities towards the + -- angle of collision + local rovx, rvy = util.rot(angle, vx, vy) + local rvx, rovy = util.rot(angle, ovx, ovy) + self.data.vel[1], self.data.vel[2] = util.rot(-angle, rvx, rvy) + o.data.vel[1], o.data.vel[2] = util.rot(-angle, rovx, rovy) + + self:collision_exit(o) + o:collision_exit(self) + -- assert(ke - (self:energy() + o:energy()) < 0.00001) end end end @@ -149,21 +170,18 @@ function obj:draw(...) love.graphics.pop() end -function obj:collision(collided, angle) - self.force = {collided.data.vel[1] * math.cos(angle), - collided.data.vel[2] * math.sin(angle)} - self.torque = -collided.data.avel - return self:overload("collision", collided, angle, self.force) +function obj:collision(...) + return self:overload("collision", ...) end -function obj:collision_exit(collided, angle) - self.data.vel[1] = self.data.vel[1] + self.force[1] - self.data.vel[2] = self.data.vel[2] + self.force[2] - collided.data.vel[1] = collided.data.vel[1] - self.force[1] - collided.data.vel[2] = collided.data.vel[2] - self.force[2] - self.data.avel = self.data.avel + self.torque - collided.data.avel = collided.data.avel + self.torque - return self:overload("collision_exit", collided, angle, self.force) +function obj:collision_exit(...) + return self:overload("collision_exit", ...) +end + +function obj:energy() + local vx, vy = unpack(self.data.vel) + local avel = self.data.avel + return 1 + avel*avel + vx*vx + vy*vy end function obj:in_hitbox(px, py) |