角色跑动：朝哪个方向跑都有正脸

mir8-walk

function gameActor:UpdateMove(dt)
    if self._moveTarget then
        local dx = self._moveTarget.x - self._x
        local dy = self._moveTarget.y - self._y
        local dist = math.sqrt(dx * dx + dy * dy)
        if dist < 2 then
            self._moveTarget = nil
            self:PlayAction(global.MMO.ANIM_IDLE)     -- 到站切站立
        else
            local step = math.min(dist, self._speed * dt)
            self._x = self._x + dx / dist * step
            self._y = self._y + dy / dist * step
            self._dir = self:CalcDir8(dx, dy)          -- 连续角量化八方向
            self:PlayAction(global.MMO.ANIM_RUN)
        end
    end
    self._frameAcc = self._frameAcc + dt               -- 换帧独立推进
    local itv = 1 / self._fps
    while self._frameAcc >= itv do
        self._frameAcc = self._frameAcc - itv
        self._frameIndex = (self._frameIndex + 1) % self:GetFrameCount(self._act, self._dir)
    end
end

function gameActor:CalcDir8(dx, dy)
    local deg = math.atan2(dy, dx) * 57.29577951 + 90  -- 0度=上
    return math.round(((deg + 360) % 360) / 45) % 8
end