1. Entry Signals
BUY SIGNAL: 1. price above EMA. 2. MACD line crosses the signal line from below, the cross happens below the zero line. 
SELL SIGNAL: 1. price below EMA. 2. MACD line crosses the signal line from above, the cross happens above the zero line. 

2. Trade examples
BUY ORDER EXAMPLE: Buy order is placed as per entry rules above.The first order is placed for 0.1 lots (also place a Stop Loss at 29 pips and a Take Profit at 30 pips). At the same time a Sell Stop order for 0.2 lots is placed 30 pips below the original order opening price with a 29 pip SL and 30 pip TP. If the first position hits SL and second order is triggered, place a Buy Stop order 30 pips above the new order for 0.4 lots. Etc… The  order sizes will be 0.1/ 0.2/ 0.4/ 0.8/ 1.6/etc… until Take Profit is hit.
If the stop loss is hit and the new order has not been triggered because price has reversed, place a new order on the opposite side, where price is now headed towards (in this situation there will be  both a buy stop and sell stop order set up for the same lot size).

SELL ORDER EXAMPLE: Sell order is placed as per entry rules above.The first order is placed for 0.1 lots (also place a Stop Loss at 29 pips and a Take Profit at 30 pips). At the same time a Buy Stop order for 0.2 lots is placed 30 pips above the original order opening price with a 29 pip SL and 30 pip TP. If the first position hits SL and second order is triggered, place a Sell Stop order 30 pips below the new order for 0.4 lots. Etc… The  order sizes will be 0.1/ 0.2/ 0.4/ 0.8/ 1.6/etc… until Take Profit is hit.
If the stop loss is hit and the new order has not been triggered because price has reversed, place a new order on the opposite side, where price is now headed towards (in this situation there will be  both a buy stop and sell stop order set up for the same lot size).

3. Orders quantity
Only 1 order per currency pair can be open at the same time. Once the sequence of trade multiplication described above starts, the MACD & EMA entry signals are ignored until the sequence ends with a take profit. Then the EA waits for a new entry signal.

4. Parameters ahat need to be adjustable

EMA
MACD
The original lot size
Take Profit
Stop Loss
Distance from the Stop Loss to the new order
Lot multiplication factor for new trades

5. Please add anyything found in a typical EA that I have not mentioned.