RogueLike Part 2

THE ESSENCE OF CODING

SET A VARIABLE

CHECK A VARIABLE

ADD or SUBTRACT FROM A VARIABLE

Conditionals

IF condition THEN DO instruction

Loops

Step

6 b

12 a

28 a

29a

29b

29c

29d

34a

36 a

38a

38b

Directions

Attacking

Image

Lets start on our attack script. This will be used by you the player and monsters. We call all these the actors in your game. Lets think about what we have set up so far in our game.

We have:

Health

Level

Armor

Weapon

So the monsters should have the same stats so all actors in the game can use the same script

Attacking

We will use classic dungeons and dragons type of attack.

Combat Step by Step

1. Determine surprise. The GM determines whether anyone involved in the combat encounter is surprised.
2. Establish positions: The GM decides where all the characters and Monsters are located. Given the adventurers’ marching order or their stated positions in the room or other location, the GM figures out where the adversaries are̶how far away and in what direction.
3. Roll initiative: Everyone involved in the combat encounter rolls initiative, determining the order of combatants’ turns.
4. Take turns. Each participant in the battle takes a turn in initiative order.
5. Begin the next round. When everyone involved in the combat has had a turn, the round ends. Repeat step 4 until the fighting stops.

In our game we do not have surprise, position or initiative. We simply walk into a monster to attack it. We may attack more than the monster or vice versa based upon speedy variable of the monster. The base speed of the character is 10. A monster will automatically attack you if you are less than 33 pixels from him.

reference

https://docs.yoyogames.com/source/dadiospice/001_advanced%20use/more%20about%20objects/parents.html

To Hit Script Flow Chart

Now that we have the variables we need lets create the script

The script will determine if we hit the monster

There are three possible outcomes:

Miss
Hit
Critical Hit

If you roll a natural 20 it is always a critical hit no matter what armor the monster has

If you roll a natural 1 it is always a miss

Create a script and call it toHit()

Before we create this complex script lets create a flowchart for it

Flow Charts are essential to break down what happens in a complex script.

Now Make your own Flow Chart we will do it in the simplest way here are your directions turn into the google class room when done

We will be using this info to create our flow charts and our scripts one script to determine if we hit the target the second to determine damage

You can modify your attack flow charts to make your script

reference

http://dnd4.wikia.com/wiki/Attack_roll

http://dnd4.wikia.com/wiki/Damage_roll

http://dnd4.wikia.com/wiki/Critical_hit

Damage Flow Chart

Can you create the damage script on your own?

Think of this script as an input output machine.

You put in a value and it spits out another value.

Scripts can also be used by any object in your game

Create Code for To Hit script

The good thing about using scripts is you can modify them at anytime without changing other code

In the script we are passing 2 arguments. What this means is that 2 numbers will be used by the script to return damage

Remember to add the /// comment this will also auto-fill the arguments needed when you call the script

We need to assign a new variable in the monster object and call it result so go to create event of the monster add result=""; and also add level = 1;

Now create the script called toHit this script will determine if the attack is a hit and what type of hit normal or critical.

The variable result will hold the result of the roll as a string value.

This string value will be used to update the Event Log

Can you follow the code by looking at the flow chart?

Create Damage Roll Script

Now we will create the damage roll script

This will use the result of the AttackRoll script to determine the damage dealt

Notice that the result that we got from previous script determine how much damage we deal

dam*=2 code is how we multiply the dam variable by 2

Add Roll Dice script

Since our monster has hit dice to hit lets create a script to roll the dice and give a number for damage

You can find this script at GMLscripts.com

Call Scripts

Now we need to "call" the scripts or run them at the correct time in the game open the monMove script

Can you find where an attack should take place i this script?

Yes when a monster is less than 33 pixels from the player and attack occurs since this will also only happen once per turn.

We need to add a new variable result=""; to the create event of your player

Also notice how we call scripts with arguments

result = toHit(level,global.armor);

level is the level of the monster

global.level is the level of the player

global.armor is the armor of the player

damage is subtracted by the players hit points

global.hp-=damage;

We also add the result of the attack to the text log with:

ds_list_add(global.text, "The "+string(name)+" "+string(result)+" you.");

Use Attack Scripts in Player

Now we will use the same script to get the result and damage when the player attacks a monster.

Open the playerMove script

When should an attack take place in this script?

We need to think about this a bit what if you are surrounded by enemies?

You can only attack one monster per turn so how do we target a particular monster?

We will have to press a key to toward the monster we want to attack

So we will have to check if there is a monster in the direction we press to start the toHit script.

If you look at the playerMove script you will notice that we check if anything solid is in the way of our character before we move in that direction. Since our monsters are flagged as solid we cant walk over the top of a monster.

So we need to make a second check after this one that looks for a monster in that direction

We also need to check to see if a monster instance exsists to avoid and error in the game ( We cant check for an instance that doesnt exsist)

This script call is codey if that is a word and can be optimized for those with the skill.

Can you think of a way to optimize this script call.

A few new things are in the call. One is getting the ID of the monster.

Every time you put and object in your room it is given an instance ID. Each one is unique and it is how game maker identifies it in the game. So if you have 5 skeletons in your room each has a different ID.

This will need to be added for all 8 directions However you could change all the code inside the instance exists and place_freecheck into a script to keep it cleaner

Add Death check to Scripts

When we test the attacking script we notice that an attack takes place damage is dealt and the text logs gives us info

The monsters and you never die when the hit points reach 0 so lets add a new check for death.

What we have to do is add a new instance variable that will be able to be changed if you kill the monster so line 22 will get the value of the name of the monster you are attacking and place it in name variable

The reason we have to do this is because we destroy the monster if its hp falls below 0

We also use the with construction to destroy the monster whos ID we have targeted previously

Add Experience to Kills

Every-time you kill an enemy you should gain some experience.

You can make the level, hit points and exp static or random like I have done

irandom_range is a function which will choose an integer between the two #'s you select

This seeds all the other variables hp = level * 6

XP = level * hp

You could just put in numbers like:

level = 3

hp = 20

monExp = 30

I like to make it more random.

You need to experiment with the monster variables to make your game balanced not to easy and not too hard.

Create XP Script

Lets create an XP to the script that will check to see if you level up after each kill

We will use a XP formula that is non linear that is it takes more XP to level as you get to higher levels

Add Level Check to playerMove script

Lets add the level check now

If monsters HP is less than 0 we run the level check script after we add the monsters exp to our global.experience variable

Here is a table of experience need to level.

How much experience is needed to get to level 10

Add Hit Points to Character if you Level Up

If you level up you should gain HP, attack and armor.

So lets add to the scr_expericene script and use a dice roll script to randomize it

We will find this script here http://www.gmlscripts.com/

This site has lots of scripts for you to use.

By seeing how others code it will help you code

Optimize the script

The playerMove script is getting big and hard to follow so lets see if we can optimize it by creating a script that will run the code

What is the only thing that is different on attacking from the 8 different directions?

The only thing different is the x,y coords we check so lets pass these coordinates to the script and run it to make our code look cleaner

Go to the Create Event of your player and add two new variables xoff and yoff these are the offsets that we will change for each direction then create a script that will move if place is free and another script for attacking the monster this will clean up the script by adding sub scripts

The scripts moveIfPlaceFree() and attMonster() are the same code as in the original except you replace the x+32 with x+xoff and the y+32 with y+yoff

Old playerMove

New playerMove

MoveIfPlaceFree script

Lets create a script that replaces the code that allows the player to move if no obstacle is in the way

Create a new script call it moveIfPlaceFree

attMonster Script

Add a new script and call it attMonster

This will replace the attacking script in playerMove

Notice I moved the energy added to obj_monster before we destroy the monster

This will stop any error from occurring when you kill the last monster in the room.

Can you predict why an error would occur if we add the energy after we destroy the monster?

Add new scripts to playerMove script

All we have to do is add the correct xoff and yoff to each direction then add the two new scripts

Make player die if HP is exhausted

Now we need to make the player die if hp runs out. Since this is a rogueLike game the game is over if the player dies

So we will make a room called the death room that displays the headstone for your player with his ending stats. You could also have high scores listed, experience, I found a gravestone sprite and added some text.

To customize player name add a global.playername = "your Name" to the obj_variables object

We also want to be able to quit the game or start a new game

So we create an object called obj_death and place it in the roomDeath

Add a step event with keyboard checks for Y and No

Add Draw Event

Add HP Check to Player

Now we need to check if the player has died we will do this whenever the player is attacked by a monster

Go to the monMove script and add the HP check

This will go to the death room the instant your character dies

You could start an alarm to make this trip delayed

Loot Drops

When you kill a monster it should drop some random loot

We already have the pick up loot in place however we want a monster to randomly drop loot based on a chance

Then if an items drops we want the item to be randomly created with more valuable items dropping the least.

We also want more valuable items to drop more frequently the higher your level is.

This is a lot so lets take them one at a time

First lets make your monster drop loot object

We need to create a script called chance that will check if we drop an item

This script will take the level of the monster to determine drop rate

So a level 1 monster has a 10% chance to drop something

level 2 20% chance

Level 10+ 100% chance to drop loot

This script will return true or false

Loot Drop Rate

This script requires us to organize our loot object so that each item is arranged from easiest to drop to hardest

And you need to figure out what chance for each to drop

Go to the create event of your obj_variables and add comments describing the drop rate of each we also need to add the drop rate for each item so we will change this to a 2D array like shown

So now we have loot[0,0] the first number indexes the item

the second number stores the name in position 0 and drop rate in position 1

the third position[0,2] stores how many you have collected

We also have turned these into global variables by declaring them with globalvar by doing it in this way we dont have to add the global. in front of it which is annoying

So gold will drop the most frequently diamond the least

scr_lootDrop

Now lets write the script we pass the level of the monster to this script then convert it to decimal

Then we run the chance script to see if the monster drops anything with the chance increasing by the monsters level

If the monster drops something then we determine what item is dropped again based on chance plus level

Line 13 creates a loot object

Line 16 rolls a random number between 0-100

Line 17 adds the percent of your level to this roll so the chance of rare item increases by 10% for each level

Line 15 - 27 determines the loot drop based upon the chance in the 2D array

with inst sets the variable type to the drop so when the instance is created it has the correct sprite

Monster Destroyed

When a monster is destroyed we want to run the loot drop script

Open the obj_monster object add a destroy event and add the script call

Add Drop to Event Log

Now that our game log is in place it it easy to add text to it

Open the scr_lootDrop script

Right after we determine what drop it is place the ds_list_add code to add the next line to the game log

Join YoYoGames forum

Join the forum and post a question about your game

Getting advise from other programmers is a great way to get help when you get stuck

You can post an error you are getting?

You can post a "How do I?" question

You can also search the forum for ideas or more efficient ways to code your game

Go to https://forum.yoyogames.com/index.php

Create account and log in I usually put my questions in the programming sections

Join Game Maker Forum and post a question

Now we want to join the yoyogames forum and post a question about your game code

Make sure you follow your post so you will be notified when a new answer is posted

A simplified example in action: Monster is killed! What does the game do to determine your reward?

Weapon Sprite

calculates the number of items to drop

selects item types

selects item qualities

selects certain unique or set items if needed

selects item properties

This would be ideal for the drops in your game.

Since we want our character to use weapons and wear armor

Weapon Variables

Lets set up some variables to use for the weapon choices

The weapons need to have the following:

//Type of equipment 0=Weapon | 1=Helmet | 2=Boots | 3=Armor

//sprite

//Item sprite index

// Name of weapon

//Attack & damage rolls

//Attack & damage dice

//Bonus 1 Amount

//Armor Increase

//Sell amount

//Equipped or not

We will set up a 2D array to keep track of these things

We will set up a single sprite with subimages for all the weapons

I have 5 different weapons in my game the sprite is in order from lowest damage weapon to highest

Our goal is to create a system that can work no matter how many items we add to the game it will still work

It is very important that you order your weapons from weakest to strongest in the sprite

By setting up things in a systematic way to start with you can use these variables to determine drop rates

notice we also set up two globalvar these are global variables that we dont have to add the global. in front of it because we set it up with globalvar

ITEMVALUES is used to keep track of how many properties each array variable has 12 in our case

We also need to create our ds_list to keep track of all our inventory items

and we will create our ds_grid to keep track of our equipped items

The weapons must keep track of rolls and damage per roll and name

The armors must keep track of name and armor increase for each type

Global Variables in obj_variables

Weapon Object

Now we will create our weapon object so that we can collect items

Create an object and call it obj_weapons give it the weapon sprite you have created

Add a Create Event and for now lets just randomly pick one of the objects using irandom_range

Add a Collision Event with your character so you can pick up the object

and add it to your ds_list

When the player collides with the object it will store all of the information in the ds_list

This will allow us to create a unique weapons on each drop by running drop scripts later for now it will just create a different weapon with no special attributes

The Draw Event will draw the sprite with the corresponding sub-image

It will also draw a glow if equipment is magical

So create a sprite called spr_magicGlow 32 x 32

Create Event obj_weapons

All your other equipment will be a child of your weapon object only the Create Events will be different for each

ds_lists are lists of numbers that are added from left to right with ds_list_add

Can you Map a ds_list?

Lets map one together to understand them better

Your other objects have to use the appropriate variable to assign its name in equipment[3] position

Only your weapons have attack and damage rolls so the rest of your equipment will have 0 for the value of equipment[4] and equipment[5]

Collision with Player Event

Draw Event

Create Inventory Page

Now that we can pick up items we want to be able to look at what we have collected and see the properties of each item

Create a new object and call it obj_inventory and variables to the create event

inventory = false this will keep track of if the inventory panel is turned on or off

equipmentSelected = 0 this will keep track of what item we have selected in the inventory

We also need to create a selection sprite to show which item we currently have selected

I mad mine 30x30 and made it a blue outlined rectangle

Create Event

Step Event

We want the inventory to pop up when we press the "I" key and game play to be paused

So in the Step Event of obj_inventory we will check if the "I" key has been pressed

If we press "I" it will toggle the variable inventory from true to false and vice versa

using inventory=!inventory

If inventory is true we do the following:

get the size of the ds_list

deactivate your player to pause the game

check if we are pressing up or down to scroll through the items in your inventory

Remember if anytime we use a new global variable set it in the obj_variable Create Event

so global.enchant is new so set it to global.enchant=false

Create Inventory Object

We want the create the inventory object from your obj_gui

So add a new step event code this will pause the game by deactivating your player

It will also create the obj_inventory

Inventory Page Draw Event

In the Draw GUI Begin Event create a new code

obj_gui Step Event

By creating a new code exe for each draw action it keeps the code compartmentalized and easier to find errors

Remember to add /// as the first line this comment will give each code a name that will show up in the action properties call this one Draw Inventory items

This code will draw the items in you ds_list by looping through the list

Each loop it will get the values of each position in the list using ds_find_value

Look through the draw code if any of the scripts are white that means you have not created it yet so remark it out by placing // in from of the code

//getBonusType is one script that has yet to be written line 29

also since the getBonusType script is not written we dont know what the value of bonus is yet so remark out the

//draw_text(500,100+(i*25),string(bonus)) on line 38

unEquip Script

Now we need to create our un-equip script so we can take off equipment and put the other piece back in your inventory

We send what type of equipment we are taking off and the script does the rest

getBonus Script

Now lets create out getBonus script

When this script runs it will first check your weapon for any bonuses

It will use a switch statement and check what type of bonus that your weapon might have

If it does have a bonus it will add it to the variable

Next it checks all armor for bonus armor and add all those up

These variables will be added to the draw stats code in the draw event of your gui

It will also be added to your attack scripts

getBonusType Script

This script will be used to get what type of bonus your enchanted equipment has

getBonusAmount Script

This script will be used when you enchant equipment

Draw Player Avatar for equipped Items

Now we will create a panel that will show what items you currently have equipped

Create a sprite that is same height as your GUI sprite so 128 px in height and 128 px wide

It will look like a tic tac toe grid

part 2

Draw GUI Event

In the middle cell we will draw the player sprite

Top cell helmet

Right cell weapon

Left cell armor

Bottom cell boots

You can use the other for cells for other items you may want to have your player wear latter

This will be draw on the GUI

Make a new Code in the Draw GUI Event of obj_gui call it

we will do the following:

Draw the new tic tac toe sprite

Draw your character Sprite

The variable xoff and yoff are used to draw the equipment sprites offset by a set amount of pixels

You may have adjust these offsets to make the sprites be drawn in the center of the grid

Next we check if you have an item equipped with ds_grid_value_exsists

If a value is stored in the grid we will draw the correct sprite in the correct spot

Challenge can you do these for events in a better way?

Could you use a for loop to draw them and make your game for efficient

Also notice that we coded the drawing of object that we dont have made yet.

However you will see that making more items is very quick once we get the weapon working

Add Weapon attributes to Characters

Now we want the equipment you wear to add their bonus to your characters armor, HP etc.

To do this we will check the ds_grid for any items you have equipped and add any bonus

Your grid contains your equipped items think of the grid as slots that contain all the information about

each piece of gear you are wearing

ds_grid Example:

We will need to check for the add all these bonuses to your characters base HP, Attack and Armor

So we need to set up some global variables which will hold the values of the bonus attributes

Open the obj_variables and add these new variables

Go to the obj_gui and add this to the Draw Stats code in the Draw GUI event

Create your Equipment Grid

We have learned about ds_list 's now we will learn about ds_grid 's

The difference between a list and a grid is a list is one list of data separated by commas

A grid is organized in rows and columns

Use this template make a copy of your own and add your weapons to the grid it will make it easier to understand where the data is stored

https://docs.google.com/spreadsheets/d/1l965lmySx8zE5rEvEy_C4KD9a3iUmoSlKTcukyBl9Kk/edit?usp=sharing

Obj_variables

Draw GUI Stats

getBonus script

Equipment DS Grid

Add Critical Bonus to Attack Script

Now we have to make these bonuses apply to our battles with monsters

Open the AttackRoll script and add the bonusCritical when it checks for a critical hit

Add Damage Bonus to damageRoll Script

Open your DamageRoll script and modify it to give you the bonus damage

Also call the script in the attMonster script

Challenge

Lets see if you can add a special effect if you get a critical hit

The code to create a special effect is

effect_create_above(ef_explosion, x+8, y+8, 0, c_red);

Try to figure out where to add this code for a nice effect on critical hits

Any problems with attack scripts?

Now that we have added bonus to the AttackRoll and DamageRoll scripts you may notice something odd

The monsters are hitting much harder that is becuase the monsters are taking advantage of your bonuses

So what can we do?

We can simply make copy of each script and customize it for the monsters so that it doesnt have the bonuses

We must also change the script name from the calling position so that the new scripts are ran when the monsters attack

Copy the toHit() script and rename MontoHit()

damageRoll Script

attMonster Script

attMonster script

monMove Script

Copy the damageRoll() script and rename MondamageRoll()

Now remove the new code from the monster scripts to make it just like it was before

Now go to the monMove() script and change the script call to point to the new script

MontoHit Script

MondamageRoll Script

Adding More Equipment

Now that we have a really cool game its time to add more equipment

Since we set up our weapon object the way we did it will be easy to add as many new types of equipment as we want

We are going to add a helmet, boots and armor

You can add more once you figure out how easy it is to add more equipment

First lets Create two scripts

One script will randomly drop a equipment based on your level

So at level 1 it can only drop a club or dagger once you reach level 10 you have a chance to get a sword but very low

The second script determines the quality of a weapon which is the plus variable

ref:

https://docs.yoyogames.com/source/dadiospice/001_advanced%20use/more%20about%20objects/parents.html

scr_equipDropKind

scr_equipPlusCheck

Change Weapon Objects Create Event to run scripts

This will make the drop rate random and weighted so at low levels only weak equipment will drop as you increase in levels you chance for a great weapon increases

Set Up Helmet variables

Open you variables object and you will add new variables for your 5 types of boots

Helmets only need a name and armor since they dont increase your attack or damage

Now make a obj_helmet and make its parent the obj_weapon

Make the helmets progressively better

Example:

helmet 0 has 1 armor

helmet 1 has 2 armor

helmet 2 has 3 armor

helmet 3 has 5 armor

helmet 4 has 7 armor

Put a few obj_helm and your room and make sure everything works just like the weapon

You should be able to:

pick up helm

helm added to inventory

helm can be equipped

helm image will show up on gui when equipped

armor is added to your character

If all this works make your obj_boots then your obj_armor objects using same procedure

You could even add rings, shields, alternate weapon etc

obj_variables

Create Event of obj_helmet

What would you need to add another piece of equipment?

Create sprite and object for new item make it parent of obj_weapon

Change Create Event of obj_shield to get the correct type range 25-29 in my case

Add another type to the variables list and create variables for new item

equipment[i,0]=4 //Type of equipment 0=Weapon | 1=Helmet | 2=Boots | 3=Armor | 4 = Shield

Make Sure your ds_grid is big enough to hold 5 items

globalvar epuipmentGrid;

equipmentGrid = ds_grid_create(11, 5); // This will create a grid for your equipment

Draw Sprite on avatar when equipped

//Get Sprite of shield postition 7

if ds_grid_value_exists(equipmentGrid, 0, 4, 0, 4, 4)

{

var shieldSprite = ds_grid_get(equipmentGrid, 1, 4)

var shieldSpritesub = ds_grid_get(equipmentGrid, 2, 4)

draw_sprite(shieldSprite,shieldSpritesub,248-xoff,688-yoff)

}

Add shield to getBonus() Script

Change size=4 to automatically get the size of the grid using ds_grid_height

Thats it so easy try it

Other Equipment

These are the create events of the other pieces of equipment

Add Bonus to attack scripts

Now that we can equip items we want those bonus to be part of the battles

Draw Collected Gems

Lets draw the gems and gold we have collected on the gui

Gems will be used later to enchant equipment and make it better

Make a new execute code in the Draw GUI event of you obj_gui

Boots

Armor

Shield

Ranged

toHit script

The Gold will be draw from the Draw_stats code

We will get the value stored in the lootGrid and draw it on the GUI

Whats Next

In the third section we will make the monsters drop equipment or loot

Give the equipment a chance to have bonuses

Make the bonuses increase as your level increases

Make a NPC that can enchant your equipment to give it more powerful bonuses

Automatic monster spawning

Boss Room design

Play the Rogue Like Game

http://munificent.github.io/hauberk/

Need a script find them here

http://www.gmlscripts.com/

Lots of code sprites and ideas from HeartBeast

https://gamemakerdiscord.github.io/

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