Equip & Use Items - How to Make a 2D Game in Java #28

[@leonkennedy701]

Literally the best java game programming tutorials right now!

[@angelos9800]

fr

[@swansongg]

Yes yes yes!

[@jay_codes]

definately

[@paaulsens6086]

i agree

[@holmdev]

I agree

[@nakanomiku8470]

I was totally at beginner level when I started this series, and so far in just 5 days of watching this and practicing, I can tell that I improve a lot and understand the basic concepts of game logic and how to construct a proper code, I really love your vids, and I'm excitedly waiting for the next episode. Thank your for this awesome tutorial

[@paul7408]

Just found this series a few days ago and binged it really hard. All caught up! This is best tutorial ive ever found on youtube. you do such a good job with pace, explanations and not skipping over fixes.

[@Mypremiumacct]

Cant believe im almost halfway through. This tutorial has been fantastic.

[@sorcerian_bootleg7112]

I love how the series is taking shape little by little. Keep it up!

[@paaulsens6086]

I am eagerly waiting for episode 29! This is some extremely good content you're putting out, keep it up!

[@flkr4153]

I dont know if you implemented this later, but I also added a canUseConsumable boolean to consumables so that if your health is full, it displays a message that your health is already full. Then for keys and similar items, you can just make them true.

[@erkangxia8424]

This series helped me a lot, cant wait to see the next episode!!!

[@FerodriEste]

And the oscar goes to... RiySnow for the best java game programming !!! 👏👏👏

[@somethingaboutmoron]

Wow, found your videos today, I cannot stop watching them! You can explain things so fluently it's honestly insane!

[@FriskTheFallen]

I went ahead and setup a default description that appears if you select any of the blank spaces, that way instead of nothing it says something sarcastic about the lack of things.

[@paulringrose5779]

Been watching and following along with this series, really is an amazing in depth series, thanks for all your hard work, please do more vids!! cant wait for the next one :D also please do a full screen option, thanks again :D

[@kikismine]

OMG! A new tutorial from RyiSnow

[@ganbarimasu9446]

You and your videos are as great as ever. Thanks for the effort you put in making this videos :)

[@woodswoody5553]

Cant wait for the next video I did all 28 and the extras in 3 weeks (a video a day) absolutely love this tutorial

[@ilyesskhayati3532]

This saved my game project!! Thank you so much for these videos! wondering if there's the possibility to add a different level with a different map and objects. It will be really helpful! looking forward to new videos!!

[@nguyentranangminh2669]

I LOVE THIS SERIES

[@holmdev]

nice work RyiSnow , i hope comes more episode soon :)

[@UnderArea51]

QUESTION: How do you change (customize the image,) the compiled Java game app icon image on the desktop? (the clickable icon to start application at the end of your Notepad tutorial?) -Thank you :)

[@RyiSnow]

Unfortunately you cannot change jar file icon because it is platform dependent. You need to export it as an exe file for that.

[@EnchikO]

Hello Mistr RyiSnow, i would like to ask you, is there any way to implement shader to this game ?

[@nikolasdemetriou126]

The inventory is great! , but a way to drop the items on the floor would be very useful for inventory space management(gameplaywise)

[@RyiSnow]

That is true. I think I will add the option later!

[@josemarioespinoza6652]

Amazing one man, thank you for your work

[@RyiSnow]

Muchas Arigatos 😄🙏

[@AppleTwentyFour]

I've been quietly following your tutorials and I think it's incredible how much I learnt in such a short time, thanks for that! One thing I've been wondering about is how could I make it so that the player can swing his weapon while he is moving instead of stopping every time? I think that would make for a much smoother gameplay! Thank you!

[@dave23145]

Hi Ryi, there is something that I've been trying to do for a while now in this project, but I just can't get it to work. So I would like to display a message every time that player touches an NPC. And that message would be something like "Press Enter to talk to the NPC". I think something like that would be quite useful for someone who hasn't played the game yet and doesn't know the controls. Would be awesome if you could help me out :).

[@sullythedon6155]

Hi, is it alright that you could make these into individual written tutorials, and make into into documentation as it would be easier to access individual things, just and idea. love the tutorials

[@nickolasthompson431]

This series is my absolute favorite! I'm only on part 9, but I have a question. This has piqued my interest in pixel art. Is there a way that we can go from 16x16 sprites to more detailed ones?

[@ganbarimasu9446]

Yes, you can. Like you can use 48x48 pixel sprite. It will be fine if you change the integer we use to scale the 16 pixel from 3 to 1

[@LORF0]

You are the best at explaining. I was wondering about how would you handle jumps? And particle system

[@RyiSnow]

It's a bit complicated to explain everything in a comment. But basically you calculate gravity for jumps. Like adding upward gravity until the player hits the highest point then start adding downward gravity until the player hits the ground. Particles are also entity. You can set their lives and the directions etc.

[@LORF0]

But visually would you make like a circly shadow appear at the pervious y cord after pressing the jump key so the player would appear above the ground?

[@RyiSnow]

That's doable but I think adding shadows to jump sprites is easier.

[@CJDaBomb69]

If I wanted to display armour over top of the player's texture when they equip armour, how would I do that?

[@BracamonteL]

add new sprites?

[@Nefarious_Production]

when is the next ep coming?

[@EuropaM64]

Hey RyiSnow! I have to thank you so much for this tutorial, it has helped me a lot! I do have a question, that I hope you wouldn't mind helping me with. Basically, I want the player sprite to look different depending on the class that the player has chosen. I tried to do it by having an int value set depending on the choice that the player made, and then set the player images depending on what the value of the int was. But, this didn't seem to work. Would you, or anyone else, know of a good way to do this?

[@RyiSnow]

Hi, your method sounds totally fine to me. As we did in this video for switching weapons, you just need to set different images based on whatever condition you'd like to use (int, boolean, String, etc.). So I think the problem is not your theory but probably how you implemented it. Try adding a line like "System.out.println("The Character B images are set")" in the method where you set new images and see if the text gets printed out on the console. If you cannot see the text, the method is not getting called for some reason so you can check why it's not.

[@EuropaM64]

@@RyiSnow Thank you so much!

[@LirDev3]

God dam you upload the next part thx god!!! i like this so much!

[@kevincolgan6651]

Very good as always

[@bencegarami8582]

Amaizing series! How would you implement that the monsters start coming towards you from a given distance and attack when next to you (maybe with an attack animation)?

[@ganbarimasu9446]

Hi, I copied my comment from the 24th video to answer your request. Ask me if it's not clear. Code: . . Here is the basic AI code I said I was gonna share. With this AI, monsters go towards the player if he is closer than 4 tiles. !!!!!! Before making any changes to your code, make sure to save it somewhere safe first. Since it would be pretty bad if your code got ruined while trying to make some changes on it !!!!!! To apply this change in code, first create 4 new counter in entity class: public int changeDirection1 = 0; public int changeDirection2 = 0; public int changeDirection3 = 0; public int changeDirection4 = 0; Then, in your MON_GreenSlime class, comment out your setAction Class (Don't delete it in case this code does not work in your java project) and replace it with the code below. public void setAction() { int xDistance; int yDistance; int Distance; for(int i = 0; i < gp.monster.length; i++) { if(gp.monster[i] != null) { xDistance = Math.abs(gp.player.worldX - gp.monster[i].worldX); yDistance = Math.abs(gp.player.worldY - gp.monster[i].worldY); Distance = Math.max(xDistance, yDistance); if(gp.monster[i].alive == true && gp.monster[i].dying ==false) { if(Distance < 4*gp.tileSize) { if(gp.player.worldX > gp.monster[i].worldX && gp.player.worldY > gp.monster[i].worldY) { if(changeDirection1 < 30) { gp.monster[i].direction = "right"; } else if(changeDirection1 >=45 && changeDirection1 < 90) { gp.monster[i].direction = "down"; } else if(changeDirection1 > 90){ changeDirection1 = 0; } changeDirection1++; } else if(gp.player.worldX > gp.monster[i].worldX && gp.player.worldY < gp.monster[i].worldY) { if(changeDirection2 < 45) { gp.monster[i].direction = "right"; } else if(changeDirection2 >=45 && changeDirection2 < 90) { gp.monster[i].direction = "up"; } else if(changeDirection2 > 90){ changeDirection2 = 0; } changeDirection2++; } else if(gp.player.worldX < gp.monster[i].worldX && gp.player.worldY > gp.monster[i].worldY) { if(changeDirection3 < 45) { gp.monster[i].direction = "left"; } else if(changeDirection3 >=45 && changeDirection3 < 90) { gp.monster[i].direction = "down"; } else if(changeDirection3 > 90){ changeDirection3 = 0; } changeDirection3++; } else if(gp.player.worldX < gp.monster[i].worldX && gp.player.worldY < gp.monster[i].worldY) { if(changeDirection4 < 45) { gp.monster[i].direction = "left"; } else if(changeDirection4 >=45 && changeDirection4 < 90) { gp.monster[i].direction = "up"; } else if(changeDirection4 > 90){ changeDirection4 = 0; } changeDirection4++; } else if(gp.player.worldX == gp.monster[i].worldX && gp.player.worldY < gp.monster[i].worldY) { gp.monster[i].direction = "up"; } else if(gp.player.worldX == gp.monster[i].worldX && gp.player.worldY > gp.monster[i].worldY) { gp.monster[i].direction = "down"; } else if(gp.player.worldX < gp.monster[i].worldX && gp.player.worldY == gp.monster[i].worldY) { gp.monster[i].direction = "left"; } else if(gp.player.worldX > gp.monster[i].worldX && gp.player.worldY == gp.monster[i].worldY) { gp.monster[i].direction = "right"; } } else { actionLockCounter++; if(actionLockCounter == 600) { Random random = new Random(); int a = random.nextInt(100)+1; //picks up a number from 1 to 100 if(a 25 && a 50 && a 75 && a

[@bencegarami8582]

@@ganbarimasu9446 Wow amaizing! Thank you so much, this really helped me a lot!

[@bastien2802]

At 4:06, I have an error with gp.obj[i].name = null; error says Exception in thread "Thread-0" java.lang.NullPointerException: Cannot read field "name" because "this.gp.obj[i]" is null. Can anyone help ?

[@WoodsGeorgeJr]

could you make a full screen function ?

[@luciuscouto4592]

It would be nice if you could implement a function that changes the position of items, in case the player wants to organize the inventory.

[@vampsz1592]

How can I remove a specific item from the inventory? I want to open a door and then remove the key from the inventory. everything works except this part:/

[@woodswoody5553]

Im stuck here as well

[@vampsz1592]

@@woodswoody5553 you can assign a key in the keyhandler to do it. Then call a method which looks like this. int itemIndex = gp.ui.getItemIndexForSlot(); inventory.remove(itemIndex); Maybe you need to change the variables but that should do it. It delets the item selected. Maybe ask for confirmation bc this will just delete it and nothing more.

[@woodswoody5553]

@@vampsz1592 yeah i figured it out and set it up so i can open doors with keys in the inventory. inventory.remove(currentKey); made a similar structure as the sword and sheild where keys open doors if selected in inventory and then are removed after use

[@darktimes574]

@@woodswoody5553 if possible could you share how you did this as I have been trying and failing 😅

[@woodswoody5553]

@@darktimes574 Yeah later tonight I'll explain got exams tomorrow RIP

[@praneetw]

Hey bro u r doing great job can u suggest how we r going to deploy this game

[@an1l492]

Hi, when will the next part come out?

[@woodswoody5553]

Hey I have an idea! What about making the water move (simple 2 or 3 tile animation)? Thank you so much and your knowlege in java is way beyond me. Also a question: How would I make it so that when I choose new game and pick a class it also changes the main character avatar according to each class.

[@flkr4153]

I have a question that i dont know if youll be able to help me with, the problem im having is that if i have multiple weapons of the same type, if i switch any any other single weapon of the same type, all of the weapons of that type highlight except the first one. I already got to the day and night cycle video, but ive tried to fix the bug since this video and cant figure it out. Thanks

[@RyiSnow]

Yes, that was a bug and I fixed it in a later video. Sorry about that! Please check this bug fix video (the inventory bug fix starts at 3:30 of the video): kzbin.info/www/bejne/e2WmhJSHfd1sg7M

[@berkayw5781]

Hi Ryi, I have an issue. When i swing sword or interact something(like taking potion, axe, key etc.) first time after the game starts, my game freezes for 0.5 - 1 seconds. Then everything goes normal. There is a bug or something i missed. I couldn't find out why it happens. Could you help me please?

[@RyiSnow]

There is a little delay when you read a sound file for the first time. Play the field music when you press Start then there's no delay after that. You can also play a blank audio file if you don't want to play music.

[@berkayw5781]

@@RyiSnow Thank you so much! Love the tutorials..!

[@solarcubing7504]

How would you make a door tile that when the user walks into it it changes the map to something else i.e. a cave

[@woodswoody5553]

Make it so that when the player comes in contact with a door the loadmap function is called

[@solarcubing7504]

@@woodswoody5553 I tried this but it just places the map ontop of world map

[@woodswoody5553]

@@solarcubing7504 Yeah I just realized that after attempting it myself

[@zmandyce]

@4:08 Hi, just wondering how may I prevent, "Inventory is full"? From spamming the side/interaction messages? Also, I moved gamePanel.objects[i] = null; to inside of the if statement. So that when inventory is full the item is not null and thus not removed from the heap. So later when inventory is not full it is still available to be picked up. Please help I've tried checking the messages array containing String "inventory is full" and removing but it disappears too quickly.

[@RyiSnow]

Hm ok, I think you can avoid that by using a counter. You just need a way to stop adding the message to the array in every frame. Here's an example: boolean pickCounterOn; int pickCounter; (pickupObject method) if(i != 999) { String text; if(inventory.size() != inventorySize) { // if inventory is not full inventory.add(gp.obj[i]); text = "Got a " + gp.obj[i].name+ "!"; gp.playSE(1); gp.obj[i] = null; gp.ui.addMessage(text); } else { text = "You cannot carry anymore!"; if(pickCounterOn == false) { // only add the message when the boolean is false gp.ui.addMessage(text); pickCounterOn = true; // turn it true after adding the message } } } (at the end of the update method) if(pickCounterOn) { pickCounter++; if(pickCounter == 180) { // set the boolean false after 3 seconds (180 frames) pickCounter = 0; pickCounterOn = false; } }

[@PatrikM]

Amazing series! Could we perhaps use instanceOf instead of manually creating a "type" integer? I used instanceOf MON_GreenSlime for the damage/collision and it worked fine :)

[@PatrikM]

I tried it and it works, looks something like this: public void equipItem() { int itemIndex = getGamePanel().getUi().getItemIndexFromSlot(); if (itemIndex < inventory.size()) { Entity selectedItem = inventory.get(itemIndex); if (selectedItem instanceof OBJ_Sword_Normal || selectedItem instanceof OBJ_Axe) { setCurrentWeapon(selectedItem); setAttackPower(getAttack()); setPlayerAttackArea(); } if (selectedItem instanceof OBJ_Shield_Wood || selectedItem instanceof OBJ_Shield_Blue) { setCurrentShield(selectedItem); setDefensePower(getDefense()); } } }

[@abikyoukan2]

so I made custom pixel arts where the character is holding an axe (not attack animation, just holding it normally). How would I go about implementing this to the normal walking images? So that when he changes to the axe, he will be actually holding it. I tried moving the " if(currentWeapon.type == type_axe)" condition to the "public void getPlayerImage()" method but with no luck.

[@michajurkiewicz5471]

if you lived in Poland I would buy you pizzas: D Thank you for the next part :)

[@RyiSnow]

Haha that would have been great. Anyway I'm glad you are enjoying the videos ;)

[@FerodriEste]

@@RyiSnow If you ever travel to Argentina, I will take you to eat the best meat in the world!!

[@RyiSnow]

@Fernando Rodriguez I'd love that :D

[@failah7411]

Hi RyiSnow! I have a problem, i managed to scale the animation attack images as you did using your same exact setup method, but that doesnt work for object images and im trying figure out why; for example, im trying to display a circus tent made in 48x32 pixels, so: down1 = setup("/structures/circus_tent_1", gp.tileSize * 3, gp.tileSize * 2); but it is always drawn in a tileSize on the map. Same thing with any other images i tryed, for example for a monster 2 tilesize tall, but didnt managed to. How should i do this?

[@michajurkiewicz5471]

I also have a question, will the game finally be full screen?

[@RyiSnow]

I haven't decided it yet but maybe I'll implement that at around the end of this series.

[@vipmember3315]

Hey I built the engine but my code broke, care tt help fix it? :) Thanks.

[@johnsussy8469]

hi! I'm having an issue with the item pick up. When I try to walk over the key to pick it up, nothing happens. I've checked everything and I don't see where I went wrong. Could you help?

[@Mypremiumacct]

its something in collision detection or your player class. I have used chat gpt to take lines of code to fix it and adding peramiters to make sure it doesnt add or change too much besides fix what may be wrong. Hope you figured it out, chatgpt has helped the headache of sittig down rereading and watching to see what went wrong and getting to it before i can find the problem

[@holmdev]

I'm adding mana, I want you to have a certain mana when you fight, then you have to add it to be able to fight on .. Am almost there to make it work :)

[@Melvin-14]

he is adding that already

[@holmdev]

@@Melvin-14 when i write that , he hade not done it yet. :) now he has done it :)

[@santanabarman7946]

Please help me I have an error I can not able to find it When I draw the object on the map after follow previous video the object are flickering

[@RyiSnow]

You mean the inventory video?

[@santanabarman7946]

From video 1 to inventory video I follow but I can't find the bug

[@RyiSnow]

@@santanabarman7946 That's a pretty wide scope. Try finding out when (which video or what process made) the issue started otherwise it's difficult to know the cause.

[@christianfryksten8524]

Hey! You never showed how to display the x and y coordinates when playing

[@knightking5735]

I created one, here is it, just replace it // DEBUG long drawStart = 0; int countWorldX = player.worldX; int countWorldY = player.worldY; int countCol = player.worldX; int countRow = player.worldY; if (countCol < 0) { countCol = 0; countRow++; } if (keyH.checkDrawTime == true) { long drawEnd = System.nanoTime(); long passed = drawEnd - drawStart; g2.setColor(Color.white); g2.drawString("Draw Time: " + passed, 10, 400); g2.drawString("Col: " + (int) Math.round((double) countCol / tileSize), 10, 320); g2.drawString("Row: " + (int) Math.round((double) countRow / tileSize), 10, 360); g2.drawString("WorldX: " + (int) Math.round((double) countWorldX), 10, 280); g2.drawString("WorldY: " + (int) Math.round((double) countWorldY), 10, 240); } I re-update it today, i made it count worldX and worldY

[@Mypremiumacct]

it was in the 7 min bugfix vid a few vids before the one on this playlist. hope you figured it out

[@MrLoser-ks2xn]

Thanks!

[@k0vier]

Hey, I commented on your "#12 - Character Creation Screen - Dungeon Crawler RPG Development in Java" video can you please answer there because I think KZbin didn't send notifications like before when we talked in the comments on your first dungeon crawler video😅

[@RyiSnow]

I'm receiving notifications. It's just a bit hard for me to reply everything. I hope you understand.

[@GutekLive]

more pls

[@Clipaholick]

thanks ryi

[@nguyentony9635]

thank you

[@matisgeretti-uyanik56]

Are you using JavaFX?

[@RyiSnow]

No

[@edward265]

That looks like Java Swing.

[@MrLoser-ks2xn]

🥰🥰🥰

[@oguzhantopaloglu9442]

You should really learn about enums and naming conventions in Java

[@havardelgsaas2603]

When I pick up an object(item), the text shows: "You got a Green Slime". Does anyone know how to fix this problem? I wrote: text = "Got a " + gp.obj[i].name + "!"; in the Player class.

[@knightking5735]

make sure u wrote it in the correct method or check the OBJ_ItemName because u must've changed it or accidentally wrote it in the name variable

[@hawkale140]

I am a bit late, but you could simply add to the different sprites the name of the weapon for example "sword _attack_left" or "axe_attack_left" and instead of doing a different if statement for each weapon you use player.currentWeapon.name +"_attack_left" to get the proper animation. so that you don't have to add an if statement when you add a new weapon. (this is usefull only if you have many weapons and don't want them to have shared animations)

[@RyiSnow]

That's a neat idea. Thanks for sharing :)