Search Results

Search found 26774 results on 1071 pages for 'distributed development'.

Page 498/1071 | < Previous Page | 494 495 496 497 498 499 500 501 502 503 504 505  | Next Page >

  • Avoid overwriting all the methods in the child class

    - by Heckel
    The context I am making a game in C++ using SFML. I have a class that controls what is displayed on the screen (manager on the image below). It has a list of all the things to draw like images, text, etc. To be able to store them in one list I created a Drawable class from which all the other drawable class inherit. The image below represents how I would organize each class. Drawable has a virtual method Draw that will be called by the manager. Image and Text overwrite this method. My problem is that I would like Image::draw method to work for Circle, Polygon, etc. since sf::CircleShape and sf::ConvexShape inherit from sf::Shape. I thought of two ways to do that. My first idea would be for Image to have a pointer on sf::Shape, and the subclasses would make it point onto their sf::CircleShape or sf::ConvexShape classes (Like on the image below). In the Polygon constructor I would write something like ptr_shape = &polygon_shape; This doesn't look very elegant because I have two variables that are, in fact, just one. My second idea is to store the sf::CircleShape and sf::ConvexShape inside the ptr_shape like ptr_shape = new sf::ConvexShape(...); and to use a function that is only in ConvexShape I would cast it like so ((sf::ConvexShape*)ptr_shape)->convex_method(); But that doesn't look very elegant either. I am not even sure I am allowed to do that. My question I added details about the whole thing because I thought that maybe my whole architecture was wrong. I would like to know how I could design my program to be safe without overwriting all the Image methods. I apologize if this question has already been asked; I have no idea what to google.

    Read the article

  • Draw Cards and Eliminate Cards Problem

    - by Jen
    I am having a problem in this question. I want a system inside a game wherein the player draws 2 cards randomly, and the enemy draws 2 cards randomly. Then, what the program does is to print out to the console the cards the player draw and the enemy's. The cards should not conflict and must not be the same. Then lastly, the program prints out the card that was not drawn by both the player and the enemy. Here's how I did it but it was lengthy and full of errors: import java.util.Random; public class Draw { public static Random random = new Random(); public static String cards[] = {"Hall", "Kitchen", "Billiard", "Study", "Pool"}; public static int playercounter; public static int enemycounter; public static String playercardA = null; public static String playercardB = null; public static String enemycardA = null; public static String enemycardB = null; public String lastcard = null; public static void playercardAdraw() { playercounter = random.nextInt(5); playercardA = cards[playercounter]; } public static void playercardBdraw() { playercounter=random.nextInt(5); playercardB= cards[playercounter]; if (playercardB==playercardA || playercardB == enemycardA || playercardB == enemycardB) { return; } } public static void enemycardAdraw () { enemycounter = random.nextInt(5); enemycardA=cards[enemycounter]; if (enemycardA == playercardA || enemycardA == playercardB) { return; } } public static void enemycardBdraw () { enemycounter = random.nextInt(5); enemycardB=cards[enemycounter]; if (enemycardB == playercardA || enemycardB == playercardB || enemycardB == enemycardA) { return; } } public static void main (String args []) { System.out.println("Starting to draw..."); System.out.println("Player's Turn: "); playercardAdraw(); System.out.println("Player's first card: " + playercardA); playercardBdraw(); System.out.println("Player's second card: " + playercardB); System.out.println("Enemy's Turn: "); enemycardAdraw(); System.out.println("Enemy's first card: " + enemycardA); enemycardBdraw(); System.out.println("Enemy's Second card: " + enemycardB); } }

    Read the article

  • Handling cameras in a large scale game engine

    - by Hannesh
    What is the correct, or most elegant, way to manage cameras in large game engines? Or should I ask, how does everybody else do it? The methods I can think of are: Binding cameras straight to the engine; if someone needs to render something, they bind their own camera to the graphics engine which is in use until another camera is bound. A camera stack; a small task can push its own camera onto the stack, and pop it off at the end to return to the "main" camera. Attaching a camera to a shader; Every shader has exactly one camera bound to it, and when the shader is used, that camera is set by the engine when the shader is in use. This allows me to implement a bunch of optimizations on the engine side. Are there other ways to do it?

    Read the article

  • How can I generate signed distance fields in real time, fast?

    - by heishe
    In a previous question, it was suggested that signed distance fields can be precomputed, loaded at runtime and then used from there. For reasons I will explain at the end of this question (for people interested), I need to create the distance fields in real time. There are some papers out there for different methods which are supposed to be viable in real-time environments, such as methods for Chamfer distance transforms and Voronoi diagram-approximation based transforms (as suggested in this presentation by the Pixeljunk Shooter dev guy), but I (and thus can be assumed a lot of other people) have a very hard time actually putting them to use, since they're usually long, largely bloated with math and not very algorithmic in their explanation. What algorithm would you suggest for creating the distance fields in real-time (favourably on the GPU) especially considering the resulting quality of the distance fields? Since I'm looking for an actual explanation/tutorial as opposed to a link to just another paper or slide, this question will receive a bounty once it's eligible for one :-). Here's why I need to do it in real time:

    Read the article

  • Locomotion-system with irregular IK

    - by htaunay
    Im having some trouble with locomtions (Unity3D asset) IK feet placement. I wouldn't call it "very bad", but it definitely isn't as smooth as the Locomotion System Examples. The strangest behavior (that is probably linked to the problem) are the rendered foot markers that "guess" where the characters next step will be. In the demo, they are smooth and stable. However, in my project, they keep flickering, as if Locomotion changed its "guess" every frame, and sometimes, the automatic defined step is too close to the previous step, or sometimes, too distant, creating a very irregular pattern. The configuration is (apparently)Identical to the human example in the demo, so I guessing the problem is my model and/or animation. Problem is, I can't figure out was it is =S Has anyone experienced the same problem? I uploaded a video of the bug to help interpreting the issue (excuse the HORRIBLE quality, I was in a hurry).

    Read the article

  • How to reference or connect a variable to another class without stack overflow?

    - by SystemNetworks
    I really need to re-arrange all my functions. I created a class. All my var, booleans, int, doubles and other things. I created every new variable so they can reference it and so they don't have an error. If your asking why I never just reference my main class vars to my sub-class becuase it will give me stack overflow! When in my main class i link my sub-class. subClass s = new subClass(); Then I reference my fake variable to my real variable for example: This is my sub-class variable(I call it fake) public int x = 0; In my main class, I put it like this: s.x = x; The problem is, it does not work! Maybe this is not the right place but I cant ask any questions on stack overflow because they banned me. If I connect my main class and connect my sub-class it will give me stack overflow. How do I stop it?

    Read the article

  • How to perform game object smoothing in multiplayer games

    - by spaceOwl
    We're developing an infrastructure to support multiplayer games for our game engine. In simple terms, each client (player) engine sends some pieces of data regarding the relevant game objects at a given time interval. On the receiving end, we step the incoming data to current time (to compensate for latency), followed by a smoothing step (which is the subject of this question). I was wondering how smoothing should be performed ? Currently the algorithm is similar to this: Receive incoming state for an object (position, velocity, acceleration, rotation, custom data like visual properties, etc). Calculate a diff between local object position and the position we have after previous prediction steps. If diff doesn't exceed some threshold value, start a smoothing step: Mark the object's CURRENT POSITION and the TARGET POSITION. Linear interpolate between these values for 0.3 seconds. I wonder if this scheme is any good, or if there is any other common implementation or algorithm that should be used? (For example - should i only smooth out the position? or other values, such as speed, etc) any help will be appreciated.

    Read the article

  • How to store bitmaps in memory?

    - by Geotarget
    I'm working with general purpose image rendering, and high-performance image processing, and so I need to know how to store bitmaps in-memory. (24bpp/32bpp, compressed/raw, etc) I'm not working with 3D graphics or DirectX / OpenGL rendering and so I don't need to use graphics card compatible bitmap formats. My questions: What is the "usual" or "normal" way to store bitmaps in memory? (in C++ engines/projects?) How to store bitmaps for high-performance algorithms, such that read/write times are the fastest? (fixed array? with/without padding? 24-bpp or 32-bpp?) How to store bitmaps for applications handling a lot of bitmap data, to minimize memory usage? (JPEG? or a faster [de]compression algorithm?) Some possible methods: Use a fixed packed 24-bpp or 32-bpp int[] array and simply access pixels using pointer access, all pixels are allocated in one continuous memory chunk (could be 1-10 MB) Use a form of "sparse" data storage so each line of the bitmap is allocated separately, reusing more memory and requiring smaller contiguous memory segments Store bitmaps in its compressed form (PNG, JPG, GIF, etc) and unpack only when its needed, reducing the amount of memory used. Delete the unpacked data if its not used for 10 secs.

    Read the article

  • Basic 3D Collision detection in XNA 4.0

    - by NDraskovic
    I have a problem with detecting collision between 2 models using BoundingSpheres in XNA 4.0. The code I'm using i very simple: private bool IsCollision(Model model1, Matrix world1, Model model2, Matrix world2) { for (int meshIndex1 = 0; meshIndex1 < model1.Meshes.Count; meshIndex1++) { BoundingSphere sphere1 = model1.Meshes[meshIndex1].BoundingSphere; sphere1 = sphere1.Transform(world1); for (int meshIndex2 = 0; meshIndex2 < model2.Meshes.Count; meshIndex2++) { BoundingSphere sphere2 = model2.Meshes[meshIndex2].BoundingSphere; sphere2 = sphere2.Transform(world2); if (sphere1.Intersects(sphere2)) return true; } } return false; } The problem I'm getting is that when I call this method from the Update method, the program behaves as if this method always returns true value (which of course is not correct). The code for calling is very simple (although this is only the test code): if (IsCollision(model1, worldModel1, model2, worldModel2)) { Window.Title = "Intersects"; } What is causing this?

    Read the article

  • Rotation of viewplatform in Java3D

    - by user29163
    I have just started with Java3D programming. I thought I had built up some basic intuition about how the scene graph works, but something that should work, does not work. I made a simple program for rotating a pyramid around the y-axis. This was done just by adding a RotationInterpolator R to the TransformGroup above the pyramid. Then I thought hey, can I now remove the RotationInterpolator from this TransformGroup, then add it to the TransformGroup above my ViewPlatform leaf. This should work if I have understood how things work. Adding the RotationInterpolator to this TransformGroup, should make the children of this TransformGroup rotate, and the ViewingPlatform is a child of the TransformGroup. Any ideas on where my reasoning is flawed? Here is the code for setting up the universe, and the view branchgroup. import java.awt.*; import java.awt.event.*; import javax.media.j3d.*; import javax.vecmath.*; public class UniverseBuilder { // User-specified canvas Canvas3D canvas; // Scene graph elements to which the user may want access VirtualUniverse universe; Locale locale; TransformGroup vpTrans; View view; public UniverseBuilder(Canvas3D c) { this.canvas = c; // Establish a virtual universe that has a single // hi-res Locale universe = new VirtualUniverse(); locale = new Locale(universe); // Create a PhysicalBody and PhysicalEnvironment object PhysicalBody body = new PhysicalBody(); PhysicalEnvironment environment = new PhysicalEnvironment(); // Create a View and attach the Canvas3D and the physical // body and environment to the view. view = new View(); view.addCanvas3D(c); view.setPhysicalBody(body); view.setPhysicalEnvironment(environment); // Create a BranchGroup node for the view platform BranchGroup vpRoot = new BranchGroup(); // Create a ViewPlatform object, and its associated // TransformGroup object, and attach it to the root of the // subgraph. Attach the view to the view platform. Transform3D t = new Transform3D(); Transform3D s = new Transform3D(); t.set(new Vector3f(0.0f, 0.0f, 10.0f)); t.rotX(-Math.PI/4); s.set(new Vector3f(0.0f, 0.0f, 10.0f)); //forandre verdier her for å endre viewing position t.mul(s); ViewPlatform vp = new ViewPlatform(); vpTrans = new TransformGroup(t); vpTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE); // Rotator stuff Transform3D yAxis = new Transform3D(); //yAxis.rotY(Math.PI/2); Alpha rotationAlpha = new Alpha( -1, Alpha.INCREASING_ENABLE, 0, 0,4000, 0, 0, 0, 0, 0); RotationInterpolator rotator = new RotationInterpolator( rotationAlpha, vpTrans, yAxis, 0.0f, (float) Math.PI*2.0f); RotationInterpolator rotator2 = new RotationInterpolator( rotationAlpha, vpTrans); BoundingSphere bounds = new BoundingSphere(new Point3d(0.0,0.0,0.0), 1000.0); rotator.setSchedulingBounds(bounds); vpTrans.addChild(rotator); vpTrans.addChild(vp); vpRoot.addChild(vpTrans); view.attachViewPlatform(vp); // Attach the branch graph to the universe, via the // Locale. The scene graph is now live! locale.addBranchGraph(vpRoot); } public void addBranchGraph(BranchGroup bg) { locale.addBranchGraph(bg); } }

    Read the article

  • How exactly to implement multiple threads in a game

    - by xerwin
    So I recently started learning Java, and having a interest in playing games as well as developing them, naturally I want to create game in Java. I have experience with games in C# and C++ but all of them were single-threaded simple games. But now, I learned how easy it is to make threads in Java, I want to take things to the next level. I started thinking about how would I actually implement threading in a game. I read couple of articles that say the same thing "Usually you have thread for rendering, for updating game logic, for AI, ..." but I haven't (or didn't look hard enough) found example of implementation. My idea how to make implementation is something like this (example for AI) public class AIThread implements Runnable{ private List<AI> ai; private Player player; /*...*/ public void run() { for (int i = 0; i < ai.size(); i++){ ai.get(i).update(player); } Thread.sleep(/* sleep until the next game "tick" */); } } I think this could work. If I also had a rendering and updating thread list of AI in both those threads, since I need to draw the AI and I need to calculate the logic between player and AI(But that could be moved to AIThread, but as an example) . Coming from C++ I'm used to do thing elegantly and efficiently, and this seems like neither of those. So what would be the correct way to handle this? Should I just keep multiple copies of resources in each thread or should I have the resources on one spot, declared with synchronized keyword? I'm afraid that could cause deadlocks, but I'm not yet qualified enough to know when a code will produce deadlock.

    Read the article

  • Strange Flash AS3 xml Socket behavior

    - by Rnd_d
    I have a problem which I can't understand. To understand it I wrote a socket client on AS3 and a server on python/twisted, you can see the code of both applications below. Let's launch two clients at the same time, arrange them so that you can see both windows and press connection button in both windows. Then press and hold any button. What I'm expecting: Client with pressed button sends a message "some data" to the server, then the server sends this message to all the clients(including the original sender) . Then each client moves right the button 'connectButton' and prints a message to the log with time in the following format: "min:secs:milliseconds". What is going wrong: The motion is smooth in the client that sends the message, but in all other clients the motion is jerky. This happens because messages to those clients arrive later than to the original sending client. And if we have three clients (let's name them A,B,C) and we send a message from A, the sending time log of B and C will be the same. Why other clients recieve this messages later than the original sender? By the way, on ubuntu 10.04/chrome all the motion is smooth. Two clients are launched in separated chromes. windows screenshot Can't post linux screenshot, need more than 10 reputation to post more hyperlinks. Listing of log, four clients simultaneously: [16:29:33.280858] 62.140.224.1 >> some data [16:29:33.280912] 87.249.9.98 << some data [16:29:33.280970] 87.249.9.98 << some data [16:29:33.281025] 87.249.9.98 << some data [16:29:33.281079] 62.140.224.1 << some data [16:29:33.323267] 62.140.224.1 >> some data [16:29:33.323326] 87.249.9.98 << some data [16:29:33.323386] 87.249.9.98 << some data [16:29:33.323440] 87.249.9.98 << some data [16:29:33.323493] 62.140.224.1 << some data [16:29:34.123435] 62.140.224.1 >> some data [16:29:34.123525] 87.249.9.98 << some data [16:29:34.123593] 87.249.9.98 << some data [16:29:34.123648] 87.249.9.98 << some data [16:29:34.123702] 62.140.224.1 << some data AS3 client code package { import adobe.utils.CustomActions; import flash.display.Sprite; import flash.events.DataEvent; import flash.events.Event; import flash.events.IOErrorEvent; import flash.events.KeyboardEvent; import flash.events.MouseEvent; import flash.events.SecurityErrorEvent; import flash.net.XMLSocket; import flash.system.Security; import flash.text.TextField; public class Main extends Sprite { private var socket :XMLSocket; private var textField :TextField = new TextField; private var connectButton :TextField = new TextField; public function Main():void { if (stage) init(); else addEventListener(Event.ADDED_TO_STAGE, init); } private function init(event:Event = null):void { socket = new XMLSocket(); socket.addEventListener(Event.CONNECT, connectHandler); socket.addEventListener(DataEvent.DATA, dataHandler); stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler); addChild(textField); textField.y = 50; textField.width = 780; textField.height = 500; textField.border = true; connectButton.selectable = false; connectButton.border = true; connectButton.addEventListener(MouseEvent.MOUSE_DOWN, connectMouseDownHandler); connectButton.width = 105; connectButton.height = 20; connectButton.text = "click here to connect"; addChild(connectButton); } private function connectHandler(event:Event):void { textField.appendText("Connect\n"); textField.appendText("Press and hold any key\n"); } private function dataHandler(event:DataEvent):void { var now:Date = new Date(); textField.appendText(event.data + " time = " + now.getMinutes() + ":" + now.getSeconds() + ":" + now.getMilliseconds() + "\n"); connectButton.x += 2; } private function keyDownHandler(event:KeyboardEvent):void { socket.send("some data"); } private function connectMouseDownHandler(event:MouseEvent):void { var connectAddress:String = "ep1c.org"; var connectPort:Number = 13250; Security.loadPolicyFile("xmlsocket://" + connectAddress + ":" + String(connectPort)); socket.connect(connectAddress, connectPort); } } } Python server code from twisted.internet import reactor from twisted.internet.protocol import ServerFactory from twisted.protocols.basic import LineOnlyReceiver import datetime class EchoProtocol(LineOnlyReceiver): ##### name = "" id = 0 delimiter = chr(0) ##### def getName(self): return self.transport.getPeer().host def connectionMade(self): self.id = self.factory.getNextId() print "New connection from %s - id:%s" % (self.getName(), self.id) self.factory.clientProtocols[self.id] = self def connectionLost(self, reason): print "Lost connection from "+ self.getName() del self.factory.clientProtocols[self.id] self.factory.sendMessageToAllClients(self.getName() + " has disconnected.") def lineReceived(self, line): print "[%s] %s >> %s" % (datetime.datetime.now().time(), self, line) if line=="<policy-file-request/>": data = """<?xml version="1.0"?> <!DOCTYPE cross-domain-policy SYSTEM "http://www.adobe.com/xml/dtds/cross-domain-policy.dtd"> <!-- Policy file for xmlsocket://ep1c.org --> <cross-domain-policy> <allow-access-from domain="*" to-ports="%s" /> </cross-domain-policy>""" % PORT self.send(data) else: self.factory.sendMessageToAllClients( line ) def send(self, line): print "[%s] %s << %s" % (datetime.datetime.now().time(), self, line) if line: self.transport.write( str(line) + chr(0)) else: print "Nothing to send" def __str__(self): return self.getName() class ChatProtocolFactory(ServerFactory): protocol = EchoProtocol def __init__(self): self.clientProtocols = {} self.nextId = 0 def getNextId(self): id = self.nextId self.nextId += 1 return id def sendMessageToAllClients(self, msg): for client in self.clientProtocols: self.clientProtocols[client].send(msg) def sendMessageToClient(self, id, msg): self.clientProtocols[id].send(msg) PORT = 13250 print "Starting Server" factory = ChatProtocolFactory() reactor.listenTCP(PORT, factory) reactor.run()

    Read the article

  • How to implment the database for event conditions and item bonuses for a browser based game

    - by Saifis
    I am currently creating a browser based game, and was wondering what was the standard approach in making diverse conditions and status bonuses database wise. Currently considering two cases. Event Conditions Needs min 1000 gold Needs min Lv 10 Needs certain item. Needs fulfillment of another event Status Bonus Reduces damage by 20% +100 attack points Deflects certain type of attack I wish to be able to continually change these parameters during the process of production and operation, so having them hard-coded isn't the best way. All I could come up with are the following two methods. Method 1 Create a table that contains each conditions with needed attributes Have a model named conditions with all the attributes it would need to set them conditions condition_type (level, money_min, money_max item, event_aquired) condition_amount prerequisite_condition_id prerequisite_item_id Method 2 write it in a DSL form that could be interpreted later in the code Perhaps something like yaml, have a text area in the setting form and have the code interpret it. condition_foo: condition_type :level min_level: 10 condition_type :item item_id: 2 At current Method 2 looks to be more practical and flexible for future changes, trade off being that all the flex must be done on the code side. Not to sure how this is supposed to be done, is it supposed to be hard coded? separate config file? Any help would be appreciated. Added For additional info, it will be implemented with Ruby on Rails

    Read the article

  • Check if an object is facing another based on angles

    - by Isaiah
    I already have something that calculates the bearing angle to get one object to face another. You give it the positions and it returns the angle to get one to face the other. Now I need to figure out how tell if on object is facing toward another object within a specified field and I can't find any information about how to do this. The objects are obj1 and obj2. Their angles are at obj1.angle and obj2.angle. Their vectors are at obj1.pos and obj2.pos. It's in the format [x,y]. The angle to have one face directly at another is found with direction(obj1.pos,obj2.pos). I want to set the function up like this: isfacing(obj1,obj2,area){...} and return true/false depending if it's in the specified field area to the angle to directly see it. I've got a base like this: var isfacing = function (obj1,obj2,area){ var toface = direction(obj1.pos,obj2.pos); if(toface+area >= obj1.angle && ob1.angle >= toface-area){ return true; } return false; } But my problem is that the angles are in 360 degrees, never above 360 and never below 0. How can I account for that in this? If the first object's angle is say at 0 and say I subtract a field area of 20 or so. It'll check if it's less than -20! If I fix the -20 it becomes 340 but x < 340 isn't what I want, I'd have to x 340 in that case. Is there someone out there with more sleep than I that can help a new dev pulling an all-nighter just to get enemies to know if they're attacking in the right direction? I hope I'm making this harder than it seems. I'd just make them always face the main char if the producer didn't want attacks from behind to work while blocking. In which case I'll need the function above anyways. I've tried to give as much info as I can think would help. Also this is in 2d.

    Read the article

  • What is the most secure way to archive a GKScore to be re-submitted later?

    - by Jonathan Sibley
    I'm looking for the safest way to archive and store a GKScore that needs to be re-submitted to Game Center (say, because the user didn't have a network connection at the time the score was earned). I would like to archive the GKScore instance in case the app is terminated before it can be successfully re-submitted to Game Center. My worry is that if it's archived to an instance of NSData and saved in a .plist, it would be easy to manipulate. Perhaps this worry is unjustified? NOTE: I posted a similar question on Stack Overflow only to realize that it's better asked here.

    Read the article

  • Flickering problem with world matrix

    - by gnomgrol
    I do have a pretty wierd problem today. As soon as I try to change my translation- or rotationmatrix for an object to something else than (0,0,0), the object starts to flicker (scaling works fine). It rapid and randomly switches between the spot it should be in and a crippled something. I first thought that the problem would be z-fighting, but now Im pretty sure it isn't. I have now clue at all what it could be, here are two screenshots of the two states the plant is switching between. I already used PIX, but could find anything of use (Im not a very good debugger anyway) I would appreciate any help, thanks a lot! Important code: D3DXMatrixIdentity(&World); D3DXVECTOR3 rotaxisX = D3DXVECTOR3(1.0f, 0.0f, 0.0f); D3DXVECTOR3 rotaxisY = D3DXVECTOR3(0.0f, 1.0f, 0.0f); D3DXVECTOR3 rotaxisZ = D3DXVECTOR3(0.0f, 0.0f, 1.0f); D3DXMATRIX temprot1, temprot2, temprot3; D3DXMatrixRotationAxis(&temprot1, &rotaxisX, 0); D3DXMatrixRotationAxis(&temprot2, &rotaxisY, 0); D3DXMatrixRotationAxis(&temprot3, &rotaxisZ, 0); Rotation = temprot1 *temprot2 * temprot3; D3DXMatrixTranslation(&Translation, 0.0f, 10.0f, 0.0f); D3DXMatrixScaling(&Scale, 0.02f, 0.02f, 0.02f); //Set objs world space using the transformations World = Translation * Rotation * Scale; shader: cbuffer cbPerObject { matrix worldMatrix; matrix viewMatrix; matrix projectionMatrix; }; // Change the position vector to be 4 units for proper matrix calculations. input.position.w = 1.0f; // Calculate the position of the vertex against the world, view, and projection matrices. output.position = mul(input.position, worldMatrix); output.position = mul(output.position, viewMatrix); output.position = mul(output.position, projectionMatrix);

    Read the article

  • Why do we use the Pythagorean theorem in game physics?

    - by Starkers
    I've recently learned that we use Pythagorean theorem a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagorean theorem! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagorean theorem to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagorean theorem so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

    Read the article

  • How can I pass an external instance to the constructor of an object that's being created using the default XNA XML content loader?

    - by Michael
    I'm trying to understand how to use the XNA XML content importer to instantiate non-trivial objects that are more than a collection of basic properties (e.g., a class that inherits from DrawableGameObject or GameObject and requires other things to be passed into its constructor). Is it possible to pass existing external instances (e.g., an instance of the current Game) to the constructor of an object that's being created using the default XNA XML content loader? For example, imagine that I have the following class, inheriting from DrawableGameComponent: public class Character : DrawableGameComponent { public string Name { get; set; } public Character(Game game) : base(game) { } public override void Update(GameTime gameTime) { } public override void Draw(GameTime gameTime) { } } If I had a simple class that did not need other parameters in its constructor (i.e., the Game instance), then I could simply use this XML: <XnaContent> <Asset Type="MyNamespace.Character"> <Name>John Doe</Name> </Asset> </XnaContent> ...and then create an instance of Character using this code: var character = Content.Load<Character>("MyXmlAssetName"); But that won't work because I need to pass the need to pass the Game into the constructor. What's the best way to handle this situation? Is there a way to pass in things like the current Game using the default XNA XML content loader? Do I need to write my own XML loader? (If so, how?) Is there a better object-oriented design that I should be using for my classes? Note: Although I used Game in this example, I'm really just asking how to pass any type of existing instance to my constructors. (For example, I'm using the Farseer Physics Engine, and some of my classes also need a reference to the Farseer World object too.) Thanks in advance.

    Read the article

  • How was 20Q made?

    - by Dan the Man
    Ever since I was a kid, I've wondered how they made the 20Q electronic game. In this game, which is it's on device, you think of an object, thing, or animal (e.g. a potato or a donkey), once you mentally choose your thing, the device goes through a series of questions such as: Is it larger than a loaf of bread? Is it found outdoors? Is it used for recreation? For each of the questions you can answer yes, no, maybe, or unknown. The way I've always thought of it to work was with immense, nested conditionals (if statements). But, I don't think that would be very likely as it would be terribly difficult to understand while coding it. I'm not looking for a discussion as SE doesn't allow it; I'm looking for concrete knowledge or solutions.

    Read the article

  • XNA - Use Mouse To Rotate & Arrow Keys To Scroll A Linearly Wrapped Texture:

    - by The Thing
    Using XNA I'm working on my first, relatively simple, videogame for the PC. At the moment my game window is 1024 X 768 and I have a 'Starfield' linearly wrapped background texture 1280 X 1280 in size whose origin has been set to its center point (width / 2, height / 2). This texture is drawn onscreen using (graphics.PreferredBackBufferWidth / 2, graphics.PreferredBackBufferHeight / 2) to place the origin in the center of the window. I want to be able to use the horizontal movement of the mouse to rotate my texture left or right and use the arrow keys to scroll the texture in four directions. From my own related coding experiments I have found that once I rotate the texture it no longer scrolls in the direction I want, it's as if somehow the XNA framework's 'sense of direction' has been 'rotated' along with the texture. As an example of what I've described above lets say I rotate the texture 45 degrees to the right, then pressing the up arrow key results in the texture scrolling diagonally from top-right to bottom-left. This is not what I want, regardless of the degree or direction of rotation I want my texture to scroll straight up, straight down, or to the left or right depending on which arrow key was pressed. How do I go about accomplishing this? Any help or guidance is appreciated. To finish up there are two points I'd like to clarify: [1] The reason I'm using linear wrapping on my starfield texture is that it gives a nice impression of an endless starfield. [2] Using a texture at least 1280 X 1280 in conjunction with a game window of 1024 X 768 means that at no point in it's rotation will the edges of the texture become visible. Thanks for reading..... Update # 1 - as requested by RCIX: The code below is what I was referring to earlier when I mentioned 'related coding experiments'. As you can see I am scrolling a linearly wrapped texture in the direction I've moved the mouse relative to the center of the screen. This works perfectly if I don't rotate the texture, but once I do rotate it the direction of the scrolling gets messed up for some reason. public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; int x; int y; float z = 250f; Texture2D Overlay; Texture2D RotatingBackground; Rectangle? sourceRectangle; Color color; float rotation; Vector2 ScreenCenter; Vector2 Origin; Vector2 scale; Vector2 Direction; SpriteEffects effects; float layerDepth; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } protected override void Initialize() { graphics.PreferredBackBufferWidth = 1024; graphics.PreferredBackBufferHeight = 768; graphics.ApplyChanges(); Direction = Vector2.Zero; IsMouseVisible = true; ScreenCenter = new Vector2(graphics.PreferredBackBufferWidth / 2, graphics.PreferredBackBufferHeight / 2); Mouse.SetPosition((int)graphics.PreferredBackBufferWidth / 2, (int)graphics.PreferredBackBufferHeight / 2); sourceRectangle = null; color = Color.White; rotation = 0.0f; scale = new Vector2(1.0f, 1.0f); effects = SpriteEffects.None; layerDepth = 1.0f; base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); Overlay = Content.Load<Texture2D>("Overlay"); RotatingBackground = Content.Load<Texture2D>("Background"); Origin = new Vector2((int)RotatingBackground.Width / 2, (int)RotatingBackground.Height / 2); } protected override void UnloadContent() { } protected override void Update(GameTime gameTime) { float timePassed = (float)gameTime.ElapsedGameTime.TotalSeconds; MouseState ms = Mouse.GetState(); Vector2 MousePosition = new Vector2(ms.X, ms.Y); Direction = ScreenCenter - MousePosition; if (Direction != Vector2.Zero) { Direction.Normalize(); } x += (int)(Direction.X * z * timePassed); y += (int)(Direction.Y * z * timePassed); //No rotation = texture scrolls as intended, With rotation = texture no longer scrolls in the direction of the mouse. My update method needs to somehow compensate for this. //rotation += 0.01f; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { spriteBatch.Begin(SpriteSortMode.Deferred, null, SamplerState.LinearWrap, null, null); spriteBatch.Draw(RotatingBackground, ScreenCenter, new Rectangle(x, y, RotatingBackground.Width, RotatingBackground.Height), color, rotation, Origin, scale, effects, layerDepth); spriteBatch.Draw(Overlay, Vector2.Zero, Color.White); spriteBatch.End(); base.Draw(gameTime); } }

    Read the article

  • Alternative to NV Occlusion Query - getting the number of fragments which passed the depth test

    - by Etan
    In "modern" environments, the "NV Occlusion Query" extension provide a method to get the number of fragments which passed the depth test. However, on the iPad / iPhone using OpenGL ES, the extension is not available. What is the most performant approach to implement a similar behaviour in the fragment shader? Some of my ideas: Render the object completely in white, then count all the colors together using a two-pass shader where first a vertical line is rendered and for each fragment the shader computes the sum over the whole row. Then, a single vertex is rendered whose fragment sums all the partial sums of the first pass. Doesn't seem to be very efficient. Render the object completely in white over a black background. Downsample recursively, abusing the hardware linear interpolation between textures until being at a reasonably small resolution. This leads to fragments which have a greyscale level depending on the number of white pixels where in their corresponding region. Is this even accurate enough? ... ?

    Read the article

  • Optimizing drawing of cubes

    - by Christian Frantz
    After googling for hours I've come to a few conclusions, I need to either rewrite my whole cube class, or figure out how to use hardware instancing. I can draw up to 2500 cubes with little lag, but after that my fps drops. Is there a way I can use my class for hardware instancing? Or would I be better off rewriting my class for optimization? public class Cube { public GraphicsDevice device; public VertexBuffer cubeVertexBuffer; public Cube(GraphicsDevice graphicsDevice) { device = graphicsDevice; var vertices = new List<VertexPositionTexture>(); BuildFace(vertices, new Vector3(0, 0, 0), new Vector3(0, 1, 1)); BuildFace(vertices, new Vector3(0, 0, 1), new Vector3(1, 1, 1)); BuildFace(vertices, new Vector3(1, 0, 1), new Vector3(1, 1, 0)); BuildFace(vertices, new Vector3(1, 0, 0), new Vector3(0, 1, 0)); BuildFaceHorizontal(vertices, new Vector3(0, 1, 0), new Vector3(1, 1, 1)); BuildFaceHorizontal(vertices, new Vector3(0, 0, 1), new Vector3(1, 0, 0)); cubeVertexBuffer = new VertexBuffer(device, VertexPositionTexture.VertexDeclaration, vertices.Count, BufferUsage.WriteOnly); cubeVertexBuffer.SetData<VertexPositionTexture>(vertices.ToArray()); } private void BuildFace(List<VertexPositionTexture> vertices, Vector3 p1, Vector3 p2) { vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 1, 0)); vertices.Add(BuildVertex(p1.X, p2.Y, p1.Z, 1, 1)); vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 0, 1)); vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 0, 1)); vertices.Add(BuildVertex(p2.X, p1.Y, p2.Z, 0, 0)); vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 1, 0)); } private void BuildFaceHorizontal(List<VertexPositionTexture> vertices, Vector3 p1, Vector3 p2) { vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 0, 1)); vertices.Add(BuildVertex(p2.X, p1.Y, p1.Z, 1, 1)); vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 1, 0)); vertices.Add(BuildVertex(p1.X, p1.Y, p1.Z, 0, 1)); vertices.Add(BuildVertex(p2.X, p2.Y, p2.Z, 1, 0)); vertices.Add(BuildVertex(p1.X, p1.Y, p2.Z, 0, 0)); } private VertexPositionTexture BuildVertex(float x, float y, float z, float u, float v) { return new VertexPositionTexture(new Vector3(x, y, z), new Vector2(u, v)); } public void Draw(BasicEffect effect) { foreach (EffectPass pass in effect.CurrentTechnique.Passes) { pass.Apply(); device.SetVertexBuffer(cubeVertexBuffer); device.DrawPrimitives(PrimitiveType.TriangleList, 0, cubeVertexBuffer.VertexCount / 3); } } } The following class is a list that draws the cubes. public class DrawableList<T> : DrawableGameComponent { private BasicEffect effect; private ThirdPersonCam camera; private class Entity { public Vector3 Position { get; set; } public Matrix Orientation { get; set; } public Texture2D Texture { get; set; } } private Cube cube; private List<Entity> entities = new List<Entity>(); public DrawableList(Game game, ThirdPersonCam camera, BasicEffect effect) : base(game) { this.effect = effect; cube = new Cube(game.GraphicsDevice); this.camera = camera; } public void Add(Vector3 position, Matrix orientation, Texture2D texture) { entities.Add(new Entity() { Position = position, Orientation = orientation, Texture = texture }); } public override void Draw(GameTime gameTime) { foreach (var item in entities) { effect.VertexColorEnabled = false; effect.TextureEnabled = true; effect.Texture = item.Texture; Matrix center = Matrix.CreateTranslation(new Vector3(-0.5f, -0.5f, -0.5f)); Matrix scale = Matrix.CreateScale(1f); Matrix translate = Matrix.CreateTranslation(item.Position); effect.World = center * scale * translate; effect.View = camera.view; effect.Projection = camera.proj; effect.FogEnabled = true; effect.FogColor = Color.CornflowerBlue.ToVector3(); effect.FogStart = 1.0f; effect.FogEnd = 50.0f; cube.Draw(effect); } base.Draw(gameTime); } } } There are probably many reasons that my fps is so slow, but I can't seem to figure out how to fix it. I've looked at techcraft as well, but what I have is too specific to what I want the outcome to be to just rewrite everything from scratch

    Read the article

  • Dynamic model interactions

    - by Richard
    I am just curious as to how in many games (namely games like arkham asylum/city, manhunt, hitman) do they make it so that your character can "grab" a character in front of you and do stuff to them. I know this may sound very confusing but for an example go to youtube and search "hitman executions", and the first video is an example of what i'm asking. Basically I'm wondering how they make your model dynamically interact with whatever other model you come across, so in hitman when you come up behind some one with the fibre wire you strangle the other character or if you have the anesthetic you come up behind some person and put your hand over there mouth while they struggle and slowly go to the floor where you lay them down. I am confused as to whether it was animated to use two models using specific bone/skeletal identifiers, if it is just two completely separate animations that are played at the correct time to make it look like they are actually interacting or something else all together. I am not an animator so i assume most of what i just said is not right but i hope that some one can understand what i mean and provide an answer. PS) I am a programmer and I am in the process of building a hitmanesque game, just because i love that style of game and I want to increase my skills on something fun, so if you do know what i'm talking about have some examples with involving both models and programming (i use c++ and mainly Ogre3D at the moment but i am getting into unity and XNA) i would greatly appreciate it. Thanks.

    Read the article

  • The Correct Usage of DLLs with a DirectX Game?

    - by smoth190
    I'm using DirectX 10 (in C++) to make a game engine, and a test driver program on top of it. Now that I've written many messy rough drafts of an engine, I want to make the final (or sorta final) clean version. I choose to follow how I've seen other engines do it, and that's to have all the core nasty messy crap in a DLL, and then you can create games with just a few functions (well, not really :D). However, I'm unsure of what nasty messy crap to put in that DLL. I don't know about speed restrictions with DLLs. What I've done is put my winproc in the DLL, and have a class that takes the messages, and sends them through to the program using the DLL. Then that program does what it needs to do, and calls a rendering functions back in the DLL that renders everything. Only problem is it gets very low FPS (2, to be exact...). I've looked through everything, and I don't know if the way I'm using DLLs in causing this, or its something different. Whether it's the DLLs or not, I still want to know how to use a DLL correctly with a game engine. I like being neat, I hate having to see all those long names of DirectX classes. I use typedef a lot.

    Read the article

  • object detection in bitmmap javacanvas

    - by user1538127
    i want to detect clicks on canvas elements which are drawn using paths. so far i have think of to store elements path in javascript data structure and then check the cordinates of hits which matches the elements cordinates. i belive there is algorithm already for thins kind o cordinate search. rendering each of element path and checking the hits would be inefficient when elements number is larger. can anyone point on me that?

    Read the article

< Previous Page | 494 495 496 497 498 499 500 501 502 503 504 505  | Next Page >