Search Results

Search found 28914 results on 1157 pages for 'cloud development'.

Page 512/1157 | < Previous Page | 508 509 510 511 512 513 514 515 516 517 518 519  | Next Page >

• How exactly does XNA's SpriteBatch work?

  - by David Gouveia

  To be more precise, if I needed to recreate this functionality from scratch in another API (e.g. in OpenGL) what would it need to be capable of doing? I do have a general idea of some of the steps, such as how it prepares an orthographic projection matrix and creates a quad for each draw call. I'm not too familiar, however, with the batching process itself. Are all quads stored in the same vertex buffer? Does it need an index buffer? How are different textures handled? If possible I'd be grateful if you could guide me through the process from when SpriteBatch.Begin() is called until SpriteBatch.End(), at least when using the default Deferred mode.

  Read the article

• How to create a thread in XNA for pathfinding?

  - by Dan

  I am trying to create a separate thread for my enemy's A* pathfinder which will give me a list of points to get to the player. I have placed the thread in the update method of my enemy. However this seems to cause jittering in the game every-time the thread is called. I have tried calling just the method and this works fine. Is there any way I can sort this out so that I can have the pathfinder on its own thread? Do I need to remove the thread start from the update and start it in the constructor? Is there any way this can work? Here is the code at the moment: bool running = false; bool threadstarted; System.Threading.Thread thread; public void update() { if (running == false && threadstarted == false) { thread = new System.Threading.Thread(PathThread); //thread.Priority = System.Threading.ThreadPriority.Lowest; thread.IsBackground = true; thread.Start(startandendobj); //PathThread(startandendobj); threadstarted = true; } } public void PathThread(object Startandend) { object[] Startandendarray = (object[])Startandend; Point startpoint = (Point)Startandendarray[0]; Point endpoint = (Point)Startandendarray[1]; bool runnable = true; // Path find from 255, 255 to 0,0 on the map foreach(Tile tile in Map) { if(tile.Color == Color.Red) { if (tile.Position.Contains(endpoint)) { runnable = false; } } } if(runnable == true) { running = true; Pathfinder p = new Pathfinder(Map); pathway = p.FindPath(startpoint, endpoint); running = false; threadstarted = false; } }

  Read the article

• OUYA and Unity set up problems

  - by Atkobeau

  I'm having trouble with the Unity / OUYA plugin. I'm using Unity 4 with the latest update on a Windows 7 machine. When I open the starter kit and try to compile the plugin I get the following error: Picked up _JAVA_OPTIONS: -Xmx512M And if I try to Build and Run I get this error: Error building Player: ArgumentException: Illegal characters in path. I'm stumped, I've gone through lots of forum posts here and on stackoverflow and I can't seem to resolve it. My environment variables look like this: PATH - C:\Users\dave\Documents\adt-bundle-windows-x86_64-20130219\sdk\tools; C:\Users\dave\Documents\adt-bundle-windows-x86_64-20130219\sdk\platform-tools\ JAVA_HOME - C:\Program Files (x86)\Java\jdk1.6.0_45\ Everything in the OUYA Panel is white Any ideas?

  Read the article

• Fastest bit-blit in C# ?

  - by AttackingHobo

  I know there is Unity, and XNA that both use C#, but I am don't know what else I could use. The reason I say C# is that the syntax and style is similar to AS3, which I am familiar with, and I want to choose the correct framework to start learning with. What should I use to be able to do the most possible bit-blit(direct pixel copy) objects per frame. EDIT: I should not need to add this, but I am looking for the most possible amount of objects per frame because I am making a few Bullet-Hell SHMUPS. I need thousands and thousands of bullets, particles, and hundreds of enemies on the screen at once. I am looking for a solution to do as many bit-blit operations per frame, I am not looking for a general purpose engine. EDIT2: I want bit-blitting because I do not want to exclude people who have lower end video cards but a fast processor from playing my games.

  Read the article

• How to convert pitch and yaw to x, y, z rotations?

  - by Aaron Anodide

  I'm a beginner using XNA to try and make a 3D Asteroids game. I'm really close to having my space ship drive around as if it had thrusters for pitch and yaw. The problem is I can't quite figure out how to translate the rotations, for instance, when I pitch forward 45 degrees and then start to turn - in this case there should be rotation being applied to all three directions to get the "diagonal yaw" - right? I thought I had it right with the calculations below, but they cause a partly pitched forward ship to wobble instead of turn.... :( So my quesiton is: how do you calculate the X, Y, and Z rotations for an object in terms of pitch and yaw? Here's current (almost working) calculations for the Rotation acceleration: float accel = .75f; // Thrust +Y / Forward if (currentKeyboardState.IsKeyDown(Keys.I)) { this.ship.AccelerationY += (float)Math.Cos(this.ship.RotationZ) * accel; this.ship.AccelerationX += (float)Math.Sin(this.ship.RotationZ) * -accel; this.ship.AccelerationZ += (float)Math.Sin(this.ship.RotationX) * accel; } // Rotation +Z / Yaw if (currentKeyboardState.IsKeyDown(Keys.J)) { this.ship.RotationAccelerationZ += (float)Math.Cos(this.ship.RotationX) * accel; this.ship.RotationAccelerationY += (float)Math.Sin(this.ship.RotationX) * accel; this.ship.RotationAccelerationX += (float)Math.Sin(this.ship.RotationY) * accel; } // Rotation -Z / Yaw if (currentKeyboardState.IsKeyDown(Keys.K)) { this.ship.RotationAccelerationZ += (float)Math.Cos(this.ship.RotationX) * -accel; this.ship.RotationAccelerationY += (float)Math.Sin(this.ship.RotationX) * -accel; this.ship.RotationAccelerationX += (float)Math.Sin(this.ship.RotationY) * -accel; } // Rotation +X / Pitch if (currentKeyboardState.IsKeyDown(Keys.F)) { this.ship.RotationAccelerationX += accel; } // Rotation -X / Pitch if (currentKeyboardState.IsKeyDown(Keys.D)) { this.ship.RotationAccelerationX -= accel; } I'm combining that with drawing code that does a rotation to the model: public void Draw(Matrix world, Matrix view, Matrix projection, TimeSpan elsapsedTime) { float seconds = (float)elsapsedTime.TotalSeconds; // update velocity based on acceleration this.VelocityX += this.AccelerationX * seconds; this.VelocityY += this.AccelerationY * seconds; this.VelocityZ += this.AccelerationZ * seconds; // update position based on velocity this.PositionX += this.VelocityX * seconds; this.PositionY += this.VelocityY * seconds; this.PositionZ += this.VelocityZ * seconds; // update rotational velocity based on rotational acceleration this.RotationVelocityX += this.RotationAccelerationX * seconds; this.RotationVelocityY += this.RotationAccelerationY * seconds; this.RotationVelocityZ += this.RotationAccelerationZ * seconds; // update rotation based on rotational velocity this.RotationX += this.RotationVelocityX * seconds; this.RotationY += this.RotationVelocityY * seconds; this.RotationZ += this.RotationVelocityZ * seconds; Matrix translation = Matrix.CreateTranslation(PositionX, PositionY, PositionZ); Matrix rotation = Matrix.CreateRotationX(RotationX) * Matrix.CreateRotationY(RotationY) * Matrix.CreateRotationZ(RotationZ); model.Root.Transform = rotation * translation * world; model.CopyAbsoluteBoneTransformsTo(boneTransforms); foreach (ModelMesh mesh in model.Meshes) { foreach (BasicEffect effect in mesh.Effects) { effect.World = boneTransforms[mesh.ParentBone.Index]; effect.View = view; effect.Projection = projection; effect.EnableDefaultLighting(); } mesh.Draw(); } }

  Read the article

• Java applet game design no keyboard focus

  - by Sri Harsha Chilakapati

  THIS IS PROBABLY THE WRONG PLACE. POSTED ITHERE (STACKOVERFLOW) I'm making an applet game and it is rendering, the game loop is running, the animations are updating, but the keyboard input is not working. Here's an SSCCE. public class Game extends JApplet implements Runnable { public void init(){ // Initialize the game when called by browser setFocusable(true); requestFocus(); requestFocusInWindow(); // Always returning false GInput.install(this); // Install the input manager for this class new Thread(this).start(); } public void run(){ startGameLoop(); } } And Here's the GInput class. public class GInput implements KeyListener { public static void install(Component c){ new GInput(c); } public GInput(Component c){ c.addKeyListener(this); } public void keyPressed(KeyEvent e){ System.out.println("A key has been pressed"); } ...... } This is my GInput class. When run as an applet, it doesn't work and when I add the Game class to a frame, it works properly. Thanks

  Read the article

• Masking OpenGL texture by a pattern

  - by user1304844

  Tiled terrain. User wants to build a structure. He presses build and for each tile there is an "allow" or "disallow" tile sprite added to the scene. FPS drops right away, since there are 600+ tiles added to the screen. Since map equals screen, there is no scrolling. I came to an idea to make an allow grid covering the whole map and mask the disallow fields. Approach 1: Create allow and disallow grid textures. Draw a polygon on screen. Pass both textures to the fragment shader. Determine the position inside the polygon and use color from allowTexture if the fragment belongs to the allow field, disallow otherwise Problem: How do I know if I'm on the field that isn't allowed if I cannot pass the matrix representing the map (enum FieldStatus[][] (Allow / Disallow)) to the shader? Therefore, inside the shader I don't know which fragments should be masked. Approach 2: Create allow texture. Create an empty texture buffer same size as the allow texture Memset the pixels of the empty texture to desired color for each pixel that doesn't allow building. Draw a polygon on screen. Pass both textures to the fragment shader. Use texture2 color if alpha 0, texture1 color otherwise. Problem: I'm not sure what is the right way to manipulate pixels on a texture. Do I just make a buffer with width*height*4 size and memcpy the color[] to desired coordinates or is there anything else to it? Would I have to call glTexImage2D after every change to the texture? Another problem with this approach is that it takes a lot more work to get a prettier effect since I'm manipulating the color pixels instead of just masking two textures. varying vec2 TexCoordOut; uniform sampler2D Texture1; uniform sampler2D Texture2; void main(void){ vec4 allowColor = texture2D(Texture1, TexCoordOut); vec4 disallowColor = texture2D(Texture2, TexCoordOut); if(disallowColor.a > 0){ gl_FragColor= disallowColor; }else{ gl_FragColor= allowColor; }} I'm working with OpenGL on Windows. Any other suggestion is welcome.

  Read the article

• Best way to do large XNA animations?

  - by Harold

  What's the best way to have large animations in XNA 4.0? I have created a spritesheet with the sprite being 250x400 (more of an image than a sprite but hey ho) and there are approximately 45 frames in the animation. This causes problems for XNA as it says that the maximum filesize for Reach is 2048. I'd rather not change to hidef as I heard that means that your game is less compatible with some computers and systems so does anyone have any idea what the best thing I could do is? The only thing I could come up with is to have a list of textures to flick through but that's not ideal.

  Read the article

• What are the reasons for MMOs to have level caps [on hold]

  - by SamStephens

  In many MMOs players character progression is artificially capped, e.g. by level 60 or 90 or 100 or whatever. Why do MMOs have these level caps in the first place? Why not just allow characters to continue to arbitrary levels with a mathematically designed leveling system that keeps the leveling experience interesting and endless? Answers to this question may help us to see the reason behind the feature and decide if and how this should be implemented in our MMOs.

  Read the article

• Sharing VBO with multiple objects and fixed size buffer data

  - by Mark Ingram

  I'm just messing around with OpenGL and getting some basic structures in place and my first attempt resulted in each SceneObject class (just contains vertex information right now) having it's own VBO inside it, however I've read that it might be better to share VBOs across multiple objects. Also, I read that you should avoid resizing a VBO (repeated calls to glBufferData with different size parameters), and instead choose a fixed size for a VBO, and just try a range from the buffer. I don't think changing the size of the buffer data would happen too often, but surely it would be better to only allocate the data you need? Choosing an arbitrary value seems risky. I'm looking for some advice on working with individual objects in a scene and their associated buffer data.

  Read the article

• Precise Touch Screen Dragging Issue: Trouble Aligning with the Finger due to Different Screen Resolution

  - by David Dimalanta

  Please, I need your help. I'm trying to make a game that will drag-n-drop a sprite/image while my finger follows precisely with the image without being offset. When I'm trying on a 900x1280 (in X [900] and Y [1280]) screen resolution of the Google Nexus 7 tablet, it follows precisely. However, if I try testing on a phone smaller than 900x1280, my finger and the image won't aligned properly and correctly except it still dragging. This is the code I used for making a sprite dragging with my finger under touchDragged(): x = ((screenX + Gdx.input.getX())/2) - (fruit.width/2); y = ((camera_2.viewportHeight * multiplier) - ((screenY + Gdx.input.getY())/2) - (fruit.width/2)); This code above will make the finger and the image/sprite stays together in place while dragging but only works on 900x1280. You'll be wondering there's camera_2.viewportHeight in my code. Here are for two reasons: to prevent inverted drag (e.g. when you swipe with your finger downwards, the sprite moves upward instead) and baseline for reading coordinate...I think. Now when I'm adding another orthographic camera named camera_1 and changing its setting, I recently used it for adjusting the falling object by meter per pixel. Also, it seems effective independently for smartphones that has smaller resolution and this is what I used here: show() camera_1 = new OrthographicCamera(); camera_1.viewportHeight = 280; // --> I set it to a smaller view port height so that the object would fall faster, decreasing the chance of drag force. camera_1.viewportWidth = 196; // --> Make it proportion to the original screen view size as possible. camera_1.position.set(camera_1.viewportWidth * 0.5f, camera_1.viewportHeight * 0.5f, 0f); camera_1.update(); touchDragged() x = ((screenX + (camera_1.viewportWidth/Gdx.input.getX()))/2) - (fruit.width/2); y = ((camera_1.viewportHeight * multiplier) - ((screenY + (camera_1.viewportHeight/Gdx.input.getY()))/2) - (fruit.width/2)); But the result instead of just following the image/sprite closely to my finger, it still has a space/gap between the sprite/image and the finger. It is possibly dependent on coordinates based on the screen resolution. I'm trying to drag the blueberry sprite with my finger. My expectation did not met since I want my finger and the sprite/image (blueberry) to stay close together while dragging until I release it. Here's what it looks like: I got to figure it out how to make independent on all screen sizes by just following the image/sprite closely to my finger while dragging even on most different screen sizes instead.

  Read the article

• glColor3f Setting colour

  - by Aaron

  This draws a white vertical line from 640 to 768 at x512: glDisable(GL_TEXTURE_2D); glBegin(GL_LINES); glColor3f((double)R/255,(double)G/255,(double)B/255); glVertex3f(SX, -SPosY, 0); // origin of the line glVertex3f(SX, -EPosY, 0); // ending point of the line glEnd(); glEnable(GL_TEXTURE_2D); This works, but after having a problem where it wouldn't draw it white (Or to any colour passed) I discovered that disabling GL_TEXTURE_2D Before drawing the line, and the re-enabling it afterwards for other things, fixed it. I want to know, is this a normal step a programmer might take? Or is it highly inefficient? I don't want to be causing any slow downs due to a mistake =) Thanks

  Read the article

• Blender to 3ds max to cal3d format

  - by Kaliber64

  There are quite a few questions on cal3d but they are old and don't apply anymore. In Blender(must be 2.49a for python script to work!!!): I have a scene with 7 meshes, 1 armature, 10 bones. I tried going to one mesh to simplify it but doesn't change anything. I found a small blend file that was used for cal3d and it exported just fine. So I tried to copy it's setup with no success. EDIT*8/13/2012 In the last week here is what I have found so far. I made the mesh in the newest blender(2.62?) and exported it to import it in the old one(2.49a). Did an animation in the old one because importing new blend files to old blenders, its just said it would lose keyframe data and all was good. And then you get the last problem of it not exporting meshes. BUT I found that meshes made in the old one export regardless. I can't find any that won't export. So if I used the old blender to remake my model I could get it to export :) At this point I found a modified release of cal3d (because the most core model variable would not initiate as I made a really small test subject in old blender instead of remaking my big one which took 4 hours.) which fixes the morph objects and adds what cal3d left off with. Under their license they have to release the modification but it has no documentation so I have to figure it out on my own. Its mostly the same. But with this lib it came with a 3ds max exporter. My question now is how do I transfer armature and mesh information from blender to 3ds max in order to export into cal3d format. Every time I try the models are see through and small and there are no bones. The formats I have tried to import are .3ds .obj(mesh only) and COLLADA. In all of them the mesh is invisible and no bones. It says the default texture is on so I should be able to see it. All the vertices are present I found a vertex highlighter so I can see those. If any of this is confusing let me know so I can clear it up. Its late .<=sleep.

  Read the article

• What calls trigger a new batch?

  - by sebf

  I am finding my project is starting to show performance degradation and I need to optimize it. The answer to my previous question and this presentation from NVidia have helped greatly in understanding the performance characteristics of code using the GPU but there are a couple of things that aren't clear that I need to know to optimize my drawing. Specifically, what calls make the distinction between batches. I know that any state changes cause a new batch, so that includes: Render State Changes Buffer Changes Shader Changes Render Target Changes Correct? What else counts as a 'state change'? Does each Draw**Primitive() call constitute a new batch? Even if I were to issue the same call twice, with no state changes, or call it once on on part of the buffer, then again on another? If I were to update a buffer, but not change the bindings, would that be a new batch? That presentation and a DX9 page suggest using all of the texture slots available, which I take to mean loading multiple objects in 'parallel' by mapping their buffers/shaders/textures to slots 1-16. But I am not sure how this works - surely to do this you would need to change the buffer binding and that would count as a state change? (or is it a case of you do but it saves 16 calls so its OK?)

  Read the article

• Register Game Object Components in Game Subsystems? (Component-based Game Object design)

  - by topright

  I'm creating a component-based game object system. Some tips: GameObject is simply a list of Components. There are GameSubsystems. For example, rendering, physics etc. Each GameSubsystem contains pointers to some of Components. GameSubsystem is a very powerful and flexible abstraction: it represents any slice (or aspect) of the game world. There is a need in a mechanism of registering Components in GameSubsystems (when GameObject is created and composed). There are 4 approaches: 1: Chain of responsibility pattern. Every Component is offered to every GameSubsystem. GameSubsystem makes a decision which Components to register (and how to organize them). For example, GameSubsystemRender can register Renderable Components. pro. Components know nothing about how they are used. Low coupling. A. We can add new GameSubsystem. For example, let's add GameSubsystemTitles that registers all ComponentTitle and guarantees that every title is unique and provides interface to quering objects by title. Of course, ComponentTitle should not be rewrited or inherited in this case. B. We can reorganize existing GameSubsystems. For example, GameSubsystemAudio, GameSubsystemRender, GameSubsystemParticleEmmiter can be merged into GameSubsystemSpatial (to place all audio, emmiter, render Components in the same hierarchy and use parent-relative transforms). con. Every-to-every check. Very innefficient. con. Subsystems know about Components. 2: Each Subsystem searches for Components of specific types. pro. Better performance than in Approach 1. con. Subsystems still know about Components. 3: Component registers itself in GameSubsystem(s). We know at compile-time that there is a GameSubsystemRenderer, so let's ComponentImageRender will call something like GameSubsystemRenderer::register(ComponentRenderBase*). pro. Performance. No unnecessary checks as in Approach 1. con. Components are badly coupled with GameSubsystems. 4: Mediator pattern. GameState (that contains GameSubsystems) can implement registerComponent(Component*). pro. Components and GameSubystems know nothing about each other. con. In C++ it would look like ugly and slow typeid-switch. Questions: Which approach is better and mostly used in component-based design? What Practice says? Any suggestions about implementation of Approach 4? Thank you.

  Read the article

• Basic AI FSM - Handling state transition

  - by Galvanize

  I'm starting to study on how to implement game AI, and it seems to me that a very simple FSM for my Pong demo would be a nice way to start. My vision on implementing this would be to have a basic state interface and a class for each state, then the NPC would have an instance of the current state. The class should have an update method and directions on wich state to go next, depending on the event received. The question is: How do I handle this event? Should I have a regular addEventListener and a costum event system? Or should I check on update for the things that could change the current state? I'm feeling a bit lost, I feel I have a good grasp on the FSM concept but a good implementation seems tricky, thanks in advance.

  Read the article

• Can I use PBOs for textures in iOS?

  - by Radu

  As far as I can see, there is no GL_PIXEL_UNPACK_BUFFER. Also, the OpenGL ES 2.0 specification (and as far as I know, no iOS device currently supports OpenGL ES 2.0) states that glMapBufferOES() can only use GL_ARRAY_BUFFER as a target, yet glTexImage2D() and glTexSubImage2D() only seem to use PBOs if GL_PIXEL_UNPACK_BUFFER is bound. The OpenGL documentation for glBindBuffer() also states that: GL_PIXEL_PACK_BUFFER and GL_PIXEL_UNPACK_BUFFER are available only if the GL version is 2.1 or greater. So, can I use PBOs for textures? Am I missing something obvious?

  Read the article

• How to manage drawing loop when changing render targets

  - by George Duckett

  I'm managing my game state by having a base GameScreen class with a Draw method. I then have (basically) a stack of GameScreens that I render. I render the bottom one first, as screens above might not completely cover the ones below. I now have a problem where one GameScreen changes render targets while doing its rendering. Anything the previous screens have drawn to the backbuffer is lost (as XNA emulates what happens on the xbox). I don't want to just set the backbuffer to preserve its contents as I want this to work on the xbox as well as PC. How should I manage this problem? A few ideas I've had: Render every GameScreen to its own render target, then render them all to the backbuffer. Create some kind of RenderAction queue where a game screen (and anything else I guess) could queue something to be rendered to the back buffer. They'd render whatever they wanted to any render target as normal, but if they wanted to render to the backbuffer they'd stick that in a queue which would get processed once all rendertarget rendering was done. Abstract away from render targets and backbuffers and have some way of representing the way graphics flows and transforms between render targets and have something manage/work out the correct rendering order (and render targets) given what rendering process needs as input and what it produces as output. I think each of my ideas have pros and cons and there are probably several other ways of approaching this general problem so I'm interested in finding out what solutions are out there.

  Read the article

• D3D9 Alpha Blending on the surfaces

  - by Indeera

  I have a surface (OffScreenPlain or RenderTarget with D3DFMT_A8R8G8B8) which I copy pixels (ARGB) to, from a third party function. Before pixel copying, Bits are accessed by LockRect. This surface is then StretchRect to the Backbuffer which is (D3DFMT_A8R8G8B8). Surface and Backbuffer are different dimensions. Filtering is set to D3DTEXF_NONE. Just after creating the d3d device I've set following RenderState settings D3DRS_ALPHABLENDENABLE -> TRUE D3DRS_BLENDOP -> D3DBLENDOP_ADD D3DRS_SRCBLEND -> D3DBLEND_SRCALPHA D3DRS_DESTBLEND -> D3DBLEND_INVSRCALPHA But I see no alpha blending happening. I've verified that alpha is specified in pixels. I've done a simple test by creating a vertex buffer and drawing a triangle (DrawPrimitive) which displays with alpha blending. In this test surface was StretchRect first and then DrawPrimitive, and the surface content displays without alpha blending and the triangle displays with alpha blending. What am I missing here? Thanks

  Read the article

• Facebook Game database design

  - by facebook-100000781341887

  Hi, I'm currently develop a facebook mafia like PHP game(of course, a light weight version), here is a simplify database(MySQL) of the game id-a <int3> <for index> uid <chr15> <facebook uid> HP <int3> <health point> exp <int3> <experience> money <int3> <money> list_inventory <chr5> <the inventory user hold...some special here, talk next> ... and 20 other fields just like reputation, num of combat... *the number next to the type is the size(byte) of the type For the list_inventory, there have 40 inventorys in my game, (actually, I have 5 these kind of list in my database), and each user can only contain 1 qty of each inventory, therefore, I assign 5 char for this field and each bit of char as 1 item(5 char * 8 bit = 40 slot), and I will do some manipulation by PHP to extract the data from this 5 byte. OK, I was thinking on this, if this game contains 100,000 user, and only 10% are active, therefore, if use my method, for the space use, 5 byte * 100,000 = 500 KB if I use another method, create a table user_hold_inventory, if the user have the inventory, then insert a record into this table, so, for 10,000 active user, I assume they got all item, but for other, I assume they got no item, here is the fields of the new table id-b <int3> <for index> id-a <int3> <id of the user table> inv_no <int1> <inventory that user hold> for the space use, ([id] (3+3) byte + [inv_no] 1 byte ) * [active user] 10,000 * [all inventory] * 40 = 2.8 MB seems method 2 have use more space, but it consume less CPU power. Please comment these 2 method or please correct me if there have another better method rather than what I think. Another question is, my database contain 26 fields, but I counted 5 of them are not change frquently, should I need to separate it on the other table or not? So many words, thanks for reading :)

  Read the article

• Understanding math used to determine if vector is clockwise / counterclockwise from your vector

  - by MTLPhil

  I'm reading Programming Game AI by Example by Mat Buckland. In the Math & Physics primer chapter there's a listing of the declaration of a class used to represent 2D vectors. This class contains a method called Sign. It's implementation is as follows //------------------------ Sign ------------------------------------------ // // returns positive if v2 is clockwise of this vector, // minus if anticlockwise (Y axis pointing down, X axis to right) //------------------------------------------------------------------------ enum {clockwise = 1, anticlockwise = -1}; inline int Vector2D::Sign(const Vector2D& v2)const { if (y*v2.x > x*v2.y) { return anticlockwise; } else { return clockwise; } } Can someone explain the vector rules that make this hold true? What do the values of y*v2.x and x*v2.y that are being compared actually represent? I'd like to have a solid understanding of why this works rather than just accepting that it does without figuring it out. I feel like it's something really obvious that I'm just not catching on to. Thanks for your help.

  Read the article

• Efficiency concerning thread granularity

  - by MaelmDev

  Lately, I've been thinking of ways to use multithreading to improve the speed of different parts of a game engine. What confuses me is the appropriate granularity of threads, especially when dealing with single-instruction-multiple-data (SIMD) tasks. Let's use line-of-sight detection as an example. Each AI actor must be able to detect objects of interest around them and mark them. There are three basic ways to go about this with multithreading: Don't use threading at all. Create a thread for each actor. Create a thread for each actor-object combination. Option 1 is obviously going to be the least efficient method. However, choosing between the next two options is more difficult. Only using one thread per actor is still running through every object in series instead of in parallel. However, are CPU's able to create and join threads in the granularity posed in Option 3 efficiently? It seems like that many calls to the OS could be really slow, and varying enormously between different hardware.

  Read the article

• How does a BSP tree work for Z sorting?

  - by Jenko

  I'm developing a 3D engine in software, and so I must compute Z sorting manually. I'm currently using the painters algorithm to sort triangles and then drawing them back-to-front. This causes artifacts that I'm trying to correct. Would using a dynamic BSP-tree ensure "correct Z sorting" of triangles? Why? Because the bounding volumes of triangles would be similar? Since I would have a single "world" BSP tree, would I have to remove and re-add any moved/scaled/rotated object into the tree? Is it possible to add triangles into a BSP tree without the expensive cutting process? Why do you need to cut triangles on the axis planes anyway? Is it faster to traverse a BSP tree from any angle, than to sort all tris each draw like the painters algorithm?

  Read the article

• Best way to implement mouse-based movement in MMOG

  - by fiftyeight

  I want to design an MMO where players click the destination they want to walk to with their mouse and the character moves there, similar to Runescape in this manner. I think it should be easier than keyboard movement since the client can simply send the server the destination each time the player clicks on a destination. The main thing I'm trying to decide is what to do when there are obstacles in the way. It's no problem to implement a simple path-finding solution on the client, the question is if the server will do path-finding as well, since it'll probably take too much Computation power from the server. What I though is that when there is an obstacle the client will send only the first coordinate it plans to go to and then when he gets there he'll send the next coordinate automatically. For example if there is a rock in the way the character will decide on a route that is made of two destinations so it goes around the rock and when it arrives at the first destination it sends the next coordinate. That way if the player changes destination is the middle he won't send unnecessary information. Is this a good way to implement it and is there a standard way MMOGs usually do it? EDIT: I should also mention that the server will make sure all movements are legal and there aren't any walls in the way etc. In the way I wrote it should be quite easy since all movements will be sent in straight lines so the server will just check there aren't any obstacles along that line.

  Read the article

• Deterministic Multiplayer RTS game questions?

  - by Martin K

  I am working on a cross-platform multiplayer RTS game where the different clients and a server(flash and C#), all need to stay deterministically synchronised. To deal with Floatpoint inconsistencies, I've come across this method: http://joshblog.net/2007/01/30/flash-floating-point-number-errors/#comment-49912 which basically truncates off the nondeterministic part: return Math.round(1000 * float) / 1000; Howewer my concern is that every time there is a division, there is further chance of creating additional floatpoint errors, in essence making it worse? . So it occured to me, how about something like this: function floatSafe(number:Number) : Number {return Math.round(float* 1024) / 1024; } ie dividing with only powers of 2 ? What do you think? . Ironically with the above method I got less accurate results: trace( floatSafe(3/5) ) // 0.599609375 where as with the other method(dividing with 1000), or just tracing the raw value I am getting 3/5 = 0.6 or Maybe thats what 3/5 actually is, IE 0.6 cannot really be represented with a floatpoint datatype, and would be more consistent across different platforms?

  Read the article

< Previous Page | 508 509 510 511 512 513 514 515 516 517 518 519  | Next Page >