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  • Algorithm for optimal control on space ship using accelerometer input data

    - by mm24
    Does someone have a good algorithm for controlling a space ship in a vertical shooter game using acceleration data? I have done a simple algorithm, but works very badly. I save an initial acceleration value (used to calibrate the movement according to the user's initial position) and I do subtract it from the current acceleration so I get a "calibrated" value. The problem is that basing the movement solely on relative acceleration has an effect of loss of sensitivity: certain movements are independent from the initial position. Would anyone be able to share a a better solution? I am wondering if I should use/integrate also inputs from gyroscope hardware. Here is my sample of code for a Cocos2d iOS game: - (void) accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration { if (calibrationLayer.visible){ [self evaluateCalibration:acceleration]; initialAccelleration=acceleration; return; } if([self evaluatePause]){ return; } ShooterScene * shooterScene = (ShooterScene *) [self parent]; ShipEntity *playerSprite = [shooterScene playerShip]; float accellerationtSensitivity = 0.5f; UIAccelerationValue xAccelleration = acceleration.x - initialAccelleration.x; UIAccelerationValue yAccelleration = acceleration.y - initialAccelleration.y; if(xAccelleration > 0.05 || xAccelleration < -0.05) { [playerSprite setPosition:CGPointMake(playerSprite.position.x + xAccelleration * 80, playerSprite.position.y + yAccelleration * 80)]; } else if(yAccelleration > 0.05 || yAccelleration < -0.05) { [playerSprite setPosition:CGPointMake(playerSprite.position.x + xAccelleration * 80, playerSprite.position.y + yAccelleration * 80)]; } }

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  • Handling Players, enemies and attacks in HTML5

    - by Chris Morris
    I'm building a simple (currently) game with free roaming player and monsters on a map built by a 2D grid. I've been looking at the methods for implementing characters and enemies onto the screen and I've seen two seperate methods for doing this online. Drawing the player onto the screen canvas directly and refreshing the entire screen every FPS tick. Having a separate canvas to handle the player and moving the player canvas on top of the screen canvas via absolute positioning. I can see some pros and cons of both methods but what is generally the best method for doing this? I assume the second due to not having to drain resources by refreshing the map when the user is not moving, but the type of game will generally have constant movement.

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  • Libgdx ParallaxScrolling and TiledMaps

    - by kirchhoff
    I implemented ParallaxScrolling for my SideScroller project, everything is working but the tiled map (the most important part!). I've been trying out everything but it doesn't work (see the code below). I'm using ParallaxCamera from GdxTests, it's working perfectly for the background layers. I can't explain myself properly in english, so I recorded 2 videos: Before parallaxScrolling After parallaxScrolling As you can see, now the platforms appear in the middle of the Y-axis. I've got a Map class with 2 tiled maps, so I need two renderers too: private TiledMapRenderer renderer1; private TiledMapRenderer renderer2; public void update(GameCamera camera) { renderer1.setView(camera.calculateParallaxMatrix(1f, 0f), camera.position.x - camera.viewportWidth / 2, **camera.position.y - camera.viewportHeight/2**, camera.viewportWidth, camera.viewportHeight); renderer2.setView(camera.calculateParallaxMatrix(1f, 0f), camera.position.x - camera.viewportWidth / 2, **camera.position.y - camera.viewportHeight/2**, camera.viewportWidth, camera.viewportHeight); } In bold, the code I think I should change. I've tried changing parameters, even adding hardcoded values, etc, but one of two: 1. Nothing happens. 2. Platforms disappear. Here is some aditional code. The render method: world.update(delta); parallaxBackground.update(camera); clear(0.5f, 0.7f, 1.0f, 1); batch.setProjectionMatrix(camera.calculateParallaxMatrix(0, 0)); batch.disableBlending(); batch.begin(); batch.draw(background, -(int)background.getRegionWidth()/2, -(int)background.getRegionHeight()/2); batch.end(); batch.enableBlending(); parallaxBackground.draw(batch, camera); renderer.render(batch);

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  • Starting point for a simple game written in action script [closed]

    - by Hossein
    Possible Duplicate: AS3/Flash Game Dev: Looking for good & current step by step. Hi, I want to develop a simple game like: http://www.albinoblacksheep.com/games/falldown2 And then making it a bit more fancy. But I don't know where to start. I have already started AS3 so I know about the syntax and stuff, but I am kinda lost. Does anyone knows of a nice starting point or a tutorial that can help me with this? Thanks

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  • Modern Shader Book?

    - by Michael Stum
    I'm interested in learning about Shaders: What are they, when/for what would I use them, and how to use them. (Specifically I'm interested in Water and Bloom effects, but I know close to 0 about Shaders, so I need a general introduction). I saw a lot of books that are a couple of years old, so I don't know if they still apply. I'm targeting XNA 4.0 at the moment (which I believe means HLSL Shaders for Shader Model 4.0), but anything that generally targets DirectX 11 and OpenGL 4 is helpful I guess.

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  • Is there any hueristic to polygonize a closed 2d-raster shape with n triangles?

    - by Arthur Wulf White
    Lets say we have a 2d image black on white that shows a closed geometric shape. Is there any (not naive brute force) algorithm that approximates that shape as closely as possible with n triangles? If you want a formal definition for as closely as possible: Approximate the shape with a polygon that when rendered into a new 2d image will match the largest number of pixels possible with the original image.

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  • OpenGL ES 2.0 example for JOGL

    - by fjdutoit
    I've scoured the internet for the last few hours looking for an example of how to run even the most basic OpenGL ES 2 example using JOGL but "by Jupiter!" it has been a total fail. I tried converting the android example from the OpenGL ES 2.0 Programming Guide examples (and at the same time looking at the WebGL example -- which worked fine) yet without any success. Are there any examples out there? If anyone else wants some extra help regarding this question see this thread on the official Jogamp forum.

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  • Beginning android games, 2nd edition engine

    - by Benjamin Stephen
    I recently bought the book from Apress and have worked my way through it, unfortunately, it seems to just be dealing with side scrolling games and not Zelda-like top down games. I was wondering if anyone out there can tell me if it's possible to use their engine to create such a game? It doesn't go into how to build a top down tile map. Using the engine in their book, how can I make a tile map easily that has walls and things like that? Any help would be appreciated. Thanks in advance.

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  • Stencil buffer appears to not be decrementing values correctly

    - by Alex Ames
    I'm attempting to use the stencil buffer as a clipper for my UI system, but I'm having trouble debugging a problem I'm running in to. This is what I'm doing: A widget can pass a rectangle to the the stencil clipper functions, which will increment the stencil buffer values that it covers. Then it will draw its children, which will only get drawn in the stencilled area (so that if they extend outside they'll be clipped). After a widget is done drawing its children, it pops that rectangle from the stack and in the process decrements the values in the stencil buffer that it has previously incremented. The slightly simplified code is below: static void drawStencil(Rect& rect, unsigned int ref) { // Save previous values of the color and depth masks GLboolean colorMask[4]; GLboolean depthMask; glGetBooleanv(GL_COLOR_WRITEMASK, colorMask); glGetBooleanv(GL_DEPTH_WRITEMASK, &depthMask); // Turn off drawing glColorMask(0, 0, 0, 0); glDepthMask(0); // Draw vertices here ... // Turn everything back on glColorMask(colorMask[0], colorMask[1], colorMask[2], colorMask[3]); glDepthMask(depthMask); // Only render pixels in areas where the stencil buffer value == ref glStencilFunc(GL_EQUAL, ref, 0xFF); glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); } void pushScissor(Rect rect) { // increment things only at the current stencil stack level glStencilFunc(GL_EQUAL, s_scissorStack.size(), 0xFF); glStencilOp(GL_KEEP, GL_INCR, GL_INCR); s_scissorStack.push_back(rect); drawStencil(rect, states, s_ScissorStack.size()); } void popScissor() { // undo what was done in the previous push, // decrement things only at the current stencil stack level glStencilFunc(GL_EQUAL, s_scissorStack.size(), 0xFF); glStencilOp(GL_KEEP, GL_DECR, GL_DECR); Rect rect = s_scissorStack.back(); s_scissorStack.pop_back(); drawStencil(rect, states, s_scissorStack.size()); } And this is how it's being used by the Widgets if (m_clip) pushScissor(m_rect); drawInternal(target, states); for (auto child : m_children) target.draw(*child, states); if (m_clip) popScissor(); This is the result of the above code: There are two things on the screen, a giant test button, and a window with some buttons and text areas on it. The text area scroll box is set to clip its children (so that the text doesn't extend outside the scroll box). The button is drawn after the window and should be on top of it completely. However, for some reason the text area is appearing on top of the button. The only reason I can think of that this would happen is if the stencil values were not getting decremented in the pop, and when it comes time to render the button, since those pixels don't have the right stencil value it doesn't draw over. But I can't figure out whats wrong with my code that would cause that to happen.

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  • Effects to make a speeding spaceship look faster

    - by Badescu Alexandru
    I have a spaceship and I've created a "boost" functionality that speeds up my spaceship, what effects should I implement to create the impression of high speed? I was thinking of making everything except my spaceship blurry but I think there would be something missing. Any ideas? Btw. I am working in XNA C# but if you aren't familiar to XNA describing some effects is still useful. The Game is 3d and i've attached some printscreens of the game This is in normal mode ( none boosted ) and here is the boosted mode ( the craft speeds up forward while the camera speeds in its normal speed , the non boosted speed )

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  • iOS : Creating a 3D Compass

    - by Md. Abdul Munim
    Originally posted here: iOS : Creating a 3D Compass Hi everybody, Quite new in this forum.Posted the same question in stackoverflow and there some people suggested to shift it here, so that I can get a quick help from more specialists in this regard. So what's the big matter? Actually, I want to make a 3D metal compass in iOS which will have a movable cover. That is when you touch it by 3 fingers and try to move your fingers upward the cover keeps moving with your fingers and after certain distance it gets opened.Once you pull it down using 3 fingers again, it gets closed.I can not attach an image here as I don't have that much reputation. So I request you to check the original question at stack overflow that I linked at top. Is it possible using core animations and CALayers? Or would I have to use OpenGL ES? Please someone help me out, I am badly in need of it.And I need to complete it asap!

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  • Is it possible to calculate or mathematically prove if a game is balanced / fair?

    - by Lurca
    This question is not focussed on video games but games in general. I went to a boardgame trade fair yesterday and asked myself if there is a way to calculate the fairness of a game. Sure, some of them require a good portion of luck, but it might be possible to calculate if some character is overpowered. Especially in role-playing games and trading card games. How, for example, can the creators of "Magic: The Gathering" make sure that there isn't the "one card that beats them all", given the impressive number of available cards?

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  • Rotate canvas along its center based on user touch - Android

    - by Ganapathy
    I want to rotate the canvas circularly on its center axis based on user touch. i want to rotate based on center but its rotating based on top left corner . so i am able to see only 1/4 for rotation of image. any idea.. Like a old phone dialer . I have tried like as follows onDraw(Canvas canvas){ canvas.save(); // do my rotation canvas.rotate(rotation,0,0); canvas.drawBitmap( ((BitmapDrawable)d).getBitmap(),0,0,p ); canvas.restore(); } @Override public boolean onTouchEvent(MotionEvent e) { float x = e.getX(); float y = e.getY(); updateRotation(x,y); mPreviousX = x; mPreviousY = y; invalidate(); } private void updateRotation(float x, float y) { double r = Math.atan2(x - centerX, centerY - y); rotation = (int) Math.toDegrees(r); }

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  • Cocos2d/Cocos2d-x Attaching an arrow (sprite) to another body sprite (person)

    - by Satchmo Brown
    I am trying to set up a simple bow and arrow game. When the arrow hits the enemy body, the arrow's body is deleted and the arrow sprite continues to update, keeping the position correct in relation to the enemy it hit. Picture an arrow sticking into a body and that body still rotating and moving. My problem is that the rotation is completely wrong when the enemy rotates. I know how to do this in 3d with matrix transformation but I can't seem to figure it out in 2d with Cocos. Here is my method. I save offset at which the arrow hit the enemy. Every frame, I make the rotation of the sprite match the rotation of the enemy. Then, I apply the offset I took initially which is where the arrow hit the enemy. When they rotate, they rotate about their respective anchors and I am wondering if I need to set the anchor of the arrow to the center of the sprite. Does anyone know of an easy way to do this. If not, I will try to create an algorithm where the anchor is set to the offset divided by the width and height of the sprite image hopefully giving me the correct anchor values. Then I assume I need to reposition the sprite. Does anyone have a simpler way to do this?

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  • 3D/perspective Top down shooter bullet issues

    - by Tseng
    I'm developing a top-down shooter with multiple levels (ground for ground units, middle level for buildings, top level for air unity). The problem is the collision. Though I can make the collider box of a bullet be long enough to reach the ground (and collide with it), the real issue is optical. When the bullet is fired from a aircraft and collides with some object on the ground (building, ground unit) it will be optically offset due to the perspective camera, because it looks like the shot "by-passed" the target as seen below Is there any way to make the bullets collide perspectively correct? I'm using Unity3d Engine and it offers only simple colliders (box, sphere, cylinder, mesh and wheel), though I don't think a cone-formed collider would solve this issue. I'd need a (cheap) way to check if it's overlapping a destructible object? I thought of casting a ray from the camera through the bullet and if it hits something destructible, trigger an action, but that's quite punctual and maybe to performance heavy on certain number of bullets

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  • Entity Component System for HUD and GUI

    - by Jason L.
    This is a very rough sketch of how I currently have things designed. It should, at least, give an idea of how my ECS is currently designed. If you notice in that diagram, I have basically split the HUD out of the ECS. They have their own set of things (HudLayer, HudComponent, etc) and are handled differently. This is where I'm struggling, though. There are many different instances in which the HUD will need to know about entities. Not just data changing (I have an event dispatcher for that), but the actual entity and all it encompasses. There are also situations where entities will need to be able to query the HUD for data. Let's take a couple examples: First, my equipment screen. On here I can change the equipment on a character (Entity). In order for this to happen, I need to know about the entity. At least I think I do? How can I handle this? The second scenario involves my Systems needing to query a HudComponent for data. A specific example would be my battle system. Each "team" is given a 3x3 grid they can move around in. See here: Skills target these cells, and not the player, so I would need a way for my systems to determine which cells are occupied and which are not. Basically I need a way for two way communication between Systems and my HUD. I know it's recommended (by some people, anyways) to take your HUD out of the ECS. Is that appropriate in my case?

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  • Circular motion on low powered hardware

    - by Akroy
    I was thinking about platforms and enemies moving in circles in old 2D games, and I was wondering how that was done. I understand parametric equations, and it's trivial to use sin and cos to do it, but could an NES or SNES make real time trig calls? I admit heavy ignorance, but I thought those were expensive operations. Is there some clever way to calculate that motion more cheaply? I've been working on deriving an algorithm from trig sum identities that would only use precalculated trig, but that seems convoluted.

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  • Appropriate level of granularity for component-based architecture

    - by Jon Purdy
    I'm working on a game with a component-based architecture. An Entity owns a set of Component instances, each of which has a set of Slot instances with which to store, send, and receive values. Factory functions such as Player produce entities with the required components and slot connections. I'm trying to determine the best level of granularity for components. For example, right now Position, Velocity, and Acceleration are all separate components, connected in series. Velocity and Acceleration could easily be rewritten into a uniform Delta component, or Position, Velocity, and Acceleration could be combined alongside such components as Friction and Gravity into a monolithic Physics component. Should a component have the smallest responsibility possible (at the cost of lots of interconnectivity) or should related components be combined into monolithic ones (at the cost of flexibility)? I'm leaning toward the former, but I could use a second opinion.

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  • What does SetTextureStage(0, D3DTSS_COLORARG2, 0) in DirectX mean?

    - by Vite Falcon
    I'm trying to convert some DirectX code to Ogre3D and was wondering what the following translates to: pDev->SetTextureStage(0, D3DTSS_TEXCOORDINDEX, 0) pDev->SetTextureStage(0, D3DTSS_COLORARG1, D3DTA_TEXTURE) pDev->SetTextureStage(0, D3DTSS_COLOROP, D3DTOP_MODULATE) pDev->SetTextureStage(0, D3DTSS_COLORARG2, 0) What is the modulation operation happening here? Is the texture getting modulated with the background? Or is it getting zeroed? I've tried searching for what this means and unfortunately I haven't come across anything meaningful. Any help to shed light on this matter will be much appreciated.

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  • Libnoise producing completely random noise

    - by Doodlemeat
    I am using libnoise in C++ taken and I have some problems with getting coherent noise. I mean, the noise produced now are completely random and it doesn't look like a noise. Here's a to the image produced by my game. I am diving the map into several chunks, but I can't seem to find any problem doing that since libnoise supports tileable noise. The code can be found below. Every chunk is 8x8 tiles large. Every tile is 64x64 pixels. I am also providing a link to download the entire project. It was made in Visual Studio 2013. Download link This is the code for generating a chunk Chunk *World::loadChunk(sf::Vector2i pPosition) { sf::Vector2i chunkPos = pPosition; pPosition.x *= mChunkTileSize.x; pPosition.y *= mChunkTileSize.y; sf::FloatRect bounds(static_cast<sf::Vector2f>(pPosition), sf::Vector2f(static_cast<float>(mChunkTileSize.x), static_cast<float>(mChunkTileSize.y))); utils::NoiseMap heightMap; utils::NoiseMapBuilderPlane heightMapBuilder; heightMapBuilder.SetSourceModule(mNoiseModule); heightMapBuilder.SetDestNoiseMap(heightMap); heightMapBuilder.SetDestSize(mChunkTileSize.x, mChunkTileSize.y); heightMapBuilder.SetBounds(bounds.left, bounds.left + bounds.width - 1, bounds.top, bounds.top + bounds.height - 1); heightMapBuilder.Build(); Chunk *chunk = new Chunk(this); chunk->setPosition(chunkPos); chunk->buildChunk(&heightMap); chunk->setTexture(&mTileset); mChunks.push_back(chunk); return chunk; } This is the code for building the chunk void Chunk::buildChunk(utils::NoiseMap *pHeightMap) { // Resize the tiles space mTiles.resize(pHeightMap->GetWidth()); for (int x = 0; x < mTiles.size(); x++) { mTiles[x].resize(pHeightMap->GetHeight()); } // Set vertices type and size mVertices.setPrimitiveType(sf::Quads); mVertices.resize(pHeightMap->GetWidth() * pHeightMap->GetWidth() * 4); // Get the offset position of all tiles position sf::Vector2i tileSize = mWorld->getTileSize(); sf::Vector2i chunkSize = mWorld->getChunkSize(); sf::Vector2f offsetPositon = sf::Vector2f(mPosition); offsetPositon.x *= chunkSize.x; offsetPositon.y *= chunkSize.y; // Build tiles for (int x = 0; x < mTiles.size(); x++) { for (int y = 0; y < mTiles[x].size(); y++) { // Sometimes libnoise can return a value over 1.0, better be sure to cap the top and bottom.. float heightValue = pHeightMap->GetValue(x, y); if (heightValue > 1.f) heightValue = 1.f; if (heightValue < -1.f) heightValue = -1.f; // Instantiate a new Tile object with the noise value, this doesn't do anything yet.. mTiles[x][y] = new Tile(this, pHeightMap->GetValue(x, y)); // Get a pointer to the current tile's quad sf::Vertex *quad = &mVertices[(y + x * pHeightMap->GetWidth()) * 4]; quad[0].position = sf::Vector2f(offsetPositon.x + x * tileSize.x, offsetPositon.y + y * tileSize.y); quad[1].position = sf::Vector2f(offsetPositon.x + (x + 1) * tileSize.x, offsetPositon.y + y * tileSize.y); quad[2].position = sf::Vector2f(offsetPositon.x + (x + 1) * tileSize.x, offsetPositon.y + (y + 1) * tileSize.y); quad[3].position = sf::Vector2f(offsetPositon.x + x * tileSize.x, offsetPositon.y + (y + 1) * tileSize.y); // find out which type of tile to render, atm only air or stone TileStop *tilestop = mWorld->getTileStopAt(heightValue); sf::Vector2i texturePos = tilestop->getTexturePosition(); // define its 4 texture coordinates quad[0].texCoords = sf::Vector2f(texturePos.x, texturePos.y); quad[1].texCoords = sf::Vector2f(texturePos.x + 64, texturePos.y); quad[2].texCoords = sf::Vector2f(texturePos.x + 64, texturePos.y + 64); quad[3].texCoords = sf::Vector2f(texturePos.x, texturePos.y + 64); } } } All the code that uses libnoise in some way are World.cpp, World.h and Chunk.cpp, Chunk.h in the project.

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  • How can I chose the depth of a quadtree?

    - by Evpok
    In a 2d world, using a quadtree to prune pairs in collision detection, how can I chose the depth of said quadtree? The world I am dealing with is mostly made of moving objects¹, so the cost of dispatching the objects between the quadtree cells matter. So what I am interested in is the balance between the gain from less collision checking and the loss from more dispatching. 1. To be completely explicit, autonomous self-replicating cells competing for food sources, in an attempt to show my pupils predator-prey dynamics and genetic evolution at work

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  • The practical cost of swapping effects

    - by sebf
    I use XNA for my projects and on those forums I sometimes see references to the fact that swapping an effect for a mesh has a relatively high cost, which surprises me as I thought to swap an effect was simply a case of copying the replacement shader program to the GPU along with appropriate parameters. I wondered if someone could explain exactly what is costly about this process? And put, if possible, 'relatively' into context? For example say I wanted to use a short shader to help with picking, I would: Change the effect on every object, calculting a unique color to identify it and providing it to the shader. Draw all the objects to a render target in memory. Get the color from the target and use it to look up the selected object. What portion of the total time taken to complete that process would be spent swapping the shaders? My instincts would say that rendering the scene again, no matter how simple the shader, would be an order of magnitude slower than any other part of the process so why all the concern over effects?

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  • OpenGL ES 2 on Android: native window

    - by ThreaderSlash
    According to OGLES specification, we have the following definition: EGLSurface eglCreateWindowSurface(EGLDisplay display, EGLConfig config, NativeWindowType native_window, EGLint const * attrib_list) More details, here: http://www.khronos.org/opengles/documentation/opengles1_0/html/eglCreateWindowSurface.html And also by definition: int32_t ANativeWindow_setBuffersGeometry(ANativeWindow* window, int32_t width, int32_t height, int32_t format); More details, here: http://mobilepearls.com/labs/native-android-api I am running Android Native App on OGLES 2 and debugging it in a Samsung Nexus device. For setting up the 3D scene graph environment, the following variables are defined: struct android_app { ... ANativeWindow* window; }; android_app* mApplication; ... mApplication=&pApplication; And to initialize the App, we run the commands in the code: ANativeWindow_setBuffersGeometry(mApplication->window, 0, 0, lFormat); mSurface = eglCreateWindowSurface(mDisplay, lConfig, mApplication->window, NULL); Funny to say is that, the command ANativeWindow_setBuffersGeometry behaves as expected and works fine according to its definition, accepting all the parameters sent to it. But the eglCreateWindowSurface does no accept the parameter mApplication-window, as it should accept according to its definition. Instead, it looks for the following input: EGLNativeWindowType hWnd; mSurface = eglCreateWindowSurface(mDisplay,lConfig,hWnd,NULL); As an alternative, I considered to use instead: NativeWindowType hWnd=android_createDisplaySurface(); But debugger says: Function 'android_createDisplaySurface' could not be resolved Is 'android_createDisplaySurface' compatible only for OGLES 1 and not for OGLES 2? Can someone tell if there is a way to convert mApplication-window? In a way that the data from the android_app get accepted to the window surface?

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  • How AlphaBlend Blendstate works in XNA 4 when accumulighting light into a RenderTarget?

    - by cubrman
    I am using a Deferred Rendering engine from Catalin Zima's tutorial: His lighting shader returns the color of the light in the rgb channels and the specular component in the alpha channel. Here is how light gets accumulated: Game.GraphicsDevice.SetRenderTarget(LightRT); Game.GraphicsDevice.Clear(Color.Transparent); Game.GraphicsDevice.BlendState = BlendState.AlphaBlend; // Continuously draw 3d spheres with lighting pixel shader. ... Game.GraphicsDevice.BlendState = BlendState.Opaque; MSDN states that AlphaBlend field of the BlendState class uses the next formula for alphablending: (source × Blend.SourceAlpha) + (destination × Blend.InvSourceAlpha), where "source" is the color of the pixel returned by the shader and "destination" is the color of the pixel in the rendertarget. My question is why do my colors are accumulated correctly in the Light rendertarget even when the new pixels' alphas equal zero? As a quick sanity check I ran the following code in the light's pixel shader: float specularLight = 0; float4 light4 = attenuation * lightIntensity * float4(diffuseLight.rgb,specularLight); if (light4.a == 0) light4 = 0; return light4; This prevents lighting from getting accumulated and, subsequently, drawn on the screen. But when I do the following: float specularLight = 0; float4 light4 = attenuation * lightIntensity * float4(diffuseLight.rgb,specularLight); return light4; The light is accumulated and drawn exactly where it needs to be. What am I missing? According to the formula above: (source x 0) + (destination x 1) should equal destination, so the "LightRT" rendertarget must not change when I draw light spheres into it! It feels like the GPU is using the Additive blend instead: (source × Blend.One) + (destination × Blend.One)

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  • How can I factor momentum into my space sim?

    - by Josh Petite
    I am trying my hand at creating a simple 2d physics engine right now, and I'm running into some problems figuring out how to incorporate momentum into movement of a spaceship. If I am moving in a given direction at a certain velocity, I am able to currently update the position of my ship easily (Position += Direction * Velocity). However, if the ship rotates at all, and I recalculate the direction (based on the new angle the ship is facing), and accelerate in that direction, how can I take momentum into account to alter the "line" that the ship travels? Currently the ship changes direction instantaneously and continues at its current velocity in that new direction when I press the thrust button. I want it to be a more gradual turning motion so as to give the impression that the ship itself has some mass. If there is already a nice post on this topic I apologize, but nothing came up in my searches. Let me know if any more information is needed, but I'm hoping someone can easily tell me how I can throw mass * velocity into my game loop update.

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