Search Results

Search found 25377 results on 1016 pages for 'development'.

Page 414/1016 | < Previous Page | 410 411 412 413 414 415 416 417 418 419 420 421  | Next Page >

  • 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.

    Read the article

  • Collision with half semi-circle

    - by heitortsergent
    I am trying to port a game I made using Flash/AS3, to the Windows Phone using C#/XNA 4.0. You can see it here: http://goo.gl/gzFiE In the flash version I used a pixel-perfect collision between meteors (it's a rectangle, and usually rotated) that spawn outside the screen, and move towards the center, and a shield in the center of the screen(which is half of a semi-circle, also rotated by the player), which made the meteor bounce back in the opposite direction it came from, when they collided. My goal now is to make the meteors bounce in different angles, depending on the position it collides with the shield (much like Pong, hitting the borders causes a change in the ball's angle). So, these are the 3 options I thought of: -Pixel-perfect collision (microsoft has a sample(http://create.msdn.com/en-US/education/catalog/tutorial/collision_2d_perpixel_transformed)) , but then I wouldn't know how to change the meteor angle after the collision -3 BoundingCircle's to represent the half semi-circle shield, but then I would have to somehow move them as I rotate the shield. -Farseer Physics. I could make a shape composed of 3 lines, and use that as the collision object for the shield. Is there any other way besides those? Which would be the best way to do it(it's aimed towards mobile devices, so pixel-perfect is probably not a good choice)? Most of the time there's always a easier/better way than what we think of...

    Read the article

  • Collision Resolution

    - by CiscoIPPhone
    I know quite well how to check for collisions, but I don't know how to handle the collision in a good way. Simplified, if two objects collide I use some calculations to change the velocity direction. If I don't move the two objects they will still overlap and if the velocity is not big enough they will still collide after next update. This can cause objects to get stuck in each other. But what if I try to move the two objects so they do not overlap. This sounds like a good idea but I have realised that if there is more than two objects this becomes very complicated. What if I move the two objects and one of them collides with other objects so I have to move them too and they may collide with walls etc. I have a top down 2D game in mind but I don't think that has much to do with it. How are collisions usually handled? This question is asked on behalf of Wooh

    Read the article

  • "has no motion" warnings

    - by Adam R. Grey
    When I reimport my project's Library, I get lots of warnings such as State combat.Ghoul Attack has no motion but I have no idea why. In this specific case, I looked up Ghoul Attack. Here's the state in which it appears, in the only animator controller that includes anything called Ghoul Attack: State: m_ObjectHideFlags: 3 m_PrefabParentObject: {fileID: 0} m_PrefabInternal: {fileID: 0} m_Name: Ghoul Attack m_Speed: 1 m_CycleOffset: 0 m_Motions: - {fileID: 7400000, guid: 0db269712a91fd641b6dd5e0e4c6d507, type: 3} - {fileID: 0} m_ParentStateMachine: {fileID: 110708233} m_Position: {x: 492, y: 132, z: 0} m_IKOnFeet: 1 m_Mirror: 0 m_Tag: I thought perhaps that second one - {fileID: 0} was throwing up the warning incorrectly, so I removed it. There was no effect, I still get warnings about Ghoul Attack. So given that the only state I know of with that name does in fact have motion, what is this warning actually trying to tell me?

    Read the article

  • 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)]; } }

    Read the article

  • D3D11 how to simulate multiple depth channels

    - by Nock
    Here's what I'd like to achieve: Rendering a first pass of objects in my scene, using standard depth comparison Rendering another pass of objects in the same scene, but with the following rules: A Pixel of the 2nd pass always override the first pass (no depth compare between them) Use Depth comparison between pixels written from the second pass. In English I want depth comparison made inside each pass but I always want the second pass pixels to override the first pass ones. Some things I've thought: I tried to think about using stencil to solve this, but I couldn't find a way. I know I could render into a separate target the second pass then composite the result into the first, but I'd like to avoid that. I could use two separate Depth Buffer, one dedicated to each pass. (I never tried, but I figure it's possible to switch the depth buffer in a Render Target "on the fly") Any idea of the best solution? Thanks

    Read the article

  • How do game engines implement certain features?

    - by Milo
    I have always wondered how modern game engines do things such as realistic water, ambient occluded lighting, eye adaptation, global illumination, etc. I'm not so much interested in the implementation details, but more on what part of the graphics API such as D3D or OpenGL allow adding such functionality. The only thing I can think of is shaders, but I do not think just shaders can do all that. So really what I'm asking is, what functions or capabilities of graphics APIs enable developers to implement these types of features into their engines? Thanks

    Read the article

  • Height Map Mapping to "Chunked" Quadrilateralized Spherical Cube

    - by user3684950
    I have been working on a procedural spherical terrain generator for a few months which has a quadtree LOD system. The system splits the six faces of a quadrilateralized spherical cube into smaller "quads" or "patches" as the player approaches those faces. What I can't figure out is how to generate height maps for these patches. To generate the heights I am using a 3D ridged multi fractals algorithm. For now I can only displace the vertices of the patches directly using the output from the ridged multi fractals. I don't understand how I generate height maps that allow the vertices of a terrain patch to be mapped to pixels in the height map. The only thing I can think of is taking each vertex in a patch, plug that into the RMF and take that position and translate into u,v coordinates then determine the pixel position directly from the u,v coordinates and determine the grayscale color based on the height. I feel as if this is the right approach but there are a few other things that may further complicate my problem. First of all I intend to use "height maps" with a pixel resolution of 192x192 while the vertex "resolution" of each terrain patch is only 16x16 - meaning that I don't have any vertices to sample for the RMF for most of the pixels. The main reason the height map resolution is higher so that I can use it to generate a normal map (otherwise the height maps serve little purpose as I can just directly displace vertices as I currently am). I am pretty much following this paper very closely. This is, essentially, the part I am having trouble with. Using the cube-to-sphere mapping and the ridged multifractal algorithm previously described, a normalized height value ([0, 1]) is calculated. Using this height value, the terrain position is calculated and stored in the first three channels of the positionmap (RGB) – this will be used to calculate the normalmap. The fourth channel (A) is used to store the height value itself, to be used in the heightmap. The steps in the first sentence are my primary problem. I don't understand how the pixel positions correspond to positions on the sphere and what positions are sampled for the RMF to generate the pixels if only vertices cannot be used.

    Read the article

  • How do I communicate with an IronPython component in a C#/XNA game?

    - by Jonathan Hobbs
    My XNA game is component-oriented, and has various components for position, physics representation, rendering, etc, all of which extend a base Component class. The player and enemies also have controllers which are currently defined in C#. I'd like to turn them into Python scripts, but I'm not sure how to interact with those scripts. The examples in Embedding IronPython in a C# Application suggest I'd have to create a wrapper class (e.g. a Script component) which compiles a Python script, and call the Update methods of the component in the script Is this the most effective way of working with a Python object? I feel that I'm missing something in my research - there must be a way to load up a script, instantiate a Python object and then work directly with it from within C#. Or is the wrapper required?

    Read the article

  • Scanline filling of polygons that share edges and vertices

    - by Belgin
    In this picture (a perspective projection of an icosahedron), the scanline (red) intersects that vertex at the top. In an icosahedron each edge belongs to two triangles. From edge a, only one triangle is visible, the other one is in the back. Same for edge d. Also, in order to determine what color the current pixel should be, each polygon has a flag which can either be 'in' or 'out', depending upon where on the scanline we currently are. Flags are flipped according to the intersection of the scanline with the edges. Now, as we go from a to d (because all edges are intersected with the scanline at that vertex), this happens: the triangle behind triangle 1 and triangle 1 itself are set 'in', then 2 is set in and 1 is 'out', then 3 is set 'in', 2 is 'out' and finally 3 is 'out' and the one behind it is set 'in', which is not the desired behavior because we only need the triangles which are facing us to be set 'in', the rest should be 'out'. How do process the edges in the Active Edge List (a list of edges that are currently intersected by the scanline) so the right polys are set 'in'? Also, I should mention that the edges are unique, which means there exists an array of edges in the data structure of the icosahedron which are pointed to by edge pointers in each of the triangles.

    Read the article

  • How do I implement smooth movement in a Box2D platform game?

    - by Romeo
    I have implemented a character in JBox2D which moves with the help of a wheel rotating at the bottom of it. The movement is the best result I've had 'till now but it's a little glitchy when the character stands on the edge. So I am thinking should I use five smaller wheels instead of a big wheel. The wheel/wheels will not be visible in the finished product, now they are drawn for debugging. Here is a video. Is there a better way to do this using JBox2D?

    Read the article

  • Do leaderboard sets (in Game Center) allow 500 unique leaderboards?

    - by Korey Hinton
    The Game Kit Programming Guide for iOS claims: The number of different leaderboards allowed increases to 500 leaderboards per game when leaderboard sets have been enabled...Leaderboard sets offer developers the ability to combine several leaderboards into a single group. But their example (see image below) implies that a single leaderboard is placed into multiple leaderboard sets. Is that the only way to be able to use the full 500 leaderboards? by combining the same leaderboard into multiple sets? I want to be able to have 500 unique leaderboards that are not duplicated between sets. Is this possible?

    Read the article

  • Understanding how texCUBE works and writing cubemaps properly into a cube rendertarget

    - by cubrman
    My goal is to create accurate reflections, sampled from a dynamic cubemap, for specific 3d objects (mostly lights) in XNA 4.0. To sample the cubemap I compute the 3d reflection vector in a classic way: half3 ReflectionVec = reflect(-directionToCamera, Normal.rgb); I then use the vector to get the actual reflected color: half3 ReflectionCol = texCUBElod(ReflectionSampler, float4(ReflectionVec, 0)); The cubemap I am sampling from is a RenderTarget with 6 flat faces. So my question is, given the 3d world position of an arbitrary 3d object, how can I make sure that I get accurate reflections of this object, when I re-render the cubemap. Should I build the ViewProjection matrix in a specific way? Or is there any other approach?

    Read the article

  • Detect collision from a particular side

    - by Fabián
    I'm making a platform sidescrolling game. All I want to do is to detect if my character is on the floor: function OnCollisionStay (col : Collision){ if(col.gameObject.tag == "Floor"){ onFloor = true; } else {onFloor = false;} } function OnCollisionExit (col : Collision){ onFloor = false; } But I know this isn't the accurate way. If I hit a cube with a "floor" tag, in the air (no matter if with the character's feet or head) I would be able to jump. Is there a way to use the same box collision to detect if I'm touching something from a specific side?

    Read the article

  • SharpDX/D3D: How to implement and draw fonts/text

    - by Dmitrij A
    I am playing with SharpDX (Direct3D for .NET) without using "Toolkit", already finished with basic rendering 3D models. But now i am wondering how to program/create fonts for game (2D), or how to simple draw variable text to output with Direct3D? (it is not as SharpDX question as common Direct3D question, how to start with game GUIs? And what should i do to program simple GUI's like menu for a game (generally i understand that it's shaders).

    Read the article

  • Embed Unity3D and load multiple games from a single app

    - by Rafael Steil
    Is is possible to export an entire unity3d project/game as an AssetBundle and load it on iOS/Android/Windows on an app that doesn't know anything about such game beforehand? What I have in mind is something like the web plugin does - it loads a series of .unity3d files over http, and render inline in the browser window. Is it even possible to do something closer for iOS/Android? I have read a lot of docs so far, but still can't be sure: http://floored.com/blog/2013/integrating-unity3d-within-ios-native-application.html http://docs.unity3d.com/Manual/LoadingResourcesatRuntime.html http://docs.unity3d.com/Manual/AssetBundlesIntro.html The code from the post at http://forum.unity3d.com/threads/112703-Override-Unity-Data-folder-path?p=749108&viewfull=1#post749108 works for Android, but how about iOS and other platforms?

    Read the article

  • Get coordinates of arraylist

    - by opiop65
    Here's my map class: public class map{ public static final int CLEAR = 0; public static final ArrayList<Integer> STONE = new ArrayList<Integer>(); public static final int GRASS = 2; public static final int DIRT = 3; public static final int WIDTH = 32; public static final int HEIGHT = 24; public static final int TILE_SIZE = 25; // static int[][] map = new int[WIDTH][HEIGHT]; ArrayList<ArrayList<Integer>> map = new ArrayList<ArrayList<Integer>>(WIDTH * HEIGHT); enum tiles { air, grass, stone, dirt } Image air, grass, stone, dirt; Random rand = new Random(); public Map() { /* default map */ /*for(int y = 0; y < WIDTH; y++){ map[y][y] = (rand.nextInt(2)); System.out.println(map[y][y]); }*/ /*for (int y = 18; y < HEIGHT; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = STONE; } } for (int y = 18; y < 19; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = GRASS; } } for (int y = 19; y < 20; y++) { for (int x = 0; x < WIDTH; x++) { map[x][y] = DIRT; } }*/ for (int y = 0; y < HEIGHT; y++) { for(int x = 0; x < WIDTH; x++){ map.set(x * WIDTH + y, STONE); } } try { init(null, null); } catch (SlickException e) { e.printStackTrace(); } render(null, null, null); } public void init(GameContainer gc, StateBasedGame sbg) throws SlickException { air = new Image("res/air.png"); grass = new Image("res/grass.png"); stone = new Image("res/stone.png"); dirt = new Image("res/dirt.png"); } public void render(GameContainer gc, StateBasedGame sbg, Graphics g) { for (int x = 0; x < WIDTH; x++) { for (int y = 0; y < HEIGHT; y++) { switch (map.get(x * WIDTH + y)) { case CLEAR: air.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case STONE: stone.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case GRASS: grass.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case DIRT: dirt.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; } } } } public static boolean blocked(float x, float y) { return map[(int) x][(int) y] == STONE; } public static Rectangle blockBounds(int x, int y) { return (new Rectangle(x, y, TILE_SIZE, TILE_SIZE)); } } Specifically I am looking at this: for (int x = 0; x < WIDTH; x++) { for (int y = 0; y < HEIGHT; y++) { switch (map.get(x * WIDTH + y).intValue()) { case CLEAR: air.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case STONE: stone.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case GRASS: grass.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; case DIRT: dirt.draw(x * TILE_SIZE, y * TILE_SIZE, TILE_SIZE, TILE_SIZE); break; } } } How can I access the coordinates of my arraylist map and then draw the tiles to the screen? Thanks!

    Read the article

  • what tool should I use for drawing 2d OpenGL shapes?

    - by Kenny Winker
    I'm working on a very simple OpenGL ES 2.0 game, and I'm not sure what tool to use to create the vertex data I need. My first thought was adobe illustrator, but I can't seem to google up any info on how to convert an .ai file to vertices. I'm only going to be using very simple 2d shapes so I wonder if I need to use a 3d modelling program? How is this typically done, when you are working with 2d non-sprite shapes?

    Read the article

  • Collision detection, stop gravity

    - by Scott Beeson
    I just started using Gamemaker Studio and so far it seems fairly intuitive. However, I set a room to "Room is Physics World" and set gravity to 10. I then enabled physics on my player object and created a block object to match a platform on my background sprite. I set up a Collision Detection event for the player and the block objects that sets the gravity to 0 (and even sets the vspeed to 0). I also put a notification in the collision event and I don't get that either. I have my key down and key up events working well, moving the player left and right and changing the sprites appropriately, so I think I understand the event system. I must just be missing something simple with the physics. I've tried making both and neither of the objects "solid". Pretty frustrating since it looks so easy. The player starting point is directly above the block object in the grid and the player does fall through the block. I even made the block sprite solid red so I could see it (initially it was invisible, obviously).

    Read the article

  • Collision detection in 3D space

    - by dreta
    I've got to write, what can be summed up as, a compelte 3D game from scratch this semester. Up untill now i have only programmed 2D games in my spare time, the transition doesn't seem tough, the game's simple. The only issue i have is collision detection. The only thing i could find was AABB, bounding spheres or recommendations of various physics engines. I have to program a submarine that's going to be moving freely inside of a cave system, AFAIK i can't use physics libraries, so none of the above solves my problem. Up untill now i was using SAT for my collision detection. Are there any similar, great algorithms, but crafted for 3D collision? I'm not talking about octrees, or other optimalizations, i'm talking about direct collision detection of one set of 3D polygons with annother set of 3D polygons. I thought about using SAT twice, project the mesh from the top and the side, but then it seems so hard to even divide 3D space into convex shapes. Also that seems like far too much computation even with octrees. How do proffessionals do it? Could somebody shed some light.

    Read the article

  • How is this lighting effect done?

    - by Mike
    This is the most beautiful 2d lighting I have ever seen. Does anyone know how he went about doing it? http://www.youtube.com/watch?v=BIQRhOFkvQY http://www.youtube.com/watch?v=tnTYXPuecMs http://www.youtube.com/watch?v=rhC_jVM8IYU http://www.youtube.com/watch?v=_Aw5BdjWqqU Or download it here: http://grantkot.com/PollutedPlanet/publish.htm edit: I am not asking how the particles are simulated; I don't care about the physics.

    Read the article

  • Flickering when accessing texture by offset

    - by TravisG
    I have this simple compute shader that basically just takes the input from one image and writes it to another. Both images are 128/128/128 in size and glDispatchCompute is called with (128/8,128/8,128/8). The source images are cleared to 0 before this compute shader is executed, so no undefined values should be floating around in there. (I have the appropriate memory barrier on the C++ side set before the 3D texture is accessed). This version works fine: #version 430 layout (location = 0, rgba16f) uniform image3D ping; layout (location = 1, rgba16f) uniform image3D pong; layout (local_size_x = 8, local_size_y = 8, local_size_z = 8) in; void main() { ivec3 sampleCoord = gl_GlobalInvocationID.xyz; imageStore(pong, imageLoad(ping,sampleCoord)); } Reading values from pong shows that it's just a copy, as intended. However, when I load data from ping with an offset: #version 430 layout (location = 0, rgba16f) uniform image3D ping; layout (location = 1, rgba16f) uniform image3D pong; layout (local_size_x = 8, local_size_y = 8, local_size_z = 8) in; void main() { ivec3 sampleCoord = gl_GlobalInvocationID.xyz; imageStore(pong, imageLoad(ping,sampleCoord+ivec3(1,0,0))); } The data that is written to pong seems to depend on the order of execution of the threads within the work groups, which makes no sense to me. When reading from the pong texture, visible flickering occurs in some spots on the texture. What am I doing wrong here?

    Read the article

  • 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?

    Read the article

  • Physics System ignores collision in some rare cases

    - by Gajoo
    I've been developing a simple physics engine for my game. since the game physics is very simple I've decided to increase accuracy a little bit. Instead of formal integration methods like fourier or RK4, I'm directly computing the results after delta time "dt". based on the very first laws of physics : dx = 0.5 * a * dt^2 + v0 * dt dv = a * dt where a is acceleration and v0 is object's previous velocity. Also to handle collisions I've used a method which is somehow different from those I've seen so far. I'm detecting all the collision in the given time frame, stepping the world forward to the nearest collision, resolving it and again check for possible collisions. As I said the world consist of very simple objects, so I'm not loosing any performance due to multiple collision checking. First I'm checking if the ball collides with any walls around it (which is working perfectly) and then I'm checking if it collides with the edges of the walls (yellow points in the picture). the algorithm seems to work without any problem except some rare cases, in which the collision with points are ignored. I've tested everything and all the variables seem to be what they should but after leaving the system work for a minute or two the system the ball passes through one of those points. Here is collision portion of my code, hopefully one of you guys can give me a hint where to look for a potential bug! void PhysicalWorld::checkForPointCollision(Vec2 acceleration, PhysicsComponent& ball, Vec2& collisionNormal, float& collisionTime, Vec2 target) { // this function checks if there will be any collision between a circle and a point // ball contains informations about the circle (it's current velocity, position and radius) // collisionNormal is an output variable // collisionTime is also an output varialbe // target is the point I want to check for collisions Vec2 V = ball.mVelocity; Vec2 A = acceleration; Vec2 P = ball.mPosition - target; float wallWidth = mMap->getWallWidth() / (mMap->getWallWidth() + mMap->getHallWidth()) / 2; float r = ball.mRadius / (mMap->getWallWidth() + mMap->getHallWidth()); // r is ball radius scaled to match actual rendered object. if (A.any()) // todo : I need to first correctly solve the collisions in case there is no acceleration return; if (V.any()) // if object is not moving there will be no collisions! { float D = P.x * V.y - P.y * V.x; float Delta = r*r*V.length2() - D*D; if(Delta < eps) return; Delta = sqrt(Delta); float sgnvy = V.y > 0 ? 1: (V.y < 0?-1:0); Vec2 c1(( D*V.y+sgnvy*V.x*Delta) / V.length2(), (-D*V.x+fabs(V.y)*Delta) / V.length2()); Vec2 c2(( D*V.y-sgnvy*V.x*Delta) / V.length2(), (-D*V.x-fabs(V.y)*Delta) / V.length2()); float t1 = (c1.x - P.x) / V.x; float t2 = (c2.x - P.x) / V.x; if(t1 > eps && t1 <= collisionTime) { collisionTime = t1; collisionNormal = c1; } if(t2 > eps && t2 <= collisionTime) { collisionTime = t2; collisionNormal = c2; } } } // this function should step the world forward by dt. it doesn't check for collision of any two balls (components) // it just checks if there is a collision between the current component and 4 points forming a rectangle around it. void PhysicalWorld::step(float dt) { for (unsigned i=0;i<mObjects.size();i++) { PhysicsComponent &current = *mObjects[i]; Vec2 acceleration = current.mForces * current.mInvMass; float rt=dt; // stores how much more the world should advance while(rt > eps) { float collisionTime = rt; Vec2 collisionNormal = Vec2(0,0); float halfWallWidth = mMap->getWallWidth() / (mMap->getWallWidth() + mMap->getHallWidth()) / 2; // we check if there is any collision with any of those 4 points around the ball // if there is a collision both collisionNormal and collisionTime variables will change // after these functions collisionTime will be exactly the value of nearest collision (if any) // and if there was, collisionNormal will report in which direction the ball should return. checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2(floor(current.mPosition.x) + halfWallWidth,floor(current.mPosition.y) + halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2(floor(current.mPosition.x) + halfWallWidth, ceil(current.mPosition.y) - halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2( ceil(current.mPosition.x) - halfWallWidth,floor(current.mPosition.y) + halfWallWidth)); checkForPointCollision(acceleration,current,collisionNormal,collisionTime,Vec2( ceil(current.mPosition.x) - halfWallWidth, ceil(current.mPosition.y) - halfWallWidth)); // either if there is a collision or if there is not we step the forward since we are sure there will be no collision before collisionTime current.mPosition += collisionTime * (collisionTime * acceleration * 0.5 + current.mVelocity); current.mVelocity += collisionTime * acceleration; // if the ball collided with anything collisionNormal should be at least none zero in one of it's axis if (collisionNormal.any()) { collisionNormal *= Dot(collisionNormal, current.mVelocity) / collisionNormal.length2(); current.mVelocity -= 2 * collisionNormal; // simply reverse velocity along collision normal direction } rt -= collisionTime; } // reset all forces for current object so it'll be ready for later game event current.mForces.zero(); } }

    Read the article

  • How to efficiently map tokens to code in a script interpreter?

    - by lithander
    I'm writing an interpreter for a simple scripting language where each line is a complete, executable command. (Like the instructions in assembler) When parsing a line I have to map the requested command to actual code. My current solution looks like this: std::string op, param1, param2; //parse line, identify op, param1, param2 ... //call command specific code if(op == "MOV") ExecuteMov(AsNumber(param1)); else if(op == "ROT") ExecuteRot(AsNumber(param1)); else if(op == "SZE") ExecuteSze(AsNumber(param1)); else if(op == "POS") ExecutePos((AsNumber(param1), AsNumber(param2)); else if(op == "DIR") ExecuteDir((AsNumber(param1), AsNumber(param2)); else if(op == "SET") ExecuteSet(param1, AsNumber(param2)); else if(op == "EVL") ... The more commands are supported the more string comparisions I'll have to do to identify and call the associated method. Can you point me to a more efficient implementation in the described scenario?

    Read the article

< Previous Page | 410 411 412 413 414 415 416 417 418 419 420 421  | Next Page >