Search Results

Search found 31839 results on 1274 pages for 'plugin development'.

Page 518/1274 | < Previous Page | 514 515 516 517 518 519 520 521 522 523 524 525  | Next Page >

  • 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.

    Read the article

  • 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.

    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

  • 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.

    Read the article

  • Huge procedurally generated 'wilderness' worlds

    - by The Communist Duck
    I'm sure you all know of games like Dwarf Fortress - massive, procedural generated wilderness and land. Something like this, taken from this very useful article. However, I was wondering how I could apply this to a much larger scale; the scale of Minecraft comes to mind (isn't that something like 8x the size of the Earth's surface?). Pseudo-infinite, I think the best term would be. The article talks about fractal perlin noise. I am no way an expert on it, but I get the general idea (it's some kind of randomly generated noise which is semi-coherent, so not just random pixel values). I could just define regions X by X in size, add some region loading type stuff, and have one bit of noise generating a region. But this would result in just huge amounts of islands. On the other extreme, I don't think I can really generate a supermassive sheet of perlin noise. And it would just be one big island, I think. I am pretty sure Perlin noise, or some noise, would be the answer in some way. I mean, the map is really nice looking. And you could replace the ascii with tiles, and get something very nice looking. Anyone have any ideas? Thanks. :D

    Read the article

  • 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?

    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

  • 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

    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

  • 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.

    Read the article

  • 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.

    Read the article

  • 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?

    Read the article

  • C++ OpenGL wireframe cube rendering blank

    - by caleb.breckon
    I'm just trying to draw a bunch of lines that make up a "cube". I can't for the life of me figure out why this is producing a black screen. The debugger does not break at any point. I'm sure it's a problem with my pointers, as I'm only decent at them in regular c++ and in OpenGL it gets even worse. const char* vertexSource = "#version 150\n" "in vec3 position;" "void main() {" " gl_Position = vec4(position, 1.0);" "}"; const char* fragmentSource = "#version 150\n" "out vec4 outColor;" "void main() {" " outColor = vec4(1.0, 1.0, 1.0, 1.0);" "}"; int main() { initializeGLFW(); // Initialize GLEW glewExperimental = GL_TRUE; glewInit(); // Create Vertex Array Object GLuint vao; glGenVertexArrays(1, &vao); glBindVertexArray(vao); // Create a Vertex Buffer Object and copy the vertex data to it GLuint vbo; glGenBuffers( 1, &vbo ); float vertices[] = { 1.0f, 1.0f, 1.0f, // Vertex 0 (X, Y, Z) -1.0f, 1.0f, 1.0f, // Vertex 1 (X, Y, Z) -1.0f, -1.0f, 1.0f, // Vertex 2 (X, Y, Z) 1.0f, -1.0f, 1.0f, // Vertex 3 (X, Y, Z) 1.0f, 1.0f, -1.0f, // Vertex 4 (X, Y, Z) -1.0f, 1.0f, -1.0f, // Vertex 5 (X, Y, Z) -1.0f, -1.0f, -1.0f, // Vertex 6 (X, Y, Z) 1.0f, -1.0f, -1.0f // Vertex 7 (X, Y, Z) }; GLuint indices[] = { 0, 1, 1, 2, 2, 3, 3, 0, 4, 5, 5, 6, 6, 7, 7, 4, 0, 4, 1, 5, 2, 6, 3, 7 }; glBindBuffer( GL_ARRAY_BUFFER, vbo ); glBufferData( GL_ARRAY_BUFFER, sizeof( vertices ), vertices, GL_STATIC_DRAW ); //glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, vbo); //glBufferData( GL_ELEMENT_ARRAY_BUFFER, sizeof( indices ), indices, GL_STATIC_DRAW ); // Create and compile the vertex shader GLuint vertexShader = glCreateShader( GL_VERTEX_SHADER ); glShaderSource( vertexShader, 1, &vertexSource, NULL ); glCompileShader( vertexShader ); // Create and compile the fragment shader GLuint fragmentShader = glCreateShader( GL_FRAGMENT_SHADER ); glShaderSource( fragmentShader, 1, &fragmentSource, NULL ); glCompileShader( fragmentShader ); // Link the vertex and fragment shader into a shader program GLuint shaderProgram = glCreateProgram(); glAttachShader( shaderProgram, vertexShader ); glAttachShader( shaderProgram, fragmentShader ); glBindFragDataLocation( shaderProgram, 0, "outColor" ); glLinkProgram (shaderProgram); glUseProgram( shaderProgram); // Specify the layout of the vertex data GLint posAttrib = glGetAttribLocation( shaderProgram, "position" ); glEnableVertexAttribArray( posAttrib ); glVertexAttribPointer( posAttrib, 3, GL_FLOAT, GL_FALSE, 0, 0 ); // Main loop while(glfwGetWindowParam(GLFW_OPENED)) { // Clear the screen to black glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); glClear( GL_COLOR_BUFFER_BIT ); // Draw lines from 2 vertices glDrawElements(GL_LINES, sizeof(indices), GL_UNSIGNED_INT, indices ); // Swap buffers glfwSwapBuffers(); } // Clean up glDeleteProgram( shaderProgram ); glDeleteShader( fragmentShader ); glDeleteShader( vertexShader ); //glDeleteBuffers( 1, &ebo ); glDeleteBuffers( 1, &vbo ); glDeleteVertexArrays( 1, &vao ); glfwTerminate(); exit( EXIT_SUCCESS ); }

    Read the article

  • 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.

    Read the article

  • Learning to optimize with Assembly

    - by niktehpui
    I am a second year student of Computer Games Technology. I recently finished my first prototype of my "kind" of own pathfinder (that doesn't use A* instead a geometrical approach/pattern recognition, the pathfinder just needs the knowledge about the terrain that is in his view to make decisions, because I wanted an AI that could actually explore, if the terrain is already known, then it will walk the shortest way easily, because the pathfinder has a memory of nodes). Anyway my question is more general: How do I start optimizing algorithms/loops/for_each/etc. using Assembly, although general tips are welcome. I am specifically looking for good books, because it is really hard to find good books on this topic. There are some small articles out there like this one, but still isn't enough knowledge to optimize an algorithm/game... I hope there is a modern good book out there, that I just couldn't find...

    Read the article

  • Need Guidance Making HTML5 Canvas Game Engine

    - by Scriptonaut
    So I have some free time this winter break and want to build a simple 2d HTML5 canvas game engine. Mostly a physics engine that will dictate the way objects move and interact(collisions, etc). I made a basic game here: http://caidenhome.com/HTML%205/pong.html and would like to make more, and thought that this would be a good reason to make a simple framework for this stuff. Here are some questions: Does the scripting language have to be Javascript? What about Ruby? I will probably write it with jQuery because of the selecting powers, but I'm curious either way. Are there any great guides you guys know of? I want a fast guide that will help me bust out this engine sometime in the next 2 weeks, hopefully sooner. What are some good conventions I should be aware of? What's the best way to get sound? At the moment I'm using something like this: var audioElement = document.createElement('audio'); audioElement.setAttribute('src', 'paddle_col.wav'); audioElement.load(); I'm interested in making this engine lightweight and extremely efficient, I will do whatever it takes to get great speeds and processing power. I know this question is fairly vague, but I just need a push in the right direction. Thanks :)

    Read the article

  • What's the best game engine to use for my PC game project? [closed]

    - by user19860
    I'm in the planning phase of creating an action-rpg for the PC, and I'd like to create a League of Legends style look for the game (animated/cartoony). Any idea which engine best replicates this look? I ask because when I look at a lot of the UDk/Unreal games, they've all got the more realistic 3-D look that I'd like to avoid, so I was wondering if an alternate look was possible on that type of engine. Source SDK and Unity also look very interesting, I just don't know what types of visual capabilities these engines have. Thanks in advance.

    Read the article

  • What methods should save/load a game state

    - by vedi
    There are a lot of articles about how to save a state of a game and they are pretty good. But I have one conceptual misunderstanding where should I save the state? My game has number of screens and pair of them are MainMenuScreen and MainSceneScreen these are inherited from Screen class. MainMenuScreen is shown at start of the game the MainSceneScreen little later. What is the problem? I navigated to MainSceneScreen, forced Android to stop the application (I change a language settings on the device to achieve it, please let me know if I'm wrong). After that I select the application again and I can see MainMenuScreen is shown. But I want MainSceneScreen to be shown. I suppose I should override resume method. But what class I should override? I have class PsGame that extends Game class of libgdx. I put breakpoints to its resume method and it turned out that method was not called. I investigated the problem and I've found little strange code in onResume method of AndroidApplication class of libgdx: if (!firstResume) graphics.resume(); else firstResume = false; My debugger said firstResume was true and didn't go to *graphics.resume()*line. Sorry for a lot of words but could you answer following question: What did I do wrong? What methods should I override? Thank you in advance.

    Read the article

  • 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.

    Read the article

  • What is the proper way to maintain the angle of a gun mounted on a car?

    - by Blair
    So I am making a simple game. I want to put a gun on top of a car. I want to be able to control the angle of the gun. Basically it can go forward all the way so that it is parallel to the ground facing the direction the car is moving or it can point behind the car and any of the angles in between these positions. I have something like the following right now but its not really working. Is there an better way to do this that I am not seeing? #This will place the car glPushMatrix() glTranslatef(self.position.x,1.5,self.position.z) glRotated(self.rotation, 0.0, 1.0, 0.0) glScaled(0.5, 0.5, 0.5) glCallList(self.model.gl_list) glPopMatrix() #This will place the gun on top glPushMatrix() glTranslatef(self.position.x,2.5,self.position.z) glRotated(self.tube_angle, self.direction.z, 0.0, self.direction.x) print self.direction.z glRotated(45, self.position.z, 0.0, self.position.x) glScaled(1.0, 0.5, 1.0) glCallList(self.tube.gl_list) glPopMatrix() This almost works. It moves the gun up and down. But when the car moves around, the angle of the gun changes. Not what I want.

    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

  • 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

  • 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

    Read the article

  • 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

    Read the article

  • Spritebatch drawing sprite with jagged borders

    - by Mutoh
    Alright, I've been on the making of a sprite class and a sprite sheet manager, but have come across this problem. Pretty much, the project is acting like so; for example: Let's take this .png image, with a transparent background. Note how it has alpha-transparent pixels around it in the lineart. Now, in the latter link's image, in the left (with CornflowerBlue background) it is shown the image drawn in another project (let's call it "Project1") with a simpler sprite class - there, it works. The right (with Purple background for differentiating) shows it drawn with a different class in "Project2" - where the problem manifests itself. This is the Sprite class of Project1: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; namespace WindowsGame2 { class Sprite { Vector2 pos = new Vector2(0, 0); Texture2D image; Rectangle size; float scale = 1.0f; // --- public float X { get { return pos.X; } set { pos.X = value; } } public float Y { get { return pos.Y; } set { pos.Y = value; } } public float Width { get { return size.Width; } } public float Height { get { return size.Height; } } public float Scale { get { return scale; } set { if (value < 0) value = 0; scale = value; if (image != null) { size.Width = (int)(image.Width * scale); size.Height = (int)(image.Height * scale); } } } // --- public void Load(ContentManager Man, string filename) { image = Man.Load<Texture2D>(filename); size = new Rectangle( 0, 0, (int)(image.Width * scale), (int)(image.Height * scale) ); } public void Become(Texture2D frame) { image = frame; size = new Rectangle( 0, 0, (int)(image.Width * scale), (int)(image.Height * scale) ); } public void Draw(SpriteBatch Desenhista) { // Desenhista.Draw(image, pos, Color.White); Desenhista.Draw( image, pos, new Rectangle( 0, 0, image.Width, image.Height ), Color.White, 0.0f, Vector2.Zero, scale, SpriteEffects.None, 0 ); } } } And this is the code in Project2, a rewritten, pretty much, version of the previous class. In this one I added sprite sheet managing and, in particular, removed Load and Become, to allow for static resources and only actual Sprites to be instantiated. using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; namespace Mobby_s_Adventure { // Actually, I might desconsider this, and instead use static AnimationLocation[] and instanciated ID and Frame; // For determining the starting frame of an animation in a sheet and being able to iterate through // the Rectangles vector of the Sheet; class AnimationLocation { public int Location; public int FrameCount; // --- public AnimationLocation(int StartingRow, int StartingColumn, int SheetWidth, int NumberOfFrames) { Location = (StartingRow * SheetWidth) + StartingColumn; FrameCount = NumberOfFrames; } public AnimationLocation(int PositionInSheet, int NumberOfFrames) { Location = PositionInSheet; FrameCount = NumberOfFrames; } public static int CalculatePosition(int StartingRow, int StartingColumn, SheetManager Sheet) { return ((StartingRow * Sheet.Width) + StartingColumn); } } class Sprite { // The general stuff; protected SheetManager Sheet; protected Vector2 Position; public Vector2 Axis; protected Color _Tint; public float Angle; public float Scale; protected SpriteEffects _Effect; // --- // protected AnimationManager Animation; // For managing the animations; protected AnimationLocation[] Animation; public int AnimationID; protected int Frame; // --- // Properties for easy accessing of the position of the sprite; public float X { get { return Position.X; } set { Position.X = Axis.X + value; } } public float Y { get { return Position.Y; } set { Position.Y = Axis.Y + value; } } // --- // Properties for knowing the size of the sprite's frames public float Width { get { return Sheet.FrameWidth * Scale; } } public float Height { get { return Sheet.FrameHeight * Scale; } } // --- // Properties for more stuff; public Color Tint { set { _Tint = value; } } public SpriteEffects Effect { set { _Effect = value; } } public int FrameID { get { return Frame; } set { if (value >= (Animation[AnimationID].FrameCount)) value = 0; Frame = value; } } // --- // The only things that will be constantly modified will be AnimationID and FrameID, anything else only // occasionally; public Sprite(SheetManager SpriteSheet, AnimationLocation[] Animations, Vector2 Location, Nullable<Vector2> Origin = null) { // Assign the sprite's sprite sheet; // (Passed by reference! To allow STATIC sheets!) Sheet = SpriteSheet; // Define the animations that the sprite has available; // (Passed by reference! To allow STATIC animation boundaries!) Animation = Animations; // Defaulting some numerical values; Angle = 0.0f; Scale = 1.0f; _Tint = Color.White; _Effect = SpriteEffects.None; // If the user wants a default Axis, it is set in the middle of the frame; if (Origin != null) Axis = Origin.Value; else Axis = new Vector2( Sheet.FrameWidth / 2, Sheet.FrameHeight / 2 ); // Now that we have the axis, we can set the position with no worries; X = Location.X; Y = Location.Y; } // Simply put, draw the sprite with all its characteristics; public void Draw(SpriteBatch Drafter) { Drafter.Draw( Sheet.Texture, Position, Sheet.Rectangles[Animation[AnimationID].Location + FrameID], // Find the rectangle which frames the wanted image; _Tint, Angle, Axis, Scale, _Effect, 0.0f ); } } } And, in any case, this is the SheetManager class found in the previous code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.Graphics; namespace Mobby_s_Adventure { class SheetManager { protected Texture2D SpriteSheet; // For storing the sprite sheet; // Number of rows and frames in each row in the SpriteSheet; protected int NumberOfRows; protected int NumberOfColumns; // Size of a single frame; protected int _FrameWidth; protected int _FrameHeight; public Rectangle[] Rectangles; // For storing each frame; // --- public int Width { get { return NumberOfColumns; } } public int Height { get { return NumberOfRows; } } // --- public int FrameWidth { get { return _FrameWidth; } } public int FrameHeight { get { return _FrameHeight; } } // --- public Texture2D Texture { get { return SpriteSheet; } } // --- public SheetManager (Texture2D Texture, int Rows, int FramesInEachRow) { // Normal assigning SpriteSheet = Texture; NumberOfRows = Rows; NumberOfColumns = FramesInEachRow; _FrameHeight = Texture.Height / NumberOfRows; _FrameWidth = Texture.Width / NumberOfColumns; // Framing everything Rectangles = new Rectangle[NumberOfRows * NumberOfColumns]; int ID = 0; for (int i = 0; i < NumberOfRows; i++) { for (int j = 0; j < NumberOfColumns; j++) { Rectangles[ID] = new Rectangle ( _FrameWidth * j, _FrameHeight * i, _FrameWidth, _FrameHeight ); ID++; } } } public SheetManager (Texture2D Texture, int NumberOfFrames): this(Texture, 1, NumberOfFrames) { } } } For even more comprehending, if needed, here is how the main code looks like (it's just messing with the class' capacities, nothing actually; the result is a disembodied feet walking in place animation on the top-left of the screen and a static axe nearby): using System; using System.Collections.Generic; using System.Linq; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Audio; using Microsoft.Xna.Framework.Content; using Microsoft.Xna.Framework.GamerServices; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; using Microsoft.Xna.Framework.Media; using System.Threading; namespace Mobby_s_Adventure { /// <summary> /// This is the main type for your game /// </summary> public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; static List<Sprite> ToDraw; static Texture2D AxeSheet; static Texture2D FeetSheet; static SheetManager Axe; static Sprite Jojora; static AnimationLocation[] Hack = new AnimationLocation[1]; static SheetManager Feet; static Sprite Mutoh; static AnimationLocation[] FeetAnimations = new AnimationLocation[2]; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; this.TargetElapsedTime = TimeSpan.FromMilliseconds(100); this.IsFixedTimeStep = true; } /// <summary> /// Allows the game to perform any initialization it needs to before starting to run. /// This is where it can query for any required services and load any non-graphic /// related content. Calling base.Initialize will enumerate through any components /// and initialize them as well. /// </summary> protected override void Initialize() { // TODO: Add your initialization logic here base.Initialize(); } /// <summary> /// LoadContent will be called once per game and is the place to load /// all of your content. /// </summary> protected override void LoadContent() { // Create a new SpriteBatch, which can be used to draw textures. spriteBatch = new SpriteBatch(GraphicsDevice); // Loading logic ToDraw = new List<Sprite>(); AxeSheet = Content.Load<Texture2D>("Sheet"); FeetSheet = Content.Load<Texture2D>("Feet Sheet"); Axe = new SheetManager(AxeSheet, 1); Hack[0] = new AnimationLocation(0, 1); Jojora = new Sprite(Axe, Hack, new Vector2(100, 100), new Vector2(5, 55)); Jojora.AnimationID = 0; Jojora.FrameID = 0; Feet = new SheetManager(FeetSheet, 8); FeetAnimations[0] = new AnimationLocation(1, 7); FeetAnimations[1] = new AnimationLocation(0, 1); Mutoh = new Sprite(Feet, FeetAnimations, new Vector2(0, 0)); Mutoh.AnimationID = 0; Mutoh.FrameID = 0; } /// <summary> /// UnloadContent will be called once per game and is the place to unload /// all content. /// </summary> protected override void UnloadContent() { // TODO: Unload any non ContentManager content here } /// <summary> /// Allows the game to run logic such as updating the world, /// checking for collisions, gathering input, and playing audio. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Update(GameTime gameTime) { // Allows the game to exit if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed) this.Exit(); // Update logic Mutoh.FrameID++; ToDraw.Add(Mutoh); ToDraw.Add(Jojora); base.Update(gameTime); } /// <summary> /// This is called when the game should draw itself. /// </summary> /// <param name="gameTime">Provides a snapshot of timing values.</param> protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.Purple); // Drawing logic spriteBatch.Begin(); foreach (Sprite Element in ToDraw) { Element.Draw(spriteBatch); } spriteBatch.Draw(Content.Load<Texture2D>("Sheet"), new Rectangle(50, 50, 55, 60), Color.White); spriteBatch.End(); base.Draw(gameTime); } } } Please help me find out what I'm overlooking! One thing that I have noticed and could aid is that, if inserted the equivalent of this code spriteBatch.Draw( Content.Load<Texture2D>("Image Location"), new Rectangle(X, Y, images width, height), Color.White ); in Project2's Draw(GameTime) of the main loop, it works. EDIT Ok, even if the matter remains unsolved, I have made some more progress! As you see, I managed to get the two kinds of rendering in the same project (the aforementioned Project2, with the more complex Sprite class). This was achieved by adding the following code to Draw(GameTime): protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.Purple); // Drawing logic spriteBatch.Begin(); foreach (Sprite Element in ToDraw) { Element.Draw(spriteBatch); } // Starting here spriteBatch.Draw( Axe.Texture, new Vector2(65, 100), new Rectangle ( 0, 0, Axe.FrameWidth, Axe.FrameHeight ), Color.White, 0.0f, new Vector2(0, 0), 1.0f, SpriteEffects.None, 0.0f ); // Ending here spriteBatch.End(); base.Draw(gameTime); } (Supposing that Axe is the SheetManager containing the texture, sorry if the "jargons" of my code confuse you :s) Thus, I have noticed that the problem is within the Sprite class. But I only get more clueless, because even after modifying its Draw function to this: public void Draw(SpriteBatch Drafter) { /*Drafter.Draw( Sheet.Texture, Position, Sheet.Rectangles[Animation[AnimationID].Location + FrameID], // Find the rectangle which frames the wanted image; _Tint, Angle, Axis, Scale, _Effect, 0.0f );*/ Drafter.Draw( Sheet.Texture, Position, new Rectangle( 0, 0, Sheet.FrameWidth, Sheet.FrameHeight ), Color.White, 0.0f, Vector2.Zero, Scale, SpriteEffects.None, 0 ); } to make it as simple as the patch of code that works, it still draws the sprite jaggedly!

    Read the article

< Previous Page | 514 515 516 517 518 519 520 521 522 523 524 525  | Next Page >