Search Results

Search found 39726 results on 1590 pages for 'iphone development'.

Page 876/1590 | < Previous Page | 872 873 874 875 876 877 878 879 880 881 882 883  | Next Page >

  • Game Physics With RK4 Implementation For A 2D Platformer

    - by oscar.rpr
    I been reading about RK4 for physics implementation in a game, so I read in some pages and all people recommend me this page: http://gafferongames.com/game-physics/fix-your-timestep/ This page shows clearly how this one works, but I can't figure out how to implement in my game, maybe I don't understand that good but I find some things that are not really clearly to me. In my game, the player decides when change direction in the X-Axis but I can't figure out how with this RK4 implementation change the direction of the object, in the example the point goes side to side but I don't understand how I can control when he goes right or left. So if anyone can give a little bit of clarity in this implementation and my problem which I do not understand I will be really grateful. Thanks beforehand

    Read the article

  • Reading from a staging 2D texture array in DirectX10

    - by Don Reba
    I have a DX10 program, where I create an array of 3 16x16 textures, then map, read, and unmap each subresource in turn. I use a single mip level, set resource usage to staging and CPU access to read. Now, here is the problem: Subresource 0 contains 1024 bytes, pitch 64, as expected. Subresource 1 contains 512 bytes, pitch 64. Subresource 2 contains 256 bytes, pitch 64. I expect all three to be the same size. Debugging output is enabled, but not reporting any warnings or errors. Am I missing something, or might this be some sort of driver issue? Here is the code. The language is Nemerle, but C# and C++ would look almost the same. I have looked through the generated code, and am fairly confident the problem is not language-related. def cpuTexture = Texture2D ( device , Texture2DDescription() <- { Width = 16; Height = 16; MipLevels = 1; ArraySize = 3; Format = Format.R32_Float; Usage = ResourceUsage.Staging; CpuAccessFlags = CpuAccessFlags.Read; SampleDescription = SampleDescription(count = 1, quality = 0); } ); foreach (subresource in [0 .. 2]) { def data = cpuTexture.Map(subresource, MapMode.Read, MapFlags.None); Console.WriteLine($"subresource $subresource"); Console.WriteLine($"length = $(data.Data.Length)"); Console.WriteLine($"pitch = $(data.Pitch)"); cpuTexture.Unmap(subresource); }

    Read the article

  • How to code UI / HUD in Entity System?

    - by Sylpheed
    I think I already got the idea of the Entity System inspired by Adam Martin (t-machine). I want to start using this for my next project. I already know the basic of Entity, Components, and Systems. My problem is how to handle UI / HUD. For example, a quest window, skill window, character info window, etc. How do you handle UI events (eg. pressing a button)? These are stuff that doesn't need to be processed every frame. Currently, I'm using MVC to code UI but I don't think that'll be compatible for Entity System. I've read that Entity System is embedded on a larger OOP. I don't know if UI is outside of ES or not. How do I approach this one?

    Read the article

  • How To Approach 360 Degree Snake

    - by Austin Brunkhorst
    I've recently gotten into XNA and must say I love it. As sort of a hello world game I decided to create the classic game "Snake". The 90 degree version was very simple and easy to implement. But as I try to make a version of it that allows 360 degree rotation using left and right arrows, I've come into sort of a problem. What i'm doing now stems from the 90 degree version: Iterating through each snake body part beginning at the tail, and ending right before the head. This works great when moving every 100 milliseconds. The problem with this is that it makes for a choppy style of gameplay as technically the game progresses at only 6 fps rather than it's potential 60. I would like to move the snake every game loop. But unfortunately because the snake moves at the rate of it's head's size it goes way too fast. This would mean that the head would need to move at a much smaller increment such as (2, 2) in it's direction rather than what I have now (32, 32). Because I've been working on this game off and on for a couple of weeks while managing school I think that I've been thinking too hard on how to accomplish this. It's probably a simple solution, i'm just not catching it. Here's some pseudo code for what I've tried based off of what makes sense to me. I can't really think of another way to do it. for(int i = SnakeLength - 1; i > 0; i--){ current = SnakePart[i], next = SnakePart[i - 1]; current.x = next.x - (current.width * cos(next.angle)); current.y = next.y - (current.height * sin(next.angle)); current.angle = next.angle; } SnakeHead.x += cos(SnakeAngle) * SnakeSpeed; SnakeHead.y += sin(SnakeAngle) * SnakeSpeed; This produces something like this: Code in Action. As you can see each part always stays behind the head and doesn't make a "Trail" effect. A perfect example of what i'm going for can be found here: Data Worm. Not the viewport rotation but the trailing effect of the triangles. Thanks for any help!

    Read the article

  • Do I need path finding to make AI avoid obstacles?

    - by yannicuLar
    How do you know when a path-finding algorithm is really needed? There are contexts, where you just want to improve AI navigation to avoid an object, like a space -ship that won't crash on a planet or a car that already knows where to steer, but needs small corrections to avoid a road bump. As I've seen on similar posts, the obvious solution is to implement some path-finding algorithm, most likely like A*, and let your AI-controlled object to navigate through the path. Now, I have the necessary skills to implement a path-finding algorithm, and I'm not being lazy here, but I'm still a bit skeptical on if this is really needed. I have the impression that path-finding is appropriate to navigate through a maze, or picking a path when there are many alternatives. But in obstacle avoidance, when you do know the path, but need to make slight corrections, is path finding really necessary? Even when the obstacles are too sparse or small ? I mean, in real life, when you're driving and notice a bump on the road, you will just have to pick between steering a bit on the left (and have the bump on your right side) or the other way around. You will not consider stopping, or going backwards. A path finding would be appropriate when you need to pick a route through the city, right ? So, are there any other methods to help AI navigation, except path-finding? And if there are, how do you know when path-fining is the appropriate algorithm ? Thanks for any thoughts

    Read the article

  • Simplex Noise Help

    - by Alex Larsen
    Im Making A Minecraft Like Gae In XNA C# And I Need To Generate Land With Caves This Is The Code For Simplex I Have /// <summary> /// 1D simplex noise /// </summary> /// <param name="x"></param> /// <returns></returns> public static float Generate(float x) { int i0 = FastFloor(x); int i1 = i0 + 1; float x0 = x - i0; float x1 = x0 - 1.0f; float n0, n1; float t0 = 1.0f - x0 * x0; t0 *= t0; n0 = t0 * t0 * grad(perm[i0 & 0xff], x0); float t1 = 1.0f - x1 * x1; t1 *= t1; n1 = t1 * t1 * grad(perm[i1 & 0xff], x1); // The maximum value of this noise is 8*(3/4)^4 = 2.53125 // A factor of 0.395 scales to fit exactly within [-1,1] return 0.395f * (n0 + n1); } /// <summary> /// 2D simplex noise /// </summary> /// <param name="x"></param> /// <param name="y"></param> /// <returns></returns> public static float Generate(float x, float y) { const float F2 = 0.366025403f; // F2 = 0.5*(sqrt(3.0)-1.0) const float G2 = 0.211324865f; // G2 = (3.0-Math.sqrt(3.0))/6.0 float n0, n1, n2; // Noise contributions from the three corners // Skew the input space to determine which simplex cell we're in float s = (x + y) * F2; // Hairy factor for 2D float xs = x + s; float ys = y + s; int i = FastFloor(xs); int j = FastFloor(ys); float t = (float)(i + j) * G2; float X0 = i - t; // Unskew the cell origin back to (x,y) space float Y0 = j - t; float x0 = x - X0; // The x,y distances from the cell origin float y0 = y - Y0; // For the 2D case, the simplex shape is an equilateral triangle. // Determine which simplex we are in. int i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords if (x0 > y0) { i1 = 1; j1 = 0; } // lower triangle, XY order: (0,0)->(1,0)->(1,1) else { i1 = 0; j1 = 1; } // upper triangle, YX order: (0,0)->(0,1)->(1,1) // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where // c = (3-sqrt(3))/6 float x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords float y1 = y0 - j1 + G2; float x2 = x0 - 1.0f + 2.0f * G2; // Offsets for last corner in (x,y) unskewed coords float y2 = y0 - 1.0f + 2.0f * G2; // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds int ii = i % 256; int jj = j % 256; // Calculate the contribution from the three corners float t0 = 0.5f - x0 * x0 - y0 * y0; if (t0 < 0.0f) n0 = 0.0f; else { t0 *= t0; n0 = t0 * t0 * grad(perm[ii + perm[jj]], x0, y0); } float t1 = 0.5f - x1 * x1 - y1 * y1; if (t1 < 0.0f) n1 = 0.0f; else { t1 *= t1; n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1]], x1, y1); } float t2 = 0.5f - x2 * x2 - y2 * y2; if (t2 < 0.0f) n2 = 0.0f; else { t2 *= t2; n2 = t2 * t2 * grad(perm[ii + 1 + perm[jj + 1]], x2, y2); } // Add contributions from each corner to get the final noise value. // The result is scaled to return values in the interval [-1,1]. return 40.0f * (n0 + n1 + n2); // TODO: The scale factor is preliminary! } public static float Generate(float x, float y, float z) { // Simple skewing factors for the 3D case const float F3 = 0.333333333f; const float G3 = 0.166666667f; float n0, n1, n2, n3; // Noise contributions from the four corners // Skew the input space to determine which simplex cell we're in float s = (x + y + z) * F3; // Very nice and simple skew factor for 3D float xs = x + s; float ys = y + s; float zs = z + s; int i = FastFloor(xs); int j = FastFloor(ys); int k = FastFloor(zs); float t = (float)(i + j + k) * G3; float X0 = i - t; // Unskew the cell origin back to (x,y,z) space float Y0 = j - t; float Z0 = k - t; float x0 = x - X0; // The x,y,z distances from the cell origin float y0 = y - Y0; float z0 = z - Z0; // For the 3D case, the simplex shape is a slightly irregular tetrahedron. // Determine which simplex we are in. int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords /* This code would benefit from a backport from the GLSL version! */ if (x0 >= y0) { if (y0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // X Y Z order else if (x0 >= z0) { i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; } // X Z Y order else { i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; } // Z X Y order } else { // x0<y0 if (y0 < z0) { i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; } // Z Y X order else if (x0 < z0) { i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; } // Y Z X order else { i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; } // Y X Z order } // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z), // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where // c = 1/6. float x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords float y1 = y0 - j1 + G3; float z1 = z0 - k1 + G3; float x2 = x0 - i2 + 2.0f * G3; // Offsets for third corner in (x,y,z) coords float y2 = y0 - j2 + 2.0f * G3; float z2 = z0 - k2 + 2.0f * G3; float x3 = x0 - 1.0f + 3.0f * G3; // Offsets for last corner in (x,y,z) coords float y3 = y0 - 1.0f + 3.0f * G3; float z3 = z0 - 1.0f + 3.0f * G3; // Wrap the integer indices at 256, to avoid indexing perm[] out of bounds int ii = i % 256; int jj = j % 256; int kk = k % 256; // Calculate the contribution from the four corners float t0 = 0.6f - x0 * x0 - y0 * y0 - z0 * z0; if (t0 < 0.0f) n0 = 0.0f; else { t0 *= t0; n0 = t0 * t0 * grad(perm[ii + perm[jj + perm[kk]]], x0, y0, z0); } float t1 = 0.6f - x1 * x1 - y1 * y1 - z1 * z1; if (t1 < 0.0f) n1 = 0.0f; else { t1 *= t1; n1 = t1 * t1 * grad(perm[ii + i1 + perm[jj + j1 + perm[kk + k1]]], x1, y1, z1); } float t2 = 0.6f - x2 * x2 - y2 * y2 - z2 * z2; if (t2 < 0.0f) n2 = 0.0f; else { t2 *= t2; n2 = t2 * t2 * grad(perm[ii + i2 + perm[jj + j2 + perm[kk + k2]]], x2, y2, z2); } float t3 = 0.6f - x3 * x3 - y3 * y3 - z3 * z3; if (t3 < 0.0f) n3 = 0.0f; else { t3 *= t3; n3 = t3 * t3 * grad(perm[ii + 1 + perm[jj + 1 + perm[kk + 1]]], x3, y3, z3); } // Add contributions from each corner to get the final noise value. // The result is scaled to stay just inside [-1,1] return 32.0f * (n0 + n1 + n2 + n3); // TODO: The scale factor is preliminary! } private static byte[] perm = new byte[512] { 151,160,137,91,90,15, 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180, 151,160,137,91,90,15, 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 }; private static int FastFloor(float x) { return (x > 0) ? ((int)x) : (((int)x) - 1); } private static float grad(int hash, float x) { int h = hash & 15; float grad = 1.0f + (h & 7); // Gradient value 1.0, 2.0, ..., 8.0 if ((h & 8) != 0) grad = -grad; // Set a random sign for the gradient return (grad * x); // Multiply the gradient with the distance } private static float grad(int hash, float x, float y) { int h = hash & 7; // Convert low 3 bits of hash code float u = h < 4 ? x : y; // into 8 simple gradient directions, float v = h < 4 ? y : x; // and compute the dot product with (x,y). return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -2.0f * v : 2.0f * v); } private static float grad(int hash, float x, float y, float z) { int h = hash & 15; // Convert low 4 bits of hash code into 12 simple float u = h < 8 ? x : y; // gradient directions, and compute dot product. float v = h < 4 ? y : h == 12 || h == 14 ? x : z; // Fix repeats at h = 12 to 15 return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v); } private static float grad(int hash, float x, float y, float z, float t) { int h = hash & 31; // Convert low 5 bits of hash code into 32 simple float u = h < 24 ? x : y; // gradient directions, and compute dot product. float v = h < 16 ? y : z; float w = h < 8 ? z : t; return ((h & 1) != 0 ? -u : u) + ((h & 2) != 0 ? -v : v) + ((h & 4) != 0 ? -w : w); } This Is My World Generation Code Block[,] BlocksInMap = new Block[1024, 256]; public bool IsWorldGenerated = false; Random r = new Random(); private void RunThread() { for (int BH = 0; BH <= 256; BH++) { for (int BW = 0; BW <= 1024; BW++) { Block b = new Block(); if (BH >= 192) { } BlocksInMap[BW, BH] = b; } } IsWorldGenerated = true; } public void GenWorld() { new Thread(new ThreadStart(RunThread)).Start(); } And This Is A Example Of How I Set Blocks Block b = new Block(); b.BlockType = = Block.BlockTypes.Air; This Is A Example Of How I Set Models foreach (Block b in MyWorld) { switch(b.BlockType) { case Block.BlockTypes.Dirt: b.Model = DirtModel; break; ect. } } How Would I Use These To Generate To World (The Block Array) And If Possible Thread It More? btw It's 1024 Wide And 256 Tall

    Read the article

  • Isometric drawing "Not Tile Stuff" on isometric map?

    - by Icebone1000
    So I got my isometric renderer working, it can draw diamond or jagged maps...Then I want to move on...How do I draw characters/objects on it in a optimal way? What Im doing now, as one can imagine, is traversing my grid(map) and drawing the tiles in a order so alpha blending works correctly. So, anything I draw in this map must be drawed at the same time the map is being drawn, with sucks a lot, screws your very modular map drawer, because now everything on the game (but the HUD) must be included on the drawer.. I was thinking whats the best approach to do this, comparing the position of all objects(not tile stuff) on the grid against the current tile being draw seems stupid, would it be better to add an id ON the grid(map)? this also seems terrible, because objects can move freely, not per tile steps (it can occupies 2 tiles if its between them, etc.) Dont know if matters, but my grid is 3D, so its not a plane with objects poping out, its a bunch of pilled cubes.

    Read the article

  • Collision filtering by object, team

    - by Bill Zimmerman
    Hi, I am looking for a good method to determine which objects will be considered for collision with other objects. My current idea is that each object has the following properties: alwaysCollidesWith = [list of objects that will always trigger a collision check] neverCollidesWith = [lost of objects that will never be considered] teamCollidesWith = [list of objects that will be checked, provided they belong to a different team] For example: -projectiles never have to be checked for collisions with other projectiles -players are always checked for collisions with players, regardless of team -projectiles are only considered for collisions if they collide with another teams players Does anyone see any weaknesses with this approach? Can anyone recommend a better approach?

    Read the article

  • Keeping crosshairs & GUI onscreen - SFML

    - by nihohit
    I read this question, but didn't understand the implementation suggestions with SFML on c#. For example, right now I'm just trying to make sure that the mouse crosshairs stay onscreen constatnly. I tried using this code: View lastView = this._mainWindow.GetView(); this._mainWindow.SetView(this._mainWindow.DefaultView); this._mainWindow.Draw(crosshair); this._mainWindow.SetView(lastView); after drawing all other sprites and before call this._mainWindow.display(), when beforehand I set crosshair.Position based on its position relative to the window, not the view. This just keeps the screen locked and prevents screen scrolling. Any suggestions?

    Read the article

  • Is the new windows 8 sdk usable with visual c++ express 2010 on windows 7?

    - by JohnB
    This is inspired by and related to Is the June 2010 DX SDK really the latest? asked recently but it's a different question. I won't likely be purchasing the full visual studio 2012 for C++, I intend to use the free visual c++ express 2012 that targets desktop applications when it is released so for now I'm using visual c++ express 2010 running on windows 7. The latest directx11 sdk is the one included in the windows 8 SDK now, it's not a separate release any more. So my question is, can I use the windows 8 SDK to build directx11 programs that work on windows 7 using visual studio express 2010 running on windows 7. Or do I need to stick to the final DirectX SDK release for now?

    Read the article

  • Making a full-screen animation on Android? Should I use OPENGL?

    - by Roger Travis
    Say I need to make several full-screen animation that would consist of about 500+ frames each, similar to the TalkingTom app ( https://play.google.com/store/apps/details?id=com.outfit7.talkingtom2free ). Animation should be playing at a reasonable speed - supposedly not less, then 20fps - and pictures should be of a reasonable quality, not overly compressed. What method do you think should I use? So far I tried: storing each frame as a compressed JPEG before animation starts, loading each frame into a byteArray as the animation plays, decode corresponding byteArray into a bitmap and draw it on a surface view. Problem - speed is too low, usually about 5-10 FPS. I have thought of two other options. turning all animations into one movie file... but I guess there might be problems with starting, pausing and seeking to the exactly right frame... what do you think? another option I thought about was using OPENGL ( while I never worked with it before ), to play animation frame by frame. What do you think, would opengl be able to handle it? Thanks!

    Read the article

  • WiX installer for XNA 4.0 game?

    - by Mathias Lykkegaard Lorenzen
    I'm trying to make a quick installer for my XNA 4.0 game which should be able to install silently. I did some research and figured out that WiX would probably be best for me. I don't like the setup projects inbuilt in Visual Studio 2010, and InstallShield LE doesn't have an XNA 4.0 redistributable. So, where can I find resources on how to make a WiX installer for an XNA 4.0 game? I've tried these links, but with no luck. They are targeting a different XNA version, and I want to make sure that a silent install would be supported (while still installing all prerequisites). http://blogs.msdn.com/b/astebner/archive/2008/11/17/9115792.aspx http://xnainstaller.codeplex.com/

    Read the article

  • Segfault when iterating over a map<string, string> and drawing its contents using SDL_TTF

    - by Michael Stahre
    I'm not entirely sure this question belongs on gamedev.stackexchange, but I'm technically working on a game and working with SDL, so it might not be entirely offtopic. I've written a class called DebugText. The point of the class is to have a nice way of printing values of variables to the game screen. The idea is to call SetDebugText() with the variables in question every time they change or, as is currently the case, every time the game's Update() is called. The issue is that when iterating over the map that contains my variables and their latest updated values, I get segfaults. See the comments in DrawDebugText() below, it specifies where the error happens. I've tried splitting the calls to it-first and it-second into separate lines and found that the problem doesn't always happen when calling it-first. It alters between it-first and it-second. I can't find a pattern. It doesn't fail on every call to DrawDebugText() either. It might fail on the third time DrawDebugText() is called, or it might fail on the fourth. Class header: #ifndef CLIENT_DEBUGTEXT_H #define CLIENT_DEBUGTEXT_H #include <Map> #include <Math.h> #include <sstream> #include <SDL.h> #include <SDL_ttf.h> #include "vector2.h" using std::string; using std::stringstream; using std::map; using std::pair; using game::Vector2; namespace game { class DebugText { private: TTF_Font* debug_text_font; map<string, string>* debug_text_list; public: void SetDebugText(string var, bool value); void SetDebugText(string var, float value); void SetDebugText(string var, int value); void SetDebugText(string var, Vector2 value); void SetDebugText(string var, string value); int DrawDebugText(SDL_Surface*, SDL_Rect*); void InitDebugText(); void Clear(); }; } #endif Class source file: #include "debugtext.h" namespace game { // Copypasta function for handling the toString conversion template <class T> inline string to_string (const T& t) { stringstream ss (stringstream::in | stringstream::out); ss << t; return ss.str(); } // Initializes SDL_TTF and sets its font void DebugText::InitDebugText() { if(TTF_WasInit()) TTF_Quit(); TTF_Init(); debug_text_font = TTF_OpenFont("LiberationSans-Regular.ttf", 16); TTF_SetFontStyle(debug_text_font, TTF_STYLE_NORMAL); } // Iterates over the current debug_text_list and draws every element on the screen. // After drawing with SDL you need to get a rect specifying the area on the screen that was changed and tell SDL that this part of the screen needs to be updated. this is done in the game's Draw() function // This function sets rects_to_update to the new list of rects provided by all of the surfaces and returns the number of rects in the list. These two parameters are used in Draw() when calling on SDL_UpdateRects(), which takes an SDL_Rect* and a list length int DebugText::DrawDebugText(SDL_Surface* screen, SDL_Rect* rects_to_update) { if(debug_text_list == NULL) return 0; if(!TTF_WasInit()) InitDebugText(); rects_to_update = NULL; // Specifying the font color SDL_Color font_color = {0xff, 0x00, 0x00, 0x00}; // r, g, b, unused int row_count = 0; string line; // The iterator variable map<string, string>::iterator it; // Gets the iterator and iterates over it for(it = debug_text_list->begin(); it != debug_text_list->end(); it++) { // Takes the first value (the name of the variable) and the second value (the value of the parameter in string form) //---------THIS LINE GIVES ME SEGFAULTS----- line = it->first + ": " + it->second; //------------------------------------------ // Creates a surface with the text on it that in turn can be rendered to the screen itself later SDL_Surface* debug_surface = TTF_RenderText_Solid(debug_text_font, line.c_str(), font_color); if(debug_surface == NULL) { // A standard check for errors fprintf(stderr, "Error: %s", TTF_GetError()); return NULL; } else { // If SDL_TTF did its job right, then we now set a destination rect row_count++; SDL_Rect dstrect = {5, 5, 0, 0}; // x, y, w, h dstrect.x = 20; dstrect.y = 20*row_count; // Draws the surface with the text on it to the screen int res = SDL_BlitSurface(debug_surface,NULL,screen,&dstrect); if(res != 0) { //Just an error check fprintf(stderr, "Error: %s", SDL_GetError()); return NULL; } // Creates a new rect to specify the area that needs to be updated with SDL_Rect* new_rect_to_update = (SDL_Rect*) malloc(sizeof(SDL_Rect)); new_rect_to_update->h = debug_surface->h; new_rect_to_update->w = debug_surface->w; new_rect_to_update->x = dstrect.x; new_rect_to_update->y = dstrect.y; // Just freeing the surface since it isn't necessary anymore SDL_FreeSurface(debug_surface); // Creates a new list of rects with room for the new rect SDL_Rect* newtemp = (SDL_Rect*) malloc(row_count*sizeof(SDL_Rect)); // Copies the data from the old list of rects to the new one memcpy(newtemp, rects_to_update, (row_count-1)*sizeof(SDL_Rect)); // Adds the new rect to the new list newtemp[row_count-1] = *new_rect_to_update; // Frees the memory used by the old list free(rects_to_update); // And finally redirects the pointer to the old list to the new list rects_to_update = newtemp; newtemp = NULL; } } // When the entire map has been iterated over, return the number of lines that were drawn, ie. the number of rects in the returned rect list return row_count; } // The SetDebugText used by all the SetDebugText overloads // Takes two strings, inserts them into the map as a pair void DebugText::SetDebugText(string var, string value) { if (debug_text_list == NULL) { debug_text_list = new map<string, string>(); } debug_text_list->erase(var); debug_text_list->insert(pair<string, string>(var, value)); } // Writes the bool to a string and calls SetDebugText(string, string) void DebugText::SetDebugText(string var, bool value) { string result; if (value) result = "True"; else result = "False"; SetDebugText(var, result); } // Does the same thing, but uses to_string() to convert the float void DebugText::SetDebugText(string var, float value) { SetDebugText(var, to_string(value)); } // Same as above, but int void DebugText::SetDebugText(string var, int value) { SetDebugText(var, to_string(value)); } // Vector2 is a struct of my own making. It contains the two float vars x and y void DebugText::SetDebugText(string var, Vector2 value) { SetDebugText(var + ".x", to_string(value.x)); SetDebugText(var + ".y", to_string(value.y)); } // Empties the list. I don't actually use this in my code. Shame on me for writing something I don't use. void DebugText::Clear() { if(debug_text_list != NULL) debug_text_list->clear(); } }

    Read the article

  • Monogame - Shader parameters missing

    - by Layoric
    I am currently working on a simple game that I am building in Windows 8 using MonoGame (develop3d). I am using some shader code from a tutorial (made by Charles Humphrey) and having an issue populating a 'texture' parameter. I'm not well versed writing shaders, so this might be caused by a more obvious problem. I have debugged through MonoGame's Content processor to see how this shader is being parsed, all the non 'texture' parameters are there and look to be loading correctly. Shader code below #include "PPVertexShader.fxh" float2 lightScreenPosition; float4x4 matVP; float2 halfPixel; float SunSize; texture flare; sampler2D Scene: register(s0){ AddressU = Clamp; AddressV = Clamp; }; sampler Flare = sampler_state { Texture = (flare); AddressU = CLAMP; AddressV = CLAMP; }; float4 LightSourceMaskPS(float2 texCoord : TEXCOORD0 ) : COLOR0 { texCoord -= halfPixel; // Get the scene float4 col = 0; // Find the suns position in the world and map it to the screen space. float2 coord; float size = SunSize / 1; float2 center = lightScreenPosition; coord = .5 - (texCoord - center) / size * .5; col += (pow(tex2D(Flare,coord),2) * 1) * 2; return col * tex2D(Scene,texCoord); } technique LightSourceMask { pass p0 { VertexShader = compile vs_4_0 VertexShaderFunction(); PixelShader = compile ps_4_0 LightSourceMaskPS(); } } I've removed default values as they are currently not support in MonoGame and also changed ps and vs to v4 instead of 2. Could this be causing the issue? As I debug through 'DXConstantBufferData' constructor (from within the MonoGameContentProcessing project) I find that the 'flare' parameter does not exist. All others seem to be getting created fine. Any help would be appreciated.

    Read the article

  • How do I implement a quaternion based camera?

    - by kudor gyozo
    I looked at several tutorials about this and when I thought I understood I tried to implement a quaternion based camera. The problem is it doesn't work correctly, after rotating for approx. 10 degrees it jumps back to -10 degrees. I have no idea what's wrong. I'm using openTK and it already has a quaternion class. I'm a noob at opengl, I'm doing this just for fun, and don't really understand quaternions, so probably I'm doing something stupid here. Here is some code: (Actually almost all the code except the methods that load and draw a vbo (it is taken from an OpenTK sample that demonstrates vbo-s)) I load a cube into a vbo and initialize the quaternion for the camera protected override void OnLoad(EventArgs e) { base.OnLoad(e); cameraPos = new Vector3(0, 0, 7); cameraRot = Quaternion.FromAxisAngle(new Vector3(0,0,-1), 0); GL.ClearColor(System.Drawing.Color.MidnightBlue); GL.Enable(EnableCap.DepthTest); vbo = LoadVBO(CubeVertices, CubeElements); } I load a perspective projection here. This is loaded at the beginning and every time I resize the window. protected override void OnResize(EventArgs e) { base.OnResize(e); GL.Viewport(0, 0, Width, Height); float aspect_ratio = Width / (float)Height; Matrix4 perpective = Matrix4.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspect_ratio, 1, 64); GL.MatrixMode(MatrixMode.Projection); GL.LoadMatrix(ref perpective); } Here I get the last rotation value and create a new quaternion that represents only the last rotation and multiply it with the camera quaternion. After this I transform this into axis-angle so that opengl can use it. (This is how I understood it from several online quaternion tutorials) protected override void OnRenderFrame(FrameEventArgs e) { base.OnRenderFrame(e); GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); double speed = 1; double rx = 0, ry = 0; if (Keyboard[Key.A]) { ry = -speed * e.Time; } if (Keyboard[Key.D]) { ry = +speed * e.Time; } if (Keyboard[Key.W]) { rx = +speed * e.Time; } if (Keyboard[Key.S]) { rx = -speed * e.Time; } Quaternion tmpQuat = Quaternion.FromAxisAngle(new Vector3(0,1,0), (float)ry); cameraRot = tmpQuat * cameraRot; cameraRot.Normalize(); GL.MatrixMode(MatrixMode.Modelview); GL.LoadIdentity(); Vector3 axis; float angle; cameraRot.ToAxisAngle(out axis, out angle); GL.Rotate(angle, axis); GL.Translate(-cameraPos); Draw(vbo); SwapBuffers(); } Here are 2 images to explain better: I rotate a while and from this: it jumps into this Any help is appreciated. Update1: I add these to a streamwriter that writes into a file: sw.WriteLine("camerarot: X:{0} Y:{1} Z:{2} W:{3} L:{4}", cameraRot.X, cameraRot.Y, cameraRot.Z, cameraRot.W, cameraRot.Length); sw.WriteLine("ry: {0}", ry); The log is available here: http://www.pasteall.org/26133/text. At line 770 the cube jumps from right to left, when camerarot.Y changes signs. I don't know if this is normal. Update2 Here is the complete project.

    Read the article

  • Disabling depth write trashes the frame buffer on some GPUs

    - by EboMike
    I sometimes disable depth buffer writing via glDepthMask(GL_FALSE) during the alpha rendering of a frame. That works perfectly fine on some GPUs (like the Motorola Droid's PowerVR), but on the HTC EVO with the Adreno GPU for example, I end up with the frame buffer being complete garbage (I see traces of the meshes I rendered somewhere, but the entire screen is mostly trashed). If I force glDepthMask to be true the entire time, everything works fine. I need glDepthMask to be off during parts of the alpha rendering. What can cause the framebuffer to get destroyed by turning the depth writing off? I do clear the depth buffer initially, and the majority of the screen has pixels rendered with depth writing turned on first before I do additional drawing with it turned off.

    Read the article

  • How to set a target as image [on hold]

    - by Zadalaxmi
    How to set a target as image in given code. public void addListenerForImage(final Image roomImage) { final DragAndDrop dragAndDrop = new DragAndDrop(); dragAndDrop.addSource(new DragAndDrop.Source(roomImage) { public DragAndDrop.Payload dragStart (InputEvent event, float x, float y, int pointer) { DragAndDrop.Payload payload = new DragAndDrop.Payload(); payload.setDragActor(roomImage); dragAndDrop.setDragActorPosition(-x, -y + roomImage.getHeight()); return payload; } public void dragStop (InputEvent event, float x, float y, int pointer,Target target) { roomImage.setBounds(50, 125, roomImage.getWidth(), roomImage.getHeight()); if(target != null) { roomImage.setPosition(target.getActor().getX(), target.getActor().getY()); } System.out.println(target); stage.addActor(roomImage); } }); My problem is i can drag the images and i am not able to set target as image; and target shows as null;One more if a invisible some of the images in group how can i test that it is overlapped or not;Please give some links and suggestion

    Read the article

  • Java Slick2d - How to translate mouse coordinates to world coordinates

    - by Corey
    I am translating in my main class render. How do I get the mouse position where my mouse actually is after I scroll the screen public void render(GameContainer gc, Graphics g) throws SlickException { float centerX = 800/2; float centerY = 600/2; g.translate(centerX, centerY); g.translate(-player.playerX, -player.playerY); gen.render(g); player.render(g); } playerX = 800 /2 - sprite.getWidth(); playerY = 600 /2 - sprite.getHeight(); Image to help with explanation I tried implementing a camera but it seems no matter what I can't get the mouse position. I was told to do this worldX = mouseX + camX; but it didn't work the mouse was still off. Here is my Camera class if that helps: public class Camera { public float camX; public float camY; Player player; public void init() { player = new Player(); } public void update(GameContainer gc, int delta) { Input input = gc.getInput(); if(input.isKeyDown(Input.KEY_W)) { camY -= player.speed * delta; } if(input.isKeyDown(Input.KEY_S)) { camY += player.speed * delta; } if(input.isKeyDown(Input.KEY_A)) { camX -= player.speed * delta; } if(input.isKeyDown(Input.KEY_D)) { camX += player.speed * delta; } } Code used to convert mouse worldX = (int) (mouseX + cam.camX); worldY = (int) (mouseY + cam.camY);

    Read the article

  • How to do the Geometry Wars gravity well effect

    - by Mykel Stone
    I'm not talking about the background grid here, I'm talking about the swirly particles going around the Gravity Wells! I've always liked the effect and decided it'd be a fun experiment to replicate it, I know GW uses Hooke's law all over the place, but I don't think the Particle-to-Well effect is done using springs, it looks like a distance-squared function. Here is a video demonstrating the effect: http://www.youtube.com/watch?v=YgJe0YI18Fg I can implement a spring or gravity effect on some particles just fine, that's easy. But I can't seem to get the effect to look similar to GWs effect. When I watch the effect in game it seems that the particles are emitted in bunches from the Well itself, they spiral outward around the center of the well, and eventually get flung outward, fall back towards the well, and repeat. How does he make the particles spiral outward when spawned? How does he keep the particle bunches together when near the Well but spread away from each other when they're flung outward? How does he keep the particles so strongly attached to the Well?

    Read the article

  • Algorithm for querying linearly through a non-linear list of questions

    - by JoshLeaves
    For a multiplayers trivia game, I need to supply my users with a new quizz in a desired subject (Science, Maths, Litt. and such) at the start of every game. I've generated about 5K quizzes for each subject and filled my database with them. So my 'Quizzes' database looks like this: |ID |Subject |Question +-----+------------+---------------------------------- | 23 |Science | What's water? | 42 |Maths | What's 2+2? | 99 |Litt. | Who wrote "Pride and Prejudice"? | 123 |Litt. | Who wrote "On The Road"? | 146 |Maths | What's 2*2? | 599 |Science | You know what's cool? |1042 |Maths | What's the Fibonacci Sequence? |1056 |Maths | What's 42? And so on... (Much more detailed/complex but I'll keep the exemple simple) As you can see, due to technical constraints (MongoDB), my IDs are not linear but I can use them as an increasing suite. So far, my algorithm to ensure two users get a new quizz when they play together is the following: // Take the last played quizzes by P1 and P2 var q_one = player_one.getLastPlayedQuizz('Maths'); var q_two = player_two.getLastPlayedQuizz('Maths'); // If both of them never played in the subject, return first quizz in the list if ((q_one == NULL) && (q_two == NULL)) return QuizzDB.findOne({subject: 'Maths'}); // If one of them never played, play the next quizz for the other player // This quizz is found by asking for the first quizz in the desired subject where // the ID is greater than the last played quizz's ID (if the last played quizz ID // is 42, this will return 146 following the above example database) if (q_one == NULL) return QuizzDB.findOne({subject: 'Maths', ID > q_two}); if (q_two == NULL) return QuizzDB.findOne({subject: 'Maths', ID > q_one}); // And if both of them have a lastPlayedQuizz, we return the next quizz for the // player whose lastPlayedQuizz got the higher ID if (q_one > q_two) return QuizzDB.findOne({subject: 'Maths', ID > q_one}); else return QuizzDB.findOne({subject: 'Maths', ID > q_two}); Now here comes the real problem: Once I get to the end of my database (let's say, P1's last played quizz in 'Maths' is 1056, P2's is 146 and P3 is 1042), following my algorithm, P1's ID is the highest so I ask for the next question in 'Maths' where ID is superior to 1056. There is nothing, so I roll back to the beginning of my quizz list (with a random skipper to avoid having the first question always show up). P1 and P2's last played will then be 42 and they will start fresh from the beginning of the list. However, if P1 (42) plays against P3 (1042), the resulting ID will be 1056...which P1 already played two games ago. Basically, players who just "rolled back" to the beginning of the list will be brought back to the end of the list by players who still haven't rolled back. The rollback WILL happen in the end, but it'll take time and there'll be a "bottleneck" at the beginning and at the end. Thus my question: What would be the best algorith to avoid this bottleneck and ensure players don't get stuck endlessly on the same quizzes? Also bear in mind that I've got some technical constraints: I can't get a random question in a subject (ie: no "QuizzDB.findOne({subject: 'Maths'}).skip(random());"). It's cool to skip on one to twenty records, but the MongoDB documentation warns against skipping too many documents. I would like to avoid building an array of every quizz played by each player and find the next non-played in the database with a $nin. Thanks for your help

    Read the article

  • Performance of pixel shaders vs. SpriteBatch: XNA

    - by ashes999
    Precondition: I read this question/answer about using shaders, or spritebatch, to render and mark a sprite. I need to do something like that. I also have a 2D lighting PoC which I need to write. The way it will work will basically be something like: Draw all the sprites Draw lighting gradients to create a lighting texture Multiply/add the lighting texture to achieve different effects (I use multiple passes of add/multiply the lighting texture to achieve different effects.) My question is really about a generalization: can I say with certainty that pixel shaders are always faster than adding/multiplying textures to the SpriteBatch? Or that adding/multiplying is always faster? Or if it's not generalizable, how do I decide which approach to take, given that I can probably code either of them? (If it matters, I'm using MonoGame 3.0 beta for Windows games)

    Read the article

  • Understanding DeviceContext and Shaders in Direct3D/SlimDX

    - by Carson Myers
    I've been working through this tutorial about drawing triangles with SlimDX, and while it works, I've been trying to structure my program differently than in the tutorial. The tutorial just has everything in the main method, I'm trying to separate components into their own classes. But I'm not sure where certain components belong: namely, contexts and shaders. The tutorial (as it's just rendering one triangle) has one device, one swapchain, one device context and one set of shaders. intuition says that there is only one device/swapchain for one game, but with contexts I don't know. I made a Triangle class and put the vertex stuff in there. Should it also create a context? Should it load its own shaders? Or should I pass some global context and shaders to the triangle class when it is constructed? Or pass the shaders and construct a new context? I'm just getting started with 3D programming, so in addition to answering this question, if anyone knows of a tutorial or article or something about the larger-scale structure of a game, I'd be interested in seeing that as well.

    Read the article

  • Sprite sheet generator

    - by Andrea Tucci
    I need to generate a sprite sheet with squared sprite for a 2D game. How can I generate a sprite sheet where each frame has x = y? The only think I have to do is to "insert" some blank space between sprites (in case y were x in the original sprite). Is there any program that I can use to trasform "irregular" sprite sheets to "squared" sprite sheets? An example of non-squared sprite sheet: http://spriters-resource.com/gameboy_advance/khcom/sheet/1138

    Read the article

  • Triangle Line-Segment Intersection - detecting near misses

    - by Will
    A ray is a very poor approximation of a player! I think approximating a player with a sphere traveling a straight line each game tick will solve my problems of the player intersecting edges of scenery because their line segment missed it yet their own model is not infinitely thin... I have a 3D triangle and a line segment. I have the normal triangle-line-segment intersection code which I admit I have only a woolly grasp of. To model movement and compute collisions of the player I have to determine if a line passes within sphere-radius of a triangle. But I can find no convenient line near-miss intersection code! Here's the classic triangle intersection ### commented ### code with my starting assumptions: function triangle_ray_intersection(a,b,c,ray_origin,ray_dir,ray_radius) { // http://softsurfer.com/Archive/algorithm_0105/algorithm_0105.htm#intersect_RayTriangle%28%29 // get triangle edge vectors and plane normal var u = vec3_sub(b,a); var v = vec3_sub(c,a); var n = vec3_cross(u,v); if(n[0]==0 && n[1]==0 && n[2]==0) return null; // triangle is degenerate var w0 = vec3_sub(ray_origin,a); var j = vec3_dot(n,ray_dir); if(Math.abs(j) < 0.00000001) { //### if parallel, might still pass within ray_radius of it return null; // parallel, disjoint or on plane } var i = -vec3_dot(n,w0); // get intersect point of ray with triangle plane var k = i / j; if(k < 0.0) return null; // ray goes away from triangle //### as its a line segment, k > 1+ray_radius means no intersect var hit = vec3_add(ray_origin,vec3_scale(ray_dir,k)); // intersect point of ray and plane // is I inside T? //### here I'm a bit lost; this is presumably computing barycentric coordinates? var uu = vec3_dot(u,u); var uv = vec3_dot(u,v); var vv = vec3_dot(v,v); var w = vec3_sub(hit,a); var wu = vec3_dot(w,u); var wv = vec3_dot(w,v); var D = uv * uv - uu * vv; var s = (uv * wv - vv * wu) / D; //### therefore, compute if its within ray_radius scaled to the 0..1 of barycentric coordinates? if(s<0.0 || s>1.0) return null; // I is outside T var t = (uv * wu - uu * wv) / D; if(t<0.0 || (s+t)>1.0) return null; // I is outside T //### finally, if it passses a barycentric test it might still be too far //### to a point; must check that its distance from a corner is within ray_radius too if more than one barycentric coord is >1 //### so we have rounded corners... return [hit,n]; // I is in T } Given the distance between the point of plane intersection and each corner, I ought to be able to determine distance at world scale of how far beyond the edge - beyond 1.0 in barycentric coordinates for each axis - that point is... At this point my head explodes! Is this the right track? What's the actual code? UPDATE: you can earn 100 pts on SO if you answer this question there...! How can you determine if a line segment passes within some distance of a triangle?

    Read the article

  • Calculating Delta time , what is wrong?

    - by SteveL
    For 2 days now i am trying to calculate the correct delta time for my game , I am starting to getting crazy since i tried all the solutions that i found on the 5 first google pages... What is wrong? I cant get the correct delta time ,whatever i tried is just not working , the delta goes from 1 to 4 and then back 1 and then to 3 even if i take the averange delta between many frames.Plus the game runs way much faster(i mean the movement) on slow devices than in fast. The game runs on android so the spikes between frames are expected. My code is this: void Game::render() { timesincestart=getTimeMil(); _director->Render(); _director->Update(); float dif=(getTimeMil()-timesincestart);//usally its about 5 milliseconds lastcheck++; sumdelta+=dif; if(lastcheck>20) { sumdelta=sumdelta/20; delta=sumdelta; sumdelta=0; lastcheck=0; } LOGI("delta:%f",delta); }

    Read the article

< Previous Page | 872 873 874 875 876 877 878 879 880 881 882 883  | Next Page >