Search Results

Search found 8262 results on 331 pages for 'optimization algorithm'.

Page 5/331 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• Algorithm to find average position

  - by Simran kaur

  In the given diagram, I have the extreme left and right points, that is -2 and 4 in this case. So, obviously, I can calculate the width which is 6 in this case. What we know: The number of partitions:3 in this case The partition number at at any point i.e which one is 1st,second or third partition (numbered starting from left) What I want: The position of the purple line drawn which is positio of average of a particular partition So, basically I just want a generalized formula to calculate position of the average at any point.

  Read the article

• 2D/Isometric map algorithm

  - by Icarus Cocksson

  First of all, I don't have much experience on game development but I do have experience on development. I do know how to make a map, but I don't know if my solution is a normal or a hacky solution. I don't want to waste my time coding things, and realise they're utterly crap and lose my motivation. Let's imagine the following map. (2D - top view - A square) X: 0 to 500 Y: 0 to 500 My character currently stands at X:250,Y:400, somewhere near center of 100px above bottom and I can control him with my keyboard buttons. LEFT button does X--, UP button does Y-- etc. This one is kid's play. I'm asking this because I know there are some engines that automate this task. For example, games like Diablo 3 uses an engine. You can pretty much drag drop a rock to map, and it is automatically being placed here - making player unable to pass through/detect the collision. But what the engine exactly does in the background? Generates a map like mine, places a rock at the center, and checks it like: unmovableObjects = array('50,50'); //we placed a rock at 50,50 location if(Map.hasUnmovableObject(CurrentPlayerX, CurrentPlayerY)) { //unable to move } else { //able to move } My question is: Is this how 2D/Isometric maps are being generated or there is a different and more complex logic behind them?

  Read the article

• Help with this optimization

  - by Milo

  Here is what I do: I have bitmaps which I draw into another bitmap. The coordinates are from the center of the bitmap, thus on a 256 by 256 bitmap, an object at 0.0,0.0 would be drawn at 128,128 on the bitmap. I also found the furthest extent and made the bitmap size 2 times the extent. So if the furthest extent is 200,200 pixels, then the bitmap's size is 400,400. Unfortunately this is a bit inefficient. If a bitmap needs to be drawn at 500,500 and the other one at 300,300, then the target bitmap only needs to be 200,200 in size. I cannot seem to find a correct way to draw in the components correctly with a reduced size. I figure out the target bitmap size like this: float AvatarComposite::getFloatWidth(float& remainder) const { float widest = 0.0f; float widestNeg = 0.0f; for(size_t i = 0; i < m_components.size(); ++i) { if(m_components[i].getSprite() == NULL) { continue; } float w = m_components[i].getX() + ( ((m_components[i].getSprite()->getWidth() / 2.0f) * m_components[i].getScale()) / getWidthToFloat()); float wn = m_components[i].getX() - ( ((m_components[i].getSprite()->getWidth() / 2.0f) * m_components[i].getScale()) / getWidthToFloat()); if(w > widest) { widest = w; } if(wn > widest) { widest = wn; } if(w < widestNeg) { widestNeg = w; } if(wn < widestNeg) { widestNeg = wn; } } remainder = (2 * widest) - (widest - widestNeg); return widest - widestNeg; } And here is how I position and draw the bitmaps: int dw = m_components[i].getSprite()->getWidth() * m_components[i].getScale(); int dh = m_components[i].getSprite()->getHeight() * m_components[i].getScale(); int cx = (getWidth() + (m_remainderX * getWidthToFloat())) / 2; int cy = (getHeight() + (m_remainderY * getHeightToFloat())) / 2; cx -= m_remainderX * getWidthToFloat(); cy -= m_remainderY * getHeightToFloat(); int dx = cx + (m_components[i].getX() * getWidthToFloat()) - (dw / 2); int dy = cy + (m_components[i].getY() * getHeightToFloat()) - (dh / 2); g->drawScaledSprite(m_components[i].getSprite(),0.0f,0.0f, m_components[i].getSprite()->getWidth(),m_components[i].getSprite()->getHeight(),dx,dy, dw,dh,0); I basically store the difference between the original 2 * longest extent bitmap and the new optimized one, then I translate by that much which I would think would cause me to draw correctly but then some of the components look cut off. Any insight would help. Thanks

  Read the article

• Need ideas for an algorithm to draw irregular blotchy shapes

  - by Yttermayn

  I'm looking to draw irregular shapes on an x,y grid, and I'd like to come up with a simple, fast method if possible. My only idea so far is to draw a bunch of circles of random sizes very near each other, but at a random distance apart from a more or less central coordinate, then fill in any blank spaces. I realize this is a clunky, inelegant method, hopefully it will give you a rough idea of the kinds of rounded, random blotchy shapesI'm shooting for. Please suggest methods to accomplish this, I'm not so much interested in code. I can noodle that part out myself. Thanks!

  Read the article

• What's wrong with this turn to face algorithm?

  - by Chan

  I implement a torpedo object that chases a rotating planet. Specifically, it will turn toward the planet each update. Initially my implement was: void move() { vector3<float> to_target = target - get_position(); to_target.normalize(); position += (to_target * speed); } which works perfectly for torpedo that is a solid sphere. Now my torpedo is actually a model, which has a forward vector, so using this method looks odd because it doesn't actually turn toward but jump toward. So I revised it a bit to get, double get_rotation_angle(vector3<float> u, vector3<float> v) const { u.normalize(); v.normalize(); double cosine_theta = u.dot(v); // domain of arccosine is [-1, 1] if (cosine_theta > 1) { cosine_theta = 1; } if (cosine_theta < -1) { cosine_theta = -1; } return math3d::to_degree(acos(cosine_theta)); } vector3<float> get_rotation_axis(vector3<float> u, vector3<float> v) const { u.normalize(); v.normalize(); // fix linear case if (u == v || u == -v) { v[0] += 0.05; v[1] += 0.0; v[2] += 0.05; v.normalize(); } vector3<float> axis = u.cross(v); return axis.normal(); } void turn_to_face() { vector3<float> to_target = (target - position); vector3<float> axis = get_rotation_axis(get_forward(), to_target); double angle = get_rotation_angle(get_forward(), to_target); double distance = math3d::distance(position, target); gl_matrix_mode(GL_MODELVIEW); gl_push_matrix(); { gl_load_identity(); gl_translate_f(position.get_x(), position.get_y(), position.get_z()); gl_rotate_f(angle, axis.get_x(), axis.get_y(), axis.get_z()); gl_get_float_v(GL_MODELVIEW_MATRIX, OM); } gl_pop_matrix(); move(); } void move() { vector3<float> to_target = target - get_position(); to_target.normalize(); position += (get_forward() * speed); } The logic is simple, I find the rotation axis by cross product, the angle to rotate by dot product, then turn toward the target position each update. Unfortunately, it looks extremely odds since the rotation happens too fast that it always turns back and forth. The forward vector for torpedo is from the ModelView matrix, the third column A: MODELVIEW MATRIX -------------------------------------------------- R U A T -------------------------------------------------- 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 -------------------------------------------------- Any suggestion or idea would be greatly appreciated.

  Read the article

• Algorithm to shift the car

  - by Simran kaur

  I have a track that can be divided into n number of tracks and a car as GamObject. The track has transforms such that some part of the track's width lies in negative x axis and other in positive. Requirement: One move should cross one track. On every move(left or right), I want the car to reach exact centre of the next track on either sides i.e left or right. My code: Problem: : Because of negative values , somewhere I am missing out something that is making car move not in desirable positions and that's because of negative values only. variable tracks is the number of tracks the whole track is divided in. variable dist is the total width of the complete track. On left movement: if (Input.GetKeyDown (KeyCode.LeftArrow)) { if (this.transform.position.x < r.renderer.bounds.min.x + box.size.x) { this.transform.position = new Vector3 (r.renderer.bounds.min.x + Mathf.FloorToInt(box.size.x), this.transform.position.y, this.transform.position.z); } else { int tracknumber = Mathf.RoundToInt(dist - transform.position.x)/tracks; float averagedistance = (tracknumber*(dist/tracks) + (tracknumber-1)*(dist/tracks))/2; if(transform.position.x > averagedistoftracks) { amountofmovement = amountofmovement + (transform.position.x - averagedistance); } else { amountofmovement = amountofmovement - (averagedistance - transform.position.x); } this.transform.position = new Vector3 (this.transform.position.x - amountofmovement, this.transform.position.y, this.transform.position.z); } }

  Read the article

• Pixel alignment algorithm

  - by user42325

  I have a set of square blocks, I want to draw them in a window. I am sure the coordinates calculation is correct. But on the screen, some squares' edge overlap with other, some are not. I remember the problem is caused by accuracy of pixels. I remember there's a specific topic related to this kind of problem in 2D image rendering. But I don't remember what exactly it is, and how to solve it. Look at this screenshot. Each block should have a fixed width margin. But in the image, the vertical white line have different width.Though, the horizontal lines looks fine.

  Read the article

• Search Engine Optimization (SEO) Tips - Content Optimization

  Content can be called with a written text and images that you add to your website. It is clear that any web developer would put both text and graphics on the website.

  Read the article

• Code optimization on minutes pr hour calculation

  - by corger

  Hi All, The following code takes a timeframe in minutes since midnight and creates an array with minutes pr hour. But, it's slow. Any better suggestions out there? (no, changing language is not an option :-) ) Const clDeparture As Long = 123 Const clArrival As Long = 233 Dim lHour As Long Dim lMinute As Long Dim alHour(25) As Long For lMinute = 0 To 1440 If lMinute >= clDeparture And lMinute < clArrival Then alHour(Int(lMinute / 60)) = alHour(Int(lMinute / 60)) + 1 End If Next The array should now contain: (0,0) (1,0) (2,57) (3,53) (4,0) ..... Regards

  Read the article

• Optimize SQL databases by adding index columns

  - by Viktor Sehr

  This might be implementation specific so the question regards how SQL databases is generally implemented. Say I have a database looking like this; Product with columns [ProductName] [Price] [Misc] [Etc] Order with columns [OrderID] [ProductName] [Quantity] [Misc] [Etc] ProductName is primary key of Product, of some string type and unique. OrderID is primary key and of some integer type, and ProductName being a foreign key. Say I change the primary key of Product to a new column of integer type ie [ProductID] Would this reduce the database size and optimize lookups joining these two tables (and likewise operations), or are these optimizations performed automatically by (most/general/main) SQL database implementations?

  Read the article

• The MYSTERY SPIRAL

  - by CVS26

  Problem statement: Given a integer N, print N*N numbers in a N x N spiral Detailed problem description: http://2600hertz.wordpress.com/2010/03/20/the-mystery-spiral/ Solution: Recently posted the following code. (managed to compress it into as few as 99 lines...) //File : spiral.c // //INPUT : Size of spiral (N) //OUTPUT : Numbers printed in a N x N spiral #include <stdio.h> #include <conio.h> #include <stdlib.h> void main() { int N; clrscr(); //get input no. N printf("\nEnter size of Matrix: "); scanf("%d",&N); //Allocate reqd. memory int* matrix_ptr= (int*)malloc(N*N); //Filling the Matrix spirally int curr_val=N*N; int* curr_ptr=matrix_ptr; int curr_level=N; while(curr_level>1) { //curr_level-1 elements horizontally //from left to right for(int x=0;x<curr_level-1;x++) { *curr_ptr=curr_val; curr_val--; curr_ptr++; } //curr_level-1 elements vertically //from top to bottom for(int y=0;y<curr_level-1;y++) { *curr_ptr=curr_val; curr_val--; curr_ptr+=N; } //curr_level-1 elements horizontally //from right to left for(int z=0;z<curr_level-1;z++) { *curr_ptr=curr_val; curr_val--; curr_ptr--; } //curr_level-1 element vertically //from bottom to top for(int w=0;w<curr_level-1;w++) { *curr_ptr=curr_val; curr_val--; curr_ptr-=N; } //Next curr_ptr+=N+1; curr_level-=2; } *curr_ptr=curr_val; //routine to print the matrix printf("\n\n\n\n\n"); for( int i=0;i<N;i++) { for( int j=0;j<N;j++) { printf("%d\t",*(matrix_ptr+(i*N+j))); } printf("\n"); } getch(); } Please comment on further optimisations (if any)...

  Read the article

• Unity3D draw call optimization : static batching VS manually draw mesh with MaterialPropertyBlock

  - by Heisenbug

  I've read Unity3D draw call batching documentation. I understood it, and I want to use it (or something similar) in order to optimize my application. My situation is the following: I'm drawing hundreds of 3d buildings. Each building can be represented using a Mesh (or a SubMesh for each building, but I don't thing this will affect performances) Each building can be textured with several combinations of texture patterns(walls, windows,..). Textures are stored into an Atlas for optimizaztion (see Texture2d.PackTextures) Texture mapping and facade pattern generation is done in fragment shader. The shader can be the same (except for few values) for all buildings, so I'd like to use a sharedMaterial in order to optimize parameters passed to the GPU. The main problem is that, even if I use an Atlas, share the material, and declare the objects as static to use static batching, there are few parameters(very fews, it could be just even a float I guess) that should be different for every draw call. I don't know exactly how to manage this situation using Unity3D. I'm trying 2 different solutions, none of them completely implemented. Solution 1 Build a GameObject for each building building (I don't like very much the overhead of a GameObject, anyway..) Prepare each GameObject to be static batched with StaticBatchingUtility.Combine. Pack all texture into an atlas Assign the parent game object of combined batched objects the Material (basically the shader and the atlas) Change some properties in the material before drawing an Object The problem is the point 5. Let's say I have to assign a different id to an object before drawing it, how can I do this? If I use a different material for each object I can't benefit of static batching. If I use a sharedMaterial and I modify a material property, all GameObjects will reference the same modified variable Solution 2 Build a Mesh for every building (sounds better, no GameObject overhead) Pack all textures into an Atlas Draw each mesh manually using Graphics.DrawMesh Customize each DrawMesh call using a MaterialPropertyBlock This would solve the issue related to slightly modify material properties for each draw call, but the documentation isn't clear on the following point: Does several consecutive calls to Graphic.DrawMesh with a different MaterialPropertyBlock would cause a new material to be instanced? Or Unity can understand that I'm modifying just few parameters while using the same material and is able to optimize that (in such a way that the big atlas is passed just once to the GPU)?

  Read the article

• SQL SERVER – Stored Procedure Optimization Tips – Best Practices

  - by pinaldave

  We will go over how to optimize Stored Procedure with making simple changes in the code. Please note there are many more other tips, which we will cover in future articles. Include SET NOCOUNT ON statement: With every SELECT and DML statement, the SQL server returns a message that indicates the number of affected rows [...]

  Read the article

• Looking for literature about graphics pipeline optimization

  - by zacharmarz

  I am looking for some books, articles or tutorials about graphics architecture and graphics pipeline optimizations. It shouldn't be too old (2008 or newer) - the newer, the better. I have found something in [Optimising the Graphics Pipeline, NVIDIA, Koji Ashida] - too old, [Real-time rendering, Akenine Moller], [OpenGL Bindless Extensions, NVIDIA, Jeff Bolz], [Efficient multifragment effects on graphics processing units, Louis Frederic Bavoil] and some internet discussions. But there is not too much information and I want to read more. It should contain something about application, driver, memory and shader units communication and data transfers. About vertices and attributes. Also pre and post T&L cache (if they still exist in nowadays architectures) etc. I don't need anything about textures, frame buffers and rasterization. It can also be about OpenGL (not about DirecX) and optimizing extensions (not old extensions like VBOs, but newer like vertex_buffer_unified_memory).

  Read the article

• Smoothing found path on grid

  - by Denis Ermolin

  I implemented several approaches such as A* and Potential fields for my tower defense game. But I want smooth paths, first I tried to find path on very small grid ( 5x5 pixels per tile) but it is extremly slow. I found nice video showing an RTS demo where paths are found on big grid but units dont move from each cell's center to center. How do I implement such behavior? Some examples would be great.

  Read the article

• Wikipedia A* pathfinding algorithm takes a lot of time

  - by Vee

  I've successfully implemented A* pathfinding in C# but it is very slow, and I don't understand why. I even tried not sorting the openNodes list but it's still the same. The map is 80x80, and there are 10-11 nodes. I took the pseudocode from here Wikipedia And this is my implementation: public static List<PGNode> Pathfind(PGMap mMap, PGNode mStart, PGNode mEnd) { mMap.ClearNodes(); mMap.GetTile(mStart.X, mStart.Y).Value = 0; mMap.GetTile(mEnd.X, mEnd.Y).Value = 0; List<PGNode> openNodes = new List<PGNode>(); List<PGNode> closedNodes = new List<PGNode>(); List<PGNode> solutionNodes = new List<PGNode>(); mStart.G = 0; mStart.H = GetManhattanHeuristic(mStart, mEnd); solutionNodes.Add(mStart); solutionNodes.Add(mEnd); openNodes.Add(mStart); // 1) Add the starting square (or node) to the open list. while (openNodes.Count > 0) // 2) Repeat the following: { openNodes.Sort((p1, p2) => p1.F.CompareTo(p2.F)); PGNode current = openNodes[0]; // a) We refer to this as the current square.) if (current == mEnd) { while (current != null) { solutionNodes.Add(current); current = current.Parent; } return solutionNodes; } openNodes.Remove(current); closedNodes.Add(current); // b) Switch it to the closed list. List<PGNode> neighborNodes = current.GetNeighborNodes(); double cost = 0; bool isCostBetter = false; for (int i = 0; i < neighborNodes.Count; i++) { PGNode neighbor = neighborNodes[i]; cost = current.G + 10; isCostBetter = false; if (neighbor.Passable == false || closedNodes.Contains(neighbor)) continue; // If it is not walkable or if it is on the closed list, ignore it. if (openNodes.Contains(neighbor) == false) { openNodes.Add(neighbor); // If it isn’t on the open list, add it to the open list. isCostBetter = true; } else if (cost < neighbor.G) { isCostBetter = true; } if (isCostBetter) { neighbor.Parent = current; // Make the current square the parent of this square. neighbor.G = cost; neighbor.H = GetManhattanHeuristic(current, neighbor); } } } return null; } Here's the heuristic I'm using: private static double GetManhattanHeuristic(PGNode mStart, PGNode mEnd) { return Math.Abs(mStart.X - mEnd.X) + Math.Abs(mStart.Y - mEnd.Y); } What am I doing wrong? It's an entire day I keep looking at the same code.

  Read the article

• How to generate portal zones?

  - by Meow

  I'm developing a portal-based scene manager. Basically all it does is to check the portals against the camera frustum, and render their associated portal zones accordingly. Is there any way my editor can generate portal zones automatically with the user having to set the portals themselves only? For example, the Max Payne 1/2 engine ("Max-FX") only required to set the portal quads, unlike the C4 engine where you also have to explicitly set the portal zones.

  Read the article

• Form development optimization

  - by Juan

  Like many web developers I do forms all the time. I found myself doing the same all the time: placing input fields, assigning a name to each, ajax the form, then create the PHP which involves to assign a PHP var to each $_REQUEST['var'], escape and validate data, build the html and emailing the results. So I found that 70% of the work is duplicated but I just can't duplicate a page and change the fields. I end up wasting more time reformatting, deleting and adding different fields than creating from scratch. I started planing to program a "list of IDs to html+php" converter in which I'd input all the IDs and this would output the basic html and php. Then I thought: there's got to be thousands of developers that go through this, I'd be reinventing the wheel. So this is my question, I'm trying to find that wheel that somebody must have invented already. I found this: http://www.trirand.com/blog/jqform/ which does more or less what I'm looking for but it's an expensive solution and it has too much functionality for what I'd be using it. Which tools do you use to optimize repetitive task about HTML and PHP?

  Read the article

• GPU optimization question: pre-computed or procedural?

  - by Jay

  Good morning, I'm learning shader program and need some general direction. I want to add noise to my laser beam (like this). Which is the best way to handle it? I could pre-compute an image and pass it to the shader. I could then use the image to change the opacity and easily animate the smoke by changing the offset of the texture lookup. I could also generate noise in the shader and do the same thing the texture was used for. Is it generally better to avoid I/O to the graphics card or the opposite? Thanks!

  Read the article

• Can I use a plaintext diff algorithm for tracking XML changes?

  - by rinogo

  Hi all! Interesting question for you here. I'm working in Flex/AS3 on (for simplicity) an XML editor. I need to provide undo/redo functionality. Of course, one solution is to store the entire source text with each edit. However, to conserve memory, I'd like to store the diffs instead (these diffs will also be used to transmit updates to the server for auto-saving). My question is - can I use a plaintext diff algorithm for tracking these XML changes? My research on the internet indicates that I cannot do so. However, I'm obviously missing something. Plaintext diff provides functionality that is purportedly: diff(text, text') - diffs patch(text, diffs) - text' XML is simply text, so why can't I just use diff() and patch() to transform the text reliably? For example: Let's say that I'm a poet. When I write poetry, I use lots of funky punctuation... You know, like <, /, and . (You might see where I'm going with this...) If I'm writing my poetry in an application that uses diffs to provide undo/redo functionality, does my poetry become garbled when I undo/redo my edits? It's just text! Why does it make a difference to the algorithm? I obviously don't get something here...Thanks for explaining! :) -Rich

  Read the article

• O(log n) algorithm for computing rank of union of two sorted lists?

  - by Eternal Learner

  Given two sorted lists, each containing n real numbers, is there a O(log?n) time algorithm to compute the element of rank i (where i coresponds to index in increasing order) in the union of the two lists, assuming the elements of the two lists are distinct? I can think of using a Merge procedure to merge the 2 lists and then find the A[i] element in constant time. But the Merge would take O(n) time. How do we solve it in O(log n) time?

  Read the article

• O(log n) algorithm to find the element having rank i in union of pre-sorted lists

  - by Eternal Learner

  Given two sorted lists, each containing n real numbers, is there a O(log?n) time algorithm to compute the element of rank i (where i coresponds to index in increasing order) in the union of the two lists, assuming the elements of the two lists are distinct? I can think of using a Merge procedure to merge the 2 lists and then find the A[i] element in constant time. But the Merge would take O(n) time. How do we solve it in O(log n) time?

  Read the article

• How to investigate if opencl is possible for an algorithm

  - by Marnix

  I have a heavy-duty algorithm in C# that takes two large Bitmaps of about 10000x5000 and performs photo and ray collision operations on a 3D model to map photos on the 3D model. I would like to know if it is possible to convert such an algorithm to OpenCL to optimize parallel operations during the algorithm. But before asking you to go into the details of the algorithm, I would like to know how I can investigate if my algorithm is convertible to OpenCL. I am not experienced in OpenCL and I would like to know if it is worth it to get into it and learn how it works. Are there things I have to look for that will definitely not work on the graphics card? (for-loops, recursion) Update: My algorithm goes something like: foreach photo split the photo in 64x64 blocks foreach block cast a ray from the camera to the 3D model foreach triangle in 3D model perform raycheck

  Read the article

• GRAPH PROBLEM: find an algorithm to determine the shortest path from one point to another in a recta

  - by newba

  I'm getting such an headache trying to elaborate an appropriate algorithm to go from a START position to a EXIT position in a maze. For what is worth, the maze is rectangular, maxsize 500x500 and, in theory, is resolvable by DFS with some branch and bound techniques ... 10 3 4 7 6 3 3 1 2 2 1 0 2 2 2 4 2 2 5 2 2 1 3 0 2 2 2 2 1 3 3 4 2 3 4 4 3 1 1 3 1 2 2 4 2 2 1 Output: 5 1 4 2 Explanation: Our agent looses energy every time he gives a step and he can only move UP, DOWN, LEFT and RIGHT. Also, if the agent arrives with a remaining energy of zero or less, he dies, so we print something like "Impossible". So, in the input 10 is the initial agent's energy, 3 4 is the START position (i.e. column 3, line 4) and we have a maze 7x6. Think this as a kind of labyrinth, in which I want to find the exit that gives the agent a better remaining energy (shortest path). In case there are paths which lead to the same remaining energy, we choose the one which has the small number of steps, of course. I need to know if a DFS to a maze 500x500 in the worst case is feasible with these limitations and how to do it, storing the remaining energy in each step and the number of steps taken so far. The output means the agent arrived with remaining energy= 5 to the exit pos 1 4 in 2 steps. If we look carefully, in this maze it's also possible to exit at pos 3 1 (column 3, row 1) with the same energy but with 3 steps, so we choose the better one. With these in mind, can someone help me some code or pseudo-code? I have troubles working this around with a 2D array and how to store the remaining energy, the path (or number of steps taken)....

  Read the article

• Fast block placement algorithm, advice needed?

  - by James Morris

  I need to emulate the window placement strategy of the Fluxbox window manager. As a rough guide, visualize randomly sized windows filling up the screen one at a time, where the rough size of each results in an average of 80 windows on screen without any window overlapping another. It is important to note that windows will close and the space that closed windows previously occupied becomes available once more for the placement of new windows. The window placement strategy has three binary options: Windows build horizontal rows or vertical columns (potentially) Windows are placed from left to right or right to left Windows are placed from top to bottom or bottom to top Why is the algorithm a problem? It needs to operate to the deadlines of a real time thread in an audio application. At this moment I am only concerned with getting a fast algorithm, don't concern yourself over the implications of real time threads and all the hurdles in programming that that brings. So far I have two choices which I have built loose prototypes for: 1) A port of the Fluxbox placement algorithm into my code. The problem with this is, the client (my program) gets kicked out of the audio server (JACK) when I try placing the worst case scenario of 256 blocks using the algorithm. This algorithm performs over 14000 full (linear) scans of the list of blocks already placed when placing the 256th window. 2) My alternative approach. Only partially implemented, this approach uses a data structure for each area of rectangular free unused space (the list of windows can be entirely separate, and is not required for testing of this algorithm). The data structure acts as a node in a doubly linked list (with sorted insertion), as well as containing the coordinates of the top-left corner, and the width and height. Furthermore, each block data structure also contains four links which connect to each immediately adjacent (touching) block on each of the four sides. IMPORTANT RULE: Each block may only touch with one block per side. The problem with this approach is, it's very complex. I have implemented the straightforward cases where 1) space is removed from one corner of a block, 2) splitting neighbouring blocks so that the IMPORTANT RULE is adhered to. The less straightforward case, where the space to be removed can only be found within a column or row of boxes, is only partially implemented - if one of the blocks to be removed is an exact fit for width (ie column) or height (ie row) then problems occur. And don't even mention the fact this only checks columns one box wide, and rows one box tall. I've implemented this algorithm in C - the language I am using for this project (I've not used C++ for a few years and am uncomfortable using it after having focused all my attention to C development, it's a hobby). The implementation is 700+ lines of code (including plenty of blank lines, brace lines, comments etc). The implementation only works for the horizontal-rows + left-right + top-bottom placement strategy. So I've either got to add some way of making this +700 lines of code work for the other 7 placement strategy options, or I'm going to have to duplicate those +700 lines of code for the other seven options. Neither of these is attractive, the first, because the existing code is complex enough, the second, because of bloat. The algorithm is not even at a stage where I can use it in the real time worst case scenario, because of missing functionality, so I still don't know if it actually performs better or worse than the first approach. What else is there? I've skimmed over and discounted: Bin Packing algorithms: their emphasis on optimal fit does not match the requirements of this algorithm. Recursive Bisection Placement algorithms: sounds promising, but these are for circuit design. Their emphasis is optimal wire length. Both of these, especially the latter, all elements to be placed/packs are known before the algorithm begins. I need an algorithm which works accumulatively with what it is given to do when it is told to do it. What are your thoughts on this? How would you approach it? What other algorithms should I look at? Or even what concepts should I research seeing as I've not studied computer science/software engineering? Please ask questions in comments if further information is needed. [edit] If it makes any difference, the units for the coordinates will not be pixels. The units are unimportant, but the grid where windows/blocks/whatever can be placed will be 127 x 127 units.

  Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >