Search Results

Search found 16473 results on 659 pages for 'game logic'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 173/659 | < Previous Page | 169 170 171 172 173 174 175 176 177 178 179 180  | Next Page >

  • Google+ Platform Office Hours for May 2nd, 2012: Hanging out with the Tabletop Forge team

    Google+ Platform Office Hours for May 2nd, 2012: Hanging out with the Tabletop Forge team This week we met with Charles Jaimet, Joshuha Owen and Fraser Cain of the Tabletop Forge team. They showed us their hangout app and shared their experience. Discussion this session on Google+: goo.gl You can learn more about our office hours here: goo.gl Here are some notable moments in this session: 1:50 - Charles explains Tabletop Forge 6:12 - Tabletop Forge Demo begins 7:45 - How do you prevent cheating on dice rolls? 14:07 - A discussion about trust in tabletop gaming 14:57 - Upcoming feature - Fog of war 24:06 - What are some challenges with the Hangouts API that you've overcome? 27:10 - It'd be cool to play a game with a separate on air game view 31:08 - Comments as a source of game material 31:58 - What else is on the roadmap for Tabletop Forge? 35:52 - Will there be a Kickstarter for Tabletop Forge? 36:42 - What do you think about saving game logs to places like Google Drive or Google Docs? 39:07 - The 7 sided die is not something possible in reality. In what other ways have you gone beyond the limits of the physical table top? 43:11 - What was your first game? From: GoogleDevelopers Views: 2401 23 ratings Time: 46:43 More in Science & Technology

    Read the article

  • Why is my ruby application running faster the second time?

    - by Omega
    I'm creating a Ruby game using the Gosu framework. All good. Sometimes, when I run the game, it has some kind of slow startup, and probably it will be rather slow during the whole game. So I close it and... open it again. It is very likely that it will startup quickly and the whole game will run smoothly and fast. Why is that? What is this phenomenon? Is it faster because of some cache stored or whatever since the first run? (But why would cache be stored? If the app dies, I would expect no references at all etc...) Ruby, Windows 7.

    Read the article

  • what do i have to do when using libraries with BSD license?

    - by androidmaster
    I am making a game using Lwjgl and this is their license. What I don't understand is what must I do? I plan on making a game and distributing it, not the source code just the .jar file and maybe sell it for a few dollars. It said that I must retain the copyright, so would that mean I must include the doc folder that the library comes with in the jar or do I have to make something in-game like credits and say "made with lwjgl"?

    Read the article

  • Name of the Countdown Numbers round problem - and algorithmic solutions?

    - by Dai
    For the non-Brits in the audience, there's a segment of a daytime game-show where contestants have a set of 6 numbers and a randomly generated target number. They have to reach the target number using any (but not necessarily all) of the 6 numbers using only arithmetic operators. All calculations must result in positive integers. An example: Youtube: Countdown - The Most Extraordinary Numbers Game Ever? A detailed description is given on Wikipedia: Countdown (Game Show) For example: The contentant selects 6 numbers - two large (possibilities include 25, 50, 75, 100) and four small (numbers 1 .. 10, each included twice in the pool). The numbers picked are 75, 50, 2, 3, 8, 7 are given with a target number of 812. One attempt is (75 + 50 - 8) * 7 - (3 * 2) = 813 (This scores 7 points for a solution within 5 of the target) An exact answer would be (50 + 8) * 7 * 2 = 812 (This would have scored 10 points exactly matching the target). Obviously this problem has existed before the advent of TV, but the Wikipedia article doesn't give it a name. I've also saw this game at a primary school I attended where the game was called "Crypto" as an inter-class competition - but searching for it now reveals nothing. I took part in it a few times and my dad wrote an Excel spreadsheet that attempted to brute-force the problem, I don't remember how it worked (only that it didn't work, what with Excel's 65535 row limit), but surely there must be an algorithmic solution for the problem. Maybe there's a solution that works the way human cognition does (e.g. in-parallel to find numbers 'close enough', then taking candidates and performing 'smaller' operations).

    Read the article

  • How do I run WarCraft Frozen Throne (DOTA)?

    - by DarKoza
    I am Using Linux for the very first time And i have one question. Dunno if it will be answered,but i hope so.. I have fujitsu ah 530 with intergrated video card(INTEL HD) so can i play my fav game on linux? And how to do it? I installed it via Wine,but when i am starting the game with It,the game windows shows soooo poor,its unplayable,i can take i screenshot. Here's a screenshot of what I'm experiencing:

    Read the article

  • What are some methods for pulling information and interacting with flash games?

    - by Xploit
    In general, how should I approach interacting with a flash game pragmatically? The flash game is online and I would like to be able to pull information from the game, make computations, and send the appropriate keystrokes back to the flash game? I'm having difficult deciding how to begin. Any specific libraries or languages that you feel would be best for accomplishing this task? I would like it to be as fast as possible. Are there ways of doing this without taking screen shots and simulating keyboard presses?

    Read the article

  • Get started with Farseer Physics 2.1.3 in Silverlight 3

    As a powerful RIA development tool, Microsoft Silverlight is being more widely used to develop data-driven business and game applications. As a famous 2D game engine, the Farseer Physics Engine supports a wide range of platforms such as Microsoft's XNA, Silverlight, WPF, and Vanilla .NET. This article aims to serve as an elementary tutorial to Silverlight 2D beginners. Three demos are given to gradually lead you into a more and more complex and practical game environment.

    Read the article

  • Ruby using the Gosu framework: why it runs slow first time?

    - by Omega
    I'm creating a Ruby game using the Gosu framework. All good. Sometimes, when I run the game, it has some kind of slow startup, and probably it will be rather slow during the whole game. So I close it and... open it again. It is very likely that it will startup quickly and the whole game will run smoothly and fast. Why is that? What is this phenomenon? Is it faster because of some cache stored or whatever since the first run? (But why would cache be stored? If the app dies, I would expect no references at all etc...) Ruby, Windows 7.

    Read the article

  • SFML: Generate a background image

    - by BlackMamba
    I want to generate a background, which is used in the game, on every instance of the game based on certain conditions. To do so, I'm using a sf::RenderTexture and a sf::Texture like this: sf::RenderTexture image; std::vector<sf::Texture> textures; sf::Texture texture; // instantiating the vector of textures and the image not shown here for (int i = 0; i < certainSize; ++i) { if(certainContition) { texture.setTexture("file"); texture.setPosition(pos1, pos2); } else { ... } image.draw(texture); } The point here is that I draw single textures on a sf::RenderTexture, but because textures always are on the graphic cards memory, I can't exceed a certain map size which I have to. I also considered using an sf::Image, but I can't find a way to draw an image (i.e. a texture) to it. The third way I found was using an sf::VertexArray, but this seems to be a bit too low-level for my rather simple purposes. So is there a common way to dynamically generate a background image based on other existing images?

    Read the article

  • SDL2 sprite batching and texture atlases

    - by jms
    I have been programming a 2D game in C++, using the SDL2 graphics API for rendering. My game concept currently features effects that could result in even tens of thousands of sprites being drawn simultaneously to the screen. I'd like to know what can be done for increasing rendering efficiency if the need arises, preferably using the SDL2 API only. I have previously given a quick look at OpenGL-based 2D rendering, and noticed that SDL2 lacks a command like int SDL_RenderCopyMulti(SDL_Renderer* renderer, SDL_Texture* texture, const SDL_Rect* srcrects, SDL_Rect* dstrects, int count) Which would permit SDL to benefit from two common techniques used for efficient 2D graphics: Texture batching: Sorting sprites by the texture used, and then simultaneously rendering as many sprites that use the same texture as possible, changing only the source area on the texture and the destination area on the render target between sprites. This allows the encapsulation of the whole operation in a single GPU command, reducing the overhead drastically from multiple distinct calls. Texture atlases: Instead of creating one texture for each frame of each animation of each sprite, combining multiple animations and even multiple sprites into a single large texture. This lessens the impact of changing the current texture when switching between sprites, as the correct texture is often ready to be used from the previous draw call. Furthemore the GPU is optimized for handling large textures, in contrast to the many tiny textures typically used for sprites. My question: Would SDL2 still get somewhat faster from any rudimentary sprite sorting or from combining multiple images into one texture thanks to automatic video driver optimizations? If I will encounter performance issues related to 2D rendering in the future, will I be forced to switch to OpenGL for lower level control over the GPU? Edit: Are there any plans to include such functionality in the near future?

    Read the article

  • "const char *" is incompatible with parameter of type "LPCWSTR" error

    - by N0xus
    I'm trying to incorporate some code from Programming an RTS Game With Direct3D into my game. Before anyone says it, I know the book is kinda old, but it's the particle effects system he creates that I'm trying to use. With his shader class, he intialise it thusly: void SHADER::Init(IDirect3DDevice9 *Dev, const char fName[], int typ) { m_pDevice = Dev; m_type = typ; if(m_pDevice == NULL)return; // Assemble and set the pixel or vertex shader HRESULT hRes; LPD3DXBUFFER Code = NULL; LPD3DXBUFFER ErrorMsgs = NULL; if(m_type == PIXEL_SHADER) hRes = D3DXCompileShaderFromFile(fName, NULL, NULL, "Main", "ps_2_0", D3DXSHADER_DEBUG, &Code, &ErrorMsgs, &m_pConstantTable); else hRes = D3DXCompileShaderFromFile(fName, NULL, NULL, "Main", "vs_2_0", D3DXSHADER_DEBUG, &Code, &ErrorMsgs, &m_pConstantTable); } How ever, this generates the following error: Error 1 error C2664: 'D3DXCompileShaderFromFileW' : cannot convert parameter 1 from 'const char []' to 'LPCWSTR' The compiler states the issue is with fName in the D3DXCompileShaderFromFile line. I know this has something to do with the character set, and my program was already running with a Unicode Character set on the go. I read that to solve the above problem, I need to switch to a multi-byte character set. But, if I do that, I get other errors in my code, like so: Error 2 error C2664: 'D3DXCreateEffectFromFileA' : cannot convert parameter 2 from 'const wchar_t *' to 'LPCSTR' With it being accredited to the following line of code: if(FAILED(D3DXCreateEffectFromFile(m_pD3DDevice9,effectFileName.c_str(),NULL,NULL,0,NULL,&m_pCurrentEffect,&pErrorBuffer))) This if is nested within another if statement checking my effectmap list. Though it is the FAILED word with the red line. Like wise I get the another error with the following line of code: wstring effectFileName = TEXT("Sky.fx"); With the error message being: Error 1 error C2440: 'initializing' : cannot convert from 'const char [7]' to 'std::basic_string<_Elem,_Traits,_Ax' If I change it back to a Uni code character set, I get the original (fewer) errors. Leaving as a multi-byte, I get more errors. Does anyone know of a way I can fix this issue?

    Read the article

  • SpriteBatch being drawn outside of Stage?

    - by pyko
    Currently working on my first game, though running into some problems with libgx and screen aspect ratio. What I have is a Stage which contains things like menu buttons etc, and the rest of the game is pretty much sprites being drawn with via SpriteBatch. To avoid having multiple SpriteBatches and cameras, I have re-used the ones that are created when Stage is created. stage = new Stage(WIDTH, HEIGHT, true); // keep aspect ratio batch = stage.getSpriteBatch(); camera = (OrthographicCamera) stage.getCamera(); // move camera so 'active' screen is centred stage.getCamera().translate(-stage.getGutterWidth(), -stage.getGutterHeight(), 0); Anything that is Stage/Actor related is drawn fine - all goes within the aspect ratio adjusted boundaries. The problem I'm having is anything that drawn via SpriteBatch, seems to ignore this viewport that is defined by Stage and can be visible outside of the Stage area. batch.begin(); ... sirWuffles.draw(batch); ... batch.end(); For example, in the above, if Sir Wuffles is generated outside of the defined WIDTH/HEIGHT it might still appear in the "gutters" of the screen. Tried to explain it in the below screenshot. It's an exaggerated screen ratio to make the gutters large. I've also covered most of the gutter area in the blue/cyan rectangle so they are very obvious. Does anyone know what is happening? and how to fix it? Currently, my "fix" is to use ShapeRenderer to draw rectangles that correspond to the gutters on top of the sprites...

    Read the article

  • Matchmaking algorithm with a set of filters

    - by Yuriy Pogrebnyak
    I'm looking for matchmaking algorithm for 1x1 online game. Players must be matched not by their skill or level, as usual, but by some specific filters. Each player sends request, where he specifies some set of parameters (generally, 2-4 parameters). If some parameter is specified, player can be matched only with those who has sent this parameter with exactly the same value, or those who hasn't specified this parameter. I need this algorithm to be thread-safe and preferably fast. It would be great if it'll work for 3-4 or even more parameters, but also I'm looking for algorithm that works with only one parameter (in my case it's game bet). Also I'd appreciate ideas on how to implement or improve this algorithm on my server platform - ASP.NET. One more problem I'm facing is that finding match can't be executed right after user sends request, because if other user sends request before matching for previous is finished, they won't be matched even is they possibly could. So it seems that match finding should be started on schedule, and I need help on how to optimize it and how to choose time interval for starting new match finding. P.S. I've also posted this question on stackoverflow

    Read the article

  • Rendering shadow sprites in cocos2d-x

    - by lukeluke
    I am writing a 2D game with cocos2d-x. I want to put a "shadow" sprite on a background sprite using the equation: MAX(0, Cd*1 - Cs*S) where Cd is the destination color (that is, a background pixel), Cs is the source color (the shadow pixel) , S is the scale factor (between 0 and 1). The MAX() function is used to avoid negative results. This is a lighting effect: when the shadow sprite pixel is 0, there is no effect on the background pixel, otherwise, the background pixel becomes darker. Now, the only way that comes to my mind is to change the blending equation to GL_FUNC_SUBTRACT, but it doesn't compile with cocos2d-x (can't found it)... I would subclass the CCSprite class in order to implement the draw() method in order to change, when needed, the blending equation, call the original draw() method and restore the blending equation to its previous state at the end of the method. So my questions are two: how to use glBlendEquation() with cocos2d-x? Keep in mind that i am writing a game for iphone/android/windows. are shadows handled this way in 2D games? Thx

    Read the article

  • Should i scrap my own leader board and go for the Facebook built in one?

    - by Magnus Johansson
    Currently I'm rolling my own score and leader board functionality in my FB canvas game. In my game, users can see what score they have, in addition I have a public leader board where everybody can see all scores from all other users.(I also have possibility for each user to set themselves as anonymous in the leader board, if desired) But now I started thinking; why do I have my own leader board system? Facebook has this scores API and I started play around with it. It, of course, integrates well with Facebook, scores and achievement showing up in the ticker and what not. But it seems that I can't let each user see a public leader board in much the same way I currently have it. But it do let the users see their friends score. Let's face it, this is all what FB is all about, right? Friends. So the question is; should i scrap my own leader board and go for the Facebook built in one (and skip the public part of it)? My gut feeling says yes, but I wanted to hear what other thinks.

    Read the article

  • Using HTML 5 SessionState to save rendered Page Content

    - by Rick Strahl
    HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which  is a simple, string based key value store that has getItem, setItem, removeitem, clear and  key methods. The objects are also pseudo array objects and so can be iterated like an array with  a length property and you have array indexers to set and get values with. Basic usage  for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab:   You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile  (or browse the base url with your browser width under 800px)   Here's what the mobile, non-frames view looks like:   As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings"  entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering  as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds  the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a  full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using  AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript  HTML5  ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

  • Texture switching with a entity system

    - by GameDev-er
    I'm using thinking of using an entity system in my game. So far I've been using Artemis with success. However, I have a question about texture switching. I read that switching textures too often is bad. So I load all the textures when the game loads like so: import org.newdawn.slick.opengl.TextureLoader; ... public HashMap<String, Texture> Textures; ... Then for each texture I do this: Texture tex = TextureLoader.getTexture("PNG", this.getClass().getResourceAsStream(texturePath)); Textures.put(textureName, tex); Then when drawing entities I do this: drawEntity() { glBindTexture(GL_TEXTURE_2D, Textures.get(entityTexture).getTextureID()); ... } Say I have 50 entities, using 10 different 3D models, each with their own texture. When the drawEntity system runs, it doesn't group by which entities use which texture. So I could be switching textures before drawing each entity! Is there a more efficient way to switch textures between entities? Or is glBindTexture() a good option?

    Read the article

  • JavaCV IplImage to LWJGL Texture

    - by rendrag
    As a side project I've been attempting to make a dynamic display (for example a screen within a game) that shows images from my webcam. I've been messing around with JavaCV and LWJGL for the past few months and have a basic understanding of how they both work. I found this after scouring google, but I get an error that the ByteBuffer isn't big enough. IplImage img = cam.getFrame(); ByteBuffer buffer = img.asByteBuffer(); int textureID = glGenTextures(); //Generate texture ID glBindTexture(GL_TEXTURE_2D, textureID); //Bind texture ID //I don't know how much of the following is necessary //Setup wrap mode glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE); //Setup texture scaling filtering glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); //Send texture data to OpenGL - this is the line that actually does stuff and that OpenGL has a problem with glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL12.GL_BGR, GL_UNSIGNED_BYTE, buffer); That last line throws this- Exception in thread "Thread-0" java.lang.IllegalArgumentException: Number of remaining buffer elements is 144, must be at least 921600. Because at most 921600 elements can be returned, a buffer with at least 921600 elements is required, regardless of actual returned element count at org.lwjgl.BufferChecks.throwBufferSizeException(BufferChecks.java:162) at org.lwjgl.BufferChecks.checkBufferSize(BufferChecks.java:189) at org.lwjgl.BufferChecks.checkBuffer(BufferChecks.java:230) at org.lwjgl.opengl.GL11.glTexImage2D(GL11.java:2845) at tests.TextureTest.getTexture(TextureTest.java:78) at tests.TextureTest.update(TextureTest.java:43) at lib.game.AbstractGame$1.run(AbstractGame.java:52) at java.lang.Thread.run(Thread.java:679)

    Read the article

  • The ship "shudders" in scrolling Asteroids

    - by Ciaran
    In my Asteroids game the user can scroll through space. When scrolling, the ship is drawn in the centre of the window. I use interpolation. I scroll the window uing glOrtho, centering it around the centre of the ship. On my first machine (7 years old, Windows XP, NVIDIA), I am doing 50 updates and 76 frames per second. This is smooth. My other machine an old compaq laptop (Pentium III) with Linux and Radeon OpenGL driver delivers 50 updates and 30 frames per second. The ship regularly seems to "shudder" back and forth when at maximum thrust. When you position the mouse cursor beside the ship it is obvious that its relative position in the window changes. Also, the stars seem blurred into short "lines". Playing the game in non-scrolling mode, the ship moves within the window, glOrtho is therefore not called repeatedly and there is no problem. I suspect a bug in my positioning of the ship and the window but I have dumped out these values and they seem to only go forward, not forward-back-forward. The driver does support double buffering. I guess if it is my bug I need to slow the frame-rate down to debug properly. My question: is this an obvious driver bug or is the slower machine uncovering a bug in my stuff and if so, some debugging tips would be appreciated. I am drawing in world co-ordinates and letting OpenGL do the scaling and translation so if I had a quick way of verifying what pixel co-ordinates OpenGL produces for the ship centre, that would help clarify this.

    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

  • Procedural Generation of tile-based 2d World

    - by Matthias
    I am writing a 2d game that uses tile-based top-down graphics to build the world (i.e. the ground plane). Manually made this works fine. Now I want to generate the ground plane procedurally at run time. In other words: I want to place the tiles (their textures) randomised on the fly. Of course I cannot create an endless ground plane, so I need to restrict how far from the player character (on which the camera focuses on) I procedurally generate the ground floor. My approach would be like this: I have a 2d grid that stores all tiles of the floor at their correct x/y coordinates within the game world. When the players moves the character, therefore also the camera, I constantly check whether there are empty locations in my x/y map within a max. distance from the character, i.e. cells in my virtual grid that have no tile set. In such a case I place a new tile there. Therefore the player would always see the ground plane without gaps or empty spots. I guess that would work, but I am not sure whether that would be the best approach. Is there a better alternative, maybe even a best-practice for my case?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 169 170 171 172 173 174 175 176 177 178 179 180  | Next Page >