Search Results

Search found 16410 results on 657 pages for 'game component'.

Page 376/657 | < Previous Page | 372 373 374 375 376 377 378 379 380 381 382 383  | Next Page >

  • OpenGL VBOs are slower then glDrawArrays.

    - by Arelius
    So, this seems odd to me. I upload a large buffer of vertices, then every frame I call glBindbuffer and then the appropriate gl*Pointer functions with offsets into the buffer, then I use glDrawArrays to draw all of my triangles. I'm only drawing about 100K triangles, however I'm getting about 15FPS. This is where it gets weird, if I change it to not call glBindBuffer, then change the gl*Pointer calls to be actual pointers into the array I have in system memory, and then call glDrawArrays the same, my framerate jumps up to about 50FPS. Any idea what I weird thing I could be doing that would cause this? Did I maybe forget to call glEnable(GL_ALLOW_VBOS_TO_RUN_FAST) or something?

    Read the article

  • Client Side Prediction

    - by user13842
    I have a question regarding Client Side prediction. Ive tried to search topics about my specific problem but couldn't find anything which really answered my problem. Most tutorials and explanations assume that the Client sends messages like "Move my player up by 1 Position", but what if i send messages like "Set my player's velocity to x"? Since it's hard to explain with text, i made a graphic explaining my problem. The main problem is, that the player sets his own velocity, due to Client Side Prediction, earlier than the Server. So if 2 different velocities overlap, the Server would get out of sync. How can i tackle that problem? Thanks a lot. Graphic: http://img27.imageshack.us/img27/6083/clientpred.png (Ignore the 5.5cm)

    Read the article

  • OpenGL : sluggish performance in extracting texture from GPU

    - by Cyan
    I'm currently working on an algorithm which creates a texture within a render buffer. The operations are pretty complex, but for the GPU this is a simple task, done very quickly. The problem is that, after creating the texture, i would like to save it. This requires to extract it from GPU memory. For this operation, i'm using glGetTexImage(). It works, but the performance is sluggish. No, i mean even slower than that. For example, an 8MB texture (uncompressed) requires 3 seconds (yes, seconds) to be extracted. That's mind puzzling. I'm almost wondering if my graphic card is connected by a serial link... Well, anyway, i've looked around, and found some people complaining about the same, but no working solution so far. The most promising advise was to "extract data in the native format of the GPU". Which i've tried and tried, but failed so far. Edit : by moving the call to glGetTexImage() in a different place, the speed has been a bit improved for the most dramatic samples : looking again at the 8MB texture, it knows requires 500ms, instead of 3sec. It's better, but still much too slow. Smaller texture sizes were not affected by the change (typical timing remained into the 60-80ms range). Using glFinish() didn't help either. Note that, if i call glFinish() (without glGetTexImage), i'm getting a fixed 16ms result, whatever the texture size or complexity. It really looks like the timing for a frame at 60fps. The timing is measured for the full rendering + saving sequence. The call to glGetTexImage() alone does not really matter. That being said, it is this call which changes the performance. And yes, of course, as stated at the beginning, the texture is "created into the GPU", hence the need to save it.

    Read the article

  • rotating an object on an arc

    - by gardian06
    I am trying to get a turret to rotate on an arc, and have hit a wall. I have 8 possible starting orientations for the turrets, and want them to rotate on a 90 degree arc. I currently take the starting rotation of the turret, and then from that derive the positive, and negative boundary of the arc. because of engine restrictions (Unity) I have to do all of my tests against a value which is between [0,360], and due to numerical precision issues I can not test against specific values. I would like to write a general test without having to go in, and jury rig cases //my current test is: // member variables public float negBound; public float posBound; // found in Start() function (called immediately after construction) // eulerAngles.y is the the degree measure of the starting y rotation negBound = transform.eulerAngles.y-45; posBound = transform.eulerAngles.y+45; // insure that values are within bounds if(negBound<0){ negBound+=360; }else if(posBound>360){ posBound-=360; } // called from Update() when target not in firing line void Rotate(){ // controlls what direction if(transform.eulerAngles.y>posBound){ dir = -1; } else if(transform.eulerAngles.y < negBound){ dir = 1; } // rotate object } follows is a table of values for my different cases (please excuse my force formatting) read as base is the starting rotation of the turret, neg is the negative boundry, pos is the positive boundry, range is the acceptable range of values, and works is if it performs as expected with the current code. |base-|-neg-|-pos--|----------range-----------|-works-| |---0---|-315-|--45--|-315-0,0-45----------|----------| |--45--|---0---|--90--|-0-45,54-90----------|----x----| |-135-|---90--|-180-|-90-135,135-180---|----x----| |-180-|--135-|-225-|-135-180,180-225-|----x----| |-225-|--180-|-270-|-180-225,225-270-|----x----| |-270-|--225-|-315-|-225-270,270-315-|----------| |-315-|--270-|---0---|--270-315,315-0---|----------| I will need to do all tests from derived, or stored values, but can not figure out how to get all of my cases to work simultaneously. //I attempted to concatenate the 2 tests: if((transform.eulerAngles.y>posBound)&&(transform.eulerAngles.y < negBound)){ dir *= -1; } this caused only the first case to be successful // I attempted to store a opposite value, and do a void Rotate(){ // controlls what direction if((transform.eulerAngles.y > posBound)&&(transform.eulerAngles.y<oposite)){ dir = -1; } else if((transform.eulerAngles.y < negBound)&&(transform.eulerAngles.y>oposite)){ dir = 1; } // rotate object } this causes the opposite situation as indicated on the table. What am I missing here?

    Read the article

  • What is the point in using real time?

    - by bobobobo
    I understand that using real time frame elapses (which should vary between 16-17ms on average) are provided by a lot of frameworks. GetTimeElapsedSinceLastFrame, and it gives you the wall clock time. But should we use this information in basic physics simulation? It looks to me to be a bad idea. Say there is a slight lag on the machine, for whatever reason (say a virus scanner starts up). The calculations all jump, and there is no need for this. Why not use a virtual second and ignore wall clock time? For gameplay on the level of Commander Keen, shouldn't you always use the virtual second and not real-time? (Besides stopwatch timing for race games) I don't see a need to use real time and not a fixed 16ms time step.

    Read the article

  • Multi-threaded JOGL Problem

    - by moeabdol
    I'm writing a simple OpenGL application in Java that implements the Monte Carlo method for estimating the value of PI. The method is pretty easy. Simply, you draw a circle inside a unit square and then plot random points over the scene. Now, for each point that is inside the circle you increment the counter for in points. After determining for all the random points wither they are inside the circle or not you divide the number of in points over the total number of points you have plotted all multiplied by 4 to get an estimation of PI. It goes something like this PI = (inPoints / totalPoints) * 4. This is because mathematically the ratio of a circle's area to a square's area is PI/4, so when we multiply it by 4 we get PI. My problem doesn't lie in the algorithm itself; however, I'm having problems trying to plot the points as they are being generated instead of just plotting everything at once when the program finishes executing. I want to give the application a sense of real-time display where the user would see the points as they are being plotted. I'm a beginner at OpenGL and I'm pretty sure there is a multi-threading feature built into it. Non the less, I tried to manually create my own thread. Each worker thread plots one point at a time. Following is the psudo-code: /* this part of the code exists in display() method in MyCanvas.java which extends GLCanvas and implements GLEventListener */ // main loop for(int i = 0; i < number_of_points; i++){ RandomGenerator random = new RandomGenerator(); float x = random.nextFloat(); float y = random.nextFloat(); Thread pointThread = new Thread(new PointThread(x, y)); } gl.glFlush(); /* this part of the code exists in run() method in PointThread.java which implements Runnable */ void run(){ try{ gl.glPushMatrix(); gl.glBegin(GL2.GL_POINTS); if(pointIsIn) gl.glColor3f(1.0f, 0.0f, 0.0f); // red point else gl.glColor3f(0.0f, 0.0f, 1.0f); // blue point gl.glVertex3f(x, y, 0.0f); // coordinates gl.glEnd(); gl.glPopMatrix(); }catch(Exception e){ } } I'm not sure if my approach to solving this issue is correct. I hope you guys can help me out. Thanks.

    Read the article

  • Making video from 3D gaphics in OpenGL

    - by MVTC
    What are some of the preferred methods or libraries for creating video from an OpenGL graphics simulation? For example, I want to create a visualization(video) of an N-Body gravity simulation by rendering non-real-time OpenGL frames. The simulation is already coded, I just don't know how to convert it to video. EDIT: I am also interested in providing the described functionality: The user can adjust parameters including the time step between captured frames and then initiate the simulation. The user waits for the simulation to complete, and then can watch the results. The user is able to increase or decrease the playback speed of the simulation whereas in slow motion, more frames are used i.e., you see higher resolution time steps, and when the speed is increased, you see lower resolution time steps at a higher rate, but the frames per second flashing on the screen is constant.

    Read the article

  • Animate sprite/texture position with VBO

    - by Dono
    I'm currently worlking on a renderer for my projects and I want animate a sprite on screen. I've got a spritesheet but I don't know what is the the best way to update the texture coordinates for each vertex. Update vertices then update vertex buffer. (Heavy ?) Send to the shader my texture coordinates (It is possible ?) Don't use VBO ? By the way, I've got this structure : Object class with Geometry (Faces + Vertex + Buffer) and Material (Shader + other stuff ) properties, it is a good structure ? Thanks!

    Read the article

  • Is IDirectInput8::FindDevice totally broken on Windows 7?

    - by Noora
    I'm developing on Windows 7, and using DirectInput8 for my input needs. I'm tracking gamepad additions and removals (that is, GUID_DEVINTERFACE_HID devices) using the DBT_DEVICEARRIVAL and DBT_DEVICEREMOVECOMPLETE messages, which works fine. However, what I've come to find out is that no matter what I do, passing the received values from DBT_DEVICEARRIVAL to IDirectInput8's FindDevice method, it will always fail to identify the device, returning DIERR_DEVICENOTREG. DirectInput still clearly knows about the device, because I can enumerate and create it just fine. I've tried with three different gamepads, and the error persists, so it's not about that either. I also tried passing some alternative interface GUIDs for the RegisterDeviceNotification call, didn't help. So, has anyone else faced the same problem, and have you found a usable workaround? I'm afraid I'll soon have to stoop down to re-enumerating all devices when something is added or removed, but I'll first give this question one last shot here. EDIT: For the record, I've also tried pretty much every single HID API & SetupAPI function for alternative ways of figuring out the needed GUIDs, with zero success. So if you're facing the same problem as me, don't bother with that route. I'm pretty sure those GUIDs are made up by DirectInput itself somehow. Short of reverse engineering dinput8.dll, I'm truly out of ideas now.

    Read the article

  • Vector reflect problem

    - by xdevel2000
    I'm testing some vector reflection and I want to check what happens when a ball collides with a paddle. So if I have: Vector2 velocity = new Vector2(-5, 2); position_ball += velocity; if (position_ball.X < 10) { Vector2 v = new Vector2(1,0); // or Vector2.UnitX velocity = Vector2.Reflect(velocity, v); } then, correctly, velocity is (5,2) after Reflect, but if I do: if (position_ball.X < 10) { Vector2 v = new Vector2(1,1); velocity = Vector2.Reflect(velocity, v); } then velocity is (1,8) and not (5, -2) that is the solution of reflection equation R = V - 2 * (V . N) Why is that?

    Read the article

  • Without using a pre-built physics engine, how can I implement 3-D collision detection from scratch?

    - by Andy Harglesis
    I want to tackle some basic 3-D collision detection and was wondering how engines handle this and give you a pretty interface and make it so easy ... I want to do it all myself, however. 2-D collision detection is extremely simple and can be done multiple ways that even beginner programmers could think up: 1.When the pixels touch; 2.when a rectangle range is exceeded; 3.when a pixel object is detected near another one in a pixel-based rendering engine. But 3-D is different with one dimension, but complex in many more so ... what are the general, basic understanding/examples on how 3-D collision detection can be implemented? Think two shaded, OpenGL cubes that are moved next to each other with a simple OpenGL rendering context and keyboard events.

    Read the article

  • CUDA 4.1 Particle Update

    - by N0xus
    I'm using CUDA 4.1 to parse in the update of my Particle system that I've made with DirectX 10. So far, my update method for the particle systems is 1 line of code within a for loop that makes each particle fall down the y axis to simulate a waterfall: m_particleList[i].positionY = m_particleList[i].positionY - (m_particleList[i].velocity * frameTime * 0.001f); In my .cu class I've created a struct which I copied from my particle class and is as follows: struct ParticleType { float positionX, positionY, positionZ; float red, green, blue; float velocity; bool active; }; Then I have an UpdateParticle method in the .cu as well. This encompass the 3 main parameters my particles need to update themselves based off the initial line of code. : __global__ void UpdateParticle(float* position, float* velocity, float frameTime) { } This is my first CUDA program and I'm at a loss to what to do next. I've tried to simply put the particleList line in the UpdateParticle method, but then the particles don't fall down as they should. I believe it is because I am not calling something that I need to in the class where the particle fall code use to be. Could someone please tell me what it is I am missing to get it working as it should? If I am doing this completely wrong in general, the please inform me as well.

    Read the article

  • Inventory Item Exist checker

    - by Annalyne
    I have a question regarding declaring my inventory. I made it a string named inventory, with a constant number as its max value. The thing is, I want the user to use an item if he / she gains an item. The problem is, I do not know what syntax should I use to determine if the user has an item and use that item. Here's my code I just started: so declaring the inventory: const int MAX_ITEMS = 15; string game_inventory [MAX_ITEMS]; int itemnum = 0; I have some items like potion, antidote, gems and others. I use the: game_inventory[itemnum++] = "Potion" to place items in my inventory. If I want to use the potion, IF I HAVE one, how can i make a function to check whether I have a potion or anything and use it?

    Read the article

  • How to handle circle penetration

    - by Kaertserif
    I've been working on cirlce to circle collision and have gotten the intersection method working correctly, but I'm having problems using the returned values to actually seperate the circles from one another. This is the method which calculates the depth of the circle collision public static Vector2 GetIntersectionDepth(Circle a, Circle b) { float xValue = a.Center.X - b.Center.X; float yValue = a.Center.Y - b.Center.Y; Vector2 depth = Vector2.Zero; float distance = Vector2.Distance(a.Center, b.Center); if (a.Radius + b.Radius > distance) { float result = (a.Radius + b.Radius) - distance; depth.X = (float)Math.Cos(result); depth.Y = (float)Math.Sin(result); } return depth; } This is where I'm trying to apply the values to actually seperate the circles. Vector2 depth = Vector2.Zero; for (int i = 0; i < circlePositions.Count; i++) { for (int j = 0; j < circlePositions.Count; j++) { Circle bounds1 = new Circle(circlePositions[i], circle.Width / 2); Circle bounds2 = new Circle(circlePositions[j], circle.Width / 2); if(i != j) depth = CircleToCircleIntersection.GetIntersectionDepth(bounds1, bounds2); if (depth != Vector2.Zero) { circlePositions[i] = new Vector2(circlePositions[i].X + depth.X, circlePositions[i].Y + depth.Y); } } } If you can offer any help in this I would really appreciate it.

    Read the article

  • What techniques can I use to render very large numbers of objects more efficiently in OpenGL?

    - by Luke
    You can think of my application as drawing a very large ball-and-stick diagram (or graph). At times, this graph can get very large, where the number of elements even outnumbers the pixels on the screen. Currently I am simply passing all of my textures (as GL_POINTS) and lines to the graphics card using VBO's. When the number of elements outnumbers the number of pixels, is this the most efficient way to do this? Or should I do some calculations on the CPU side before handing everything over to the GPU? If it matters, I do use GL_DEPTH_TEST and GL_ALPHA_TEST. I do some alpha blending, but probably not enough to make a huge performance difference. My scene can be static at times, but the user has control over a typical arc-ball camera and can pan, rotate, or zoom. It is during these operations that performance degradation is noticeable.

    Read the article

  • Andengine. Put bullet to pool, when it leaves screen

    - by Ashot
    i'm creating a bullet with physics body. Bullet class (extends Sprite class) has die() method, which unregister physics connector, hide sprite and put it in pool public void die() { Log.d("bulletDie", "See you in hell!"); if (this.isVisible()) { this.setVisible(false); mPhysicsWorld.unregisterPhysicsConnector(physicsConnector); physicsConnector.setUpdatePosition(false); body.setActive(false); this.setIgnoreUpdate(true); bulletsPool.recyclePoolItem(this); } } in onUpdate method of PhysicsConnector i executes die method, when sprite leaves screen physicsConnector = new PhysicsConnector(this,body,true,false) { @Override public void onUpdate(final float pSecondsElapsed) { super.onUpdate(pSecondsElapsed); if (!camera.isRectangularShapeVisible(_bullet)) { Log.d("bulletDie","Dead?"); _bullet.die(); } } }; it works as i expected, but _bullet.die() executes TWICE. what i`m doing wrong and is it right way to hide sprites? here is full code of Bullet class (it is inner class of class that represents player) private class Bullet extends Sprite implements PhysicsConstants { private final Body body; private final PhysicsConnector physicsConnector; private final Bullet _bullet; private int id; public Bullet(float x, float y, ITextureRegion texture, VertexBufferObjectManager vertexBufferObjectManager) { super(x,y,texture,vertexBufferObjectManager); _bullet = this; id = bulletId++; body = PhysicsFactory.createCircleBody(mPhysicsWorld, this, BodyDef.BodyType.DynamicBody, bulletFixture); physicsConnector = new PhysicsConnector(this,body,true,false) { @Override public void onUpdate(final float pSecondsElapsed) { super.onUpdate(pSecondsElapsed); if (!camera.isRectangularShapeVisible(_bullet)) { Log.d("bulletDie","Dead?"); Log.d("bulletDie",id+""); _bullet.die(); } } }; mPhysicsWorld.registerPhysicsConnector(physicsConnector); $this.getParent().attachChild(this); } public void reset() { final float angle = canon.getRotation(); final float x = (float) ((Math.cos(MathUtils.degToRad(angle))*radius) + centerX) / PIXEL_TO_METER_RATIO_DEFAULT; final float y = (float) ((Math.sin(MathUtils.degToRad(angle))*radius) + centerY) / PIXEL_TO_METER_RATIO_DEFAULT; this.setVisible(true); this.setIgnoreUpdate(false); body.setActive(true); mPhysicsWorld.registerPhysicsConnector(physicsConnector); body.setTransform(new Vector2(x,y),0); } public Body getBody() { return body; } public void setLinearVelocity(Vector2 velocity) { body.setLinearVelocity(velocity); } public void die() { Log.d("bulletDie", "See you in hell!"); if (this.isVisible()) { this.setVisible(false); mPhysicsWorld.unregisterPhysicsConnector(physicsConnector); physicsConnector.setUpdatePosition(false); body.setActive(false); this.setIgnoreUpdate(true); bulletsPool.recyclePoolItem(this); } } }

    Read the article

  • How do I swap two objects in a GC language without triggering GC?

    - by TenFour04
    I have two array lists. that I want to swap each frame. My question is, does the variable 'temp' need to be a member variable to avoid triggering GC, assuming this method is called on dozens of objects each frame? I'm not creating a new object, just a new reference to an object. public void LateUpdate(){ ArrayList<int> temp = previousFrameCollisions; previousFrameCollisions = currentFrameCollisions; currentFrameCollisions = temp; currentFrameCollisions.clear(); } I've been told there's no reason to make a primitive into a member variable just to avoid GC, so my best guess is that this also applies to object references.

    Read the article

  • Minecraft Coding Pack: Stair block texture

    - by JamerTheProgrammer
    I have MCP setup and working nicely. I would like to make another stair block. I have copied the wooden stair block file and then pasted it and renamed it BlahStairBlock. I'm trying to set a texture for the stair block but it wont work. public int getBlockTextureFromSide(int side) { if(i==side) { // Workshop top return 43; } return blockIndexInTexture; } This is what I'm using to set the texture.... It just isn't working. Any ideas of why?

    Read the article

  • Simulate 'Shock absorbtion' with tire rubber in PhysX (2.8.x)

    - by Mungoid
    This is a kinda tricky question and I fear there is no easy enough solution, but I figured I'd hit SE up before giving up on it and just doing what I can. A machine I am working on has no suspension or shocks or springs of any sort in the real machine, so you would think that when it drives over bumps, it would shake like crazy but because its tires (6 of them) are quite large they seem to absorb a lot of shock from the bumps. Part of this is because the machine is around 30k lbs and it just smashes/compresses any bumps in the ground down (This is another issue im still working on) and the other part is that the tires seem to have a lot of flex to them with a lot of air as well. So my current task is to simulate shock absorption in physx without visibly separating the tires from the spindle/axle.. I have been messing with all kinds of NxMaterial, NxSpring, Joints, etc. and have had no luck getting this to work. The main problem is that the spindle attached to the tire is directly in the center and the axle is basically solidly attached to the chassis, so if i give it any spring or suspension travel, that spindle on the tires will move upwards or downwards, looking very odd because now its not any longer in the center of the tire. I tried giving it a higher restitution but that just makes it bouncy without any shock absorption. Another avenue I am messing with is to actively smooth the terrain in front of the tires so that before it hits a bumpy patch, that patch is smoothed and it doesn't bounce. The only issue with this is that it is pretty expensive to do with 6 tires, high tesselation of the terrain and other complex things going on at the same time in this simulation. I am still working on this but I am hoping to mix and match a few different aspects to get the best possible outcome. This is a bit of a complex issue so I'm not expecting anyone to have a definitive answer, just hoping someone may think of something I haven't =-) -Side note: Yes i know PhysX 2.8.x is quite outdated but we have to stick with it for this implementation. We are in the process of going to another physics engine but it is out of scope to apply that engine to this project.

    Read the article

  • How can I stop pixel seams appearing in adjacent mesh boundaries due to floating point imprecision?

    - by ufomorace
    Graphics cards are mathematically imprecise. So when some meshes are joined by their borders, the graphics card often makes mistakes and decides that some pixels at the seam represent neither object, and unwanted pixels appear. It's a natural behaviour on all graphics cards. How are such worries avoided in Pro Games? Batching? Shaders? Different tangent vectors? Merging? Overlaping seams? Dark backgrounds? Extra vertices at borders? Z precision? Camera distance tweaks? Screencap of a fix that ended up not working:

    Read the article

  • How can I determine the first visible tile in an isometric perspective?

    - by alekop
    I am trying to render the visible portion of a diamond-shaped isometric map. The "world" coordinate system is a 2D Cartesian system, with the coordinates increasing diagonally (in terms of the view coordinate system) along the axes. The "view" coordinates are simply mouse offsets relative to the upper left corner of the view. My rendering algorithm works by drawing diagonal spans, starting from the upper right corner of the view and moving diagonally to the right and down, advancing to the next row when it reaches the right view edge. When the rendering loop reaches the lower left corner, it stops. There are functions to convert a point from view coordinates to world coordinates and then to map coordinates. Everything works when rendering from tile 0,0, but as the view scrolls around the rendering needs to start from a different tile. I can't figure out how to determine which tile is closest to the upper right corner. At the moment I am simply converting the coordinates of the upper right corner to map coordinates. This works as long as the view origin (upper right corner) is inside the world, but when approaching the edges of the map the starting tile coordinate obviously become invalid. I guess this boils down to asking "how can I find the intersection between the world X axis and the view X axis?"

    Read the article

  • Calculating the force of an impact?

    - by meds
    I'm trying to figure out a way to determine the force two objects collide in. I have two vectors defining their linear velocity at the time of impact, their mass and their angular velocity. Keep in mind this is all for a 2D physics engine. I don't think it's as simple as adding up these values and figuring out if it's large enogh it makes a large impact since that doesn't take into account if the two objects are travelling in the same direction (as an example). Any ideas?

    Read the article

  • Playing a death anim on an enemy that I want to remove

    - by Max
    I've been trying to find a tutorial on how to best make animations in Android. I already have some animations for my enemies and my character that are controlled by rectangles and changing rectangleframe between updates using a picture like this: When I'm shooting my enemies they lose HP, and when their HP == 0 they get removed. As long as I'm using an arrayList (which I do for all enemies and bullets) I'm fine, since I can just use list.remove(i). But when I'm on a boss-level and the Boss's HP == 0, I want to remove him and play an animation of an explosion of stars before the "End-screen". Is there a preferred way to do temporary animations like this? If you can give me an example or redirect me to a tutorial, I'd be really grateful!

    Read the article

  • How to rotate camera centered around the camera's position?

    - by tnutty
    Currently I am using gluLook at like so: gluLookAt(position.x, position.y, position.z, viewPoint.x, viewPoint.y, viewPoint.z, upVector.x, upVector.y, upVector.z); with the above, don't know if you need more information, how could I change it so that the camera acts like its rotating around itself, instead rotating around its viewpoint. You can see the current code at https://github.com/dchhetri/OpenGL-City/blob/master/opengl_camera.cpp, that class was adapted from codecolony.com.

    Read the article

  • Control HelpButton, HelpRequested, HelpButtonClicked - Instant help for windows Dialog Form components

    Instant help for windows dialog components is a great feature and very much known since windows 98. but I saw many many people are not aware it and query on Google to get help, but “help button” for dialogs helps you or your customers to get the help instantly. Every dialog window has help icon if that dialog was coded to enable it. it really helps to know the functionality of the components quickly. For example I was trying to pint a document from acrobat reader and opened printer properties to print the content front and back of the paper. If you observe there is a help button before close button. To get help on options of “Print on Both Sides” you would need to click on help button first and then click on the area on which you want to see the help. above picture shows help text for the options of “Print on Both Sides”. If you would like to get the help using keyboard you can use F1 key. Help button can be displayed only if minimize button and maximize button both are not shown unless you want go with custom buttons. below is the way if you want to get Help button for windows forms.   In this sample demo I want to have a checkbox and need to show help when I click on F1 on check box. So I created a form which country check box and help label as show in adjacent picture. Below is the code for your code bind file. using System; using System.Windows.Forms; namespace WindowsFormsApplication1 {     public partial classForm1: Form    {         publicForm1()         {             InitializeComponent();         }         private void Form1_Load(objectsender, EventArgs e)         {             this.Text = "Help Button Demo Form";             lblHelp.Text = "Press F1 on any component to get Instant Help";             this.HelpButton = true;             this.MaximizeBox = false;             this.MinimizeBox = false;             chkCountry.Tag = "Check or Uncheck Coutry Check Box";             chkCountry.HelpRequested += newHelpEventHandler(chkCountry_HelpRequested);             chkCountry.MouseLeave += newEventHandler(chkCountry_MouseLeave);         }         void chkCountry_HelpRequested(objectsender, HelpEventArgs hlpevent)         {             ControlrequestingControl = (Control)sender;             lblHelp.Text = (string)requestingControl.Tag;             hlpevent.Handled = true;         }         void chkCountry_MouseLeave(objectsender, EventArgs e)         {             lblHelp.Text = "Press F1 on any component to get Instant Help";         }     } } In above code  “HelpRequested” is an event will be fired when you click on F1 on Country checkbox. I stored the help information in the checkbox property called “Tag”. You might also maintain a property file to keep help text for each component differently. If you click on F1 when focus is on main form instead on individual component then generally separate help window opens. This can be done using the event “Form.HelpRequested” to open help windows as in below code. this.HelpRequested += newHelpEventHandler(Form1_HelpRequested); voidForm1_HelpRequested(objectsender, HelpEventArgs hlpevent) {     frmHelp.Show(); } span.fullpost {display:none;}

    Read the article

< Previous Page | 372 373 374 375 376 377 378 379 380 381 382 383  | Next Page >