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  • If a NSView uses autolayout, do all of its subviews also need to use autolayout for positioning?

    - by boyfarrell
    I have a view in a window, the position and size of the view are calculated with autolayout. The view has a subview, a draggable NSView subclass. It is really easy to make a NSView "draggable" by overriding -mouseDown: and -mouseDragged: and changing the frame of the view directly. The view hierarchy is as follows, What is the best way of making the subview draggable in this case? For example, Is it possible for the subview to not use autolayout, so that it can be positioned by changing the frame directly? i.e. the window positions the main view, but then autolayout does not layout the subview inside the main view. Or to all views in the hierarchy need to use autolayout. When I have used autolayout before, I have used it to make "fixed" layout that respond to resizing. But dragging a view with a mouse does't seems like a natural use case for autolayout.

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  • How should nested components interact with model in a GUI application?

    - by fig-gnuton
    Broad design/architecture question. If you have nested components in a GUI, what's the most common way for those components to interact with data? For example, let's say a component receives a click on one of its buttons to save data. Should the save request be delegated up that component's ancestors, with the uppermost ancestor ultimately passing the request to a controller? Or are models/datastores in a GUI application typically singletons, so that a component at any level of a hierarchy can directly get/set data? Or is a controller injected as a dependency down the hierarchy of components, so that any given component is only one intermediary away from the datastore/model?

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  • What is the purpose of AnyVal?

    - by DaoWen
    I can't think of any situation where the type AnyVal would be useful, especially with the addition of the Numeric type for abstracting over Int, Long, etc. Are there any actual use cases for AnyVal, or is it just an artifact that makes the type hierarchy a bit prettier? Just to clarify, I know what AnyVal is, I just can't think of any time that I would actually need it in Scala. When would I ever need a type that encompassed Int, Character and Double? It seems like it's just there to make the type hierarchy prettier (i.e. it looks nicer to have AnyVal and AnyRef as siblings rather than having Int, Character, etc. inherit directly from Any).

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  • Camera frustum calculation coming out wrong

    - by Telanor
    I'm trying to calculate a view/projection/bounding frustum for the 6 directions of a point light and I'm having trouble with the views pointing along the Y axis. Our game uses a right-handed, Y-up system. For the other 4 directions I create the LookAt matrix using (0, 1, 0) as the up vector. Obviously that doesn't work when looking along the Y axis so for those I use an up vector of (-1, 0, 0) for -Y and (1, 0, 0) for +Y. The view matrix seems to come out correctly (and the projection matrix always stays the same), but the bounding frustum is definitely wrong. Can anyone see what I'm doing wrong? This is the code I'm using: camera.Projection = Matrix.PerspectiveFovRH((float)Math.PI / 2, ShadowMapSize / (float)ShadowMapSize, 1, 5); for(var i = 0; i < 6; i++) { var renderTargetView = shadowMap.GetRenderTargetView((TextureCubeFace)i); var up = DetermineLightUp((TextureCubeFace) i); var forward = DirectionToVector((TextureCubeFace) i); camera.View = Matrix.LookAtRH(this.Position, this.Position + forward, up); camera.BoundingFrustum = new BoundingFrustum(camera.View * camera.Projection); } private static Vector3 DirectionToVector(TextureCubeFace direction) { switch (direction) { case TextureCubeFace.NegativeX: return -Vector3.UnitX; case TextureCubeFace.NegativeY: return -Vector3.UnitY; case TextureCubeFace.NegativeZ: return -Vector3.UnitZ; case TextureCubeFace.PositiveX: return Vector3.UnitX; case TextureCubeFace.PositiveY: return Vector3.UnitY; case TextureCubeFace.PositiveZ: return Vector3.UnitZ; default: throw new ArgumentOutOfRangeException("direction"); } } private static Vector3 DetermineLightUp(TextureCubeFace direction) { switch (direction) { case TextureCubeFace.NegativeY: return -Vector3.UnitX; case TextureCubeFace.PositiveY: return Vector3.UnitX; default: return Vector3.UnitY; } } Edit: Here's what the values are coming out to for the PositiveX and PositiveY directions: Constants: Position = {X:0 Y:360 Z:0} camera.Projection = [M11:0.9999999 M12:0 M13:0 M14:0] [M21:0 M22:0.9999999 M23:0 M24:0] [M31:0 M32:0 M33:-1.25 M34:-1] [M41:0 M42:0 M43:-1.25 M44:0] PositiveX: up = {X:0 Y:1 Z:0} target = {X:1 Y:360 Z:0} camera.View = [M11:0 M12:0 M13:-1 M14:0] [M21:0 M22:1 M23:0 M24:0] [M31:1 M32:0 M33:0 M34:0] [M41:0 M42:-360 M43:0 M44:1] camera.BoundingFrustum: Matrix = [M11:0 M12:0 M13:1.25 M14:1] [M21:0 M22:0.9999999 M23:0 M24:0] [M31:0.9999999 M32:0 M33:0 M34:0] [M41:0 M42:-360 M43:-1.25 M44:0] Top = {A:0.7071068 B:-0.7071068 C:0 D:254.5584} Bottom = {A:0.7071068 B:0.7071068 C:0 D:-254.5584} Left = {A:0.7071068 B:0 C:0.7071068 D:0} Right = {A:0.7071068 B:0 C:-0.7071068 D:0} Near = {A:1 B:0 C:0 D:-1} Far = {A:-1 B:0 C:0 D:5} PositiveY: up = {X:0 Y:0 Z:-1} target = {X:0 Y:361 Z:0} camera.View = [M11:-1 M12:0 M13:0 M14:0] [M21:0 M22:0 M23:-1 M24:0] [M31:0 M32:-1 M33:0 M34:0] [M41:0 M42:0 M43:360 M44:1] camera.BoundingFrustum: Matrix = [M11:-0.9999999 M12:0 M13:0 M14:0] [M21:0 M22:0 M23:1.25 M24:1] [M31:0 M32:-0.9999999 M33:0 M34:0] [M41:0 M42:0 M43:-451.25 M44:-360] Top = {A:0 B:0.7071068 C:0.7071068 D:-254.5585} Bottom = {A:0 B:0.7071068 C:-0.7071068 D:-254.5585} Left = {A:-0.7071068 B:0.7071068 C:0 D:-254.5585} Right = {A:0.7071068 B:0.7071068 C:0 D:-254.5585} Near = {A:0 B:1 C:0 D:-361} Far = {A:0 B:-1 C:0 D:365} When I use the resulting BoundingFrustum to cull regions outside of it, this is the result: Pass PositiveX: Drew 3 regions Pass NegativeX: Drew 6 regions Pass PositiveY: Drew 400 regions Pass NegativeY: Drew 36 regions Pass PositiveZ: Drew 3 regions Pass NegativeZ: Drew 6 regions There are only 400 regions to draw and the light is in the center of them. As you can see, the PositiveY direction is drawing every single region. With the near/far planes of the perspective matrix set as small as they are, there's no way a single frustum could contain every single region.

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  • Determining explosion radius damage - Circle to Rectangle 2D

    - by Paul Renton
    One of the Cocos2D games I am working on has circular explosion effects. These explosion effects need to deal a percentage of their set maximum damage to all game characters (represented by rectangular bounding boxes as the objects in question are tanks) within the explosion radius. So this boils down to circle to rectangle collision and how far away the circle's radius is from the closest rectangle edge. I took a stab at figuring this out last night, but I believe there may be a better way. In particular, I don't know the best way to determine what percentage of damage to apply based on the distance calculated. Note : All tank objects have an anchor point of (0,0) so position is according to bottom left corner of bounding box. Explosion point is the center point of the circular explosion. TankObject * tank = (TankObject*) gameSprite; float distanceFromExplosionCenter; // IMPORTANT :: All GameCharacter have an assumed (0,0) anchor if (explosionPoint.x < tank.position.x) { // Explosion to WEST of tank if (explosionPoint.y <= tank.position.y) { //Explosion SOUTHWEST distanceFromExplosionCenter = ccpDistance(explosionPoint, tank.position); } else if (explosionPoint.y >= (tank.position.y + tank.contentSize.height)) { // Explosion NORTHWEST distanceFromExplosionCenter = ccpDistance(explosionPoint, ccp(tank.position.x, tank.position.y + tank.contentSize.height)); } else { // Exp center's y is between bottom and top corner of rect distanceFromExplosionCenter = tank.position.x - explosionPoint.x; } // end if } else if (explosionPoint.x > (tank.position.x + tank.contentSize.width)) { // Explosion to EAST of tank if (explosionPoint.y <= tank.position.y) { //Explosion SOUTHEAST distanceFromExplosionCenter = ccpDistance(explosionPoint, ccp(tank.position.x + tank.contentSize.width, tank.position.y)); } else if (explosionPoint.y >= (tank.position.y + tank.contentSize.height)) { // Explosion NORTHEAST distanceFromExplosionCenter = ccpDistance(explosionPoint, ccp(tank.position.x + tank.contentSize.width, tank.position.y + tank.contentSize.height)); } else { // Exp center's y is between bottom and top corner of rect distanceFromExplosionCenter = explosionPoint.x - (tank.position.x + tank.contentSize.width); } // end if } else { // Tank is either north or south and is inbetween left and right corner of rect if (explosionPoint.y < tank.position.y) { // Explosion is South distanceFromExplosionCenter = tank.position.y - explosionPoint.y; } else { // Explosion is North distanceFromExplosionCenter = explosionPoint.y - (tank.position.y + tank.contentSize.height); } // end if } // end outer if if (distanceFromExplosionCenter < explosionRadius) { /* Collision :: Smaller distance larger the damage */ int damageToApply; if (self.directHit) { damageToApply = self.explosionMaxDamage + self.directHitBonusDamage; [tank takeDamageAndAdjustHealthBar:damageToApply]; CCLOG(@"Explsoion-> DIRECT HIT with total damage %d", damageToApply); } else { // TODO adjust this... turning out negative for some reason... damageToApply = (1 - (distanceFromExplosionCenter/explosionRadius) * explosionMaxDamage); [tank takeDamageAndAdjustHealthBar:damageToApply]; CCLOG(@"Explosion-> Non direct hit collision with tank"); CCLOG(@"Damage to apply is %d", damageToApply); } // end if } else { CCLOG(@"Explosion-> Explosion distance is larger than explosion radius"); } // end if } // end if Questions: 1) Can this circle to rect collision algorithm be done better? Do I have too many checks? 2) How to calculate the percentage based damage? My current method generates negative numbers occasionally and I don't understand why (Maybe I need more sleep!). But, in my if statement, I ask if distance < explosion radius. When control goes through, distance/radius must be < 1 right? So 1 - that intermediate calculation should not be negative. Appreciate any help/advice!

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  • Resolving collisions between dynamic game objects

    - by TheBroodian
    I've been building a 2D platformer for some time now, I'm getting to the point where I am adding dynamic objects to the stage for testing. This has prompted me to consider how I would like my character and other objects to behave when they collide. A typical staple in many 2D platformer type games is that the player takes damage upon touching an enemy, and then essentially becomes able to pass through enemies during a period of invulnerability, and at the same time, enemies are able to pass through eachother freely. I personally don't want to take this approach, it feels strange to me that the player should receive arbitrary damage for harmless contact to an enemy, despite whether the enemy is attacking or not, and I would like my enemies' interactions between each other (and my player) to be a little more organic, so to speak. In my head I sort of have this idea where a game object (player, or non player) would be able to push other game objects around by manner of 'pushing' each other out of one anothers' bounding boxes if there is an intersection, and maybe correlate the repelling force to how much their bounding boxes are intersecting. The problem I'm experiencing is I have no idea what the math might look like for something like this? I'll show what work I've done so far, it sort of works, but it's jittery, and generally not quite what I would pass in a functional game: //Clears the anti-duplicate buffer collisionRecord.Clear(); //pick a thing foreach (GameObject entity in entities) { //pick another thing foreach (GameObject subject in entities) { //check to make sure both things aren't the same thing if (!ReferenceEquals(entity, subject)) { //check to see if thing2 is in semi-near proximity to thing1 if (entity.WideProximityArea.Intersects(subject.CollisionRectangle) || entity.WideProximityArea.Contains(subject.CollisionRectangle)) { //check to see if thing2 and thing1 are colliding. if (entity.CollisionRectangle.Intersects(subject.CollisionRectangle) || entity.CollisionRectangle.Contains(subject.CollisionRectangle) || subject.CollisionRectangle.Contains(entity.CollisionRectangle)) { //check if we've already resolved their collision or not. if (!collisionRecord.ContainsKey(entity.GetHashCode())) { //more duplicate resolution checking. if (!collisionRecord.ContainsKey(subject.GetHashCode())) { //if thing1 is traveling right... if (entity.Velocity.X > 0) { //if it isn't too far to the right... if (subject.CollisionRectangle.Contains(new Microsoft.Xna.Framework.Rectangle(entity.CollisionRectangle.Right, entity.CollisionRectangle.Y, 1, entity.CollisionRectangle.Height)) || subject.CollisionRectangle.Intersects(new Microsoft.Xna.Framework.Rectangle(entity.CollisionRectangle.Right, entity.CollisionRectangle.Y, 1, entity.CollisionRectangle.Height))) { //Find how deep thing1 is intersecting thing2's collision box; float offset = entity.CollisionRectangle.Right - subject.CollisionRectangle.Left; //Move both things in opposite directions half the length of the intersection, pushing thing1 to the left, and thing2 to the right. entity.Velocities.Add(new Vector2(-(((offset * 4) * (float)gameTime.ElapsedGameTime.TotalMilliseconds)), 0)); subject.Velocities.Add(new Vector2((((offset * 4) * (float)gameTime.ElapsedGameTime.TotalMilliseconds)), 0)); } } //if thing1 is traveling left... if (entity.Velocity.X < 0) { //if thing1 isn't too far left... if (entity.CollisionRectangle.Contains(new Microsoft.Xna.Framework.Rectangle(subject.CollisionRectangle.Right, subject.CollisionRectangle.Y, 1, subject.CollisionRectangle.Height)) || entity.CollisionRectangle.Intersects(new Microsoft.Xna.Framework.Rectangle(subject.CollisionRectangle.Right, subject.CollisionRectangle.Y, 1, subject.CollisionRectangle.Height))) { //Find how deep thing1 is intersecting thing2's collision box; float offset = subject.CollisionRectangle.Right - entity.CollisionRectangle.Left; //Move both things in opposite directions half the length of the intersection, pushing thing1 to the right, and thing2 to the left. entity.Velocities.Add(new Vector2((((offset * 4) * (float)gameTime.ElapsedGameTime.TotalMilliseconds)), 0)); subject.Velocities.Add(new Vector2(-(((offset * 4) * (float)gameTime.ElapsedGameTime.TotalMilliseconds)), 0)); } } //Make record that thing1 and thing2 have interacted and the collision has been solved, so that if thing2 is picked next in the foreach loop, it isn't checked against thing1 a second time before the next update. collisionRecord.Add(entity.GetHashCode(), subject.GetHashCode()); } } } } } } } } One of the biggest issues with my code aside from the jitteriness is that if one character were to land on top of another character, it very suddenly and abruptly resolves the collision, whereas I would like a more subtle and gradual resolution. Any thoughts or ideas are incredibly welcome and helpful.

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  • XNA - 3D AABB collision detection and response

    - by fastinvsqrt
    I've been fiddling around with 3D AABB collision in my voxel engine for the last couple of days, and every method I've come up with thus far has been almost correct, but each one never quite worked exactly the way I hoped it would. Currently what I do is get two bounding boxes for my entity, one modified by the X translation component and the other by the Z component, and check if each collides with any of the surrounding chunks (chunks have their own octrees that are populated only with blocks that support collision). If there is a collision, then I cast out rays into that chunk to get the shortest collision distance, and set the translation component to that distance if the component is greater than the distance. The problem is that sometimes collisions aren't even registered. Here's a video on YouTube that I created showing what I mean. I suspect the problem may be with the rays that I cast to get the collision distance not being where I think they are, but I'm not entirely sure what would be wrong with them if they are indeed the problem. Here is my code for collision detection and response in the X direction (the Z direction is basically the same): // create the XZ offset vector Vector3 offsXZ = new Vector3( ( _translation.X > 0.0f ) ? SizeX / 2.0f : ( _translation.X < 0.0f ) ? -SizeX / 2.0f : 0.0f, 0.0f, ( _translation.Z > 0.0f ) ? SizeZ / 2.0f : ( _translation.Z < 0.0f ) ? -SizeZ / 2.0f : 0.0f ); // X physics BoundingBox boxx = GetBounds( _translation.X, 0.0f, 0.0f ); if ( _translation.X > 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Right, offsXZ ) - 0.0001f; if ( dist < _translation.X ) { _translation.X = dist; } } } } else if ( _translation.X < 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Left, offsXZ ) - 0.0001f; if ( dist < -_translation.X ) { _translation.X = -dist; } } } } And here is my implementation for GetShortestCollisionDistance: private float GetShortestCollisionDistance( Chunk chunk, Vector3 rayDir, Vector3 offs ) { int startY = (int)( -SizeY / 2.0f ); int endY = (int)( SizeY / 2.0f ); int incY = (int)Cube.Size; float dist = Chunk.Size; for ( int y = startY; y <= endY; y += incY ) { // Position is the center of the entity's bounding box Ray ray = new Ray( new Vector3( Position.X + offs.X, Position.Y + offs.Y + y, Position.Z + offs.Z ), rayDir ); // Chunk.GetIntersections(Ray) returns Dictionary<Block, float?> foreach ( var pair in chunk.GetIntersections( ray ) ) { if ( pair.Value.HasValue && pair.Value.Value < dist ) { dist = pair.Value.Value; } } } return dist; } I realize some of this code can be consolidated to help with speed, but my main concern right now is to get this bit of physics programming to actually work.

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  • OpenCV: Shift/Align face image relative to reference Image (Image Registration)

    - by Abhischek
    I am new to OpenCV2 and working on a project in emotion recognition and would like to align a facial image in relation to a reference facial image. I would like to get the image translation working before moving to rotation. Current idea is to run a search within a limited range on both x and y coordinates and use the sum of squared differences as error metric to select the optimal x/y parameters to align the image. I'm using the OpenCV face_cascade function to detect the face images, all images are resized to a fixed (128x128). Question: Which parameters of the Mat image do I need to modify to shift the image in a positive/negative direction on both x and y axis? I believe setImageROI is no longer supported by Mat datatypes? I have the ROIs for both faces available however I am unsure how to use them. void alignImage(vector<Rect> faceROIstore, vector<Mat> faceIMGstore) { Mat refimg = faceIMGstore[1]; //reference image Mat dispimg = faceIMGstore[52]; // "displaced" version of reference image //Rect refROI = faceROIstore[1]; //Bounding box for face in reference image //Rect dispROI = faceROIstore[52]; //Bounding box for face in displaced image Mat aligned; matchTemplate(dispimg, refimg, aligned, CV_TM_SQDIFF_NORMED); imshow("Aligned image", aligned); } The idea for this approach is based on Image Alignment Tutorial by Richard Szeliski Working on Windows with OpenCV 2.4. Any suggestions are much appreciated.

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  • Why does this Object wonk out & get deleted ?

    - by brainydexter
    Stepping through the debugger, the BBox object is okay at the entry of the function, but as soon as it enters the function, the vfptr object points to 0xccccc. I don't get it. What is causing this ? Why is there a virtual table reference in there when the object is not derived from other class. (Though, it resides in GameObject from which my Player class inherits and I retrieve the BBox from within player. But, why does the BBox have the reference ? Shouldn't it be player who should be maintained in that reference ?) For 1; some code for reference: A. I retrieve the bounding box from player. This returns a bounding box as expected. I then send its address to GetGridCells. const BoundingBox& l_Bbox = l_pPlayer-GetBoundingBox(); boost::unordered_set < Cell*, CellPHash & l_GridCells = GetGridCells ( &l_Bbox ); B. This is where a_pBoundingBox goes crazy and gets that garbage value. boost::unordered_set< Cell*, CellPHash CollisionMgr::GetGridCells(const BoundingBox *a_pBoundingBox) { I think the following code is also pertinent, so I'm sticking this in here anyways: const BoundingBox& Player::GetBoundingBox(void) { return BoundingBox( &GetBoundingSphere() ); } const BoundingSphere& Player::GetBoundingSphere(void) { BoundingSphere& l_BSphere = m_pGeomMesh-m_BoundingSphere; l_BSphere.m_Center = GetPosition(); return l_BSphere; } // BoundingBox Constructor BoundingBox(const BoundingSphere* a_pBoundingSphere); Can anyone please give me some idea as to why this is happening? Also, if you want me to post more code, please do let me know. Thanks!

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  • Choosing circle radius to fully fill a rectangle

    - by Andy
    Hi, the pixman image library can draw radial color gradients between two circles. I'd like the radial gradient to fill a rectangular area defined by "width" and "height" completely. Now my question, how should I choose the radius of the outer circle? My current parameters are the following: A) inner circle (start of gradient) center pointer of inner circle: (width*0.5|height*0.5) radius of inner circle: 1 color: black B) outer circle (end of gradient) center pointer of outer circle: (width*0.5|height*0.5) radius of outer circle: ??? color: white How should I choose the radius of the outer circle to make sure that the outer circle will entirely fill my bounding rectangle defined by width*height. There shall be no empty areas in the corners, the area shall be completely covered by the circle. In other words, the bounding rectangle width,height must fit entirely into the outer circle. Choosing outer_radius = max(width, height) * 0.5 as the radius for the outer circle is obviously not enough. It must be bigger, but how much bigger? Thanks!

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  • Raphael SVG VML Implement Multi Pivot Points for Rotation

    - by Cody N
    Over the last two days I've effectively figured out how NOT to rotate Raphael Elements. Basically I am trying to implement a multiple pivot points on element to rotate it by mouse. When a user enters rotation mode 5 pivots are created. One for each corner of the bounding box and one in the center of the box. When the mouse is down and moving it is simple enough to rotate around the pivot using Raphael elements.rotate(degrees, x, y) and calculating the degrees based on the mouse positions and atan2 to the pivot point. The problem arises after I've rotated the element, bbox, and the other pivots. There x,y position in the same only there viewport is different. In an SVG enabled browser I can create new pivot points based on matrixTransformation and getCTM. However after creating the first set of new pivots, every rotation after the pivots get further away from the transformed bbox due to rounding errors. The above is not even an option in IE since in is VML based and cannot account for transformation. Is the only effective way to implement element rotation is by using rotate absolute or rotating around the center of the bounding box? Is it possible at all the create multi pivot points for an object and update them after mouseup to remain in the corners and center of the transformed bbox?

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  • Is there a good digraph layout library callable from C++?

    - by Steve314
    The digraphs represent finite automata. Up until now my test program has been writing out dot files for testing. This is pretty good both for regression testing (keep the verified output files in subversion, ask it if there has been a change) and for visualisation. However, there are some problems... Basically, I want something callable from C++ and which plans a layout for my states and transitions but leaves the drawing to me - something that will allow me to draw things however I want and draw on GUI (wxWidgets) windows. I also want a license which will allow commercial use - I don't need that at present, and I may very well release as open source, but I don't want to limit my options ATM. The problems with GraphViz are (1) the warnings about building from source on Windows, (2) all the unnecessary dependencies for rendering and parsing, and (3) the (presumed) lack of a documented API specifically and purely for layout. Basically, I want to be able to specify my states (with bounding rectangle sizes) and transitions, and read out positions for the states and waypoints for each transition, then draw based on those co-ordinates myself. I haven't really figured out how annotations on transitions should be handled, but there should be some kind of provision for specifying bounding-box-sizes for those, associating them with transitions, and reading out positions. Does anyone know of a library that can handle those requirements? I'm not necessarily against implementing something for myself, but in this case I'd rather avoid it if possible.

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  • What is the best approach to 2D collision detection on the iPhone?

    - by Magic Bullet Dave
    Been working on this problem of collision detection and there appears to be 3 main approaches I could take: Sprite and mask approach. (AND the overlap of the sprites and check for a non-zero number in the resulting sprite pixel data). Bounding circles, rectangles or polygons. (Create one or more shapes that enclose the sprites and do the basic maths to check for overlaps). Use an existing sprite library. The first approach, even though it would have been the way I would have done it in the old days of 16x16 sprite blocks, it appears that there just isn’t an easy way of getting at the individual image pixel data and/or alpha channel within Quartz (or OPENGL for that matter). Detecting the overlap of the bounding box is easy, but then creating a 3rd image from the overlap and then testing it for pixels is complicated and my gut feel is that even if we could get it to work would be slow. Am I missing something neat here? The second approach involves dividing up our sprites into several polygons and testing them for overlaps. The more polygons the more accurate the collision detection. The benefit is that it is fast, and can be accurate. The downside is it makes the sprite creation more complicated. i.e., we have to create the polygons for each sprite. For speed the best approach is to create a tree of polygons. The 3rd approach I’m not sure about as it involves buying code (or using an open source licence). I am not sure what the best library to use is or whether this would make life easier or give us a problem integrating this into our app. So in short I am favouring the polygon and tree approach and would appreciate you views on this before I go and write lots of code. Best regards Dave

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  • How to -accurately- measure size in pixels of text being drawn on a canvas by drawTextOnPath()

    - by Nick
    I'm using drawTextOnPath() to display some text on a Canvas and I need to know the dimensions of the text being drawn. I know this is not feasible for paths composed of multiple segments, curves, etc. but my path is a single segment which is perfectly horizontal. I am using Paint.getTextBounds() to get a Rect with the dimensions of the text I want to draw. I use this rect to draw a bounding box around the text when I draw it at an arbitrary location. Here's some simplified code that reflects what I am currently doing: // to keep this example simple, always at origin (0,0) public drawBoundedText(Canvas canvas, String text, Paint paint) { Rect textDims = new Rect(); paint.getTextBounds(text,0, text.length(), textDims); float hOffset = 0; float vOffset = paint.getFontMetrics().descent; // vertically centers text float startX = textDims.left; / 0 float startY = textDims.bottom; float endX = textDims.right; float endY = textDims.bottom; path.moveTo(startX, startY); path.lineTo(endX, endY); path.close(); // draw the text canvas.drawTextOnPath(text, path, 0, vOffset, paint); // draw bounding box canvas.drawRect(textDims, paint); } The results are -close- but not perfect. If I replace the second to last line with: canvas.drawText(text, startX, startY - vOffset, paint); Then it works perfectly. Usually there is a gap of 1-3 pixels on the right and bottom edges. The error seems to vary with font size as well. Any ideas? It's possible I'm doing everything right and the problem is with drawTextOnPath(); the text quality very visibly degrades when drawing along paths, even if the path is horizontal, likely because of the interpolation algorithm or whatever its using behind the scenes. I wouldnt be surprised to find out that the size jitter is also coming from there.

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  • How to get results efficiently out of an Octree/Quadtree?

    - by Reveazure
    I am working on a piece of 3D software that has sometimes has to perform intersections between massive numbers of curves (sometimes ~100,000). The most natural way to do this is to do an N^2 bounding box check, and then those curves whose bounding boxes overlap get intersected. I heard good things about octrees, so I decided to try implementing one to see if I would get improved performance. Here's my design: Each octree node is implemented as a class with a list of subnodes and an ordered list of object indices. When an object is being added, it's added to the lowest node that entirely contains the object, or some of that node's children if the object doesn't fill all of the children. Now, what I want to do is retrieve all objects that share a tree node with a given object. To do this, I traverse all tree nodes, and if they contain the given index, I add all of their other indices to an ordered list. This is efficient because the indices within each node are already ordered, so finding out if each index is already in the list is fast. However, the list ends up having to be resized, and this takes up most of the time in the algorithm. So what I need is some kind of tree-like data structure that will allow me to efficiently add ordered data, and also be efficient in memory. Any suggestions?

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  • UIComponent in Swc

    - by mustISignUp
    In Flash, if i create a custom Movieclip, and compile it to a SWC, i can use it in .fla files (by linking to the .swc).. var mcInstance = new CustomMovieClip(); addChild(mcInstance); All the arrangement of graphics on the custom movieClip's layers is preserved. If i subclass UIComponent and compile to a swc, I can use the custom Class in my .fla file, but the new instance doesn't seem to construct the children arranged on the layers. I know that the correct way to make a custom component is to have the two frames, first to specify bounding box, second frame for assets, and that the first graphic in frame 1 is removed at runtime. But i'm not really trying to make a reusable component - i just want to use the UIComponent class (It seems to have some nice extensions to Sprite). As i really want some hand-positioned layers inside the component i figured i could have the bounding box as the first element on frame 1 (knowing that it would be removed), but any other items i put on frame 1 would be preserved - buttons, images, lines, etc. Is this possible?

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  • Espeak SAPI/dll usage on Windows ?

    - by Quandary
    Question: I am trying to use the espeak text-to-speech engine. So for I got it working wounderfully on linux (code below). Now I wanted to port this basic program to windows, too, but it's nearly impossible... Part of the problem is that the windows dll only allows for AUDIO_OUTPUT_SYNCHRONOUS, which means it requires a callback, but I can't figure out how to play the audio from the callback... First it crashed, then I realized, I need a callback function, now I get the data in the callback function, but I don't know how to play it... as it is neither a wav file nor plays automatically as on Linux. The sourceforge site is rather useless, because it basically says use the SAPI version, but then there is no example on how to use the sapi espeak dll... Anyway, here's my code, can anybody help? #ifdef __cplusplus #include <cstdio> #include <cstdlib> #include <cstring> else #include <stdio.h> #include <stdlib.h> #include <string.h> endif include include //#include "speak_lib.h" include "espeak/speak_lib.h" // libespeak-dev: /usr/include/espeak/speak_lib.h // apt-get install libespeak-dev // apt-get install libportaudio-dev // g++ -o mine mine.cpp -lespeak // g++ -o mine mine.cpp -I/usr/include/espeak/ -lespeak // gcc -o mine mine.cpp -I/usr/include/espeak/ -lespeak char voicename[40]; int samplerate; int quiet = 0; static char genders[4] = {' ','M','F',' '}; //const char *data_path = "/usr/share/"; // /usr/share/espeak-data/ const char *data_path = NULL; // use default path for espeak-data int strrcmp(const char *s, const char *sub) { int slen = strlen(s); int sublen = strlen(sub); return memcmp(s + slen - sublen, sub, sublen); } char * strrcpy(char *dest, const char *source) { // Pre assertions assert(dest != NULL); assert(source != NULL); assert(dest != source); // tk: parentheses while((*dest++ = *source++)) ; return(--dest); } const char* GetLanguageVoiceName(const char* pszShortSign) { #define LANGUAGE_LENGTH 30 static char szReturnValue[LANGUAGE_LENGTH] ; memset(szReturnValue, 0, LANGUAGE_LENGTH); for (int i = 0; pszShortSign[i] != '\0'; ++i) szReturnValue[i] = (char) tolower(pszShortSign[i]); const espeak_VOICE **voices; espeak_VOICE voice_select; voices = espeak_ListVoices(NULL); const espeak_VOICE *v; for(int ix=0; (v = voices[ix]) != NULL; ix++) { if( !strrcmp( v->languages, szReturnValue) ) { strcpy(szReturnValue, v->name); return szReturnValue; } } // End for strcpy(szReturnValue, "default"); return szReturnValue; } // End function getvoicename void ListVoices() { const espeak_VOICE **voices; espeak_VOICE voice_select; voices = espeak_ListVoices(NULL); const espeak_VOICE *v; for(int ix=0; (v = voices[ix]) != NULL; ix++) { printf("Shortsign: %s\n", v->languages); printf("age: %d\n", v->age); printf("gender: %c\n", genders[v->gender]); printf("name: %s\n", v->name); printf("\n\n"); } // End for } // End function getvoicename int main() { printf("Hello World!\n"); const char* szVersionInfo = espeak_Info(NULL); printf("Espeak version: %s\n", szVersionInfo); samplerate = espeak_Initialize(AUDIO_OUTPUT_PLAYBACK,0,data_path,0); strcpy(voicename, "default"); // espeak --voices strcpy(voicename, "german"); strcpy(voicename, GetLanguageVoiceName("DE")); if(espeak_SetVoiceByName(voicename) != EE_OK) { printf("Espeak setvoice error...\n"); } static char word[200] = "Hello World" ; strcpy(word, "TV-fäns aufgepasst, es ist 20 Uhr 15. Zeit für Rambo 3"); strcpy(word, "Unnamed Player wurde zum Opfer von GSG9"); int speed = 220; int volume = 500; // volume in range 0-100 0=silence int pitch = 50; // base pitch, range 0-100. 50=normal // espeak.cpp 625 espeak_SetParameter(espeakRATE, speed, 0); espeak_SetParameter(espeakVOLUME,volume,0); espeak_SetParameter(espeakPITCH,pitch,0); // espeakRANGE: pitch range, range 0-100. 0-monotone, 50=normal // espeakPUNCTUATION: which punctuation characters to announce: // value in espeak_PUNCT_TYPE (none, all, some), espeak_VOICE *voice_spec = espeak_GetCurrentVoice(); voice_spec->gender=2; // 0=none 1=male, 2=female, //voice_spec->age = age; espeak_SetVoiceByProperties(voice_spec); espeak_Synth( (char*) word, strlen(word)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, NULL, NULL); espeak_Synchronize(); strcpy(voicename, GetLanguageVoiceName("EN")); espeak_SetVoiceByName(voicename); strcpy(word, "Geany was fragged by GSG9 Googlebot"); strcpy(word, "Googlebot"); espeak_Synth( (char*) word, strlen(word)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, NULL, NULL); espeak_Synchronize(); espeak_Terminate(); printf("Espeak terminated\n"); return EXIT_SUCCESS; } /* if(espeak_SetVoiceByName(voicename) != EE_OK) { memset(&voice_select,0,sizeof(voice_select)); voice_select.languages = voicename; if(espeak_SetVoiceByProperties(&voice_select) != EE_OK) { fprintf(stderr,"%svoice '%s'\n",err_load,voicename); exit(2); } } */ The above code is for Linux. The below code is about as far as I got on Vista x64 (32 bit emu): #ifdef __cplusplus #include <cstdio> #include <cstdlib> #include <cstring> else #include <stdio.h> #include <stdlib.h> #include <string.h> endif include include include "speak_lib.h" //#include "espeak/speak_lib.h" // libespeak-dev: /usr/include/espeak/speak_lib.h // apt-get install libespeak-dev // apt-get install libportaudio-dev // g++ -o mine mine.cpp -lespeak // g++ -o mine mine.cpp -I/usr/include/espeak/ -lespeak // gcc -o mine mine.cpp -I/usr/include/espeak/ -lespeak char voicename[40]; int iSampleRate; int quiet = 0; static char genders[4] = {' ','M','F',' '}; //const char *data_path = "/usr/share/"; // /usr/share/espeak-data/ //const char *data_path = NULL; // use default path for espeak-data const char *data_path = "C:\Users\Username\Desktop\espeak-1.43-source\espeak-1.43-source\"; int strrcmp(const char *s, const char *sub) { int slen = strlen(s); int sublen = strlen(sub); return memcmp(s + slen - sublen, sub, sublen); } char * strrcpy(char *dest, const char *source) { // Pre assertions assert(dest != NULL); assert(source != NULL); assert(dest != source); // tk: parentheses while((*dest++ = *source++)) ; return(--dest); } const char* GetLanguageVoiceName(const char* pszShortSign) { #define LANGUAGE_LENGTH 30 static char szReturnValue[LANGUAGE_LENGTH] ; memset(szReturnValue, 0, LANGUAGE_LENGTH); for (int i = 0; pszShortSign[i] != '\0'; ++i) szReturnValue[i] = (char) tolower(pszShortSign[i]); const espeak_VOICE **voices; espeak_VOICE voice_select; voices = espeak_ListVoices(NULL); const espeak_VOICE *v; for(int ix=0; (v = voices[ix]) != NULL; ix++) { if( !strrcmp( v->languages, szReturnValue) ) { strcpy(szReturnValue, v->name); return szReturnValue; } } // End for strcpy(szReturnValue, "default"); return szReturnValue; } // End function getvoicename void ListVoices() { const espeak_VOICE **voices; espeak_VOICE voice_select; voices = espeak_ListVoices(NULL); const espeak_VOICE *v; for(int ix=0; (v = voices[ix]) != NULL; ix++) { printf("Shortsign: %s\n", v->languages); printf("age: %d\n", v->age); printf("gender: %c\n", genders[v->gender]); printf("name: %s\n", v->name); printf("\n\n"); } // End for } // End function getvoicename /* Callback from espeak. Directly speaks using AudioTrack. */ define LOGI(x) printf("%s\n", x) static int AndroidEspeakDirectSpeechCallback(short *wav, int numsamples, espeak_EVENT *events) { char buf[100]; sprintf(buf, "AndroidEspeakDirectSpeechCallback: %d samples", numsamples); LOGI(buf); if (wav == NULL) { LOGI("Null: speech has completed"); } if (numsamples > 0) { //audout->write(wav, sizeof(short) * numsamples); sprintf(buf, "AudioTrack wrote: %d bytes", sizeof(short) * numsamples); LOGI(buf); } return 0; // continue synthesis (1 is to abort) } static int AndroidEspeakSynthToFileCallback(short *wav, int numsamples,espeak_EVENT *events) { char buf[100]; sprintf(buf, "AndroidEspeakSynthToFileCallback: %d samples", numsamples); LOGI(buf); if (wav == NULL) { LOGI("Null: speech has completed"); } // The user data should contain the file pointer of the file to write to //void* user_data = events->user_data; FILE* user_data = fopen ( "myfile1.wav" , "ab" ); FILE* fp = static_cast<FILE *>(user_data); // Write all of the samples fwrite(wav, sizeof(short), numsamples, fp); return 0; // continue synthesis (1 is to abort) } int main() { printf("Hello World!\n"); const char* szVersionInfo = espeak_Info(NULL); printf("Espeak version: %s\n", szVersionInfo); iSampleRate = espeak_Initialize(AUDIO_OUTPUT_SYNCHRONOUS, 4096, data_path, 0); if (iSampleRate <= 0) { printf("Unable to initialize espeak"); return EXIT_FAILURE; } //samplerate = espeak_Initialize(AUDIO_OUTPUT_PLAYBACK,0,data_path,0); //ListVoices(); strcpy(voicename, "default"); // espeak --voices //strcpy(voicename, "german"); //strcpy(voicename, GetLanguageVoiceName("DE")); if(espeak_SetVoiceByName(voicename) != EE_OK) { printf("Espeak setvoice error...\n"); } static char word[200] = "Hello World" ; strcpy(word, "TV-fäns aufgepasst, es ist 20 Uhr 15. Zeit für Rambo 3"); strcpy(word, "Unnamed Player wurde zum Opfer von GSG9"); int speed = 220; int volume = 500; // volume in range 0-100 0=silence int pitch = 50; // base pitch, range 0-100. 50=normal // espeak.cpp 625 espeak_SetParameter(espeakRATE, speed, 0); espeak_SetParameter(espeakVOLUME,volume,0); espeak_SetParameter(espeakPITCH,pitch,0); // espeakRANGE: pitch range, range 0-100. 0-monotone, 50=normal // espeakPUNCTUATION: which punctuation characters to announce: // value in espeak_PUNCT_TYPE (none, all, some), //espeak_VOICE *voice_spec = espeak_GetCurrentVoice(); //voice_spec->gender=2; // 0=none 1=male, 2=female, //voice_spec->age = age; //espeak_SetVoiceByProperties(voice_spec); //espeak_SetSynthCallback(AndroidEspeakDirectSpeechCallback); espeak_SetSynthCallback(AndroidEspeakSynthToFileCallback); unsigned int unique_identifier; espeak_ERROR err = espeak_Synth( (char*) word, strlen(word)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, &unique_identifier, NULL); err = espeak_Synchronize(); /* strcpy(voicename, GetLanguageVoiceName("EN")); espeak_SetVoiceByName(voicename); strcpy(word, "Geany was fragged by GSG9 Googlebot"); strcpy(word, "Googlebot"); espeak_Synth( (char*) word, strlen(word)+1, 0, POS_CHARACTER, 0, espeakCHARS_AUTO, NULL, NULL); espeak_Synchronize(); */ // espeak_Cancel(); espeak_Terminate(); printf("Espeak terminated\n"); system("pause"); return EXIT_SUCCESS; }

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  • 17 new features in Visual Studio 2010

    - by vik20000in
    Visual studio 2010 has been released to RTM a few days back. This release of Visual studio 2010 comes with a big number of improvements on many fronts. In this post I will try and point out some of the major improvements in Visual Studio 2010. 1)      Visual studio IDE Improvement. Visual studio IDE has been rewritten in WPF. The look and feel of the studio has been improved for improved readability. Start page has been redesigned and template so that anyone can change the start page as they wish. 2)      Multiple Monitor - Support for Multiple Monitor was already there in Visual studio. But in this edition it has been improved as much that we can now place the document, design and code window outside the IDE in another monitor. 3)      ZOOM in Code Editor – Making the editors in WPF has made significant improvement for them. The best one that I like is the ZOOM feature. We can now zoom in the code editor with the help of the ctrl + Mouse scroll. The zoom feature does not work on the Design surface or windows with icon like solution view and toolbox. 4)      Box Selection - Another Important improvement in the Visual studio 2010 is the box selection. We can select a rectangular by holding down the Alt Key and selecting with mouse.  Now in the rectangular selection we can insert text, Paste same code in different line etc. This is helpful if you want to convert a number of variables from public to private etc… 5)      New Improved Search – One of the best productivity improvements in Visual studio 2010 is its new search as you type support. This has been done in the Navigate To window which can be brought up by pressing (Ctrl + ,). The navigate To windows also take help of the Camel casing and will be able to search with the help of camel casing when character is entered in upper case. For example we can search AOH for AddOrederHeader. 6)      Call Hierarchy – This feature is only available to the Visual C# and Visual C++ editor. The call hierarchy windows displays the calls made to and from (yes both to and from) a selected method property or a constructor. The call hierarchy also shows the implementation of interface and the overrides of virtual or abstract methods. This window is very helpful in understanding the code flow, and evaluating the effect of making changes. The best part is it is available at design time and not at runtime only like a debugger. 7)      Highlighting references – One of the very cool stuff in Visual Studio 2010 is the fact if you select a variable then all the use of that variable will be highlighted alongside. This should work for all the result of symbols returned by Find all reference. This also works for Name of class, objects variable, properties and methods. We can also use the Ctrl + Shift + Down Arrow or Up Arror to move through them. 8)      Generate from usage - The Generate from usage feature lets you use classes and members before you define them. You can generate a stub for any undefined class, constructor, method, property, field, or enum that you want to use but have not yet defined. You can generate new types and members without leaving your current location in code, This minimizes interruption to your workflow.9)      IntelliSense Suggestion Mode - IntelliSense now provides two alternatives for IntelliSense statement completion, completion mode and suggestion mode. Use suggestion mode for situations where classes and members are used before they are defined. In suggestion mode, when you type in the editor and then commit the entry, the text you typed is inserted into the code. When you commit an entry in completion mode, the editor shows the entry that is highlighted on the members list. When an IntelliSense window is open, you can press CTRL+ALT+SPACEBAR to toggle between completion mode and suggestion mode. 10)   Application Lifecycle Management – A client application for management of application lifecycle like version control, work item tracking, build automation, team portal etc is available for free (this is not available for express edition.). 11)   Start Page – The start page has been redesigned with WPF for new functionality and look. Tabbed areas are provided for content from different source including MSDN. Once you open some project the start page closes automatically. The list of recent project also lets you remove project from the list. And above all the start page is customizable enough to be changed as per individual requirement. 12)   Extension Manager – Visual Studio 2010 has provided good ways to be extended. We can also use MEF to extend most of the features of Visual Studio. The new extension manager now can go the visual studio gallery and install the extension without even opening any explorer. 13)   Code snippets – Visual studio 2010 for HTML, Jscript and Asp.net also. 14)   Improved Intelligence for JavaScript has been improved vastly (around 2-5 times). Intelligence now also shows the XML documentation comment on the go. 15)   Web Deployment – Web Deployment has been vastly improved. We can package and publish the web application in one click. Three major supported deployment scenarios are Web packages, one click deployment and Web configuration Transformation. 16)   SharePoint - Visual Studio 2010 also brings vastly improved development experience for SharePoint. We can create, edit, debug, package, deploy and activate SharePoint project from within Visual Studio. Deployment of Site is as easy as hitting F5. 17)   Azure – Visual Studio 2010 also comes with handy improvement for developing on windows Azure environment. Vikram

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  • SQL SERVER – Introduction to Rollup Clause

    - by pinaldave
    In this article we will go over basic understanding of Rollup clause in SQL Server. ROLLUP clause is used to do aggregate operation on multiple levels in hierarchy. Let us understand how it works by using an example. Consider a table with the following structure and data: CREATE TABLE tblPopulation ( Country VARCHAR(100), [State] VARCHAR(100), City VARCHAR(100), [Population (in Millions)] INT ) GO INSERT INTO tblPopulation VALUES('India', 'Delhi','East Delhi',9 [...]

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  • C#/.NET Little Pitfalls: The Dangers of Casting Boxed Values

    - by James Michael Hare
    Starting a new series to parallel the Little Wonders series.  In this series, I will examine some of the small pitfalls that can occasionally trip up developers. Introduction: Of Casts and Conversions What happens when we try to assign from an int and a double and vice-versa? 1: double pi = 3.14; 2: int theAnswer = 42; 3:  4: // implicit widening conversion, compiles! 5: double doubleAnswer = theAnswer; 6:  7: // implicit narrowing conversion, compiler error! 8: int intPi = pi; As you can see from the comments above, a conversion from a value type where there is no potential data loss is can be done with an implicit conversion.  However, when converting from one value type to another may result in a loss of data, you must make the conversion explicit so the compiler knows you accept this risk.  That is why the conversion from double to int will not compile with an implicit conversion, we can make the conversion explicit by adding a cast: 1: // explicit narrowing conversion using a cast, compiler 2: // succeeds, but results may have data loss: 3: int intPi = (int)pi; So for value types, the conversions (implicit and explicit) both convert the original value to a new value of the given type.  With widening and narrowing references, however, this is not the case.  Converting reference types is a bit different from converting value types.  First of all when you perform a widening or narrowing you don’t really convert the instance of the object, you just convert the reference itself to the wider or narrower reference type, but both the original and new reference type both refer back to the same object. Secondly, widening and narrowing for reference types refers the going down and up the class hierarchy instead of referring to precision as in value types.  That is, a narrowing conversion for a reference type means you are going down the class hierarchy (for example from Shape to Square) whereas a widening conversion means you are going up the class hierarchy (from Square to Shape).  1: var square = new Square(); 2:  3: // implicitly convers because all squares are shapes 4: // (that is, all subclasses can be referenced by a superclass reference) 5: Shape myShape = square; 6:  7: // implicit conversion not possible, not all shapes are squares! 8: // (that is, not all superclasses can be referenced by a subclass reference) 9: Square mySquare = (Square) myShape; So we had to cast the Shape back to Square because at that point the compiler has no way of knowing until runtime whether the Shape in question is truly a Square.  But, because the compiler knows that it’s possible for a Shape to be a Square, it will compile.  However, if the object referenced by myShape is not truly a Square at runtime, you will get an invalid cast exception. Of course, there are other forms of conversions as well such as user-specified conversions and helper class conversions which are beyond the scope of this post.  The main thing we want to focus on is this seemingly innocuous casting method of widening and narrowing conversions that we come to depend on every day and, in some cases, can bite us if we don’t fully understand what is going on!  The Pitfall: Conversions on Boxed Value Types Can Fail What if you saw the following code and – knowing nothing else – you were asked if it was legal or not, what would you think: 1: // assuming x is defined above this and this 2: // assignment is syntactically legal. 3: x = 3.14; 4:  5: // convert 3.14 to int. 6: int truncated = (int)x; You may think that since x is obviously a double (can’t be a float) because 3.14 is a double literal, but this is inaccurate.  Our x could also be dynamic and this would work as well, or there could be user-defined conversions in play.  But there is another, even simpler option that can often bite us: what if x is object? 1: object x; 2:  3: x = 3.14; 4:  5: int truncated = (int) x; On the surface, this seems fine.  We have a double and we place it into an object which can be done implicitly through boxing (no cast) because all types inherit from object.  Then we cast it to int.  This theoretically should be possible because we know we can explicitly convert a double to an int through a conversion process which involves truncation. But here’s the pitfall: when casting an object to another type, we are casting a reference type, not a value type!  This means that it will attempt to see at runtime if the value boxed and referred to by x is of type int or derived from type int.  Since it obviously isn’t (it’s a double after all) we get an invalid cast exception! Now, you may say this looks awfully contrived, but in truth we can run into this a lot if we’re not careful.  Consider using an IDataReader to read from a database, and then attempting to select a result row of a particular column type: 1: using (var connection = new SqlConnection("some connection string")) 2: using (var command = new SqlCommand("select * from employee", connection)) 3: using (var reader = command.ExecuteReader()) 4: { 5: while (reader.Read()) 6: { 7: // if the salary is not an int32 in the SQL database, this is an error! 8: // doesn't matter if short, long, double, float, reader [] returns object! 9: total += (int) reader["annual_salary"]; 10: } 11: } Notice that since the reader indexer returns object, if we attempt to convert using a cast to a type, we have to make darn sure we use the true, actual type or this will fail!  If the SQL database column is a double, float, short, etc this will fail at runtime with an invalid cast exception because it attempts to convert the object reference! So, how do you get around this?  There are two ways, you could first cast the object to its actual type (double), and then do a narrowing cast to on the value to int.  Or you could use a helper class like Convert which analyzes the actual run-time type and will perform a conversion as long as the type implements IConvertible. 1: object x; 2:  3: x = 3.14; 4:  5: // if you want to cast, must cast out of object to double, then 6: // cast convert. 7: int truncated = (int)(double) x; 8:  9: // or you can call a helper class like Convert which examines runtime 10: // type of the value being converted 11: int anotherTruncated = Convert.ToInt32(x); Summary You should always be careful when performing a conversion cast from values boxed in object that you are actually casting to the true type (or a sub-type). Since casting from object is a widening of the reference, be careful that you either know the exact, explicit type you expect to be held in the object, or instead avoid the cast and use a helper class to perform a safe conversion to the type you desire. Technorati Tags: C#,.NET,Pitfalls,Little Pitfalls,BlackRabbitCoder

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  • SQL SERVER – Guest Post – Architecting Data Warehouse – Niraj Bhatt

    - by pinaldave
    Niraj Bhatt works as an Enterprise Architect for a Fortune 500 company and has an innate passion for building / studying software systems. He is a top rated speaker at various technical forums including Tech·Ed, MCT Summit, Developer Summit, and Virtual Tech Days, among others. Having run a successful startup for four years Niraj enjoys working on – IT innovations that can impact an enterprise bottom line, streamlining IT budgets through IT consolidation, architecture and integration of systems, performance tuning, and review of enterprise applications. He has received Microsoft MVP award for ASP.NET, Connected Systems and most recently on Windows Azure. When he is away from his laptop, you will find him taking deep dives in automobiles, pottery, rafting, photography, cooking and financial statements though not necessarily in that order. He is also a manager/speaker at BDOTNET, Asia’s largest .NET user group. Here is the guest post by Niraj Bhatt. As data in your applications grows it’s the database that usually becomes a bottleneck. It’s hard to scale a relational DB and the preferred approach for large scale applications is to create separate databases for writes and reads. These databases are referred as transactional database and reporting database. Though there are tools / techniques which can allow you to create snapshot of your transactional database for reporting purpose, sometimes they don’t quite fit the reporting requirements of an enterprise. These requirements typically are data analytics, effective schema (for an Information worker to self-service herself), historical data, better performance (flat data, no joins) etc. This is where a need for data warehouse or an OLAP system arises. A Key point to remember is a data warehouse is mostly a relational database. It’s built on top of same concepts like Tables, Rows, Columns, Primary keys, Foreign Keys, etc. Before we talk about how data warehouses are typically structured let’s understand key components that can create a data flow between OLTP systems and OLAP systems. There are 3 major areas to it: a) OLTP system should be capable of tracking its changes as all these changes should go back to data warehouse for historical recording. For e.g. if an OLTP transaction moves a customer from silver to gold category, OLTP system needs to ensure that this change is tracked and send to data warehouse for reporting purpose. A report in context could be how many customers divided by geographies moved from sliver to gold category. In data warehouse terminology this process is called Change Data Capture. There are quite a few systems that leverage database triggers to move these changes to corresponding tracking tables. There are also out of box features provided by some databases e.g. SQL Server 2008 offers Change Data Capture and Change Tracking for addressing such requirements. b) After we make the OLTP system capable of tracking its changes we need to provision a batch process that can run periodically and takes these changes from OLTP system and dump them into data warehouse. There are many tools out there that can help you fill this gap – SQL Server Integration Services happens to be one of them. c) So we have an OLTP system that knows how to track its changes, we have jobs that run periodically to move these changes to warehouse. The question though remains is how warehouse will record these changes? This structural change in data warehouse arena is often covered under something called Slowly Changing Dimension (SCD). While we will talk about dimensions in a while, SCD can be applied to pure relational tables too. SCD enables a database structure to capture historical data. This would create multiple records for a given entity in relational database and data warehouses prefer having their own primary key, often known as surrogate key. As I mentioned a data warehouse is just a relational database but industry often attributes a specific schema style to data warehouses. These styles are Star Schema or Snowflake Schema. The motivation behind these styles is to create a flat database structure (as opposed to normalized one), which is easy to understand / use, easy to query and easy to slice / dice. Star schema is a database structure made up of dimensions and facts. Facts are generally the numbers (sales, quantity, etc.) that you want to slice and dice. Fact tables have these numbers and have references (foreign keys) to set of tables that provide context around those facts. E.g. if you have recorded 10,000 USD as sales that number would go in a sales fact table and could have foreign keys attached to it that refers to the sales agent responsible for sale and to time table which contains the dates between which that sale was made. These agent and time tables are called dimensions which provide context to the numbers stored in fact tables. This schema structure of fact being at center surrounded by dimensions is called Star schema. A similar structure with difference of dimension tables being normalized is called a Snowflake schema. This relational structure of facts and dimensions serves as an input for another analysis structure called Cube. Though physically Cube is a special structure supported by commercial databases like SQL Server Analysis Services, logically it’s a multidimensional structure where dimensions define the sides of cube and facts define the content. Facts are often called as Measures inside a cube. Dimensions often tend to form a hierarchy. E.g. Product may be broken into categories and categories in turn to individual items. Category and Items are often referred as Levels and their constituents as Members with their overall structure called as Hierarchy. Measures are rolled up as per dimensional hierarchy. These rolled up measures are called Aggregates. Now this may seem like an overwhelming vocabulary to deal with but don’t worry it will sink in as you start working with Cubes and others. Let’s see few other terms that we would run into while talking about data warehouses. ODS or an Operational Data Store is a frequently misused term. There would be few users in your organization that want to report on most current data and can’t afford to miss a single transaction for their report. Then there is another set of users that typically don’t care how current the data is. Mostly senior level executives who are interesting in trending, mining, forecasting, strategizing, etc. don’t care for that one specific transaction. This is where an ODS can come in handy. ODS can use the same star schema and the OLAP cubes we saw earlier. The only difference is that the data inside an ODS would be short lived, i.e. for few months and ODS would sync with OLTP system every few minutes. Data warehouse can periodically sync with ODS either daily or weekly depending on business drivers. Data marts are another frequently talked about topic in data warehousing. They are subject-specific data warehouse. Data warehouses that try to span over an enterprise are normally too big to scope, build, manage, track, etc. Hence they are often scaled down to something called Data mart that supports a specific segment of business like sales, marketing, or support. Data marts too, are often designed using star schema model discussed earlier. Industry is divided when it comes to use of data marts. Some experts prefer having data marts along with a central data warehouse. Data warehouse here acts as information staging and distribution hub with spokes being data marts connected via data feeds serving summarized data. Others eliminate the need for a centralized data warehouse citing that most users want to report on detailed data. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Business Intelligence, Data Warehousing, Database, Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • OWB 11gR2 &ndash; Degenerate Dimensions

    - by David Allan
    Ever wondered how to build degenerate dimensions in OWB and get the benefits of slowly changing dimensions and cube loading? Now its possible through some changes in 11gR2 to make the dimension and cube loading much more flexible. This will let you get the benefits of OWB's surrogate key handling and slowly changing dimension reference when loading the fact table and need degenerate dimensions (see Ralph Kimball's degenerate dimensions design tip). Here we will see how to use the cube operator to load slowly changing, regular and degenerate dimensions. The cube and cube operator can now work with dimensions which have no surrogate key as well as dimensions with surrogates, so you can get the benefit of the cube loading and incorporate the degenerate dimension loading. What you need to do is create a dimension in OWB that is purely used for ETL metadata; the dimension itself is never deployed (its table is, but has not data) it has no surrogate keys has a single level with a business attribute the degenerate dimension data and a dummy attribute, say description just to pass the OWB validation. When this degenerate dimension is added into a cube, you will need to configure the fact table created and set the 'Deployable' flag to FALSE for the foreign key generated to the degenerate dimension table. The degenerate dimension reference will then be in the cube operator and used when matching. Create the degenerate dimension using the regular wizard. Delete the Surrogate ID attribute, this is not needed. Define a level name for the dimension member (any name). After the wizard has completed, in the editor delete the hierarchy STANDARD that was automatically generated, there is only a single level, no need for a hierarchy and this shouldn't really be created. Deploy the implementing table DD_ORDERNUMBER_TAB, this needs to be deployed but with no data (the mapping here will do a left outer join of the source data with the empty degenerate dimension table). Now, go ahead and build your cube, use the regular TIMES dimension for example and your degenerate dimension DD_ORDERNUMBER, can add in SCD dimensions etc. Configure the fact table created and set Deployable to false, so the foreign key does not get generated. Can now use the cube in a mapping and load data into the fact table via the cube operator, this will look after surrogate lookups and slowly changing dimension references.   If you generate the SQL you will see the ON clause for matching includes the columns representing the degenerate dimension columns. Here we have seen how this use case for loading fact tables using degenerate dimensions becomes a whole lot simpler using OWB 11gR2. I'm sure there are other use cases where using this mix of dimensions with surrogate and regular identifiers is useful, Fact tables partitioned by date columns is another classic example that this will greatly help and make the cube operator much more useful. Good to hear any comments.

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  • How to get sound on macbook pro 4,1

    - by Thomas
    I have just installed Xubuntu 12.04.2. My soundcard is detected: thomas@thomas-pc:~$ sudo aplay -l **** List of PLAYBACK Hardware Devices **** Home directory /home/thomas not ours. card 0: Intel [HDA Intel], device 0: ALC889A Analog [ALC889A Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC889A Digital [ALC889A Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 Everything is put to max in alsamixer and nothing is muted (all the sliders are on OO. My speakers do not work, but when I plug in a headphone I hear it very soft. When I connect my stereo and put the sound VERY loud (3-blocks-of-complaining-neighbours loud) I hear it on a normal level but crackling. I added options snd-hda-intel model=mbp5 amixer set IEC958 off to at the end of /etc/modprobe.d/alsa-base.conf. When it's still not working I tried everything here: https://help.ubuntu.com/community/SoundTroubleshooting 1 >>> list-sinks 1 sink(s) available. * index: 0 name: <alsa_output.pci-0000_00_1b.0.analog-stereo> driver: <module-alsa-card.c> flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY state: SUSPENDED suspend cause: IDLE priority: 9959 volume: 0: 100% 1: 100% 0: 0.00 dB 1: 0.00 dB balance 0.00 base volume: 100% 0.00 dB volume steps: 65537 muted: no current latency: 0.00 ms max request: 0 KiB max rewind: 0 KiB monitor source: 0 sample spec: s16le 2ch 44100Hz channel map: front-left,front-right Stereo used by: 0 linked by: 0 configured latency: 0.00 ms; range is 0.50 .. 371.52 ms card: 0 <alsa_card.pci-0000_00_1b.0> module: 4 properties: alsa.resolution_bits = "16" device.api = "alsa" device.class = "sound" alsa.class = "generic" alsa.subclass = "generic-mix" alsa.name = "ALC889A Analog" alsa.id = "ALC889A Analog" alsa.subdevice = "0" alsa.subdevice_name = "subdevice #0" alsa.device = "0" alsa.card = "0" alsa.card_name = "HDA Intel" alsa.long_card_name = "HDA Intel at 0x9b500000 irq 46" alsa.driver_name = "snd_hda_intel" device.bus_path = "pci-0000:00:1b.0" sysfs.path = "/devices/pci0000:00/0000:00:1b.0/sound/card0" device.bus = "pci" device.vendor.id = "8086" device.vendor.name = "Intel Corporation" device.product.name = "82801H (ICH8 Family) HD Audio Controller" device.form_factor = "internal" device.string = "front:0" device.buffering.buffer_size = "65536" device.buffering.fragment_size = "32768" device.access_mode = "mmap+timer" device.profile.name = "analog-stereo" device.profile.description = "Analog Stereo" device.description = "Built-in Audio Analog Stereo" alsa.mixer_name = "Realtek ALC889A" alsa.components = "HDA:10ec0885,106b3a00,00100103" module-udev-detect.discovered = "1" device.icon_name = "audio-card-pci" ports: analog-output-speaker: Speakers (priority 10000, available: unknown) properties: analog-output-headphones: Headphones (priority 9000, available: no) properties: active port: <analog-output-speaker> 2 and 3: Doesn't seem an permission issue, the sound is very far away (See opening paragraph). 4 thomas@thomas-pc:~$ sudo aplay -l **** List of PLAYBACK Hardware Devices **** Home directory /home/thomas not ours. card 0: Intel [HDA Intel], device 0: ALC889A Analog [ALC889A Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: ALC889A Digital [ALC889A Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 5 thomas@thomas-pc:~$ find /lib/modules/`uname -r` | grep snd /lib/modules/3.2.0-48-generic/kernel/sound/core/snd-hwdep.ko /lib/modules/3.2.0-48-generic/kernel/sound/core/snd-pcm.ko [.. huge lists continues ..] /lib/modules/3.2.0-48-generic/kernel/sound/pcmcia/pdaudiocf/snd-pdaudiocf.ko /lib/modules/3.2.0-48-generic/kernel/sound/pcmcia/vx/snd-vxpocket.ko thomas@thomas-pc:~$ 6 thomas@thomas-pc:~$ lspci -v | grep -A7 -i "audio" 00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) Subsystem: Apple Inc. Device 00a4 Flags: bus master, fast devsel, latency 0, IRQ 46 Memory at 9b500000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd-hda-intel 7 I guess it's supported. Linux mint and Xubuntu 13.04 had no trouble with sounds. Everything worked out of the box Thanks in advance Edit: alsa-info.sh output: WARNING: /etc/modprobe.d/alsa-base.conf line 45: ignoring bad line starting with 'amixer' ALSA Information Script v 0.4.62 -------------------------------- This script visits the following commands/files to collect diagnostic information about your ALSA installation and sound related hardware. dmesg lspci lsmod aplay amixer alsactl /proc/asound/ /sys/class/sound/ ~/.asoundrc (etc.) See './alsa-info.sh --help' for command line options. WARNING: /etc/modprobe.d/alsa-base.conf line 45: ignoring bad line starting with 'amixer' Automatically upload ALSA information to www.alsa-project.org? [y/N] : y Uploading information to www.alsa-project.org ... Done! Your ALSA information is located at http://www.alsa-project.org/db/?f=6cffc584284d4c0b266eb53249824ef83d6c4e3e Please inform the person helping you. thomas@thomas-pc:~$

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  • Using Telerik RadTreeView With DotNetNuke To Manage Hierarchies

    Article shows how to create a hierarchy management with create / rename / delele nodes, drag and drop, nodes deffered (lazy) load....Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • How you can extend Tasklists in Fusion Applications

    - by Elie Wazen
    In this post we describe the process of modifying and extending a Tasklist available in the Regional Area of a Fusion Applications UI Shell. This is particularly useful to Customers who would like to expose Setup Tasks (generally available in the Fusion Setup Manager application) in the various functional pillars workareas. Oracle Composer, the tool used to implement such extensions allows changes to be made at runtime. The example provided in this document is for an Oracle Fusion Financials page. Let us examine the case of a customer role who requires access to both, a workarea and its associated functional tasks, and to an FSM (setup) task.  Both of these tasks represent ADF Taskflows but each is accessible from a different page.  We will show how an FSM task is added to a Functional tasklist and made accessible to a user from within a single workarea, eliminating the need to navigate between the FSM application and the Functional workarea where transactions are conducted. In general, tasks in Fusion Applications are grouped in two ways: Setup tasks are grouped in tasklists available to implementers in the Functional Setup Manager (FSM). These Tasks are accessed by implementation users and in general do not represent daily operational tasks that fit into a functional business process and were consequently included in the FSM application. For these tasks, the primary organizing principle is precedence between tasks. If task "Manage Suppliers" has prerequisites, those tasks must precede it in a tasklist. Task Lists are organized to efficiently implement an offering. Tasks frequently performed as part of business process flows are made available as links in the tasklist of their corresponding menu workarea. The primary organizing principle in the menu and task pane entries is to group tasks that are generally accessed together. Customizing a tasklist thus becomes required for business scenarios where a task packaged under FSM as a setup task, is for a particular customer a regular maintenance task that is accessed for record updates or creation as part of normal operational activities and where the frequency of this access merits the inclusion of that task in the related operational tasklist A user with the role of maintaining Journals in General Ledger is also responsible for maintaining Chart of Accounts Mappings.  In the Fusion Financials Product Family, Manage Journals is a task available from within the Journals Menu whereas Chart of Accounts Mapping is available via FSM under the Define Chart of Accounts tasklist Figure 1. The Manage Chart of Accounts Mapping Task in FSM Figure 2. The Manage Journals Task in the Task Pane of the Journals Workarea Our goal is to simplify cross task navigation and allow the user to access both tasks from a single tasklist on a single page without having to navigate to FSM for the Mapping task and to the Journals workarea for the Manage task. To accomplish that, we use Oracle Composer to customize  the Journals tasklist by adding to it the Mapping task. Identify the Taskflow name and path of the FSM Task The first step in our process is to identify the underlying taskflow for the Manage Chart of Accounts Mappings task. We select to Setup and Maintenance from the Navigator to launch the FSM Application, and we query the task from Manage Tasklists and Tasks Figure 3. Task Details including Taskflow path The Manage Chart of Accounts Mapping Task Taskflow is: /WEB-INF/oracle/apps/financials/generalLedger/sharedSetup/coaMappings/ui/flow /CoaMappingsMainAreaFlow.xml#CoaMappingsMainAreaFlow We copy that value and use it later as a parameter to our new task in the customized Journals Tasklist. Customize the Journals Page A user with Administration privileges can start the run time customization directly from the Administration Menu of the Global Area.  This customization is done at the Site level and once implemented becomes available to all users with access to the Journals Workarea. Figure 4.  Customization Menu The Oracle Composer Window is displayed in the same browser and the Hierarchy of the page component is displayed and available for modification. Figure 5.  Oracle Composer In the composer Window select the PanelFormLayout node and click on the Edit Button.  Note that the selected component is simultaneously highlighted in the lower pane in the browser. In the Properties popup window, select the Tasks List and Task Properties Tab, where the user finds the hierarchy of the Tasklist and is able to Edit nodes or create new ones. src="https://blogs.oracle.com/FunctionalArchitecture/resource/TL5.jpg" Figure 6.  The Tasklist in edit mode Add a Child Task to the Tasklist In the Edit Window the user will now create a child node at the desired level in the hierarchy by selecting the immediate parent node and clicking on the insert node button.  This process requires four values to be set as described in Table 1 below. Parameter Value How to Determine the Value Focus View Id /JournalEntryPage This is the Focus View ID of the UI Shell where the Tasklist we want to customize is.  A simple way to determine this value is to copy it from any of the Standard tasks on the Tasklist Label COA Mapping This is the Display name of the Task as it will appear in the Tasklist Task Type dynamicMain If the value is dynamicMain, the page contains a new link in the Regional Area. When you click the link, a new tab with the loaded task opens Taskflowid /WEB-INF/oracle/apps/financials/generalLedger/sharedSetup/ coaMappings/ui/flow/ CoaMappingsMainAreaFlow.xml#CoaMappingsMainAreaFlow This is the Taskflow path we retrieved from the Task Definition in FSM earlier in the process Table 1.  Parameters and Values for the Task to be added to the customized Tasklist Figure 7.   The parameters window of the newly added Task   Access the FSM Task from the Journals Workarea Once the FSM task is added and its parameters defined, the user saves the record, closes the Composer making the new task immediately available to users with access to the Journals workarea (Refer to Figure 8 below). Figure 8.   The COA Mapping Task is now visible and can be invoked from the Journals Workarea   Additional Considerations If a Task Flow is part of a product that is deployed on the same app server as the Tasklist workarea then that task flow can be added to a customized tasklist in that workarea. Otherwise that task flow can be invoked from its parent product’s workarea tasklist by selecting that workarea from the Navigator menu. For Example The following Taskflows  belong respectively to the Subledger Accounting, and to the General Ledger Products.  /WEB-INF/oracle/apps/financials/subledgerAccounting/accountingMethodSetup/mappingSets/ui/flow/MappingSetFlow.xml#MappingSetFlow /WEB-INF/oracle/apps/financials/generalLedger/sharedSetup/coaMappings/ui/flow/CoaMappingsMainAreaFlow.xml#CoaMappingsMainAreaFlow Since both the Subledger Accounting and General Ledger products are part of the LedgerApp J2EE Applicaton and are both deployed on the General Ledger Cluster Server (Figure 8 below), the user can add both of the above taskflows to the  tasklist in the  /JournalEntryPage FocusVIewID Workarea. Note:  both FSM Taskflows and Functional Taskflows can be added to the Tasklists as described in this document Figure 8.   The Topology of the Fusion Financials Product Family. Note that SubLedger Accounting and General Ledger are both deployed on the Ledger App Conclusion In this document we have shown how an administrative user can edit the Tasklist in the Regional Area of a Fusion Apps page using Oracle Composer. This is useful for cases where tasks packaged in different workareas are frequently accessed by the same user. By making these tasks available from the same page, we minimize the number of steps in the navigation the user has to do to perform their transactions and queries in Fusion Apps.  The example explained above showed that tasks classified as Setup tasks, meaning made accessible to implementation users from the FSM module can be added to the workarea of their respective Fusion application. This eliminates the need to navigate to FSM to access tasks that are both setup and regular maintenance tasks. References Oracle Fusion Applications Extensibility Guide 11g Release 1 (11.1.1.5) Part Number E16691-02 (Section 3.2) Oracle Fusion Applications Developer's Guide 11g Release 1 (11.1.4) Part Number E15524-05

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