Search Results

Search found 21563 results on 863 pages for 'game testing'.

Page 438/863 | < Previous Page | 434 435 436 437 438 439 440 441 442 443 444 445  | Next Page >

• Mouse Speed in GLUT and OpenGL?

  - by CroCo

  I would like to simulate a point that moves in 2D. The input should be the speed of the mouse, so the new position will be computed as following new_position = old_position + delta_time*mouse_velocity As far as I know in GLUT there is no function to acquire the current speed of the mouse between each frame. What I've done so far to compute the delta_time as following void Display() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glColor3f(1.0f, 0.0f, 0.0f); static int delta_t, current_t, previous_t; current_t = glutGet(GLUT_ELAPSED_TIME); delta_t = current_t - previous_t; std::cout << delta_t << std::endl; previous_t = current_t; glutSwapBuffers(); } Where should I start from here? (Note: I have to get the speed of the mouse because I'm modeling a system) Edit: Based on the above code, delta_time fluctuates so much 34 19 2 20 1 20 0 16 1 1 10 21 0 13 1 19 34 0 13 0 6 1 14 Why does this happen?

  Read the article

• Good resources for learning about graphics hardware

  - by Ken

  I'm looking for some good learning resources for graphics hardware (and associated low level software). Basically I want to learn more about what goes on underneath the opengl/direcx API layers in terms of how things are implemented. I familiar with what happens in principle during the various stages of the rendering pipeline (viewing, projection, clipping, rasterization etc). My goal is to be able to make better and more informed decisions about tradeoffs and potential optimisations when graphics/shader programming with respect to the following kinds of issues; batching view culling occlusions draw order avoiding state changes triangles vs pointsprites texture sampling etc Basically whatever the graphics programmer needs to know about modern graphics hardware in order to become more effective. I'm not really looking for specific optimisation techniques, rather I need more general knowledge so that I will naturally write more efficient code.

  Read the article

• Dynamic content realoding

  - by Kikaimaru

  Is there a relatively simple way to dynamicaly reload content files? (ie: effect files) I know i can do following: Detect change of file Run content pipeline to rebuild that specific file Unload ALL content that was loaded Load All content And use double references to reference content files. Problem is with step 3 (and step 2 isn't that nice too). But i need to unload everything because if i have model Hero.x which references Model.fx effect, and i change Model.fx file, i need to reload Hero.x file which will then call LoadExternalReference on Model.fx. So I guess question is, did someone mange to make this work without rewriting whole ContentManager (and every ContentReader) and tracking calls to LoadExternalReference?

  Read the article

• Learning C++ but wanting to develop iOS Apps

  - by DiscreteGenius

  I'm a computer engineering student and taking my second programming class. I'm learning C++ using "C++ Primer Plus" 5th edition by Prata. I want to develop for iOS. I understand the main language for Xcode is Objective-C. Am I hurting myself by learning C++ before any other language (notably before my desired lang Objective-C)? There's got to be a reason the university requires C++ to learn as a basis language. Please offer any helpful guidance or how I should go about this. Thanks//

  Read the article

• a flexible data structure for geometries

  - by AkiRoss

  What data structure would you use to represent meshes that are to be altered (e.g. adding or removing new faces, vertices and edges), and that have to be "studied" in different ways (e.g. finding all the triangles intersecting a certain ray, or finding all the triangles "visible" from a given point in the space)? I need to consider multiple aspects of the mesh: their geometry, their topology and spatial information. The meshes are rather big, say 500k triangles, so I am going to use the GPU when computations are heavy. I tried using arrays with vertices and arrays with indices, but I do not love adding and removing vertices from them. Also, using arrays totally ignore spatial and topological information, which I may need studying the mesh. So, I thought about using custom double-linked list data structures, but I believe doing so will require me to copy the data to array buffers before going on the GPU. I also thought about using BST, but not sure it fits. Any help is appreciated. If I have been too fuzzy and you require other information feel free to ask.

  Read the article

• Low CPU/Memory/Memory-bandwith Pathfinding (maybe like in Warcraft 1)

  - by Valmond

  Dijkstra and A* are all nice and popular but what kind of algorithm was used in Warcraft 1 for pathfinding? I remember that the enemy could get trapped in bowl-like caverns which means there were (most probably) no full-path calculations from "start to end". If I recall correctly, the algorithm could be something like this: A) Move towards enemy until success or hitting a wall B) If blocked by a wall, follow the wall until you can move towards the enemy without being blocked and then do A) But I'd like to know, if someone knows :-) [edit] As explained to Byte56, I'm searching for a low cpu/mem/mem-bandwidth algo and wanted to know if Warcraft had some special secrets to deliver (never seen that kind of pathfinding elsewhere), I hope that that is more concordant with the stackexchange rules.

  Read the article

• What are the steps taken by this GLSL code?

  - by user827992

  1 void main(void) 2 { 3 vec2 pos = mod(gl_FragCoord.xy, vec2(50.0)) - vec2(25.0); 4 float dist_squared = dot(pos, pos); 5 6 gl_FragColor = (dist_squared < 400.0) 7 ? vec4(.90, .90, .90, 1.0) 8 : vec4(.20, .20, .40, 1.0); 9 } taken from http://people.freedesktop.org/~idr/OpenGL_tutorials/03-fragment-intro.html Now, this looks really trivial and simple, but my problem is with the mod function. This function is taking 2 vec2 as inputs but is supposed to take just 2 atomic arguments according to the official documentation, also this function makes an implicit use of the floor function that only accepts, again, 1 atomic argument. Can someone explain this to me step by step and point out what I'm not getting here? It's some kind of OpenGL trick? OpenGL Math trick? in the GLSL docs i always find and explicit reference to the type accepted by the function and vec2 it's not there.

  Read the article

• XNA - 2D Rotation of an object to a selected direction

  - by lobsterhat

  I'm trying to figure out the best way of rotating an object towards the directional input of the user. I'm attempting to mimic making turns on ice skates. For instance, if the player is moving right and the input is down and left, the player should start rotating to the right a set amount each tick. I'll calculate a new vector based on current velocity and rotation and apply that to the current velocity. That should give me nice arcing turns, correct? At the moment I've got eight if/else statements for each key combination which in turn check the current rotation: // Rotate to 225 if (keyboardState.IsKeyDown(Keys.Up) && keyboardState.IsKeyDown(Keys.Left)) { // Rotate right if (rotation >= 45 || rotation < 225) { rotation += ROTATION_PER_TICK; } // Rotate left else if (rotation < 45 || rotation > 225) { rotation -= ROTATION_PER_TICK; } } This seems like a sloppy way to do this and eventually, I'll need to do this check about 10 times a tick. Any help toward a more efficient solution is appreciated.

  Read the article

• I get GL_INVALID_VALUE after calling glTexSubImage2D

  - by user892644

  I am trying to figure out why my texture allocation does not work. Here is the code: glTexStorage2D(GL_TEXTURE_2D, 2, GL_RGBA8, 2048, 2048); glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 2048, 2048, GL_RGB, GL_UNSIGNED_SHORT_5_6_5_REV, &BitMap[0]); glTexSubImage2D returns GL_INVALID_VALUE but the maximum texture allowed is 16384x16384 on my card. The source of the image is 16bit (Red 5, Green 6, Blue 5).

  Read the article

• OpenGL doesn't draw (3.3+) [on hold]

  - by Dhiego Magalhães

  Brief: I've been following this tutorial about OpenGL for 2 days, and I still can't have a triangle drawn, so I'm asking for help here. The tutorial is turned to OpenGL version 3.3 programing, using vertex arrays, buffers, etc. The libraries are: GLFW3 and GLEW, and I setted them by myself. The screen keeps black all the time. Full code: link here (It's just like a Hello World opengl program) Further Details: I get no errors at all. I downloaded a software to test my video card, and it supports OpenGL 4.1+ Standard OpenGL code for drawing (from earlier version) such as this one works normally. I'm using Microsoft Visual Studio 10.0 I presume all the OpenGL implementation was dune right: I added Additional Dependences to the linker as glew32.lib, opengl32.lib, glfw3.lib. The glew.dll was placed at SysWOW64 - because I'm running window 64bits, and glew is 32. Notes: I've been working hard to find out what this is, but I can't find. I would appreciate if anyone could test this code for me, so I can know if I implemented something wrong, and that its not my code.

  Read the article

• Nice function for "rolling score up"?

  - by bobobobo

  I'm adding to the player's score, and I'm using a per-frame formula like: int score, displayedScore ;// score is ACTUAL score player has, // displayedScore is what is shown this frame to the player // (the creeping/"rolling" number) float disparity = score - displayedScore ; int d = disparity * .1f ; // add 1/10 of the difference, if( !d ) d = signum( disparity ) ; // last 10 go by 1's score += d ; Where inline int signum( float val ){ if( val > 0 ) return 1 ; else if( val < 0 ) return -1 ; else return 0 ; } So, it kind of works where it makes big changes rapidly, then it creeps in the last few one at a time. But I'm looking for better (or possibly well known?) score-creeping functions. Any one?

  Read the article

• How do I draw a dotted or dashed line?

  - by Gagege

  I'm trying to draw a dashed or dotted line by placing individual segments(dashes) along a path and then separating them. The only algorithm I could come up with for this gave me a dash length that was variable based on the angle of the line. Like this: private function createDashedLine(fromX:Float, fromY:Float, toX:Float, toY:Float):Sprite { var line = new Sprite(); var currentX = fromX; var currentY = fromY; var addX = (toX - fromX) * 0.0075; var addY = (toY - fromY) * 0.0075; line.graphics.lineStyle(1, 0xFFFFFF); var count = 0; // while line is not complete while (!lineAtDestination(fromX, fromY, toX, toY, currentX, currentY)) { /// move line draw cursor to beginning of next dash line.graphics.moveTo(currentX, currentY); // if dash is even if (count % 2 == 0) { // draw the dash line.graphics.lineTo(currentX + addX, currentY + addY); } // add next dash's length to current cursor position currentX += addX; currentY += addY; count++; } return line; } This just happens to be written in Haxe, but the solution should be language neutral. What I would like is for the dash length to be the same no matter what angle the line is. As is, it's just adding 75 thousandths of the line length to the x and y, so if the line is and a 45 degree angle you get pretty much a solid line. If the line is at something shallow like 85 degrees then you get a nice looking dashed line. So, the dash length is variable, and I don't want that. How would I make a function that I can pass a "dash length" into and get that length of dash, no matter what the angle is? If you need to completely disregard my code, be my guest. I'm sure there's a better solution.

  Read the article

• HTML5 Canvas Converting between cartesian and isometric coordinates

  - by Amir

  I'm having issues wrapping my head around the Cartesian to Isometric coordinate conversion in HTML5 canvas. As I understand it, the process is two fold: (1) Scale down the y-axis by 0.5, i.e. ctx.scale(1,0.5); or ctx.setTransform(1,0,0,0.5,0,0); This supposedly produces the following matrix: [x; y] x [1, 0; 0, 0.5] (2) Rotate the context by 45 degrees, i.e. ctx.rotate(Math.PI/4); This should produce the following matrix: [x; y] x [cos(45), -sin(45); sin(45), cos(45)] This (somehow) results in the final matrix of ctx.setTransform(2,-1,1,0.5,0,0); which I cannot seem to understand... How is this matrix derived? I cannot seem to produce this matrix by multiplying the scaling and rotation matrices produced earlier... Also, if I write out the equation for the final transformation matrix, I get: newX = 2x + y newY = -x + y/2 But this doesn't seem to be correct. For example, the following code draws an isometric tile at cartesian coordinates (500, 100). ctx.setTransform(2,-1,1,0.5,0,0); ctx.fillRect(500, 100, width*2, height); When I check the result on the screen, the actual coordinates are (285, 215) which do not satisfy the equations I produced earlier... So what is going on here? I would be very grateful if you could: (1) Help me understand how the final isometric transformation matrix is derived; (2) Help me produce the correct equation for finding the on-screen coordinates of an isometric projection. Many thanks and kind regards

  Read the article

• WndProc(ref Message m), Prevent minimize Games, Send key strokes.

  - by Stanomatic

  Overview: I am going to create a touch application that interfaces with games and other apps. This concept is similar to the app found on touch-buddy.com but I will be using C# and WPF instead of how the application is written in Perl. I have a few challenges I would like to evaluate. The touch-buddy app uses two approaches while interacting with games; 1. Client mode (Same machine runs both game and touch-buddy). 2. Server / Client mode where a separate box sends commands to the game machine. The reason I believe for this method was to circumvent the issue with games minimizing. In Client only mode I am faced with the issue where I touch a screen OTHER than the main screen where the game is viewed and then the game minimizes. Not all games have this behavior but I would like to conquer the games that do minimize and prevent it. Is it possible to keep a game front and center Focused and prevent minimizing utilizing C# WndProc(ref Message m)? I have been experimenting with WndProc(ref Message m) where I created a win form and when I press minimize on my own Win form and it will close an instance of notepad. This proves to me that I can capture a message, prevent that message from bubbling up and then send a message to another application. I then tried to click on notepad with my touch screen and keep my win form application in focus and not minimize. At this point I am unsuccessful. I need more time understanding message codes. Is this the right approach? Can it be done? Should I look at other libraries such as Windows Automation? Key input is my other concern. What is the best way to send key strokes to other apps/games. Should I tap into DirectX, use some kind of send key, Automation Framework? Can any of these handle the multiple key strokes that some simulation games require? I appreciate any links and or insight you may have. If you have gone down this path for any reason I would love to hear your comments. Stan

  Read the article

• Adding delay between damage

  - by iQue

  I have a bunch of enemies chasing my main-character, and if they intersect I want them to damage him and that's all good. The problem is that right now they damage him as long as they stand around him, every frame! and since it gets called every frame my character's HP reaches 0 almost instantly. I've tried adding delay and I've tried a timertask, but can't get it to work. This is the code I use to check for intersection: private void checkCollision(Canvas canvas) { synchronized (getHolder()) { Rect h1 = happy.getBounds(); for (int i = 0; i < enemies.size(); i++) { for (int j = 0; j < bullets.size(); j++) { Rect b1 = bullets.get(j).getBounds(); Rect e1 = enemies.get(i).getBounds(); if (b1.intersect(e1)) { enemies.get(i).damageHP(5); bullets.remove(j); } if(e1.intersect(h1)){ happy.damageHP(5); // this is the statement that needs some sort of delay, I want them to damage him every 2 seconds they intersect him. } if(enemies.get(i).getHP() <= 0){ enemies.get(i).death(canvas, enemies); score.incScore(5); break; } if(happy.getHP() <= 0){ score.incScore(-50); //end-screen } } } } } If anyone knows the logic to do this please do tell.

  Read the article

• Maya is lagging in a specific way...?

  - by Aerovistae

  My Maya installation worked perfectly. It is not my computer. Something caused it to stop working overnight, somehow. When I try to drag a vertex or something like that, it moves the vertex, but then I have to click like 3 times somewhere outside the mesh before the actual mesh will catch up and follow the vertex. Until I do that, it just stays as it was, with a floating vertex somewhere inside it or outside it. It makes modeling borderline impossible and completely infuriating. What ought to be happening is what we're all used to-- as I move the vertex, the mesh follows it actively, so I can see what it looks like at every given moment until I release the vertex in its new position. Other weird thing: this only applies to complex meshes, like a couple thousand faces. A simple cube works fine. What gives?? Anybody?

  Read the article

• TGA loader: reverse height

  - by aVoX

  I wrote a TGA image loader in Java which is working perfectly for files created with GIMP as long as they are saved with the option "origin" set to "Top Left" (Note: Actually TGA files are meant to be stored upside down - "Bottom Left" in GIMP). My problem is that I want my image loader to be capable of reading all different kinds of TGAs, so my question is, how do I flip the image upside down? Note that I store all image data inside a one-dimensional byte array, because OpenGL (glTexImage2D to be specific) requires it that way. Thanks in advance.

  Read the article

• Simple 2D Flight Physics with Box2D

  - by MarkPowell

  I'm trying to build a simple side scroller with an airplane being the player. As such, I want to build simple flight controls with simple but realistic-feeling physics. I'm making use of cocos2D and Box2D. I have a basic system working, but just can't get the physics feeling correct. I am applying force to the plane (which is a b2CircleShape) based on the user's input. So, basically, if the user pushes up, body_->ApplyForce(b2Vec2(10,30), body_->GetPosition()) is called. Similarly, for down -30 is used. This works and the plane flys along with up/down causing it to dive or climb. But it just doesn't feel right. There is no slowdown on climbs, nor speed up during dives. My simple solution is far to simple. How can I get a better feel for a plane climbing/diving? Thanks!

  Read the article

• Which 3D file formats support multiple animations? [on hold]

  - by Justin

  I'm working on a 3D application that uses Assimp to import 3D models with animations. Personally, I use Blender to create the models and animations. I'm having trouble exporting multiple animations, however. For example, I'd like to have an idle animation, a walk animation, a run animation, etc. So far I've tried COLLADA and DirectX without much success. The COLLADA export will include the first animation, but not any of the others. The DirectX doesn't include any animation. Which 3D file formats support multiple animations? (Preferably one that Assimp can import. Also, the Assimp website says that it doesn't support .blend files with animation, otherwise I'd just do that.)

  Read the article

• How does this circle collision detection math work?

  - by Griffin

  I'm going through the wildbunny blog to learn about collision detection. I'm confused about how the vectors he's talking about come into play. Here's the part that confuses me: p = ||A-B|| – (r1+r2) The two spheres are penetrating by distance p. We would also like the penetration vector so that we can correct the penetration once we discover it. This is the vector that moves both circles to the point where they just touch, correcting the penetration. Importantly it is not only just a vector that does this, it is the only vector which corrects the penetration by moving the minimum amount. This is important because we only want to correct the error, not introduce more by moving too much when we correct, or too little. N = (A-B) / ||A-B|| P = N*p Here we have calculated the normalised vector N between the two centres and the penetration vector P by multiplying our unit direction by the penetration distance. I understand that p is the distance by which the circles penetrate, but I don't get what exactly N and P are. It seems to me N is just the coordinates of the 3rd point of the right trianlge formed by point A and B (A-B) then being divided by the hypotenuse of that triangle or distance between A and B (||A-B||). What's the significance of this? Also, what is the penetration vector used for? It seems to me like a movement that one of the circles would perform to get un-penetrated.

  Read the article

• Collision 2D Quads

  - by Vico Pelaez

  I want to detect collision between two 2D squares, one square is static and the other one moves according to keyboard arrows. I have implemented some code, however nothing happens when they overlap each other and what I tried to achieve in the code was to detect an overlapping between them. I think I am either not understanding the concept really well or that because one of the squares is moving this is not working. Please I would really appreciate your help. Thank you! float x1=0.05 ,Y1=0.05; float x2=0.05 ,Y2=0.05; float posX1 =0.5, posY1 = 0.5; float movX2 = 0.0 , movY2 = 0.0; struct box{ int width=0.1; int heigth=0.1; }; void init(){ glClearColor(0.0, 0.0, 0.0, 0.0); glColor3f(1.0, 1.0, 1.0); } void quad1(){ glTranslatef(posX1, posY1, 0.0); glBegin(GL_POLYGON); glColor3f(0.5, 1.0, 0.5); glVertex2f(-x1, -Y1); glVertex2f(-x1, Y1); glVertex2f(x1,Y1); glVertex2f(x1,-Y1); glEnd(); } void quad2(){ glMatrixMode(GL_PROJECTION); glLoadIdentity(); glPushMatrix(); glTranslatef(movX2, movY2, 0.0); glBegin(GL_POLYGON); glColor3f(1.5, 1.0, 0.5); glVertex2f(-x2, -Y2); glVertex2f(-x2, Y2); glVertex2f(x2,Y2); glVertex2f(x2,-Y2); glEnd(); glPopMatrix(); } void reset(){ //Reset position of square??? movX2 = 0.0; movY2 = 0.0; collisionB = false; } bool collision(box A, box B){ int leftA, leftB; int rightA, rightB; int topA, topB; int bottomA, bottomB; //Calculate the sides of box A leftA = x1; rightA = x1 + A.width; topA = Y1; bottomA = Y1 + A.heigth; //Calculate the sides of box B leftB = x2; rightB = x2 + B.width; topB = Y1; bottomB = Y1+ B.heigth ; if( bottomA <= topB ) return false; if( topA >= bottomB ) return false; if( rightA <= leftB ) return false; if( leftA >= rightB ) return false; return true; } float move_unit = 0.1; void keyboardown(int key, int x, int y) { switch (key){ case GLUT_KEY_UP: movY2 += move_unit; break; case GLUT_KEY_RIGHT: movX2 += move_unit; break; case GLUT_KEY_LEFT: movX2 -= move_unit; break; case GLUT_KEY_DOWN: movY2 -= move_unit; break; default: break; } glutPostRedisplay(); } void display(){ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glMatrixMode(GL_PROJECTION); glLoadIdentity(); cuad1(); if (!collision) { cuad2(); } else{ reset(); } glFlush(); } int main(int argc, char** argv){ glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(500,500); glutInitWindowPosition(0, 0); glutCreateWindow("Collision Practice"); glutSpecialFunc(keyboardown); glutDisplayFunc(display); init(); glutMainLoop(); }

  Read the article

• LibGDX - SpriteBatch's .draw() method requiring float[]

  - by just_a_programmer

  Please excuse my lack of knowledge with LibGDX, as I have just started learning it. I am going through some simple tutorials, and in one of them, I draw a string onto the screen like so: // the following code is in the main file in the core project folder: // this is in the create() method: private SpriteBatch batch; batch = new SpriteBatch(); // this is in the render() method: batch.draw(batch, "Hello world", 200, 200); I am getting an error saying: The method draw(texture, float[], int, int) in the type SpriteBatch is not applicable for the arguments (SpriteBatch, int, int) So, LibGDX wants a float array to draw instead of a string? Thanks in advance.

  Read the article

• glTranslate, how exactly does it work?

  - by mykk

  I have some trouble understanding how does glTranslate work. At first I thought it would just simply add values to axis to do the transformation. However then I have created two objects that would load bitmaps, one has matrix set to GL_TEXTURE: public class Background { float[] vertices = new float[] { 0f, -1f, 0.0f, 4f, -1f, 0.0f, 0f, 1f, 0.0f, 4f, 1f, 0.0f }; .... private float backgroundScrolled = 0; public void scrollBackground(GL10 gl) { gl.glLoadIdentity(); gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glTranslatef(0f, 0f, 0f); gl.glPushMatrix(); gl.glLoadIdentity(); gl.glMatrixMode(GL10.GL_TEXTURE); gl.glTranslatef(backgroundScrolled, 0.0f, 0.0f); gl.glPushMatrix(); this.draw(gl); gl.glPopMatrix(); backgroundScrolled += 0.01f; gl.glLoadIdentity(); } } and another to GL_MODELVIEW: public class Box { float[] vertices = new float[] { 0.5f, 0f, 0.0f, 1f, 0f, 0.0f, 0.5f, 0.5f, 0.0f, 1f, 0.5f, 0.0f }; .... private float boxScrolled = 0; public void scrollBackground(GL10 gl) { gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glLoadIdentity(); gl.glTranslatef(0f, 0f, 0f); gl.glPushMatrix(); gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glLoadIdentity(); gl.glTranslatef(boxScrolled, 0.0f, 0.0f); gl.glPushMatrix(); this.draw(gl); gl.glPopMatrix(); boxScrolled+= 0.01f; gl.glLoadIdentity(); } } Now they are both drawn in Renderer.OnDraw. However background moves exactly 5 times faster. If I multiply boxScrolled by 5 they will be in sinc and will move together. If I modify backgrounds vertices to be float[] vertices = new float[] { 1f, -1f, 0.0f, 0f, -1f, 0.0f, 1f, 1f, 0.0f, 0f, 1f, 0.0f }; It will also be in sinc with the box. So, what is going under glTranslate?

  Read the article

• OpenGL Application displays only 1 frame

  - by Avi

  EDIT: I have verified that the problem is not the VBO class or the vertex array class, but rather something else. I have a problem where my vertex buffer class works the first time its called, but displays nothing any other time its called. I don't know why this is, and it's also the same in my vertex array class. I'm calling the functions in this order to set up the buffers: enable client states bind buffers set buffer / array data unbind buffers disable client states Then in the draw function, that's called every frame: enable client states bind buffers set pointers unbind buffers bind index buffer draw elements unbind index buffer disable client states Is there something wrong with the order in which I'm calling the functions, or is it a more specific code error? EDIT: here's some of the code Code for setting pointers: //element is the vertex attribute being drawn (e.g. normals, colors, etc.) static void makeElementPointer(VertexBufferElements::VBOElement element, Shader *shade, void *elementLocation) { //elementLocation is BUFFER_OFFSET(n) if a buffer is bound switch (element) { .... glVertexPointer(3, GL_FLOAT, 0, elementLocation); //changes based on element .... //but I'm only dealing with } //vertices for now } And that's basically all the code that isn't just a straight OpenGL function call.

  Read the article

• What is going on in this SAT/vector projection code?

  - by ssb

  I'm looking at the example XNA SAT collision code presented here: http://www.xnadevelopment.com/tutorials/rotatedrectanglecollisions/rotatedrectanglecollisions.shtml See the following code: private int GenerateScalar(Vector2 theRectangleCorner, Vector2 theAxis) { //Using the formula for Vector projection. Take the corner being passed in //and project it onto the given Axis float aNumerator = (theRectangleCorner.X * theAxis.X) + (theRectangleCorner.Y * theAxis.Y); float aDenominator = (theAxis.X * theAxis.X) + (theAxis.Y * theAxis.Y); float aDivisionResult = aNumerator / aDenominator; Vector2 aCornerProjected = new Vector2(aDivisionResult * theAxis.X, aDivisionResult * theAxis.Y); //Now that we have our projected Vector, calculate a scalar of that projection //that can be used to more easily do comparisons float aScalar = (theAxis.X * aCornerProjected.X) + (theAxis.Y * aCornerProjected.Y); return (int)aScalar; } I think the problems I'm having with this come mostly from translating physics concepts into data structures. For example, earlier in the code there is a calculation of the axes to be used, and these are stored as Vector2, and they are found by subtracting one point from another, however these points are also stored as Vector2s. So are the axes being stored as slopes in a single Vector2? Next, what exactly does the Vector2 produced by the vector projection code represent? That is, I know it represents the projected vector, but as it pertains to a Vector2, what does this represent? A point on a line? Finally, what does the scalar at the end actually represent? It's fine to tell me that you're getting a scalar value of the projected vector, but none of the information I can find online seems to tell me about a scalar of a vector as it's used in this context. I don't see angles or magnitudes with these vectors so I'm a little disoriented when it comes to thinking in terms of physics. If this final scalar calculation is just a dot product, how is that directly applicable to SAT from here on? Is this what I use to calculate maximum/minimum values for overlap? I guess I'm just having trouble figuring out exactly what the dot product is representing in this particular context. Clearly I'm not quite up to date on my elementary physics, but any explanations would be greatly appreciated.

  Read the article

< Previous Page | 434 435 436 437 438 439 440 441 442 443 444 445  | Next Page >