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  • Software emulated OpenGL with higher version than my graphics card supports

    - by leemes
    I have an Intel GMA 950 chipset in my netbook. I want to learn how to write OpenGL shader programs with this fantastic tutorial and therefore need OpenGL 3.3. Sadly, my graphics card only supports OpenGL 1.4. I think that MESA can emulate OpenGL in software, so I'm wondering if it can emulate OpenGL 3.3 without any hardware accelleration (performance is very much no problem, since this is only for learning and testing puroses). Is there any possibility to do this?

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  • DirectX 11 Constant Buffers vs Effect Framework

    - by Alex
    I'm having some trouble understanding the differences between using constant buffers or using the effect framework of DirectX11 for updating shader constants. From what I understand they both do exactly the same thing, although from reading the documentation it appears as if using effects is meant to be 'easier'. However they seem the same to me, one uses VSSetConstantBuffers and the other GetConstantBufferByName. Is there something I'm missing here?

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  • How do I get a new license for gDEBugger after the 1 free year?

    - by Byte56
    I downloaded the gDEBugger from gremedy over a year ago, with their one year free license. The license has since expired and their site says that I'll be presented with the option for 1 year free license the first time I run it after install. This doesn't happen when re-installing, it just tells me the license has expired. How do I get a new license? I use this regularly for debugging shader problems and performance testing my game.

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  • Are these non-standard applications of rendering practical in games?

    - by maul
    I've recently got into 3D and I came up with a few different "tricky" rendering techniques. Unfortunately I don't have the time to work on this myself, but I'd like to know if these are known methods and if they can be used in practice. Hybrid rendering Now I know that ray-tracing is still not fast enough for real-time rendering, at least on home computers. I also know that hybrid rendering (a combination of rasterization and ray-tracing) is a well known theory. However I had the following idea: one could separate a scene into "important" and "not important" objects. First you render the "not important" objects using traditional rasterization. In this pass you also render the "important" objects using a special shader that simply marks these parts on the image using a special color, or some stencil/depth buffer trickery. Then in the second pass you read back the results of the first pass and start ray tracing, but only from the pixels that were marked by the "important" object's shader. This would allow you to only ray-trace exactly what you need to. Could this be fast enough for real-time effects? Rendered physics I'm specifically talking about bullet physics - intersection of a very small object (point/bullet) that travels across a straight line with other, relatively slow-moving, fairly constant objects. More specifically: hit detection. My idea is that you could render the scene from the point of view of the gun (or the bullet). Every object in the scene would draw a different color. You only need to render a 1x1 pixel window - the center of the screen (again, from the gun's point of view). Then you simply check that central pixel and the color tells you what you hit. This is pixel-perfect hit detection based on the graphical representation of objects, which is not common in games. Afaik traditional OpenGL "picking" is a similar method. This could be extended in a few ways: For larger (non-bullet) objects you render a larger portion of the screen. If you put a special-colored plane in the middle of the scene (exactly where the bullet will be after the current frame) you get a method that works as the traditional slow-moving iterative physics test as well. You could simulate objects that the bullet can pass through (with decreased velocity) using alpha blending or some similar trick. So are these techniques in use anywhere, and/or are they practical at all?

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  • How effects found in "Autodesk Fluid FX" are implemented using OpenGL ES?

    - by afds
    How this kind of effects are technically implemented using OpenGL ES? Are they performing simulation on GPU (using Shaders) or CPU while using some smart vertex positioning and texturing? Why it appears so fast (in terms of performance)? You might check the video of that app here: http://www.youtube.com/watch?v=F4KOk6QP6kQ edit Here is the presentation for the app: http://www.futuregameon.com/FGO2010_JosStam.pdf

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  • How can I render multiple windows with DirectX 9 in C++?

    - by Friso1990
    I'm trying to render multiple windows, using DirectX 9 and swap chains, but even though I create 2 windows, I only see the first one that I've created. My RendererDX9 header is this: #include <d3d9.h> #include <Windows.h> #include <vector> #include "RAT_Renderer.h" namespace RAT_ENGINE { class RAT_RendererDX9 : public RAT_Renderer { public: RAT_RendererDX9(); ~RAT_RendererDX9(); void Init(RAT_WindowManager* argWMan); void CleanUp(); void ShowWin(); private: LPDIRECT3D9 renderInterface; // Used to create the D3DDevice LPDIRECT3DDEVICE9 renderDevice; // Our rendering device LPDIRECT3DSWAPCHAIN9* swapChain; // Swapchain to make multi-window rendering possible WNDCLASSEX wc; std::vector<HWND> hwindows; void Render(int argI); }; } And my .cpp file is this: #include "RAT_RendererDX9.h" static LRESULT CALLBACK MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ); namespace RAT_ENGINE { RAT_RendererDX9::RAT_RendererDX9() : renderInterface(NULL), renderDevice(NULL) { } RAT_RendererDX9::~RAT_RendererDX9() { } void RAT_RendererDX9::Init(RAT_WindowManager* argWMan) { wMan = argWMan; // Register the window class WNDCLASSEX windowClass = { sizeof( WNDCLASSEX ), CS_CLASSDC, MsgProc, 0, 0, GetModuleHandle( NULL ), NULL, NULL, NULL, NULL, "foo", NULL }; wc = windowClass; RegisterClassEx( &wc ); for (int i = 0; i< wMan->getWindows().size(); ++i) { HWND hWnd = CreateWindow( "foo", argWMan->getWindow(i)->getName().c_str(), WS_OVERLAPPEDWINDOW, argWMan->getWindow(i)->getX(), argWMan->getWindow(i)->getY(), argWMan->getWindow(i)->getWidth(), argWMan->getWindow(i)->getHeight(), NULL, NULL, wc.hInstance, NULL ); hwindows.push_back(hWnd); } // Create the D3D object, which is needed to create the D3DDevice. renderInterface = (LPDIRECT3D9)Direct3DCreate9( D3D_SDK_VERSION ); // Set up the structure used to create the D3DDevice. Most parameters are // zeroed out. We set Windowed to TRUE, since we want to do D3D in a // window, and then set the SwapEffect to "discard", which is the most // efficient method of presenting the back buffer to the display. And // we request a back buffer format that matches the current desktop display // format. D3DPRESENT_PARAMETERS deviceConfig; ZeroMemory( &deviceConfig, sizeof( deviceConfig ) ); deviceConfig.Windowed = TRUE; deviceConfig.SwapEffect = D3DSWAPEFFECT_DISCARD; deviceConfig.BackBufferFormat = D3DFMT_UNKNOWN; deviceConfig.BackBufferHeight = 1024; deviceConfig.BackBufferWidth = 768; deviceConfig.EnableAutoDepthStencil = TRUE; deviceConfig.AutoDepthStencilFormat = D3DFMT_D16; // Create the Direct3D device. Here we are using the default adapter (most // systems only have one, unless they have multiple graphics hardware cards // installed) and requesting the HAL (which is saying we want the hardware // device rather than a software one). Software vertex processing is // specified since we know it will work on all cards. On cards that support // hardware vertex processing, though, we would see a big performance gain // by specifying hardware vertex processing. renderInterface->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwindows[0], D3DCREATE_SOFTWARE_VERTEXPROCESSING, &deviceConfig, &renderDevice ); this->swapChain = new LPDIRECT3DSWAPCHAIN9[wMan->getWindows().size()]; this->renderDevice->GetSwapChain(0, &swapChain[0]); for (int i = 0; i < wMan->getWindows().size(); ++i) { renderDevice->CreateAdditionalSwapChain(&deviceConfig, &swapChain[i]); } renderDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CCW); // Set cullmode to counterclockwise culling to save resources renderDevice->SetRenderState(D3DRS_AMBIENT, 0xffffffff); // Turn on ambient lighting renderDevice->SetRenderState(D3DRS_ZENABLE, TRUE); // Turn on the zbuffer } void RAT_RendererDX9::CleanUp() { renderDevice->Release(); renderInterface->Release(); } void RAT_RendererDX9::Render(int argI) { // Clear the backbuffer to a blue color renderDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB( 0, 0, 255 ), 1.0f, 0 ); LPDIRECT3DSURFACE9 backBuffer = NULL; // Set draw target this->swapChain[argI]->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &backBuffer); this->renderDevice->SetRenderTarget(0, backBuffer); // Begin the scene renderDevice->BeginScene(); // End the scene renderDevice->EndScene(); swapChain[argI]->Present(NULL, NULL, hwindows[argI], NULL, 0); } void RAT_RendererDX9::ShowWin() { for (int i = 0; i < wMan->getWindows().size(); ++i) { ShowWindow( hwindows[i], SW_SHOWDEFAULT ); UpdateWindow( hwindows[i] ); // Enter the message loop MSG msg; while( GetMessage( &msg, NULL, 0, 0 ) ) { if (PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) ) { TranslateMessage( &msg ); DispatchMessage( &msg ); } else { Render(i); } } } } } LRESULT CALLBACK MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) { switch( msg ) { case WM_DESTROY: //CleanUp(); PostQuitMessage( 0 ); return 0; case WM_PAINT: //Render(); ValidateRect( hWnd, NULL ); return 0; } return DefWindowProc( hWnd, msg, wParam, lParam ); } I've made a sample function to make multiple windows: void RunSample1() { //Create the window manager. RAT_ENGINE::RAT_WindowManager* wMan = new RAT_ENGINE::RAT_WindowManager(); //Create the render manager. RAT_ENGINE::RAT_RenderManager* rMan = new RAT_ENGINE::RAT_RenderManager(); //Create a window. //This is currently needed to initialize the render manager and create a renderer. wMan->CreateRATWindow("Sample 1 - 1", 10, 20, 640, 480); wMan->CreateRATWindow("Sample 1 - 2", 150, 100, 480, 640); //Initialize the render manager. rMan->Init(wMan); //Show the window. rMan->getRenderer()->ShowWin(); } How do I get the multiple windows to work?

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  • Ubuntu 11.10 Virtual-box Unity 3D not working

    - by naveen
    After struggling for four hours, I still cannot get Unity 3D of Gnome 3 to work on my VirtualBox - I have been pouring through Internet and forum posts but to no avail. Here's what I've done so far: VirtualBox 4.1.4r74921 on Windows 7 Installed Ubuntu Desktop 11.10 ( 32 bit ) Enabled 3D acceleration Allocated 1.5GB of RAM Allocated 50MB video memory (hope this is not the culprit) Installed Guest edition 4.1.4 Did apt-get update and apt-get upgrade Booted back in to Ubuntu - falls back to Unity 2D Shared folder, mouse integration all works, so guest edition is properly installed Tried the command and below is the output /usr/lib/nux/unity_support_test –p OpenGL vendor string: Mesa Project OpenGL renderer string: Software Rasterizer OpenGL version string: 2.1 Mesa 7.11 Not software rendered: no Not blacklisted: yes GLX fbconfig: yes GLX texture from pixmap: no GL npot or rect textures: yes GL vertex program: yes GL fragment program: yes GL vertex buffer object: yes GL framebuffer object: yes GL version is 1.4+: yes Unity 3D supported: no I am trying to find what the "no" means but cannot find any good answers. Inter Core i5 processor 4GB of RAM on the host Display adapter: NVIDIA GeForce 8400GS Is anyone else facing the same problem? If so, can you point me to a solution or any reference where I can find a solution?

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  • In Windows 7 power management, is it possible to set different sleep settings for different SATA disks?

    - by Ben Voigt
    I'm having an issue with Windows 7 either freezing up or generating a BSOD coming out of sleep. I suspect that it is related to my boot/OS drive, an OCZ Vertex SE SSD, because numerous other Vertex users have reported sleep problems. Notably, if I put the computer to sleep, it almost always wakes correctly. If it goes to sleep after a timeout, it almost always BSODs. I disabled timed sleep and now it freezes when left unattended. My next step is to disable "Put hard disks to sleep after X minutes", but I'd like to change this setting only for the SSD and not for the rotating data disks, which I would like to spin down normally. Does anyone know a place to configure sleep on a per-disk basis? I don't need to set different timeouts on different disks (although that would be nice), simply setting "this disk sleeps" and "sleep is disabled for this disk" would be great. Additional system information: Windows 7 Ultimate x64, Core i5 - P55 chipset, Intel RST drivers are installed. One SSD, two rotating HDD, and a DVD-RW drive are all connected to the Intel SATA ports. I could potentially move some of these to my motherboard's other SATA controller if that would help.

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  • LWJGL SlickUtil Texture Binding

    - by Matthew Dockerty
    I am making a 3D game using LWJGL and I have a texture class with static variables so that I only need to load textures once, even if I need to use them more than once. I am using Slick Util for this. When I bind a texture it works fine, but then when I try to render something else after I have rendered the model with the texture, the texture is still being bound. How do I unbind the texture and set the rendermode to the one that was in use before any textures were bound? Some of my code is below. The problem I am having is the player texture is being used in the box drawn around the player after it the model has been rendered. Model.java public class Model { public List<Vector3f> vertices = new ArrayList<Vector3f>(); public List<Vector3f> normals = new ArrayList<Vector3f>(); public ArrayList<Vector2f> textureCoords = new ArrayList<Vector2f>(); public List<Face> faces = new ArrayList<Face>(); public static Model TREE; public static Model PLAYER; public static void loadModels() { try { TREE = OBJLoader.loadModel(new File("assets/model/tree_pine_0.obj")); PLAYER = OBJLoader.loadModel(new File("assets/model/player.obj")); } catch (Exception e) { e.printStackTrace(); } } public void render(Vector3f position, Vector3f scale, Vector3f rotation, Texture texture, float shinyness) { glPushMatrix(); { texture.bind(); glColor3f(1, 1, 1); glTranslatef(position.x, position.y, position.z); glScalef(scale.x, scale.y, scale.z); glRotatef(rotation.x, 1, 0, 0); glRotatef(rotation.y, 0, 1, 0); glRotatef(rotation.z, 0, 0, 1); glMaterialf(GL_FRONT, GL_SHININESS, shinyness); glBegin(GL_TRIANGLES); { for (Face face : faces) { Vector2f t1 = textureCoords.get((int) face.textureCoords.x - 1); glTexCoord2f(t1.x, t1.y); Vector3f n1 = normals.get((int) face.normal.x - 1); glNormal3f(n1.x, n1.y, n1.z); Vector3f v1 = vertices.get((int) face.vertex.x - 1); glVertex3f(v1.x, v1.y, v1.z); Vector2f t2 = textureCoords.get((int) face.textureCoords.y - 1); glTexCoord2f(t2.x, t2.y); Vector3f n2 = normals.get((int) face.normal.y - 1); glNormal3f(n2.x, n2.y, n2.z); Vector3f v2 = vertices.get((int) face.vertex.y - 1); glVertex3f(v2.x, v2.y, v2.z); Vector2f t3 = textureCoords.get((int) face.textureCoords.z - 1); glTexCoord2f(t3.x, t3.y); Vector3f n3 = normals.get((int) face.normal.z - 1); glNormal3f(n3.x, n3.y, n3.z); Vector3f v3 = vertices.get((int) face.vertex.z - 1); glVertex3f(v3.x, v3.y, v3.z); } texture.release(); } glEnd(); } glPopMatrix(); } } Textures.java public class Textures { public static Texture FLOOR; public static Texture PLAYER; public static Texture SKYBOX_TOP; public static Texture SKYBOX_BOTTOM; public static Texture SKYBOX_FRONT; public static Texture SKYBOX_BACK; public static Texture SKYBOX_LEFT; public static Texture SKYBOX_RIGHT; public static void loadTextures() { try { FLOOR = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/model/floor.png"))); FLOOR.setTextureFilter(GL11.GL_NEAREST); PLAYER = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/model/tree_pine_0.png"))); PLAYER.setTextureFilter(GL11.GL_NEAREST); SKYBOX_TOP = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_top.png"))); SKYBOX_TOP.setTextureFilter(GL11.GL_NEAREST); SKYBOX_BOTTOM = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_bottom.png"))); SKYBOX_BOTTOM.setTextureFilter(GL11.GL_NEAREST); SKYBOX_FRONT = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_front.png"))); SKYBOX_FRONT.setTextureFilter(GL11.GL_NEAREST); SKYBOX_BACK = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_back.png"))); SKYBOX_BACK.setTextureFilter(GL11.GL_NEAREST); SKYBOX_LEFT = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_left.png"))); SKYBOX_LEFT.setTextureFilter(GL11.GL_NEAREST); SKYBOX_RIGHT = TextureLoader.getTexture("PNG", new FileInputStream(new File("assets/textures/skybox_right.png"))); SKYBOX_RIGHT.setTextureFilter(GL11.GL_NEAREST); } catch (Exception e) { e.printStackTrace(); } } } Player.java public class Player { private Vector3f position; private float yaw; private float moveSpeed; public Player(float x, float y, float z, float yaw, float moveSpeed) { this.position = new Vector3f(x, y, z); this.yaw = yaw; this.moveSpeed = moveSpeed; } public void update() { if (Keyboard.isKeyDown(Keyboard.KEY_W)) walkForward(moveSpeed); if (Keyboard.isKeyDown(Keyboard.KEY_S)) walkBackwards(moveSpeed); if (Keyboard.isKeyDown(Keyboard.KEY_A)) strafeLeft(moveSpeed); if (Keyboard.isKeyDown(Keyboard.KEY_D)) strafeRight(moveSpeed); if (Mouse.isButtonDown(0)) yaw += Mouse.getDX(); LowPolyRPG.getInstance().getCamera().setPosition(-position.x, -position.y, -position.z); LowPolyRPG.getInstance().getCamera().setYaw(yaw); } public void walkForward(float distance) { position.setX(position.getX() + distance * (float) Math.sin(Math.toRadians(yaw))); position.setZ(position.getZ() - distance * (float) Math.cos(Math.toRadians(yaw))); } public void walkBackwards(float distance) { position.setX(position.getX() - distance * (float) Math.sin(Math.toRadians(yaw))); position.setZ(position.getZ() + distance * (float) Math.cos(Math.toRadians(yaw))); } public void strafeLeft(float distance) { position.setX(position.getX() + distance * (float) Math.sin(Math.toRadians(yaw - 90))); position.setZ(position.getZ() - distance * (float) Math.cos(Math.toRadians(yaw - 90))); } public void strafeRight(float distance) { position.setX(position.getX() + distance * (float) Math.sin(Math.toRadians(yaw + 90))); position.setZ(position.getZ() - distance * (float) Math.cos(Math.toRadians(yaw + 90))); } public void render() { Model.PLAYER.render(new Vector3f(position.x, position.y + 12, position.z), new Vector3f(3, 3, 3), new Vector3f(0, -yaw + 90, 0), Textures.PLAYER, 128); GL11.glPushMatrix(); GL11.glTranslatef(position.getX(), position.getY(), position.getZ()); GL11.glRotatef(-yaw, 0, 1, 0); GL11.glScalef(5.8f, 21, 2.2f); GL11.glDisable(GL11.GL_LIGHTING); GL11.glLineWidth(3); GL11.glBegin(GL11.GL_LINE_STRIP); GL11.glColor3f(1, 1, 1); glVertex3f(1f, 0f, -1f); glVertex3f(-1f, 0f, -1f); glVertex3f(-1f, 1f, -1f); glVertex3f(1f, 1f, -1f); glVertex3f(-1f, 0f, 1f); glVertex3f(1f, 0f, 1f); glVertex3f(1f, 1f, 1f); glVertex3f(-1f, 1f, 1f); glVertex3f(1f, 1f, -1f); glVertex3f(-1f, 1f, -1f); glVertex3f(-1f, 1f, 1f); glVertex3f(1f, 1f, 1f); glVertex3f(1f, 0f, 1f); glVertex3f(-1f, 0f, 1f); glVertex3f(-1f, 0f, -1f); glVertex3f(1f, 0f, -1f); glVertex3f(1f, 0f, 1f); glVertex3f(1f, 0f, -1f); glVertex3f(1f, 1f, -1f); glVertex3f(1f, 1f, 1f); glVertex3f(-1f, 0f, -1f); glVertex3f(-1f, 0f, 1f); glVertex3f(-1f, 1f, 1f); glVertex3f(-1f, 1f, -1f); GL11.glEnd(); GL11.glEnable(GL11.GL_LIGHTING); GL11.glPopMatrix(); } public Vector3f getPosition() { return new Vector3f(-position.x, -position.y, -position.z); } public float getX() { return position.getX(); } public float getY() { return position.getY(); } public float getZ() { return position.getZ(); } public void setPosition(Vector3f position) { this.position = position; } public void setPosition(float x, float y, float z) { this.position.setX(x); this.position.setY(y); this.position.setZ(z); } } Thanks for the help.

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  • CSG operations on implicit surfaces with marching cubes [SOLVED]

    - by Mads Elvheim
    I render isosurfaces with marching cubes, (or perhaps marching squares as this is 2D) and I want to do set operations like set difference, intersection and union. I thought this was easy to implement, by simply choosing between two vertex scalars from two different implicit surfaces, but it is not. For my initial testing, I tried with two spheres circles, and the set operation difference. i.e A - B. One circle is moving and the other one is stationary. Here's the approach I tried when picking vertex scalars and when classifying corner vertices as inside or outside. The code is written in C++. OpenGL is used for rendering, but that's not important. Normal rendering without any CSG operations does give the expected result. void march(const vec2& cmin, //min x and y for the grid cell const vec2& cmax, //max x and y for the grid cell std::vector<vec2>& tri, float iso, float (*cmp1)(const vec2&), //distance from stationary circle float (*cmp2)(const vec2&) //distance from moving circle ) { unsigned int squareindex = 0; float scalar[4]; vec2 verts[8]; /* initial setup of the grid cell */ verts[0] = vec2(cmax.x, cmax.y); verts[2] = vec2(cmin.x, cmax.y); verts[4] = vec2(cmin.x, cmin.y); verts[6] = vec2(cmax.x, cmin.y); float s1,s2; /********************************** ********For-loop of interest****** *******Set difference between **** *******two implicit surfaces****** **********************************/ for(int i=0,j=0; i<4; ++i, j+=2){ s1 = cmp1(verts[j]); s2 = cmp2(verts[j]); if((s1 < iso)){ //if inside circle1 if((s2 < iso)){ //if inside circle2 scalar[i] = s2; //then set the scalar to the moving circle } else { scalar[i] = s1; //only inside circle1 squareindex |= (1<<i); //mark as inside } } else { scalar[i] = s1; //inside neither circle } } if(squareindex == 0) return; /* Usual interpolation between edge points to compute the new intersection points */ verts[1] = mix(iso, verts[0], verts[2], scalar[0], scalar[1]); verts[3] = mix(iso, verts[2], verts[4], scalar[1], scalar[2]); verts[5] = mix(iso, verts[4], verts[6], scalar[2], scalar[3]); verts[7] = mix(iso, verts[6], verts[0], scalar[3], scalar[0]); for(int i=0; i<10; ++i){ //10 = maxmimum 3 triangles, + one end token int index = triTable[squareindex][i]; //look up our indices for triangulation if(index == -1) break; tri.push_back(verts[index]); } } This gives me weird jaggies: It looks like the CSG operation is done without interpolation. It just "discards" the whole triangle. Do I need to interpolate in some other way, or combine the vertex scalar values? I'd love some help with this. A full testcase can be downloaded HERE EDIT: Basically, my implementation of marching squares works fine. It is my scalar field which is broken, and I wonder what the correct way would look like. Preferably I'm looking for a general approach to implement the three set operations I discussed above, for the usual primitives (circle, rectangle/square, plane)

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  • CSG operations on implicit surfaces with marching cubes

    - by Mads Elvheim
    I render isosurfaces with marching cubes, (or perhaps marching squares as this is 2D) and I want to do set operations like set difference, intersection and union. I thought this was easy to implement, by simply choosing between two vertex scalars from two different implicit surfaces, but it is not. For my initial testing, I tried with two spheres, and the set operation difference. i.e A - B. One sphere is moving and the other one is stationary. Here's the approach I tried when picking vertex scalars and when classifying corner vertices as inside or outside. The code is written in C++. OpenGL is used for rendering, but that's not important. Normal rendering without any CSG operations does give the expected result. void march(const vec2& cmin, //min x and y for the grid cell const vec2& cmax, //max x and y for the grid cell std::vector<vec2>& tri, float iso, float (*cmp1)(const vec2&), //distance from stationary sphere float (*cmp2)(const vec2&) //distance from moving sphere ) { unsigned int squareindex = 0; float scalar[4]; vec2 verts[8]; /* initial setup of the grid cell */ verts[0] = vec2(cmax.x, cmax.y); verts[2] = vec2(cmin.x, cmax.y); verts[4] = vec2(cmin.x, cmin.y); verts[6] = vec2(cmax.x, cmin.y); float s1,s2; /********************************** ********For-loop of interest****** *******Set difference between **** *******two implicit surfaces****** **********************************/ for(int i=0,j=0; i<4; ++i, j+=2){ s1 = cmp1(verts[j]); s2 = cmp2(verts[j]); if((s1 < iso)){ //if inside sphere1 if((s2 < iso)){ //if inside sphere2 scalar[i] = s2; //then set the scalar to the moving sphere } else { scalar[i] = s1; //only inside sphere1 squareindex |= (1<<i); //mark as inside } } else { scalar[i] = s1; //inside neither sphere } } if(squareindex == 0) return; /* Usual interpolation between edge points to compute the new intersection points */ verts[1] = mix(iso, verts[0], verts[2], scalar[0], scalar[1]); verts[3] = mix(iso, verts[2], verts[4], scalar[1], scalar[2]); verts[5] = mix(iso, verts[4], verts[6], scalar[2], scalar[3]); verts[7] = mix(iso, verts[6], verts[0], scalar[3], scalar[0]); for(int i=0; i<10; ++i){ //10 = maxmimum 3 triangles, + one end token int index = triTable[squareindex][i]; //look up our indices for triangulation if(index == -1) break; tri.push_back(verts[index]); } } This gives me weird jaggies: It looks like the CSG operation is done without interpolation. It just "discards" the whole triangle. Do I need to interpolate in some other way, or combine the vertex scalar values? I'd love some help with this. A full testcase can be downloaded HERE

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  • SharpGL: Can't draw all lines from List

    - by Miko Kronn
    I have: float[,] nodesN = null; //indexes: //number of node; //value index 0->x, 1->y, 2->temperature int[,] elements = null; //indexes: //indexof element (triangle) //1, 2, 3 - vertexes (from nodesN) List<Pair> edges = null; //Pair is a class containing two int values which are //indexes of nodesN And function which is supposed do all elements and edges on SharpGL.OpenGLCtrl private void openGLCtrl1_Load(object sender, EventArgs e) { gl = this.glCtrl.OpenGL; gl.ClearColor(this.BackColor.R / 255.0f, this.BackColor.G / 255.0f, this.BackColor.B / 255.0f, 1.0f); gl.Clear(OpenGL.COLOR_BUFFER_BIT | OpenGL.DEPTH_BUFFER_BIT); } float glMinX = -2f; float glMaxX = 2f; float glMinY = -2f; float glMaxY = 2f; private void openGLControl1_OpenGLDraw(object sender, PaintEventArgs e) { gl.Clear(OpenGL.COLOR_BUFFER_BIT | OpenGL.DEPTH_BUFFER_BIT); gl.LoadIdentity(); gl.Translate(0.0f, 0.0f, -6.0f); if (!draw) return; bool drawElements = false; if (drawElements) { gl.Begin(OpenGL.TRIANGLES); for (int i = 0; i < elementNo; i++) { for (int j = 0; j < 3; j++) { float x, y, t; x = nodesN[elements[i, j], 0]; y = nodesN[elements[i, j], 1]; t = nodesN[elements[i, j], 2]; gl.Color(t, 0.0f, 1.0f - t); gl.Vertex(x, y, 0.0f); } } gl.End(); } gl.Color(0f, 0f, 0f); gl.Begin(OpenGL.LINES); //for(int i=edges.Count-1; i>=0; i--) for(int i=0; i<edges.Count; i++) { float x1, y1, x2, y2; x1 = nodesN[edges[i].First, 0]; y1 = nodesN[edges[i].First, 1]; x2 = nodesN[edges[i].Second, 0]; y2 = nodesN[edges[i].Second, 1]; gl.Vertex(x1, y1, 0.0f); gl.Vertex(x2, y2, 0.0f); } gl.End(); } But it doesn't draw all the edges. If i change drawElements it draws different number of edges. Changing for(int i=0; i<edges.Count; i++) to for(int i=edges.Count-1; i>=0; i--) shows that esges are generated correctly, but they are not drawn. Images: for(int i=0; i<edges.Count; i++) drawElements=false for(int i=edges.Count-1; i>=0; i--) drawElements=false for(int i=0; i<edges.Count; i++) drawElements=true for(int i=edges.Count-1; i>=0; i--) drawElements=true What is wrong with this? How can I draw all edges?

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  • GPGPU

    WhatGPU obviously stands for Graphics Processing Unit (the silicon powering the display you are using to read this blog post). The extra GP in front of that stands for General Purpose computing.So, altogether GPGPU refers to computing we can perform on GPU for purposes beyond just drawing on the screen. In effect, we can use a GPGPU a bit like we already use a CPU: to perform some calculation (that doesn’t have to have any visual element to it). The attraction is that a GPGPU can be orders of magnitude faster than a CPU.WhyWhen I was at the SuperComputing conference in Portland last November, GPGPUs were all the rage. A quick online search reveals many articles introducing the GPGPU topic. I'll just share 3 here: pcper (ignoring all pages except the first, it is a good consumer perspective), gizmodo (nice take using mostly layman terms) and vizworld (answering the question on "what's the big deal").The GPGPU programming paradigm (from a high level) is simple: in your CPU program you define functions (aka kernels) that take some input, can perform the costly operation and return the output. The kernels are the things that execute on the GPGPU leveraging its power (and hence execute faster than what they could on the CPU) while the host CPU program waits for the results or asynchronously performs other tasks.However, GPGPUs have different characteristics to CPUs which means they are suitable only for certain classes of problem (i.e. data parallel algorithms) and not for others (e.g. algorithms with branching or recursion or other complex flow control). You also pay a high cost for transferring the input data from the CPU to the GPU (and vice versa the results back to the CPU), so the computation itself has to be long enough to justify the overhead transfer costs. If your problem space fits the criteria then you probably want to check out this technology.HowSo where can you get a graphics card to start playing with all this? At the time of writing, the two main vendors ATI (owned by AMD) and NVIDIA are the obvious players in this industry. You can read about GPGPU on this AMD page and also on this NVIDIA page. NVIDIA's website also has a free chapter on the topic from the "GPU Gems" book: A Toolkit for Computation on GPUs.If you followed the links above, then you've already come across some of the choices of programming models that are available today. Essentially, AMD is offering their ATI Stream technology accessible via a language they call Brook+; NVIDIA offers their CUDA platform which is accessible from CUDA C. Choosing either of those locks you into the GPU vendor and hence your code cannot run on systems with cards from the other vendor (e.g. imagine if your CPU code would run on Intel chips but not AMD chips). Having said that, both vendors plan to support a new emerging standard called OpenCL, which theoretically means your kernels can execute on any GPU that supports it. To learn more about all of these there is a website: gpgpu.org. The caveat about that site is that (currently) it completely ignores the Microsoft approach, which I touch on next.On Windows, there is already a cross-GPU-vendor way of programming GPUs and that is the DirectX API. Specifically, on Windows Vista and Windows 7, the DirectX 11 API offers a dedicated subset of the API for GPGPU programming: DirectCompute. You use this API on the CPU side, to set up and execute the kernels that run on the GPU. The kernels are written in a language called HLSL (High Level Shader Language). You can use DirectCompute with HLSL to write a "compute shader", which is the term DirectX uses for what I've been referring to in this post as a "kernel". For a comprehensive collection of links about this (including tutorials, videos and samples) please see my blog post: DirectCompute.Note that there are many efforts to build even higher level languages on top of DirectX that aim to expose GPGPU programming to a wider audience by making it as easy as today's mainstream programming models. I'll mention here just two of those efforts: Accelerator from MSR and Brahma by Ananth. Comments about this post welcome at the original blog.

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  • Improving performance of a particle system (OpenGL ES)

    - by Jason
    I'm in the process of implementing a simple particle system for a 2D mobile game (using OpenGL ES 2.0). It's working, but it's pretty slow. I start getting frame rate battering after about 400 particles, which I think is pretty low. Here's a summary of my approach: I start with point sprites (GL_POINTS) rendered in a batch just using a native float buffer (I'm in Java-land on Android, so that translates as a java.nio.FloatBuffer). On GL context init, the following are set: GLES20.glViewport(0, 0, width, height); GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); GLES20.glEnable(GLES20.GL_CULL_FACE); GLES20.glDisable(GLES20.GL_DEPTH_TEST); Each draw frame sets the following: GLES20.glEnable(GLES20.GL_BLEND); GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA); And I bind a single texture: GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle); GLES20.glUniform1i(mUniformTextureHandle, 0); Which is just a simple circle with some blur (and hence some transparency) http://cl.ly/image/0K2V2p2L1H2x Then there are a bunch of glVertexAttribPointer calls: mBuffer.position(position); mGlEs20.glVertexAttribPointer(mAttributeRGBHandle, valsPerRGB, GLES20.GL_FLOAT, false, stride, mBuffer); ...4 more of these Then I'm drawing: GLES20.glUniformMatrix4fv(mUniformProjectionMatrixHandle, 1, false, Camera.mProjectionMatrix, 0); GLES20.glDrawArrays(GLES20.GL_POINTS, 0, drawCalls); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0); My vertex shader does have some computation in it, but given that they're point sprites (with only 2 coordinate values) I'm not sure this is the problem: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform mat4 u_ProjectionMatrix; attribute vec4 a_Position; attribute float a_PointSize; attribute vec3 a_RGB; attribute float a_Alpha; attribute float a_Burn; varying vec4 v_Color; void main() { vec3 v_FGC = a_RGB * a_Alpha; v_Color = vec4(v_FGC.x, v_FGC.y, v_FGC.z, a_Alpha * (1.0 - a_Burn)); gl_PointSize = a_PointSize; gl_Position = u_ProjectionMatrix * a_Position; } My fragment shader couldn't really be simpler: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform sampler2D u_Texture; varying vec4 v_Color; void main() { gl_FragColor = texture2D(u_Texture, gl_PointCoord) * v_Color; } That's about it. I had read that transparent pixels in point sprites can cause issues, but surely not at only 400 points? I'm running on a fairly new device (12 month old Galaxy Nexus). My question is less about my approach (although I'm open to suggestion) but more about whether there are any specific OpenGL "no no's" that have leaked into my code. I'm sure there's GL master out there facepalming right now... I'd love to hear any critique.

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  • Why are my Unity procedural animations jerky?

    - by Phoenix Perry
    I'm working in Unity and getting some crazy weird motion behavior. I have a plane and I'm moving it. It's ever so slightly getting about 1 pixel bigger and smaller. It looks like the it's kind of getting squeezed sideways by a pixel. I'm moving a plane by cos and sin so it will spin on the x and z axes. If the planes are moving at Time.time, everything is fine. However, if I put in slower speed multiplier, I get an amazingly weird jerk in my animation. I get it with or without the lerp. How do I fix it? I want it to move very slowly. Is there some sort of invisible grid in unity? Some sort of minimum motion per frame? I put a visual sample of the behavior here. Here's the relevant code: public void spin() { for (int i = 0; i < numPlanes; i++ ) { GameObject g = planes[i] as GameObject; //alt method //currentRotation += speed * Time.deltaTime * 100; //rotation.eulerAngles = new Vector3(0, currentRotation, 0); //g.transform.position = rotation * rotationRadius; //sine method g.GetComponent<PlaneSetup>().pos.x = g.GetComponent<PlaneSetup>().radiusX * (Mathf.Cos((Time.time*speed) + g.GetComponent<PlaneSetup>().startAngle)); g.GetComponent<PlaneSetup>().pos.z = g.GetComponent<PlaneSetup>().radius * Mathf.Sin((Time.time*speed) + g.GetComponent<PlaneSetup>().startAngle); g.GetComponent<PlaneSetup>().pos.y = g.GetComponent<Transform>().position.y; ////offset g.GetComponent<PlaneSetup>().pos.z += 20; g.GetComponent<PlaneSetup>().posLerp.x = Mathf.Lerp(g.transform.position.x,g.GetComponent<PlaneSetup>().pos.x, .5f); g.GetComponent<PlaneSetup>().posLerp.z = Mathf.Lerp(g.transform.position.z, g.GetComponent<PlaneSetup>().pos.z, .5f); g.GetComponent<PlaneSetup>().posLerp.y = g.GetComponent<Transform>().position.y; g.transform.position = g.GetComponent<PlaneSetup>().posLerp; } Invoke("spin",0.0f); } The full code is on github. There is literally nothing else going on. I've turned off all other game objects so it's only the 40 planes with a texture2D shader. I removed it from Invoke and tried it in Update -- still happens. With a set frame rate or not, the same problem occurs. Tested it in Fixed Update. Same issue. The script on the individual plane doesn't even have an update function in it. The data on it could functionally live in a struct. I'm getting between 90 and 123 fps. Going to investigate and test further. I put this in an invoke function to see if I could get around it just occurring in update. There are no physics on these shapes. It's a straight procedural animation. Limited it to 1 plane - still happens. Thoughts? Removed the shader - still happening.

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  • Texture errors in CubeMap

    - by shade4159
    I am trying to apply this texture as a cubemap. This is my result: Clearly I am doing something with my texture coordinates, but I cannot for the life of me figure out what. I don't even see a pattern to the texture fragments. They just seem like a jumble of different faces. Can anyone shed some light on this? Vertex shader: #version 400 in vec4 vPosition; in vec3 inTexCoord; smooth out vec3 texCoord; uniform mat4 projMatrix; void main() { texCoord = inTexCoord; gl_Position = projMatrix * vPosition; } My fragment shader: #version 400 smooth in vec3 texCoord; out vec4 fColor; uniform samplerCube textures void main() { fColor = texture(textures,texCoord); } Vertices of cube: point4 worldVerts[8] = { vec4( 15, 15, 15, 1 ), vec4( -15, 15, 15, 1 ), vec4( -15, 15, -15, 1 ), vec4( 15, 15, -15, 1 ), vec4( -15, -15, 15, 1 ), vec4( 15, -15, 15, 1 ), vec4( 15, -15, -15, 1 ), vec4( -15, -15, -15, 1 ) }; Cube rendering: void worldCube(point4* verts, int& Index, point4* points, vec3* texVerts) { quadInv( verts[0], verts[1], verts[2], verts[3], 1, Index, points, texVerts); quadInv( verts[6], verts[3], verts[2], verts[7], 2, Index, points, texVerts); quadInv( verts[4], verts[5], verts[6], verts[7], 3, Index, points, texVerts); quadInv( verts[4], verts[1], verts[0], verts[5], 4, Index, points, texVerts); quadInv( verts[5], verts[0], verts[3], verts[6], 5, Index, points, texVerts); quadInv( verts[4], verts[7], verts[2], verts[1], 6, Index, points, texVerts); } Backface function (since this is the inside of the cube): void quadInv( const point4& a, const point4& b, const point4& c, const point4& d , int& Index, point4* points, vec3* texVerts) { quad( a, d, c, b, Index, points, texVerts, a.to_3(), b.to_3(), c.to_3(), d.to_3()); } And the quad drawing function: void quad( const point4& a, const point4& b, const point4& c, const point4& d, int& Index, point4* points, vec3* texVerts, const vec3& tex_a, const vec3& tex_b, const vec3& tex_c, const vec3& tex_d) { texVerts[Index] = tex_a.normalized(); points[Index] = a; Index++; texVerts[Index] = tex_b.normalized(); points[Index] = b; Index++; texVerts[Index] = tex_c.normalized(); points[Index] = c; Index++; texVerts[Index] = tex_a.normalized(); points[Index] = a; Index++; texVerts[Index] = tex_c.normalized(); points[Index] = c; Index++; texVerts[Index] = tex_d.normalized(); points[Index] = d; Index++; } Edit: I forgot to mention, in the image, the camera is pointed directly at the back face of the cube. You can kind of see the diagonals leading out of the corners, if you squint.

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  • Why do my pyramids fade black and then back to colour again

    - by geminiCoder
    I have the following vertecies and norms GLfloat verts[36] = { -0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 1, 0, -0.5, 0, 0.5, 0, 0, -0.5, 0, 1, 0, 0.5, 0, 0.5, -0.5, 0, 0.5, 0, 1, 0 }; GLfloat norms[36] = { 0, -1, 0, 0, -1, 0, 0, -1, 0, -1, 0.25, 0.5, -1, 0.25, 0.5, -1, 0.25, 0.5, 1, 0.25, -0.5, 1, 0.25, -0.5, 1, 0.25, -0.5, 0, -0.5, -1, 0, -0.5, -1, 0, -0.5, -1 }; I am writing my fists Open GL game, But I need to know for sure if my Normals are correct as the colours aren't rendering correctly. my Pyramids are coloured then fade to black every half rotation then back again. My app so far is based on the boiler plate code provided by apple. heres my modified setUp Method [EAGLContext setCurrentContext:self.context]; [self loadShaders]; self.effect = [[GLKBaseEffect alloc] init]; self.effect.light0.enabled = GL_TRUE; self.effect.light0.diffuseColor = GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f); glEnable(GL_DEPTH_TEST); glGenVertexArraysOES(1, &_vertexArray); //create vertex array glBindVertexArrayOES(_vertexArray); glGenBuffers(1, &_vertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(verts) + sizeof(norms), NULL, GL_STATIC_DRAW); //create vertex buffer big enough for both verts and norms and pass NULL as data.. uint8_t *ptr = (uint8_t *)glMapBufferOES(GL_ARRAY_BUFFER, GL_WRITE_ONLY_OES); //map buffer to pass data to it memcpy(ptr, verts, sizeof(verts)); //copy verts memcpy(ptr+sizeof(verts), norms, sizeof(norms)); //copy norms to position after verts glUnmapBufferOES(GL_ARRAY_BUFFER); glEnableVertexAttribArray(GLKVertexAttribPosition); glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0)); //tell GL where verts are in buffer glEnableVertexAttribArray(GLKVertexAttribNormal); glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(sizeof(verts))); //tell GL where norms are in buffer glBindVertexArrayOES(0); And the update method. - (void)update { float aspect = fabsf(self.view.bounds.size.width / self.view.bounds.size.height); GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0f), aspect, 0.1f, 100.0f); self.effect.transform.projectionMatrix = projectionMatrix; GLKMatrix4 baseModelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -4.0f); baseModelViewMatrix = GLKMatrix4Rotate(baseModelViewMatrix, _rotation, 0.0f, 1.0f, 0.0f); // Compute the model view matrix for the object rendered with GLKit GLKMatrix4 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -1.5f); modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f); modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix); self.effect.transform.modelviewMatrix = modelViewMatrix; // Compute the model view matrix for the object rendered with ES2 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, 1.5f); modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f); modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix); _normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix), NULL); _modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, modelViewMatrix); _rotation += self.timeSinceLastUpdate * 0.5f; } But providing I understand this correct one pyramid is using the GLKit base effect shaders and the other the shaders which are included in the project. So for both of them to have the same error, I thought it would be the Norms?

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  • How to get this wavefront .obj data onto the frustum?

    - by NoobScratcher
    I've finally figured out how to get the data from a .obj file and store the vertex positions x,y,z into a structure called Points with members x y z which are of type float. I want to know how to get this data onto the screen. Here is my attempt at doing so: //make a fileobject and store list and the index of that list in a c string ifstream file (list[index].c_str() ); std::vector<int>faces; std::vector<Point>points; points.push_back(Point()); Point p; int face[4]; while ( !file.eof() ) { char modelbuffer[10000]; //Get lines and store it in line string file.getline(modelbuffer, 10000); switch(modelbuffer[0]) { case 'v' : sscanf(modelbuffer, "v %f %f %f", &p.x, &p.y, &p.z); points.push_back(p); cout << "Getting Vertex Positions" << endl; cout << "v" << p.x << endl; cout << "v" << p.y << endl; cout << "v" << p.z << endl; break; case 'f': sscanf(modelbuffer, "f %d %d %d %d", face, face+1, face+2, face+3 ); cout << face[0] << endl; cout << face[1] << endl; cout << face[2] << endl; cout << face[3] << endl; faces.push_back(face[0]); faces.push_back(face[1]); faces.push_back(face[2]); faces.push_back(face[3]); } GLuint vertexbuffer; glGenBuffers(1, &vertexbuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBufferData(GL_ARRAY_BUFFER, points.size(), points.data(), GL_STATIC_DRAW); //glBufferData(GL_ARRAY_BUFFER,sizeof(points), &(points[0]), GL_STATIC_DRAW); glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0); glVertexPointer(3, GL_FLOAT, sizeof(points),points.data()); glIndexPointer(GL_DOUBLE, 0, faces.data()); glDrawArrays(GL_QUADS, 0, points.size()); glDrawElements(GL_QUADS, faces.size(), GL_UNSIGNED_INT, faces.data()); } As you can see I've clearly failed the end part but I really don't know why its not rendering the data onto the frustum? Does anyone have a solution for this?

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  • error C2146: syntax error : missing ';' before identifier 'vertices'

    - by numerical25
    I would usually search for this error. But in VS C++ Express, this error comes up for just about every mistake you do. Any how I recieve this error below error C2146: syntax error : missing ';' before identifier 'vertices' everytime I add the following code at the top of my document // Create vertex buffer SimpleVertex vertices[] = { D3DXVECTOR3( 0.0f, 0.5f, 0.5f ), D3DXVECTOR3( 0.5f, -0.5f, 0.5f ), D3DXVECTOR3( -0.5f, -0.5f, 0.5f ), }; below is the code in it's entirety. Cant figure out whats wrong. thanks // include the basic windows header file #include "D3Dapp.h" class MyGame: public D3Dapp { public: bool Init3d(); }; MyGame game; // Create vertex buffer SimpleVertex vertices[] = { D3DXVECTOR3( 0.0f, 0.5f, 0.5f ), D3DXVECTOR3( 0.5f, -0.5f, 0.5f ), D3DXVECTOR3( -0.5f, -0.5f, 0.5f ), }; // the entry point for any Windows program int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { game.InitWindow(hInstance , nCmdShow); return game.Run(); } bool MyGame::Init3d() { D3Dapp::Init3d(); return true; }

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  • iPod/iPhone OpenGL ES UIView flashes when updating

    - by Dave Viner
    I have a simple iPhone application which uses OpenGL ES (v1) to draw a line based on the touches of the user. In the XCode Simulator, the code works perfectly. However, when I install the app onto an iPod or iPhone, the OpenGL ES view "flashes" when drawing the line. If I disable the line drawing, the flash disappears. By "flash", I mean that the background image (which is an OpenGL texture) disappears momentarily, and then reappears. It appears as if the entire scene is completely erased and redrawn. The code which handles the line drawing is the following: renderLineFromPoint:(CGPoint)start toPoint:(CGPoint)end { static GLfloat* vertexBuffer = NULL; static NSUInteger vertexMax = 64; NSUInteger vertexCount = 0, count, i; //Allocate vertex array buffer if(vertexBuffer == NULL) vertexBuffer = malloc(vertexMax * 2 * sizeof(GLfloat)); //Add points to the buffer so there are drawing points every X pixels count = MAX(ceilf(sqrtf((end.x - start.x) * (end.x - start.x) + (end.y - start.y) * (end.y - start.y)) / kBrushPixelStep), 1); for(i = 0; i < count; ++i) { if(vertexCount == vertexMax) { vertexMax = 2 * vertexMax; vertexBuffer = realloc(vertexBuffer, vertexMax * 2 * sizeof(GLfloat)); } vertexBuffer[2 * vertexCount + 0] = start.x + (end.x - start.x) * ((GLfloat)i / (GLfloat)count); vertexBuffer[2 * vertexCount + 1] = start.y + (end.y - start.y) * ((GLfloat)i / (GLfloat)count); vertexCount += 1; } //Render the vertex array glVertexPointer(2, GL_FLOAT, 0, vertexBuffer); glDrawArrays(GL_POINTS, 0, vertexCount); //Display the buffer [context presentRenderbuffer:GL_RENDERBUFFER_OES]; } (This function is based on the function of the same name from the GLPaint sample application.) For the life of me, I can not figure out why this causes the screen to flash. The line is drawn properly (both in the Simulator and in the iPod). But, the flash makes it unusable. Anyone have ideas on how to prevent the "flash"?

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  • YUV Textures and Shaders

    - by Luca
    I've always used RGB textures. Now comes up the need of use of YUV textures (a set of three texture, specifying 1 luminance and 2 chrominance channels). Of course the YUV texture could be converted on CPU, getting the RGB texture usable as usual... but I need to get RGB pixel directly on GPU, to avoid unnecessary processor load... The problem became strange, since I require to specifyin the shader source, because a single texture, the following items: Three samplers uniforms, one for each channel Two integer uniforms, for specifying the chrominance channels sampling a mat3 uniform, for specific YUV to RGB conversion matrix. This should be done for each YUV texture... Is it possible to "compress" required uniforms, and getting RGB values quite easily? Actually i think this could aid: Texture sizes, including mipmaps, could be queried. With this, its possible to save the two integer uniforms, since the uniform values are derived the ratio between texture extents The mat3 uniforms could be collected as globals, and with preprocessor could be selected. But what design should I use for specify three (related) textures? Is it possible to use textures levels for accessing multiple textures? Texture arrays could be usable? And what about using rectangle textures, which doesn't supports mipmaps? Maybe a shader abstraction (struct definition and related function) could aid? Thank you.

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  • OpenGL-ES: Change (multiply) color when using color arrays?

    - by arberg
    Following the ideas in OpenGL ES iPhone - drawing anti aliased lines, I am trying to draw stroked anti-aliased lines and I am successful so far. After line is draw by the finger, I wish to fade the path, that is I need to change the opacity (color) of the entire path. I have computed a large array of vertex positions, vertex colors, texture coordinates, and indices and then I give these to opengl but I would like reduce the opacity of all the drawn triangles without having to change each of the color coordinates. Normally I would use glColor4f(r,g,b,a) before calling drawElements, but it has no effect due to the color array. I am working on Android, but I believe it shouldn't make the big difference, as long as it is OpenGL-ES 1.1 (or 1.0). I have the following code : gl.glEnable(GL10.GL_BLEND); gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); gl.glShadeModel(GL10.GL_SMOOTH); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); gl.glEnable(GL10.GL_TEXTURE_2D); // Should set rgb to greyish, and alpha to half-transparent, the greyish is // just there to make the question more general its the alpha i'm interested in gl.glColor4f(.75f, .75f, .75f, 0.5f); gl.glVertexPointer(mVertexSize, GL10.GL_FLOAT, 0, mVertexBuffer); gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer); gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTexCoordBuffer); gl.glDrawElements(GL10.GL_TRIANGLES, indexCount, GL10.GL_UNSIGNED_SHORT, mIndexBuffer.position(startIndex)); If I disable the color array gl.glEnableClientState(GL10.GL_COLOR_ARRAY);, then the glColor4f works, if I enable the color array it does nothing. Is there any way in OpenGl-ES to change the coloring without changing all the color coordinates? I think that in OpenGl one might use a fragment shader, but it seems OpenGL does not have a fragment shader (not that I know how to use one).

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  • GPGPU programming with OpenGL ES 2.0

    - by Albus Dumbledore
    I am trying to do some image processing on the GPU, e.g. median, blur, brightness, etc. The general idea is to do something like this framework from GPU Gems 1. I am able to write the GLSL fragment shader for processing the pixels as I've been trying out different things in an effect designer app. I am not sure however how I should do the other part of the task. That is, I'd like to be working on the image in image coords and then outputting the result to a texture. I am aware of the gl_FragCoords variable. As far as I understand it it goes like that: I need to set up a view (an orthographic one maybe?) and a quad in such a way so that the pixel shader would be applied once to each pixel in the image and so that it would be rendering to a texture or something. But how can I achieve that considering there's depth that may make things somewhat awkward to me... I'd be very grateful if anyone could help me with this rather simple task as I am really frustrated with myself. UPDATE It seems I'll have to use an FBO, getting one like this: glBindFramebuffer(...)

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  • How to modulate every texture unit in OpenGL ES 1.1?

    - by Jesse Beder
    I have two textures and a "blend factor", and I'd like to mix them, modulated by the current color; in effect, I want to use the following shader: gl_FragColor = gl_Color * mix(tex0, tex1, blendFactor); I'm using OpenGL ES 1.1, targeting all versions of the iPhone, so I can't use shaders, and I have two texture units. My best attempt is: // texture 0 glActiveTexture(GL_TEXTURE0); image1.Bind(); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); // texture 1 glActiveTexture(GL_TEXTURE1); image2.Bind(); glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE); glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_INTERPOLATE); glTexEnvi(GL_TEXTURE_ENV, GL_SRC0_RGB, GL_PREVIOUS); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR); glTexEnvi(GL_TEXTURE_ENV, GL_SRC1_RGB, GL_TEXTURE); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR); glTexEnvi(GL_TEXTURE_ENV, GL_SRC2_RGB, GL_CONSTANT); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_RGB, GL_SRC_ALPHA); glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_INTERPOLATE); glTexEnvi(GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_PREVIOUS); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA); glTexEnvi(GL_TEXTURE_ENV, GL_SRC1_ALPHA, GL_TEXTURE); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_ALPHA, GL_SRC_ALPHA); glTexEnvi(GL_TEXTURE_ENV, GL_SRC2_ALPHA, GL_CONSTANT); glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND2_ALPHA, GL_SRC_ALPHA); const float factor[] = { 0, 0, 0, blendFactor }; glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, factor); This has the effect of the shader: gl_FragColor = mix(gl_Color * tex0, tex1, blendFactor); but I don't see how to module texture 1 by the color. Is there any way to have the color provided by a texture unit automatically modulated by the incoming primary color? Or any other way to do what I want that I'm missing? Multiple passes are definitely allowed, but they have to have the proper blend effect; I have glBlend(GL_ONE, GL_ONE_MINUS_SRC_ALPHA); enabled, so it can be tricky to get right with multiple passes.

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  • Problem Loading multiple textures using multiple shaders with GLSL

    - by paj777
    I am trying to use multiple textures in the same scene but no matter what I try the same texture is loaded for each object. So this what I am doing at the moment, I initialise each shader: rightWall.SendShaders("wall.vert","wall.frag","brick3.bmp", "wallTex", 0); demoFloor.SendShaders("floor.vert","floor.frag","dirt1.bmp", "floorTex", 1); The code in SendShaders is: GLuint vert,frag; glEnable(GL_DEPTH_TEST); glEnable(GL_TEXTURE_2D); char *vs = NULL,*fs = NULL; vert = glCreateShader(GL_VERTEX_SHADER); frag = glCreateShader(GL_FRAGMENT_SHADER); vs = textFileRead(vertFile); fs = textFileRead(fragFile); const char * ff = fs; const char * vv = vs; glShaderSource(vert, 1, &vv, NULL); glShaderSource(frag, 1, &ff, NULL); free(vs); free(fs); glCompileShader(vert); glCompileShader(frag); program = glCreateProgram(); glAttachShader(program, frag); glAttachShader(program, vert); glLinkProgram(program); glUseProgram(program); LoadGLTexture(textureImage, texture); GLint location = glGetUniformLocation(program, textureName); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture); glUniform1i(location, 0); And then in the main loop: rightWall.UseShader(); rightWall.Draw(); demoFloor.UseShader(); demoFloor.Draw(); Which ever shader is initialised last is the texture which is used for both objects. Thank you for your time and I appreciate any comments.

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