framebuffer

问题 Displaying images on a computer monitor involves the usage of a graphic API, which dispatches a series of asynchronous calls... and at some given time, put the wanted stuff on the computer screen. But, what if you are interested in knowing the exact CPU time at the point where the required image is fully drawn (and visible to the user)? I really need to grab a CPU timestamp when everything is displayed to relate this point in time to other measurements I take. Without taking account of the

问题 Is it possible to render totally offscreen in a QGLWidget with Qt without the need to repaint the scene to screen thus avoiding totally the buffers flip on monitor? I need to save every frame generated on the framebuffer but, since the sequence is made of 4000 frames and the time interval on the screen is 15ms I spend 4000*15ms=60s but I need to be much much faster than 60s (computations are not a bottleneck here, is just the update the problem). Can rendering offscreen on a framebuffer be

问题 #import "AppDelegate.h" #import <MapKit/MapKit.h> @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions { [self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]]; [self.window makeKeyAndVisible]; UIViewController *vc = [[UIViewController alloc] init]; self.window.rootViewController = vc; vc.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

问题 #import "AppDelegate.h" #import <MapKit/MapKit.h> @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions { [self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]]; [self.window makeKeyAndVisible]; UIViewController *vc = [[UIViewController alloc] init]; self.window.rootViewController = vc; vc.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

问题 I have checked this similar question, but the suggestions did not solve my problem: Low precision and clamping when writing to floating point FBO . I am rendering a float image using a framebuffer object as render target. However, the values read by glReadPixels are clamped between 0 and 1. If I try to render my image using normalized values in this range, it works, but values outside this range are clamped to 1 or 0. Follows some parts of the code. Here is how I created the texture that I

问题 I haven't found a clear explanation on how the Android graphics system works, specifically, does it use a display server, is it based on DirectFB or X11, etc. From what I've managed to piece together, Android depends on the Linux frame buffer. I haven't found much on what sort of display server or window manager Android uses to multiplex access to the framebuffer though, so any pointers would be much appreciated! Finally, from what I understand the ARM instruction set provides instructions to

问题 My device is Nexus 4 running Jelly Bean 4.2. I'm trying to record the screen and send it out. Most codes on internet do the cap by read /dev/graphics/fb0. It works fine in some devices and the older systems. But when I try it on my device, it fail. It only gives me blackscreen and all "0" in the raw data. I have run "adb root" to get the root permission, tried "chmod 777 fb0", "cat fb0 > /sdcard/fb0". Also I have tried codes like "mmap" and "memcpy" to get the data. But all fail. I have

问题 I am looking for code (any language) of a basic graphical list which can be reordered by drag and drop. So exactly this functionality http://jqueryui.com/sortable/ but written directly on the frame buffer/canvas without any frameworks (or low level 'put pixel' libraries at most) and probably not in HTML/JS (unless it's Canvas only without CSS). The simpler the better as I will be using it in assembler and I don't want to reinvent the wheel if not needed. 回答1: heh I hate frameworks so this is

问题 I am working on an IOS game using the OpenGL pipeline. I have been able to render the graphics I want to the screen, however, I am calling glDrawElements too many times and have some concerns about running into performance issues eventually. I have several static elements in my game that do not need to be render on every render cycle. Is there a way I can render static elements to one frame buffer and dynamic elements to another? Here's the code I have tried: static BOOL renderThisFrameBuffer

问题 When I try to attach a texture to a framebuffer, glCheckFramebufferStatus reports GL_FRAMEBUFFER_UNSUPPORTED for certain texture sizes. I've tested on both a 2nd and 4th generation iPod Touch. The sizes of texture that fail are not identical between the two models. Here are some interesting results: 2nd generation - 8x8 failed, 16x8 failed, but 8x16 succeeded! 4th generation - 8x8 succeeded, 8x16 succeeded, but 16x8 failed! Here's some code I used to test attaching textures of different sizes