framebuffer

I am rendering to a texture through a framebuffer object, and when I draw transparent primitives, the primitives are blended properly with other primitives drawn in that single draw step, but they are not blended properly with the previous contents of the framebuffer. Is there a way to properly blend the contents of the texture with the new data coming in? EDIT: More information requsted, I will attempt to explain more clearly; The blendmode I am using is GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA. (I believe that is typically the standard blendmode) I am creating an application that tracks mouse

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 accelerate OpenGL, but how this integrates with the display server isn't clear, ie. do client

I have a hidden QOpenGLWidget (Qt 5.4.2, NOT QGLWidget) and I want to basically continually do grab() or grabFramebuffer() to get its content (and write it to disk). The widget renders fine when visible, but does not when hidden. If I do a show() followed by a hide() call it works. This seems strange because QOpenGLWidget does internally already render to a framebuffer according to the docs. What is the easiest way to achieve this (if possible without creating another framebuffer)? Bonus points for being able to capture an offscreen QGraphicsView using an QOpenGLWidget as its viewport with

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 searched on internet and there seems no solution. And some threads said that the kernel may forbid you

I'm trying to develop a GUI application for an embedded platform, without any windowing whatsoever and I'm doing that with DirectFB, and it suits my needs very fine. Since the embedded I develop for is not that powerful, I would really like to try to develop on my own Ubuntu desktop. The problem is Framebuffer is conflicting with X.org causing me to leave the whole desktop, and shutdown X.org just to see the result of my changes. Is there a good framebuffer simulator that suits my needs? Qt has one, called QVFb, but it only works for developing Qt apps, and the VNC back-end of DirectFB always

I'm using an i5 core with builtin graphics accelerator GMA-HD running on an RHEL 6.0 OS. I needed to test the graphics acceleration capabilities of the graphics driver(which I found out was i915 in my PC). I used the following code(which I got from the internet with some modifications) for writing to framebuffer. #include <unistd.h> #include <stdio.h> #include <fcntl.h> #include <linux/fb.h> #include <sys/mman.h> int main() { int fbfd = 0; struct fb_var_screeninfo vinfo; struct fb_fix_screeninfo finfo; long int screensize = 0; char *fbp = 0; int x = 0, y = 0; long int location = 0; int count ;