framebuffer

问题 I found a lot about /dev/graphics/fb0. It is fast. But It doesn't seems to be working. If i do manually. Neither programmatically. But I am sure that this feature works on my mobile as i have an application that works using same method. I have tried to change permission. i have root access. chmod 666 /dev/graphics/fb0 Permission is changed. But when i try to run command adb pull /dev/graphics/fb0 /mnt/sdcard/tmp I tried to redirect input using cat /dev/graphics/fb0 > /sdcard/frame.raw I get

问题 I'm trying to use the new EffectFactory/Effect to add effects to images off screen (i.e. framebuffer). I've looked at the HelloEffects.java example provided in the SDK and I've tried it out and it works. Except it obviously uses a GLSurfaceView and that isn't what I want. So I've taken tests/effect/src/android/effect/cts/GLEnv.java to setup the EGL stuff and I've also grabbed TextureRenderer.java and GLToolbox from the HelloEffects example. Mashed them all up and I've got the code below. (On

问题 I'm developing a little gamedev library. One of the elements of this library is a Canvas (offscreen drawing area), which is implemented through an OpenGL framebuffer. So far, everything's been good, I generate a texture, attach it to a framebuffer, render to it, then use the framebuffer's texture as Texture2D. Now, I'd like to add antialiasing to my library, so I'd like to be able to set multisampling on a Canvas. Now I'm confused because I've found that you need to alter shaders to use

问题 I'm trying to get pixel data from my X11 instance, I've seen this thread (How do take a screenshot correctly with xlib?) and the double for loop is taking just too long for me (over a million loops, as the system I'm building requires the highest amount of efficiency possible, sitting around for 600 miliseconds is just not an option). Is there no way to just get a raw array of pixels to avoid the for loop? I know the XImage class has a "data" member which is supposed to contain all of the

问题 The program renders a bunch of things into an intermediate framebuffer that uses an unsigned normalized texture to store the data. The intermediate framebuffer is blended with the default framebuffer. The pixel shader used to render the intermediate for the blend with framebuffer 0 is the following: #version 300 es precision mediump float; out vec4 fragColor; in vec2 texCoords; uniform sampler2D textureToDraw; void main() { vec4 sampleColor = texture(textureToDraw, texCoords); fragColor =

问题 I am trying to change the screen configuration with FBIOPUT_VSCREENINFO, but I do not have a clue how to compute: __u32 pixclock; /* pixel clock in ps (pico seconds) */ __u32 left_margin; /* time from sync to picture */ __u32 right_margin; /* time from picture to sync */ __u32 upper_margin; /* time from sync to picture */ __u32 lower_margin; __u32 hsync_len; /* length of horizontal sync */ __u32 vsync_len; (see: http://lxr.free-electrons.com/source/include/linux/fb.h#L245 ) for the fb_var

问题 I'm creating an extra framebuffer and renderbuffer for offscreen rendering in my OpenGL ES 1.1 iOS app. When I render into the additional renderbuffer I start to see memory warnings in the XCode console. What is the proper way to "release", "clear" etc these additional buffers? I experimented with glClear(GL_COLOR_BUFFER_BIT) but the memory warnings continued. Commenting out the rendering code causes the warnings to go away. 回答1: I don't know what you mean, glClear clears the content of the

问题 I ran the framebuffers example in this page -original code- (using glfw3 and glew in xcode 4.6 in osx 10.8), it worked fine, then I wanted to add multisampling (to avoid jagged edges on cube edges and on the floor, glfwWindowHint (GLFW_SAMPLES, 4) was enough when rendering directly to the back-buffer), found some answers directing to opengl.org, tried to use glTexImage2DMultisample but it displayed nothing (black screen). The framebuffer settings and rendering loop is: // Create frame buffer

问题 3D Physics simulation needs access to neighbor vertices' positions and attributes in shader to calculate a vertex's new position. 2D version works but am having trouble porting solution to 3D. Flip-Flopping two 3D textures seems right, inputting sets of x,y and z coordinates for one texture, and getting vec4s which contains position-velocity-acceleration data of neighboring points to use to calculate new positions and velocities for each vertex. The 2D version uses 1 draw call with a

问题 I dot a pixel right next first pixel but the result is different. Second pixel is far away from first one. What's wrong? org 100h ;change to 320x200 graphic mode mov ax, 13 int 10h ;frame buffer location push 0xa000 pop es xor di, di ;dot 2 pixels mov ax, 1 mov [es:di], ax inc di mov [es:di], ax ;prevent ending a: jmp a thanks! 回答1: There are two bugs. First, BIOS 320x200 at 8 bits/pixel is video mode 13h ( 19d ), not 13d as you have. To fix it: mov ax,13h int 10h The other bug is that you