2014/10/15 下午 10:13:38

iphone Programming Glossary: sampling

OpenGL ES 2.0 texture distortion on large geometry GL_REPEAT

http://stackoverflow.com/questions/11370074/opengl-es-2-0-texture-distortion-on-large-geometry-gl-repeat

ES 2.0 texture distortion on large geometry GL_REPEAT OpenGL ES 2.0 has serious precision issues with texture sampling I've seen topics with a similar problem but I haven't seen a real solution to this distorted OpenGL ES 2.0 texture problem.. i49.tinypic.com b4jc6c.png The texture issue is limited to small scale geometry on OpenGL ES 2.0 otherwise the texture sampling appears normal but the grainy effect gradually worsens the further the vertex data is from the origin of XYZ 0 0 0 These..

Fragment Shader - Average Luminosity

http://stackoverflow.com/questions/12168072/fragment-shader-average-luminosity

by a factor of four in both width and height rather than the normal factor of two used for mipmaps. I did this by sampling from four texture locations that were in the middle of the four squares of four pixels each that made up a 4x4 area in the..

What does the Tiler Utilization statistic mean in the iPhone OpenGL ES instrument?

http://stackoverflow.com/questions/1287811/what-does-the-tiler-utilization-statistic-mean-in-the-iphone-opengl-es-instrumen

and the size of the attributes sent per vertex and Fragment Utilization generally increases with overdraw and texture sampling. In your case the best thing would be to reduce the size of each vertex you 胩e sending. For starters I 羮 try binning your..

How to crop a UIImageView to a custom shape

http://stackoverflow.com/questions/13015676/how-to-crop-a-uiimageview-to-a-custom-shape

path see apple docs . When the user starts stroking the region call CGContextBeginPath then follow user gestures sampling the touches and adding small segments by calling CGContextMoveToPoint repeatedly as touchesMoved. Create mask To turn the..

Understanding the Instrument for memory leak checking - iPhone

http://stackoverflow.com/questions/1329535/understanding-the-instrument-for-memory-leak-checking-iphone

a view up to 10 or more seconds if there is a leak leak will be detected by Instruments Because instruments works by sampling memory every so often so it might take a little bit for instruments to get around to reading the memory after an action...

how to detect and program around shakes for the iphone

http://stackoverflow.com/questions/1340492/how-to-detect-and-program-around-shakes-for-the-iphone

to handle shake events. That is a high power operation and should only be used by apps that need a high accelerometer sampling rate. Use the new motion events instead which have been added to UIEvent http developer.apple.com IPhone library documentation..

removing jagged edges of my ropes using antialiasing of OpenGLES

http://stackoverflow.com/questions/17500418/removing-jagged-edges-of-my-ropes-using-antialiasing-of-opengles

image my output looks like this iphone cocos2d iphone share improve this question You will have to enable multisampling if you want to get rid of the edges of textures. Multisampling will act on the entire screen and enabling it will have a.. improve this question You will have to enable multisampling if you want to get rid of the edges of textures. Multisampling will act on the entire screen and enabling it will have a performance penalty most severely on older devices iPhone 3GS.. severely on older devices iPhone 3GS . Locate the line where CCGLView is instantiated in AppDelegate and enable multi sampling and set the number of samples to 2 or 4. CCGLView glView CCGLView viewWithFrame window bounds pixelFormat kEAGLColorFormatRGBA8..

What is the maximum number of touch events per second I can receive?

http://stackoverflow.com/questions/2195382/what-is-the-maximum-number-of-touch-events-per-second-i-can-receive

higher resolution time wise for these touch events. iphone share improve this question Yes I think the iPhone is sampling the touches roughly 60 times per second. When you spend time in touchedMoved that number decreases relative to how much..

How do you use a moving average to filter out accelerometer values in iPhone OS

http://stackoverflow.com/questions/2272527/how-do-you-use-a-moving-average-to-filter-out-accelerometer-values-in-iphone-os

RHS and the new output values on the LHS of the expression above. Note also that we are assuming here that you will be sampling the accelerometer signals at regular time intervals e.g. every 10 ms. The time constant will be a function both of k and..

Determining the magnitude of a certain frequency on the iPhone

http://stackoverflow.com/questions/2921674/determining-the-magnitude-of-a-certain-frequency-on-the-iphone

2 1 N 1 2 for odd N or k F N Fs for F 0Hz ... Fs 2 Fs N where F is the frequency in Hz N is the FFT size and Fs is the sampling frequency Hz . Some things to note k is an integer so not all frequencies will map to an integer k. Find the closest k If..

Apple gyroscope sample code

http://stackoverflow.com/questions/3245733/apple-gyroscope-sample-code

call it from the init method. The following will store the initial device attitude and cause the device to continue sampling the gyro and updating its attitude property. void enableGyro CMDeviceMotion deviceMotion motionManager.deviceMotion CMAttitude..

Using the apple FFT and accelerate Framework

http://stackoverflow.com/questions/3398753/using-the-apple-fft-and-accelerate-framework

set it up so that some callback gets triggered every time the microphone gets in 1024 floats. Supposing the microphone sampling rate was 44.1kHz so that's ~44 frames sec. So our time window is whatever the time duration of 1024 samples is ie 1 44 s...

Javascript iPhone Scroll Effect in an iFrame / Javascript Mouse Acceleration

http://stackoverflow.com/questions/379917/javascript-iphone-scroll-effect-in-an-iframe-javascript-mouse-acceleration

positions in variables mouseX and mouseY. It then starts the timer monitorMouse which measures mouse cursor speed by sampling the values in these variables at regular intervals. The variables mouseLeft and mouseTop hold each samplings mouse positions.. speed by sampling the values in these variables at regular intervals. The variables mouseLeft and mouseTop hold each samplings mouse positions and the sampling rate is set to 100 milliseconds in the variable monitor.timerDelay. And some of the author's.. these variables at regular intervals. The variables mouseLeft and mouseTop hold each samplings mouse positions and the sampling rate is set to 100 milliseconds in the variable monitor.timerDelay. And some of the author's code nn4 document.layers true..

iPhone - What does the gyroscope measures? Can I get an absolute degree measurement in all axis?

http://stackoverflow.com/questions/5112536/iphone-what-does-the-gyroscope-measures-can-i-get-an-absolute-degree-measurem

the gyroscope measuring absolute angles I mean suppose I hold my phone in portrait at exactly 90 degrees and start sampling. These may be not the correct values but suppose that at this position the gyroscope gives me 0 0 and 0 degrees for yaw.. way to measure absolute degrees in all axis As absolute degrees I mean assuming 0 0 0 as the position it was when the sampling started. thanks iphone core motion share improve this question The iPhone uses accelerometers for its internal angle..

Need to find Distance using Gyro+Accelerometer

http://stackoverflow.com/questions/6647314/need-to-find-distance-using-gyroaccelerometer

theorem So once you have your accelerometer signals passed through a low pass filter and binned in time with sampling interval dt you can find the displacement in x as pardon my C... float dx 0.0f float vx 0.0f for int i 1 i n i vx acceleration_x..

How can I use a 3-D texture in iOS?

http://stackoverflow.com/questions/9241583/how-can-i-use-a-3-d-texture-in-ios

Notice also that you're doing one access that's tied to a particular z slice. So you're limited to GL_NEAREST type sampling in at least one dimension unless you want to do two samples and mix the result yourself at even greater cost. I've also..