Alex Forrence aforren1

Reducing Chrome’s Presentation Latency on Windows

Intro

For this project, I improved presentation latency in Chrome on Windows by introducing waitable swap chains. Waitable swap chains allow us to both reduce latency by shortening the queue of pending frames and aligning frame production for optimal consumption by the operating system, and reduce latency spikes by dropping frames under load.

Initial proposal:

IDE

rstudio

Reproducible research tools

packrat - roughly equivalent to python's virtualenv (isolated package env)
drake/remake - like GNU make (I think drake is better maintained at this point, but few examples)
RStudio's projects - at least drops you in the right working directory & ties in with packrat
Make a package! - higher startup cost, but user installation is trivial
rocker (R through Docker)

We'll stick to 32-bit installation (to make iohub happy?)

Install python 2.7.12 x86 (make sure to add python to your PATH var, just for ease-of-use)

We use this version solely for compatibility with the nidaqmx package (2.7.14 being compatible when it comes out)
Ideally, psychopy will eventually support 3.x, which is actively developed

Install wheels for numpy and scipy from http://www.lfd.uci.edu/~gohlke/pythonlibs/

for instance, use numpy‑1.12.1+mkl‑cp27‑cp27m‑win32.whl because we're using python 2.7 on 32 bit
python -m pip install <path_to_numpy_whl>.whl
We install these two globally because they're cumbersome to keep re-installing and rather large

	import moderngl as mgl
	import glfw
	import numpy as np
	import glm
	import mapbox_earcut as earcut
	from timeit import default_timer
	from xxhash import xxh32

	vao_cache = {}


	Install raspbian (https://www.raspberrypi.org/downloads/raspbian/)

	run `sudo apt update && sudo apt upgrade --yes`

	Turn on desktop GL in `sudo raspi-config`
	(sudo apt install mesa-utils & run glxgears for verification)

	edit /boot/config.txt and add `gpu_freq=500` (overclocks the GPU from 400->500) and `gpu_mem=320` (gives the GPU more memory)


	# Install preemptive kernel
	apt install build-essential git linux-image-rt-amd64 -y # check with `uname -r`

	# Install miniconda (update later via `conda update conda`
	wget http://repo.continuum.io/miniconda/Miniconda3-3.7.0-Linux-x86_64.sh -O ~/miniconda.sh
	bash ~/miniconda.sh -b -p $HOME/miniconda # accept license, add to path
	echo 'export PATH="$HOME/miniconda3/bin:$PATH"' >> ~/.bashrc

	# update audio settings

	class Experiment(Machine):
	def is_line_crossed(self): return self.line_crossed

	def reset_line(self): self.line_crossed = False

	def done_countdown(self):
	self.countdown_done = True
	print "Done the countdown"

	def start_countdown(self):

	# install dependencies, lzip (for extracting compressed file), and checkinstall (for easy uninstall)
	sudo apt-get install gcc g++ gfortran make libblas-dev liblapack-dev libpcre3-dev libarpack2-dev libcurl4-gnutls-dev epstool libfftw3-dev transfig libfltk1.3-dev libfontconfig1-dev libfreetype6-dev libgl2ps-dev libglpk-dev libreadline-dev gnuplot-x11 libgraphicsmagick++1-dev libhdf5-serial-dev openjdk-8-jdk libsndfile1-dev llvm-dev lpr texinfo libgl1-mesa-dev libosmesa6-dev pstoedit portaudio19-dev libqhull-dev libqrupdate-dev libqscintilla2-dev libqt4-dev libqtcore4 libqtwebkit4 libqt4-network libqtgui4 libqt4-opengl-dev libsuitesparse-dev texlive libxft-dev zlib1g-dev autoconf automake bison flex gperf gzip icoutils librsvg2-bin libtool perl rsync tar lzip checkinstall

	# make an octave directory
	cd ~
	mkdir octave
	cd octave

	# fetch and extract files -- go to https://ftp.gnu.org/gnu/octave/
	# to see if there's a more recent version