A Better 2D Scene Manipulation Widget for Qt
IntroductionI'm currently working on a project which requires a good 2D scene manipulation system. The application is being built with the Qt C++ framework. Initially I investigated using the base...
View ArticleScene Navigation Zoom Tracking
In my last post I began working on a 2D scene manipulation system for an upcoming project. One of the design goals was to have a "smart zoom" feature which would track to where the mouse was. This is...
View ArticleThat One Bug That Just Won't Go Away...
So I was recently trying to get a piece of C++ code to compile and I just could not figure out what was going on. Here's a sample roughly of what the code looked like. It's not quite the same code I...
View ArticleA Safer Way to test the Validity/Safety of a Link
One thing that's always bothered me is figuring out if a link is legitimate or potentially a security risk. This is especially problematic with shortened URL's. I really dislike these and don't follow...
View ArticleMore Fun with Sieving Primes
I was playing around with my prime sieving implementation and I managed to improve the performance by making some simple changes. The code looks quite a bit different, but functionally it does...
View ArticleTracking Pre-Regulator Design Analysis
IntroductionI was watching a rather interesting EEVBlog video where Dave Jones showed a tracking pre-regulator design someone named "John Barnes" sent him (hopefully I got that right). Unlike his first...
View ArticleOptimizing the Tracking Pre-Regulator Design
In my last post I investigated a bit into a novel tracking pre-regulator design by John Barnes (I originally heard of this design in Dave Jones' EEVBlog #329 video). I had modeled mathematically the...
View ArticleSegmented Sieve of Eratosthenes
From my last playing around with primes post, I've finally managed to segment the sieving algorithm. This does a few different things: Reduces memory usage. Now the usage is proportional to the number...
View ArticleAVR Microcontrollers Part 2
IntroductionThis is part 2 of my playing around with AVR microcontrollers. Last time, I had a basic setup which could program an AVR using the Arduino ISP. I used it to drive a simple 7-segment,...
View ArticleTransmission Line Simulation
IntroductionWhen dealing with fast changing signals or long transmission distances the signal propogation time becomes very important. In these cases we must use a transmission line model for signal...
View ArticleOnline Transmission Line Simulation
This is a finite element simulation of the Telegrapher's Equations. I outlined the details of the simulation in my last post and had a SciPy implementation, and this time I've created a javascript port...
View ArticleWindows, NginX, MySQL, and PHP
IntroductionA while back I setup a LEMP server (Linux, NginX, MySQL, and PHP) using Virtual Box. This is fine for testing out how a live server might behave, or even for using as a virtual server if...
View ArticleSome Tests with HTML5 and Scalable Vector Graphics
These are a few tests with HTML and SVG vector graphics. There are a variety of good resources available online on how to use SVG, particularly the Mozilla Development Network (MDN). This is still a...
View ArticleSVG Navigable Viewport Part 1: Theory and Frustrations
This is a continuation of my previous tests to try and develop a navigatable 2D scene using HTML5 and Scalable Vector Graphics. The features I want to discuss are: Panning the sceneScaling/Zooming in...
View ArticleSVG Navigable Viewport Part 2: Some Cross-Browser Support
So last time I presented a basic SVG viewport navigation strategy. I tested it in Chrome and it worked a treat. However, when I decided to test in the other browsers at my disposal (FF20, IE10), the...
View ArticleSVG Navigable Viewport Part 3: Adding Rotations and Extending Functionality
This is a sample of how to rotate a SVG viewport using matrix transformations. There are two methods I explored. They basically are implemented near-identically, but operate somewhat differently. I'm...
View ArticleSVG Navigable Viewport Part 4: The Quad Viewport and Fixing some Assumptions...
In my last post I had implemented viewport rotations, and I had assumed that I had fixed the problem with nested SVG elements. Unfortunately, as I started working on a "quad" viewport demo, I realized...
View ArticleRudimentary Wheel Factorization using Bit Masks
Time to have more fun with prime numbers! I've made a few updates to my sieving code making it faster and more robust. I've also worked through a basic wheel-factorization implementation, which had...
View ArticleWheel Factorization with Variable Increments
Just a quick update to my previous wheel factorization code. I found a better way to implement the wheel factorization code which doesn't use bit masks to sieve out values. This version has a decent...
View ArticleThread-Safe Signals/Slots using C++11
IntroductionFor any C++ developer who's used Qt, we've grown to love the Signals/Slots idiom it presents for creating clean Observer code. However, it relied on the Qt Moc pre-compiler tool, which...
View ArticleSignals/Slots Improvements: Better and Faster
IntroductionLast time I presented basic work on my implementation of Signals/Slots which was thread safe, full-featured (well, is capable of being full-featured), and performed quite well. I had a...
View ArticleSignals3 Source Code and Performance Testing Update
IntroductionSince my last post on a fast thread-safe Signals/Slots implementation I've had to do a major re-write. The problem was that I had merged "slots" with nodes. This made implementing...
View ArticleClik here to view.
Don't Throw Away your Common Sense
Just because you have a fancy computer machine, don't throw away your common sense. To find out why, just click this link: \(\sin(2 \pi x) = 0\)If Wolfram fixes this, here's a screenshot to savor this...
View ArticleExperimenting with Diodes and Non-Linear Curve Fitting
How much does a diode's characteristics actually diviate from diode to diode? I measured a small number of diodes, and then recovered the SPICE DC parameters. Due to the limitations of my equipment, I...
View ArticleFun with Finite Volume Methods part 1
This post is about how to view the world with advection-equation glasses for simulating computational fluid mechanics. I will be discussing how to derive the numerical flux of for a coupled set of...
View Article