iOS indie developers writing every day about their stuff.

Tips for Mobile Devs – Image Magick Command Line

Jake Gundersen
indieambitions.com

When I first began contracting I stumbled on to a tool that I now use all the time, Image Magick. Image Magick is a C library that can be used in all kinds of ways, including inside your iOS app if you want. But, I use it as a command line tool to manipulate image …read more

Mixing two Videos with GPUImage

Jake Gundersen
indieambitions.com

There was some discussion on the GPUImage github a little while back about how to mix two video input sources. I have been meaning to investigate this capability for a while. Well, last night I had a burst of productive energy so I was up late playing with it. This morning I can report my …read more

Perform a blur using vImage from the Accelerate framework Tutorial

Jake Gundersen
indieambitions.com

Last week I attended 360iDev for the first time. It was tres awesome. One of my favorite sessions was on the accelerate framework from Jeff Biggus (@hyperjeff). One of the biggest barriers to using the framework is a lack of easy to follow documentation/sample code. I went looking for some sample code on how to …read more

Perlin Noise on GPU in GPUImage

Jake Gundersen
indieambitions.com

Perlin noise has all kinds of applications, from realistic looking texutres to fire effects to flow fields. It’s a useful tool to have in the belt. If you’ve never heard of perlin noise here’s the wikipedia article and here’s a … Continue reading →

Learning OpenGL with GPUImage

Jake Gundersen
indieambitions.com

Writing an Image Processing Filter In this post we’re going to cover the basics of how to write an image processing filter using glsl. We’ll be producing a variant of an existing filter. Here’s a look at our final project: … Continue reading →

More Fun With Cocos2d Particles

Jake Gundersen
indieambitions.com

My latest attempt is to extend the Cocos2d particle system to include a variety of things, multiple particle sprites, animated sprites, flow fields, and eventually a boids algorithm implementation. Today I have a work in progress class that’s by no means ready for any kind of production. I though I’d share it anyway. In it’s current form, it’s a class that uses a Texture Packer plist and spritesheet to import an animation into a particle system structure. It also uses a flow field to apply different velocities based on position. I’m trying to put together some environmental effects for a […]

My Quest to Learn OpenGL

Jake Gundersen
indieambitions.com

This post is going to be all about openGL. I don’t explain it from a beginner’s perspective, so if you are new the the openGL API, it may not be easy to follow. I have listed what I think are the best resources in the bottom paragraph. If you’re new, definitely read those, especially Jeff Lamarche’s stuff. I haven’t written anything here for a little while. The main reason is that my attention has turned toward learning openGL and I haven’t gotten to the point that I have anything worth showing off for a little bit. I remember telling a […]

Cocos2D Particle Engine w/Different Sprites

Jake Gundersen
indieambitions.com

Most of my development work is centered around educational games. I am co-founder of Third Rail Games, LLC. A while back I wanted to modify the particle system in Cocos2D so that it would put out streams of letters in a given sequence instead of the one sprite. Here’s what I ended up with: Here’s the code. I’ll explain the simple modification required to create a particle system that puts out a string of letters, and you’ll see that the same logic could be used to create a particle system that pulls from a sprite sheet. Here’s the code from […]

Easiest Twitter App Ever (plus NSLinguisticTagger)

Jake Gundersen
indieambitions.com

My very first idea for an iphone app was something that would allow me to navigate the language used in tweets. I wanted to create an app that pulled twitter data, based on a search phrase, parse the words in that request, pull out represent those words by frequency or importance, and present that visually to the user. Then, the user could pick from the resulting words and start the whole process again. Well I eventually was able to create that application, it’s called TweetViz and it’s available on the store. It just uses a word frequency count to display […]

Conway’s Game of Life Painted with Incoming Video (Core Image Tut)

Jake Gundersen
indieambitions.com

Using Core Graphics to create a CIImage A few months ago I heard about this great app called Composite. This app lets you draw to the canvas using the video feed input as paint. It’s really quite cool and when … Continue reading →