Thoughts from Ash

wow!

Tue, 26 May 2009 11:49:22 +0100

My two new iPhone apps were accepted into the store yesterday, and Astro Smash became my best seller overnight! After the failure of Double Flip, I was pretty sure that gaming wasn’t the way to go, so I’ve no idea where all the sales came from, and I figured that Curry Finder would be my money spinner. It looks like I was wrong. Let’s hope I can keep it up.

Keep 'em coming

Tue, 19 May 2009 01:18:00 +0100

I submitted my fourth application to Apple for review last night, less than 2 months from my first approval. I was planning on one a month, so I’m pretty pleased with my progress so far. I’m even more pleased with my latest app, Astro Smash. It’s awesome! It took a while, and a bit of maths, but it plays perfectly. It’s similar in style to the 70s classic, Asteroids, but on steroids. Asteroidsteroids, sort of.

The roll of honour so far:
• No Chalk Required
• Double Flip
• Curry Finder
• Astro Smash

DoubleTwist now in the App Store

Fri, 24 Apr 2009 10:52:06 +0100

I’ve not had the official email from Apple yet but my new game, DoubleTwist, is now available on the app store.

It’s catering to a little less of a niche market than No Chalk Required, so I’m hoping for big things!

In the meantime, development of retro arcade style Astro Miner continues apace... I’m expecting to have something ready to test by the end of next week.

... and a torus too

Fri, 17 Apr 2009 12:43:36 +0100

Following on from the previous post, here’s a similar function to create the points for a torus:

GLfloat * createTorus (GLfloat aRadius, GLfloat bRadius, GLfloat step, int *pointCount)
{
NSLog(@"Torus");
GLfloat uStep = DEGREES_TO_RADIANS (step);
GLfloat vStep = uStep;

int totalPoints = ((2 * M_PI) / uStep) * ((2 * M_PI) / vStep) * 12.0 *1.5f;

GLfloat * torusPoints = calloc(totalPoints, sizeof(GLfloat));

int point = 0;

for (GLfloat u = 0.0f; u <= (2 * M_PI); u += uStep) {
for (GLfloat v = -M_PI; v <= M_PI; v += vStep) {

point++;
torusPoints[(point - 1) * 3] = (aRadius + bRadius * cosf(v)) * cosf(u); // x
torusPoints[((point - 1) * 3) + 1] = (aRadius + bRadius * cosf(v)) * sinf(u); // y
torusPoints[((point - 1) * 3) + 2] = bRadius * sinf(v); // z

point++;
torusPoints[(point - 1) * 3] = (aRadius + bRadius * cosf(v + vStep)) * cosf(u);
torusPoints[((point - 1) * 3) + 1] = (aRadius + bRadius * cosf(v + vStep)) * sinf(u);
torusPoints[((point - 1) * 3) + 2] = bRadius * sinf(v + vStep);

point++;
torusPoints[(point - 1) * 3] = (aRadius + bRadius * cosf(v)) * cosf(u + uStep);
torusPoints[((point - 1) * 3) + 1] = (aRadius + bRadius * cosf(v)) * sinf(u + uStep);
torusPoints[((point - 1) * 3) + 2] = bRadius * sinf(v);

point++;
torusPoints[(point - 1) * 3] = (aRadius + bRadius * cosf(v + vStep)) * cosf(u + uStep);
torusPoints[((point - 1) * 3) + 1] = (aRadius + bRadius * cosf(v + vStep)) *
sinf(u + uStep);
torusPoints[((point - 1) * 3) + 2] = bRadius * sinf(v + vStep);
}
}

*pointCount = point;

return torusPoints;
}

There’s something not quite right with the calculation of totalPoints though (hence the 1.5 multiplier), so if you figure it out, please let me know :-)

How to draw a sphere in 3D

Thu, 16 Apr 2009 00:35:02 +0100

Working through the OpenGl SuperBible, and converting the examples for the iPhone, I came across a problem – the book’s use of GLUT makes sphere drawing a simple task. Just a quick call to glutSolidSphere and it’s done. This, of course, isn’t available on the iPhone, so I needed to figure out some way create a sphere myself. Maybe my Googling ability isn’t up to par, but I struggled to find much useful info out there... I guess most other people have GLUT to rely on.

Luckily though, I do have a copy of Kreyszig’s Advanced Engineering Mathematics gathering dust on a shelf, and page 493 gave me:

which translates into:

The tricky bit was figuring out the path for the triangle strips, but a bit of trial and error gave me the following:

Source for exercises up to 4.1 here: files.me.com/ashleymills/jg2uam.