Home › Archive for Developement › Page 2

Developement

MOGA Virtual Keyboard

Posted on by — No Comments ↓

About a month ago I released Moga VK.  This is an application that can turn a standard MOGA controller into a keyboard.  This is useful for games or applications like my emulators that do not directly support MOGA.  There is an application to do this already called MOGA Universal.  The major difference is it handles the Bluetooth connection on its own, this leads to many benefits but also adds a whole layer of complexity and potential crashes.  MOGA VK uses MOGA Pivot to manage the connection, this guarantees a stable and hassle free connection at a loss to some expert level features.  The app is very easy to use, merely start it up, enable the MOGA IME and it is ready to go for my emulators.

Enjoy!

Download

Eclipse – See All Shortcuts Available

Posted on by — No Comments ↓

A short post but a big tip.  It seems I have somehow used Eclipse for years without learning this very simple hotkey.

CTLR+SHIFT+L

This will bring up a window showing all available shortcuts given the current context.  There are hundreds of hotkeys available in Eclipse and the only way to make them habit is to find and use them.

Android NDK Standalone GCC 4.6

Posted on by — No Comments ↓

Not entirely sure when Google started to include the GCC 4.6 sources.  I have first noticed it at the current NDK r8 when running the download-toolchain-sources.sh

You have to compile it yourself.  There are instructions out there but now that google is including it things have gotten easier.  These instructions only apply to Linux.  Specifically tested in Ubuntu 12.04.

  • sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl
  • Download NDK
  • Untar NDK to [SOME_LOCATION], using /opt/ndk/
  • Set NDK_ROOT=/opt/ndk/
  •  ./build/tools/download-toolchain-sources.sh src/
  • Download MPC 0.9
  • Move mpc tar to ./src/mpc/
  • ./build/tools/build-gcc.sh --gmp-version=4.3.2 --mpc-version=0.9 --mpfr-version=2.4.2 --binutils-version=2.21 $(pwd)/src $(pwd) arm-linux-androideabi-4.6
  • ./build/tools/build-gcc.sh --gmp-version=4.3.2 --mpc-version=0.9 --mpfr-version=2.4.2 --binutils-version=2.21 $(pwd)/src $(pwd) x86-4.6
  • ./build/tools/build-gcc.sh --gmp-version=4.3.2 --mpc-version=0.9 --mpfr-version=2.4.2 --binutils-version=2.21 $(pwd)/src $(pwd) mipsel-linux-android-4.6
  • (Patience)

Now you can generate a standalone toolchain for distribution:

  • ./build/tools/make-standalone-toolchain.sh --toolchain=arm-linux-androideabi-4.6 --platform=android-9 --install-dir=/opt/android-9_arm/
  • ./build/tools/make-standalone-toolchain.sh --toolchain=x86-4.6 --platform=android-9 --install-dir=/opt/android-9_x86/
  • ./build/tools/make-standalone-toolchain.sh --toolchain=mipsel-linux-android-4.6 --platform=android-9 --install-dir=/opt/android-9_mips/

Done.

Similar steps can be applied to MAC OS X however setting up the development environment is far more annoying.  I have a feeling this might be near impossible to pull off in Windows without jumping through major hoops.

Swap with no Temp Variable

Posted on by — No Comments ↓

When I used to TA for the University of Saskatchewan in our intro C/C++ first year classes I used to try and challenge the students sometimes.  When the assignment rolled out on sorting the students were instructed to swap two variables.  As brand new programmers sometimes something as simple as swapping two variables doesn’t leap out at you.  Of course we just teach them that you need a temp variable and mission accomplished.  Well I always offered bonus marks for anyone who could derive the variable swap with no temp variable.   Years pass, no student ever got back to me with the answer ( they obviously didn’t have Google Fu ).  I find myself writing a routine today that required a swap.  I still remembered the trick:

int main()
{

int x = 42;
int y = 51236;

printf(“X before swap = %d\n”, x);

x ^= y;
y ^= x;
x ^= y;

printf(“X after swap = %d\n”, x);

return 0;

}

XOR god mode and fairly easy to remember. X xor Y, Y xor X, X xor Y.  Useful for any POD that is expressed as bytes consistently across architectures.

Needless to say this is a fun trick to blow the minds of long time programmers.

Google’s Coding Style Guide

Posted on by — No Comments ↓

Regardless of personal preference you will often be forced to adapt to the coding style of someone else.  Generally this will be an enforced style at the company you work for.  Some see this as a minor annoyance.  I personally see this as important and practical.  It helps maintain code readability, this is important for new comers or looking back at your own code.  By making code more readable you also make it more understandable, this makes maintenance even easier.   Decision about style have more impact than arguments like whether braces should be on the same line.

The coding preference which most closely matched my habits turned out to be Google’s C++ Coding Guide.  This made most sense to me as I learned programming starting with C then C++.  In reality I started coding in BASIC on a Commodore 64 but that is a different story.

I find this style guide has a lot of good habits one can derive from it.

Google’s C++ Style Guide

There are some changes to the style I make, here are some important ones:

  • Class members are all prefixed with an underscore
  • Two spaces between functions implementations