Questions about the code

[JadTawil-theonly]

I have a few questions about the code.

I will ask one:
In PlatformIndependence.h:

#define THREADPTR(x) thread x
#define DEVICEPTR(x) device x
#define THREADGRPPTR(x) threadgroup x
#define CONSTPTR(x) constant x

Can you explain what 'thread', 'device', 'threadgroup', and 'constant' are in terms of programming? I guess i am not sure what they mean to a c++ compiler.

[JadTawil-theonly]

Would you mind explaining the settings:

mSettings.mImageSize.x = width;
mSettings.mImageSize.y = height;
mSettings.mNumSegments = numSegments;
mSettings.mSpixelSize = spixelSize;
mSettings.mCohWeight = 0.6f;
mSettings.mNumIteration = 5;
mSettings.mColorSpace = RGB;
mSettings.mSegmentationMethod = GIVEN_NUM;
mSettings.mForceConnectivity = true;
mSettings.mSegColors = new int[mSettings.mNumSegments];