Can you help me understand why there is a discrepancy in SPAN_HEIGHT_BITS and SPAN_MAX_HEIGHT values between recastnavigation and recast4j?

[ikpil]

Hello, I am currently comparing the original source code of recastnavigation with the relevant section in recast4j to understand the differences.

recastnavigation code:

/// Defines the number of bits allocated to rcSpan::smin and rcSpan::smax.
static const int RC_SPAN_HEIGHT_BITS = 13;
/// Defines the maximum value for rcSpan::smin and rcSpan::smax.
static const int RC_SPAN_MAX_HEIGHT = (1 << RC_SPAN_HEIGHT_BITS) - 1;

recast4j code:

/// Defines the number of bits allocated to rcSpan::smin and rcSpan::smax.
public static int SPAN_HEIGHT_BITS = 20;
/// Defines the maximum value for rcSpan::smin and rcSpan::smax.
public static int SPAN_MAX_HEIGHT = (1 << SPAN_HEIGHT_BITS) - 1;

The values for SPAN_HEIGHT_BITS and SPAN_MAX_HEIGHT are set differently between these two code snippets.
Why is the value of SPAN_HEIGHT_BITS greater in recast4j compared to recastnavigation?

[ppiastucki]

rcSpan struct is defined as follows in recastnavigation:

struct rcSpan
{
	unsigned int smin : RC_SPAN_HEIGHT_BITS;
	unsigned int smax : RC_SPAN_HEIGHT_BITS;
	unsigned int area : 6;
	rcSpan* next;
};

Which means smin occupies 13 bits, smax another 13 bits and area the remaining 6 bits of the 32-bit word.

These values are expended to full 32-bit integers in recast4j as follows:

public class Span {
    public int smin;
    public int smax;
    public int area;
    public Span next;
}

Hence the limits are increased, potentially they could be increased to 31 bits instead of 20 if really needed.

[ikpil]

thank you