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Add code to convert the 16bit float format used by the hardware back into float 754 format. 16bit floats are used for the culling radiuses in the nodes.

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This commit is contained in:
Ian Curtis 2016-06-03 00:01:34 +00:00
parent 6dc5845d47
commit 5081ee99dc
2 changed files with 23 additions and 1 deletions
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21
Src/Graphics/New3D/New3D.cpp
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@ -351,7 +351,7 @@ void CNew3D::DescendCullingNode(UINT32 addr)
sibling2Ptr = node[0x08 - m_offset] & 0x1FFFFFF; // mask colour table bits
matrixOffset = node[0x03 - m_offset] & 0xFFF;
short extent = node[9 - m_offset] >> 16;
float test = ToFloat(Convert16BitProFloat(node[9 - m_offset] >> 16));
if ((node[0x00] & 0x07) != 0x06) { // colour table seems to indicate no siblings
if (!(sibling2Ptr & 0x1000000) && sibling2Ptr) {
@ -1175,5 +1175,24 @@ void CNew3D::CalcTexOffset(int offX, int offY, int page, int x, int y, int& newX
newY += ((oldPage + page) & 1) * 1024; // max page 0-1
}
UINT32 CNew3D::ConvertProFloat(UINT32 a1)
{
int exponent = ((a1 & 0x7E000000) >> 25) + 127;
int mantissa = (a1 & 0x1FFFFFF) >> 2;
return (a1 & 0x80000000) | (exponent << 23) | mantissa;
}
UINT32 CNew3D::Convert16BitProFloat(UINT32 a1)
{
return ConvertProFloat(a1 << 15);
}
float CNew3D::ToFloat(UINT32 a1)
{
return *(float*)(&a1);
}
} // New3D

3
Src/Graphics/New3D/New3D.h
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@ -178,6 +178,9 @@ private:
void CalcTexOffset(int offX, int offY, int page, int x, int y, int& newX, int& newY);
UINT32 ConvertProFloat(UINT32 a1); // return float in hex or integer format
UINT32 Convert16BitProFloat(UINT32 a1);
float ToFloat(UINT32 a1); // integer float to actual IEEE 754 float
/*
* Data