isle-portable/LEGO1/mxmatrix.cpp

#include "mxmatrix.h"

#include "decomp.h"
#include "math.h"

#include <memory.h>

DECOMP_SIZE_ASSERT(MxMatrix, 0x8);
DECOMP_SIZE_ASSERT(MxMatrixData, 0x48);

// OFFSET: LEGO1 0x10002340
void MxMatrix::EqualsMxMatrix(const MxMatrix* p_other)
{
	memcpy(m_data, p_other->m_data, 16 * sizeof(float));
}

// OFFSET: LEGO1 0x10002320
void MxMatrix::EqualsMatrixData(const float* p_matrix)
{
	memcpy(m_data, p_matrix, 16 * sizeof(float));
}

// OFFSET: LEGO1 0x10002370
void MxMatrix::SetData(float* p_data)
{
	m_data = p_data;
}

// OFFSET: LEGO1 0x10002360
void MxMatrix::AnotherSetData(float* p_data)
{
	m_data = p_data;
}

// OFFSET: LEGO1 0x10002390
float* MxMatrix::GetData()
{
	return m_data;
}

// OFFSET: LEGO1 0x10002380
const float* MxMatrix::GetData() const
{
	return m_data;
}

// OFFSET: LEGO1 0x100023c0
float* MxMatrix::Element(int p_row, int p_col)
{
	return &m_data[p_row * 4 + p_col];
}

// OFFSET: LEGO1 0x100023a0
const float* MxMatrix::Element(int p_row, int p_col) const
{
	return &m_data[p_row * 4 + p_col];
}

// OFFSET: LEGO1 0x100023e0
void MxMatrix::Clear()
{
	memset(m_data, 0, 16 * sizeof(float));
}

// OFFSET: LEGO1 0x100023f0
void MxMatrix::SetIdentity()
{
	Clear();
	m_data[0] = 1.0f;
	m_data[5] = 1.0f;
	m_data[10] = 1.0f;
	m_data[15] = 1.0f;
}

// OFFSET: LEGO1 0x10002850
void MxMatrix::operator=(const MxMatrix& p_other)
{
	EqualsMxMatrix(&p_other);
}

// OFFSET: LEGO1 0x10002430
MxMatrix* MxMatrix::operator+=(const float* p_matrix)
{
	for (int i = 0; i < 16; ++i)
		m_data[i] += p_matrix[i];
	return this;
}

// Matches but instructions are significantly out of order. Probably not wrong
// code given that the very similar SetTranslation does match.
// OFFSET: LEGO1 0x10002460
void MxMatrix::TranslateBy(const float* p_x, const float* p_y, const float* p_z)
{
	m_data[12] += *p_x;
	m_data[13] += *p_y;
	m_data[14] += *p_z;
}

// OFFSET: LEGO1 0x100024a0
void MxMatrix::SetTranslation(const float* p_x, const float* p_y, const float* p_z)
{
	m_data[12] = *p_x;
	m_data[13] = *p_y;
	m_data[14] = *p_z;
}

// OFFSET: LEGO1 0x10002530
void MxMatrix::EqualsMxProduct(const MxMatrix* p_a, const MxMatrix* p_b)
{
	EqualsDataProduct(p_a->m_data, p_b->m_data);
}

// OFFSET: LEGO1 0x100024d0
void MxMatrix::EqualsDataProduct(const float* p_a, const float* p_b)
{
	float* cur = m_data;
	for (int row = 0; row < 4; ++row) {
		for (int col = 0; col < 4; ++col) {
			*cur = 0.0f;
			for (int k = 0; k < 4; ++k) {
				*cur += p_a[row * 4 + k] * p_b[k * 4 + col];
			}
			cur++;
		}
	}
}

// Not close, Ghidra struggles understinging this method so it will have to
// be manually worked out. Included since I at least figured out what it was
// doing with rotateIndex and what overall operation it's trying to do.
// OFFSET: LEGO1 0x10002550 STUB
void MxMatrix::ToQuaternion(MxVector4* p_outQuat)
{
	float trace = m_data[0] + m_data[5] + m_data[10];
	if (trace > 0) {
		trace = sqrt(trace + 1.0);
		p_outQuat->GetData()[3] = trace * 0.5f;
		p_outQuat->GetData()[0] = (m_data[9] - m_data[6]) * trace;
		p_outQuat->GetData()[1] = (m_data[2] - m_data[8]) * trace;
		p_outQuat->GetData()[2] = (m_data[4] - m_data[1]) * trace;
		return;
	}

	// OFFSET: LEGO1 0x100d4090
	static int rotateIndex[] = {1, 2, 0};

	// Largest element along the trace
	int largest = m_data[0] < m_data[5];
	if (*Element(largest, largest) < m_data[10])
		largest = 2;

	int next = rotateIndex[largest];
	int nextNext = rotateIndex[next];
	float valueA = *Element(nextNext, nextNext);
	float valueB = *Element(next, next);
	float valueC = *Element(largest, largest);

	// Above is somewhat decomped, below is pure speculation since the automatic
	// decomp becomes very garbled.
	float traceValue = sqrt(valueA - valueB - valueC + 1.0);

	p_outQuat->GetData()[largest] = traceValue * 0.5f;
	traceValue = 0.5f / traceValue;

	p_outQuat->GetData()[3] = (m_data[next + 4 * nextNext] - m_data[nextNext + 4 * next]) * traceValue;
	p_outQuat->GetData()[next] = (m_data[next + 4 * largest] + m_data[largest + 4 * next]) * traceValue;
	p_outQuat->GetData()[nextNext] = (m_data[nextNext + 4 * largest] + m_data[largest + 4 * nextNext]) * traceValue;
}

// No idea what this function is doing and it will be hard to tell until
// we have a confirmed usage site.
// OFFSET: LEGO1 0x10002710 STUB
MxResult MxMatrix::FUN_10002710(const MxVector3* p_vec)
{
	return FAILURE;
}

// OFFSET: LEGO1 0x10002860
void MxMatrixData::operator=(const MxMatrixData& p_other)
{
	EqualsMxMatrix(&p_other);
}