D3D12学习笔记2.3——DirecXMath矩阵类型

·本节为实际操作，就之前几节的学习进行对DirectXMath矩阵库的学习。

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·首先说一下在DirectXMath头文件中使用XMMATRIX来表示4x4矩阵类型。

·设置函数步骤如下：

#include "DirectXMath.h"
DirectX::XMMATRIX XMMatrixSet(float m00, float m01, float m02, float m03,
    float m10, float m11, float m12, float m13,
    float m20, float m21, float m22, float m23,
    float m30, float m31, float m32, float m33);

·矩阵相关实用函数：

注意：在传递vector参数的时候务必注意传递格式（在windows32位下的操作），比如使用_fastcall时，32位调用约定通过寄存器传递前3个XMVECTOR,其余的参数则存在堆栈中。而_vectorcall调用约定通过寄存器传递前6个XMVECTOR实参。参数类型命名格式要注意。实际操作时可以详见文档DirectXMath中的库内部细节。

下面是矩阵函数代码实用过程：

//使用函数操作开始
#include "windows.h"
#include "iostream"
#include "DirectXMath.h"
#include "DirectXPackedVector.h"
using namespace std;
using namespace DirectX;
using namespace DirectX::PackedVector;

//首先重载“<<”运算符，之前写过不多赘述。
ostream& XM_CALLCONV operator << (ostream& os, FXMVECTOR v) {
	XMFLOAT4 dest;
	XMStoreFloat4(&dest, v);
	os << "(" << dest.x << "," << dest.y << "," << dest.z << "," << dest.w << ")";
	return os;
}

//上面重载vector类型，这里重载matri类型
ostream& XM_CALLCONV operator <<(ostream& os, FXMMATRIX m) {
	for (int i = 0; i < 4; i++) {
		os << XMVectorGetX(m.r[i]) << "\t";
		os << XMVectorGetY(m.r[i]) << "\t";
		os << XMVectorGetZ(m.r[i]) << "\t";
		os << XMVectorGetW(m.r[i]) ;
		os << endl;
	}
	return os;
}

int main() {
	//同样的一上来先看是否支持SSE2指令集
	if (!XMVerifyCPUSupport()) {
		cout << "directx math not supported!" << endl;
		return 0;
	}

	//进入正题
	XMMATRIX A(1.0f,0.0f,0.0f,0.0f,
							0.0f,2.0f,0.0f,0.0f,
							0.0f,0.0f,4.0f,1.0f,
							1.0f,2.0f,3.0f,1.0f);

	//输入单位矩阵
	XMMATRIX B = XMMatrixIdentity();
	
	//简单乘法
	XMMATRIX C = A * B;

	//转置
	XMMATRIX D = XMMatrixTranspose(A);

	//detA
	XMVECTOR det = XMMatrixDeterminant(A);

	//逆矩阵
	XMMATRIX E = XMMatrixInverse(&det, A);

	//验证逆矩阵与原矩阵相乘是否为单位矩阵
	XMMATRIX F = A * E;

	cout << "A=" << endl << A << endl;
	cout << "B=" << endl <<B << endl;
	cout << "C=A*B" << endl << C << endl;
	cout << "D=transpose(A)=" << endl << D << endl;
	cout << "det=determinant(A)=" << det << endl << endl;
	cout << "E=inverse(A)=" << endl << E << endl;
	cout << "F=A*E=" << endl << F << endl;



}

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下面是运行结果：