//获取旋转矩阵 XYZ轴旋转
public static HMatrix GetRotateMat(float x, float y, float z)
{
//X Y Z矩阵相乘 这里是为了好理解 但是这样做效率有浪费 6次三角函数 2次矩阵乘法
HMatrix matRet = GetRotateMatX(x).Mul(GetRotateMatY(y)).Mul(GetRotateMatZ(z));
return(matRet);
}
//获取LookAt矩阵
//相机的位置 相机的看着那个位置（决定相机方向） 相机上方位置
// see:https://zhuanlan.zhihu.com/p/66384929
// Rx Ry Rz 0
// Ux Uy Uz 0
// Dx Dy Dz 0
// 0 0 0 1 相机空间是左手系
public static HMatrix GetLookAtMat(HVector camera, HVector at, HVector up)
{
HMatrix matRet = new HMatrix();
HVector CameraXAxis, CameraYAxis, CameraZAxis;
CameraZAxis = at.Sub(camera);
CameraZAxis = CameraZAxis.Normalize();
CameraYAxis = up.Normalize();
CameraXAxis = CameraZAxis.CrossProduct(CameraYAxis);
CameraXAxis = CameraXAxis.Normalize();
matRet.m[0, 0] = CameraXAxis.x;
matRet.m[1, 0] = CameraXAxis.y;
matRet.m[2, 0] = CameraXAxis.z;
matRet.m[3, 0] = -CameraXAxis.DotProduct(camera);
matRet.m[0, 1] = CameraYAxis.x;
matRet.m[1, 1] = CameraYAxis.y;
matRet.m[2, 1] = CameraYAxis.z;
matRet.m[3, 1] = -CameraYAxis.DotProduct(camera);
matRet.m[0, 2] = CameraZAxis.x;
matRet.m[1, 2] = CameraZAxis.y;
matRet.m[2, 2] = CameraZAxis.z;
matRet.m[3, 2] = -CameraZAxis.DotProduct(camera);
matRet.m[0, 3] = matRet.m[1, 3] = matRet.m[2, 3] = 0.0f;
matRet.m[3, 3] = 1.0f;
return(matRet);
}
//更新MVP矩阵
void UpdateMVPMat()
{
HMatrix mat = MathHelper.GetRotateMat(0, 0.8f, 0.8f);
Transform.ModleMat = mat;
Transform.UpdateMVPMat();
}
//获取缩放矩阵
public static HMatrix GetScaleMat(float x, float y, float z)
{
HMatrix matRet = new HMatrix();
matRet = GetIdentityMat();
matRet.m[0, 0] = x;
matRet.m[1, 1] = y;
matRet.m[2, 2] = z;
return(matRet);
}
//获取平移矩阵
public static HMatrix GetTranslateMat(float x, float y, float z)
{
HMatrix matRet = new HMatrix();
matRet = GetIdentityMat();
matRet.m[3, 0] = x;
matRet.m[3, 1] = y;
matRet.m[3, 2] = z;
return(matRet);
}
//获取0矩阵
public static HMatrix GetZeroMat()
{
HMatrix matRet = new HMatrix();
matRet.m[0, 0] = matRet.m[0, 1] = matRet.m[0, 2] = matRet.m[0, 3] = 0.0f;
matRet.m[1, 0] = matRet.m[1, 1] = matRet.m[1, 2] = matRet.m[1, 3] = 0.0f;
matRet.m[2, 0] = matRet.m[2, 1] = matRet.m[2, 2] = matRet.m[2, 3] = 0.0f;
matRet.m[3, 0] = matRet.m[3, 1] = matRet.m[3, 2] = matRet.m[3, 3] = 0.0f;
return(matRet);
}
//向量乘矩阵
public HVector MulMat(HMatrix mat)
{
HVector vec = new HVector();
float X = x, Y = y, Z = z, W = w;
vec.x = X * mat.m[0, 0] + Y * mat.m[1, 0] + Z * mat.m[2, 0] + W * mat.m[3, 0];
vec.y = X * mat.m[0, 1] + Y * mat.m[1, 1] + Z * mat.m[2, 1] + W * mat.m[3, 1];
vec.z = X * mat.m[0, 2] + Y * mat.m[1, 2] + Z * mat.m[2, 2] + W * mat.m[3, 2];
vec.w = X * mat.m[0, 3] + Y * mat.m[1, 3] + Z * mat.m[2, 3] + W * mat.m[3, 3];
return(vec);
}
//获取投影矩阵 乘以这个矩阵之后得到的是相机空间的坐标
public static HMatrix GetPerspectiveMat(float fovy, float aspect, float zn, float zf)
{
float fax = 1.0f / (float)Math.Tan(fovy * 0.5f);
HMatrix matRet = GetZeroMat();
matRet.m[0, 0] = (float)(fax / aspect);
matRet.m[1, 1] = (float)(fax);
matRet.m[2, 2] = zf / (zf - zn);
matRet.m[3, 2] = -zn * zf / (zf - zn);
matRet.m[2, 3] = 1;
return(matRet);
}
//获取旋转矩阵 Z轴旋转
// https://blog.csdn.net/csxiaoshui/article/details/65446125
public static HMatrix GetRotateMatZ(float z)
{
HMatrix matRet = GetIdentityMat(); //单位矩阵
float SinValue = (float)Math.Sin(z);
float CosValue = (float)Math.Cos(z);
matRet.m[0, 0] = CosValue; matRet.m[1, 0] = -SinValue; matRet.m[2, 0] = 0; matRet.m[3, 0] = 0;
matRet.m[0, 1] = SinValue; matRet.m[1, 1] = CosValue; matRet.m[2, 1] = 0; matRet.m[3, 1] = 0;
matRet.m[0, 2] = 0; matRet.m[1, 2] = 0; matRet.m[2, 2] = 1; matRet.m[3, 2] = 0;
matRet.m[0, 3] = 0; matRet.m[1, 3] = 0; matRet.m[2, 3] = 0; matRet.m[3, 3] = 1;
return(matRet);
}
//矩阵缩放
public HMatrix Scale(float f)
{
HMatrix matRet = new HMatrix();
int i, j;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
matRet.m[i, j] = m[i, j] * f;
}
}
return(matRet);
}
//矩阵减法
public HMatrix Sub(HMatrix mat)
{
HMatrix matRet = new HMatrix();
int i, j;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
matRet.m[i, j] = m[i, j] - mat.m[i, j];
}
}
return(matRet);
}
//补充单元测试
public bool UnitTest()
{
HMatrix mat1 = new HMatrix();
HMatrix mat2 = new HMatrix();
HMatrix mat3 = new HMatrix();
mat1.m[0, 0] = 0; mat1.m[1, 0] = 0; mat1.m[2, 0] = 0; mat1.m[3, 0] = 0;
mat1.m[0, 1] = 0; mat1.m[1, 1] = 0; mat1.m[2, 1] = 0; mat1.m[3, 1] = 0;
mat1.m[0, 2] = 0; mat1.m[1, 2] = 0; mat1.m[2, 2] = 0; mat1.m[3, 2] = 0;
mat1.m[0, 3] = 0; mat1.m[1, 3] = 0; mat1.m[2, 3] = 0; mat1.m[3, 3] = 0;
if (mat1.Add(mat2) != mat3)
{
return(false);
}
return(true);
}
//矩阵乘法
public HMatrix Mul(HMatrix mat)
{
HMatrix matRet = new HMatrix();
int i, j;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
matRet.m[i, j] = (m[i, 0] * mat.m[0, j]) +
(m[i, 1] * mat.m[1, j]) +
(m[i, 2] * mat.m[2, j]) +
(m[i, 3] * mat.m[3, j]);
}
}
return(matRet);
}
public void Init()
{
int ScreenWidth = HScreenDevice.GetInstance().ScreenWidth;
int ScreenHeight = HScreenDevice.GetInstance().ScreenHeight;
ModleMat = MathHelper.GetIdentityMat();
HVector camera = new HVector(5, 0, 0, 1);
HVector at = new HVector(0, 0, 0, 1);
HVector up = new HVector(0, 1, 0, 1);
ViewMat = MathHelper.GetLookAtMat(
camera,
at,
up
);
// fov = 90度 0.5pai
ProjectionMat = MathHelper.GetPerspectiveMat(3.1415926f * 0.5f, (float)ScreenWidth / (float)ScreenHeight, 1.0f, 500.0f);
UpdateMVPMat();
}
// 更新投影矩阵
public void UpdateMVPMat()
{
MVPMat = ModleMat.Mul(ViewMat).Mul(ProjectionMat);
}
