public static D2D_MATRIX_4X4_F Rotation(float degrees, float centerX = 0, float centerY = 0, float centerZ = 0)
{
var magnitude = D2D1Functions.D2D1Vec3Length(centerX, centerY, centerZ);
centerX /= magnitude;
centerY /= magnitude;
centerZ /= magnitude;
var radians = degrees * (3.141592654f / 180.0f);
D2D1Functions.D2D1SinCos(radians, out var sin, out var cos);
var oneMinusCos = 1 - cos;
return(new D2D_MATRIX_4X4_F(
1 + oneMinusCos * (centerX * centerX - 1),
centerZ * sin + oneMinusCos * centerX * centerY,
-centerY * sin + oneMinusCos * centerX * centerZ,
0,
-centerZ * sin + oneMinusCos * centerY * centerX,
1 + oneMinusCos * (centerY * centerY - 1),
centerX * sin + oneMinusCos * centerY * centerZ,
0,
centerY * sin + oneMinusCos * centerZ * centerX,
-centerX * sin + oneMinusCos * centerZ * centerY,
1 + oneMinusCos * (centerZ * centerZ - 1),
0,
0, 0, 0, 1
));
}
public static D2D_MATRIX_4X4_F RotationX(float degrees)
{
var radians = degrees * (3.141592654f / 180f);
D2D1Functions.D2D1SinCos(radians, out var sin, out var cos);
return(new D2D_MATRIX_4X4_F(
1, 0, 0, 0,
0, cos, sin, 0,
0, -sin, cos, 0,
0, 0, 0, 1
));
}
public static D2D_MATRIX_4X4_F SkewY(float degrees)
{
var radians = degrees * (3.141592654f / 180.0f);
var tan = D2D1Functions.D2D1Tan(radians);
return(new D2D_MATRIX_4X4_F(
1, tan, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1
));
}
