void MatrixBuildOrtho( VMatrix& dst, double left, double top, double right, double bottom, double zNear, double zFar )
{
// FIXME: This is being used incorrectly! Should read:
// D3DXMatrixOrthoOffCenterRH( &matrix, left, right, bottom, top, zNear, zFar );
// Which is certainly why we need these extra -1 scales in y. Bleah
// NOTE: The camera can be imagined as the following diagram:
// /z
// /
// /____ x Z is going into the screen
// |
// |
// |y
//
// (0,0,z) represents the upper-left corner of the screen.
// Our projection transform needs to transform from this space to a LH coordinate
// system that looks thusly:
//
// y| /z
// | /
// |/____ x Z is going into the screen
//
// Where x,y lies between -1 and 1, and z lies from 0 to 1
// This is because the viewport transformation from projection space to pixels
// introduces a -1 scale in the y coordinates
// D3DXMatrixOrthoOffCenterRH( &matrix, left, right, top, bottom, zNear, zFar );
dst.Init( 2.0f / ( right - left ), 0.0f, 0.0f, ( left + right ) / ( left - right ),
0.0f, 2.0f / ( bottom - top ), 0.0f, ( bottom + top ) / ( top - bottom ),
0.0f, 0.0f, 1.0f / ( zNear - zFar ), zNear / ( zNear - zFar ),
0.0f, 0.0f, 0.0f, 1.0f );
}
void MatrixBuildPerspectiveX( VMatrix& dst, double flFovX, double flAspect, double flZNear, double flZFar )
{
float flWidth = 2.0f * flZNear * tanf( flFovX * M_PI / 360.0f );
float flHeight = flWidth / flAspect;
dst.Init( 2.0f * flZNear / flWidth, 0.0f, 0.0f, 0.0f,
0.0f, 2.0f * flZNear/ flHeight, 0.0f, 0.0f,
0.0f, 0.0f, flZFar / ( flZNear - flZFar ), flZNear * flZFar / ( flZNear - flZFar ),
0.0f, 0.0f, -1.0f, 0.0f );
}
void CSplinePatch::SetupPatchQuery( float s, float t )
{
m_is = (int)s;
m_it = (int)t;
if( m_is >= m_Width )
{
m_is = m_Width - 1;
m_fs = 1.0f;
}
else
{
m_fs = s - m_is;
}
if( m_it >= m_Height )
{
m_it = m_Height - 1;
m_ft = 1.0f;
}
else
{
m_ft = t - m_it;
}
ComputeIndices( );
// The patch equation is:
// px = S * M * Gx * M^T * T^T
// py = S * M * Gy * M^T * T^T
// pz = S * M * Gz * M^T * T^T
// where S = [s^3 s^2 s 1], T = [t^3 t^2 t 1]
// M is the patch type matrix, in my case I'm using a catmull-rom
// G is the array of control points. rows have constant t
// We're gonna cache off S * M and M^T * T^T...
Vector4D svec, tvec;
float fs2 = m_fs * m_fs;
svec[0] = fs2 * m_fs; svec[1] = fs2; svec[2] = m_fs; svec[3] = 1.0f;
float ft2 = m_ft * m_ft;
tvec[0] = ft2 * m_ft; tvec[1] = ft2; tvec[2] = m_ft; tvec[3] = 1.0f;
// This sets up the catmull rom matrix based on the blend factor!!
// we can go from linear to curvy!
s_CatmullRom.Init( -0.5 * m_LinearFactor, 1.5 * m_LinearFactor, -1.5 * m_LinearFactor, 0.5 * m_LinearFactor,
m_LinearFactor, -2.5 * m_LinearFactor, 2 * m_LinearFactor, -0.5 * m_LinearFactor,
-0.5 * m_LinearFactor, -1 + m_LinearFactor, 1 - 0.5 * m_LinearFactor, 0,
0, 1, 0, 0 );
Vector4DMultiplyTranspose( s_CatmullRom, svec, m_SVec );
Vector4DMultiplyTranspose( s_CatmullRom, tvec, m_TVec );
}
void MatrixBuildPerspectiveOffCenterX( VMatrix& dst, double flFovX, double flAspect, double flZNear, double flZFar, double bottom, double top, double left, double right )
{
float flWidth = 2.0f * flZNear * tanf( flFovX * M_PI / 360.0f );
float flHeight = flWidth / flAspect;
// bottom, top, left, right are 0..1 so convert to -<val>/2..<val>/2
float flLeft = -(flWidth/2.0f) * (1.0f - left) + left * (flWidth/2.0f);
float flRight = -(flWidth/2.0f) * (1.0f - right) + right * (flWidth/2.0f);
float flBottom = -(flHeight/2.0f) * (1.0f - bottom) + bottom * (flHeight/2.0f);
float flTop = -(flHeight/2.0f) * (1.0f - top) + top * (flHeight/2.0f);
dst.Init( (2.0f * flZNear) / (flRight-flLeft), 0.0f, (flLeft+flRight)/(flRight-flLeft), 0.0f,
0.0f, 2.0f*flZNear/(flTop-flBottom), (flTop+flBottom)/(flTop-flBottom), 0.0f,
0.0f, 0.0f, flZFar/(flZNear-flZFar), flZNear*flZFar/(flZNear-flZFar),
0.0f, 0.0f, -1.0f, 0.0f );
}
void VMatrix::MatrixMul( const VMatrix &vm, VMatrix &out ) const
{
out.Init(
m[0][0]*vm.m[0][0] + m[0][1]*vm.m[1][0] + m[0][2]*vm.m[2][0] + m[0][3]*vm.m[3][0],
m[0][0]*vm.m[0][1] + m[0][1]*vm.m[1][1] + m[0][2]*vm.m[2][1] + m[0][3]*vm.m[3][1],
m[0][0]*vm.m[0][2] + m[0][1]*vm.m[1][2] + m[0][2]*vm.m[2][2] + m[0][3]*vm.m[3][2],
m[0][0]*vm.m[0][3] + m[0][1]*vm.m[1][3] + m[0][2]*vm.m[2][3] + m[0][3]*vm.m[3][3],
m[1][0]*vm.m[0][0] + m[1][1]*vm.m[1][0] + m[1][2]*vm.m[2][0] + m[1][3]*vm.m[3][0],
m[1][0]*vm.m[0][1] + m[1][1]*vm.m[1][1] + m[1][2]*vm.m[2][1] + m[1][3]*vm.m[3][1],
m[1][0]*vm.m[0][2] + m[1][1]*vm.m[1][2] + m[1][2]*vm.m[2][2] + m[1][3]*vm.m[3][2],
m[1][0]*vm.m[0][3] + m[1][1]*vm.m[1][3] + m[1][2]*vm.m[2][3] + m[1][3]*vm.m[3][3],
m[2][0]*vm.m[0][0] + m[2][1]*vm.m[1][0] + m[2][2]*vm.m[2][0] + m[2][3]*vm.m[3][0],
m[2][0]*vm.m[0][1] + m[2][1]*vm.m[1][1] + m[2][2]*vm.m[2][1] + m[2][3]*vm.m[3][1],
m[2][0]*vm.m[0][2] + m[2][1]*vm.m[1][2] + m[2][2]*vm.m[2][2] + m[2][3]*vm.m[3][2],
m[2][0]*vm.m[0][3] + m[2][1]*vm.m[1][3] + m[2][2]*vm.m[2][3] + m[2][3]*vm.m[3][3],
m[3][0]*vm.m[0][0] + m[3][1]*vm.m[1][0] + m[3][2]*vm.m[2][0] + m[3][3]*vm.m[3][0],
m[3][0]*vm.m[0][1] + m[3][1]*vm.m[1][1] + m[3][2]*vm.m[2][1] + m[3][3]*vm.m[3][1],
m[3][0]*vm.m[0][2] + m[3][1]*vm.m[1][2] + m[3][2]*vm.m[2][2] + m[3][3]*vm.m[3][2],
m[3][0]*vm.m[0][3] + m[3][1]*vm.m[1][3] + m[3][2]*vm.m[2][3] + m[3][3]*vm.m[3][3]
);
}