NAME

hwMatrix - HoverWare matrix utilities

SYNOPSIS

    #include "hw.h"

    void hwIdentity( hwFloat res[4][4] )
    void hwScale( hwFloat res[4][4], hwFloat sx, hwFloat sy, hwFloat sz )
    void hwRotateX( hwFloat res[4][4], hwFloat angle )
    void hwRotateY( hwFloat res[4][4], hwFloat angle )
    void hwRotateZ( hwFloat res[4][4], hwFloat angle )
    void hwRotateAxis( hwFloat res[4][4], hwFloat angle, hwFloat axis[3] )
    void hwMatMult( hwFloat res[4][4], hwFloat a[4][4], hwFloat b[4][4] )
    void hwTransform( hwFloat mat[4][4], hwFloat point[3] )
    hwInt32 hwInvertMat( hwFloat mat[4][4], hwFloat dst[4][4] )

    void hwDisplay->pushMatrix( hwDisplay disp, hwFloat mat[4][4] )
    void hwDisplay->popMatrix( hwDisplay disp )

DESCRIPTION

These routines manipulate 4x4 transformations useful as modelling transforms in HoverWare. Their full descriptions are as follows:

hwIdentity

Initialize a 4x4 matrix to "identity".

hwScale

Place the X, Y, and Z scale factors xs, ys, and zs along the diagonal of the matrix

hwRotateX

Create a matrix which rotates about the X axis by angle radians.

hwRotateY

Create a matrix which rotates about the Y axis by angle radians.

hwRotateZ

Create a matrix which rotates about the Z axis by angle radians.

hwRotateAxis

Create a matrix which rotates about an arbitrary axis by angle radians

hwMatMult

Post-multiply matrix a by matrix b, placing the result in res.

hwTransform

Transform a point by the given matrix

hwInvertMat

Calculate the inverse of a given mat, putting the result in dst. The return value is 1 if the matrix is invertible, 0 otherwise.

hwDisplay->pushMatrix

Push a matrix on the HoverWare matrix stack. The depth of this stack is system-dependent, but it is at least 8. The matrix is pre-concatenated with the other matrices on the stack.

hwDisplay->popMatrix

Pop the top of the HoverWare matrix stack.

The model matrix affects all graphics primitives in HoverWare, including cameras and lights. Note that pushMatrix() and popMatrix() are actually methods in the hwDisplay class and need to be called through an instance of hwDisplay.

EXAMPLES

    /* Push a rotation about X on the matrix stack */
    hwFloat
        mat[4][4];

    hwRotateX( mat, 30.0 * M_PI / 180.0 );
    disp->pushMatrix( disp, mat );

SEE ALSO

hwSpinner