com.sun.scenario.effect.impl.state.PerspectiveTransformState Maven / Gradle / Ivy
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package com.sun.scenario.effect.impl.state;
public class PerspectiveTransformState {
private float itx[][] = new float[3][3];
public float[][] getITX() {
return itx;
}
public void updateTx(float[][] tx) {
// First calculate the matrix inversion
float det = get3x3Determinant(tx);
if (Math.abs(det) < 1e-10) {
itx[0][0] = itx[1][0] = itx[2][0] = 0f;
itx[0][1] = itx[1][1] = itx[2][1] = 0f;
itx[0][2] = itx[1][2] = -1f;
itx[2][2] = 1f;
} else {
float invdet = 1.0f / det;
// Note that we calculate the matrix subdeterminants in
// row-column order, but we store them into the inverted
// matrix in column-row order. This performs the transpose
// operation needed for matrix inversion as we go.
itx[0][0] = invdet * (tx[1][1]*tx[2][2] - tx[1][2]*tx[2][1]);
itx[1][0] = invdet * (tx[1][2]*tx[2][0] - tx[1][0]*tx[2][2]); // flipped sign
itx[2][0] = invdet * (tx[1][0]*tx[2][1] - tx[1][1]*tx[2][0]);
itx[0][1] = invdet * (tx[0][2]*tx[2][1] - tx[0][1]*tx[2][2]); // flipped sign
itx[1][1] = invdet * (tx[0][0]*tx[2][2] - tx[0][2]*tx[2][0]);
itx[2][1] = invdet * (tx[0][1]*tx[2][0] - tx[0][0]*tx[2][1]); // flipped sign
itx[0][2] = invdet * (tx[0][1]*tx[1][2] - tx[0][2]*tx[1][1]);
itx[1][2] = invdet * (tx[0][2]*tx[1][0] - tx[0][0]*tx[1][2]); // flipped sign
itx[2][2] = invdet * (tx[0][0]*tx[1][1] - tx[0][1]*tx[1][0]);
}
}
private static float get3x3Determinant(float m[][]) {
return ( (m[0][0] * ((m[1][1] * m[2][2]) - (m[1][2] * m[2][1]))) -
(m[0][1] * ((m[1][0] * m[2][2]) - (m[1][2] * m[2][0]))) +
(m[0][2] * ((m[1][0] * m[2][1]) - (m[1][1] * m[2][0]))) );
}
}