void drawingCommands() {
// Rotation about z:
double theta = Math.PI / 3.0;
double a11 = Math.cos(theta);
double a12 = -Math.sin(theta);
double a21 = Math.sin(theta);
double a22 = Math.cos(theta);
double[][] A = {
{a11, a12, 0, 0},
{a21, a22, 0, 0},
{0, 0, 1, 0},
{0, 0, 0, 1}
};
/*
// INSERT YOUR CODE for rotation about x by 30 degrees
double[][] B = {
};
// INSERT YOUR CODE for translation by (2,3,4)
double[][] C = {
};
double[][] temp = MatrixTool.matrixMult (B,A);
double[][] transform = MatrixTool.matrixMult (C,temp);
*/
// Replace this transform with the above after implementing
// matrices B and C
double[][] transform = A;
double x0 = 0, y0 = 0; // Center of original 2D ellipse.
double a = 7; // Major axis
double b = 4; // Minor axis
double delT = 0.25; // t-increment for drawing
d3.setDrawColor(Color.RED);
for (double t = 0; t <= 2 * Math.PI + delT; t += delT) {
double[] x = new double[4];
x[0] = a * Math.cos(t);
x[1] = b * Math.sin(t);
x[2] = 0;
x[3] = 1;
double[] z = MatrixTool.matrixVectorMult(transform, x);
d3.drawPoint(z[0], z[1], z[2]);
}
}
