gistfile1.java

public static void gluPerspective(float fovy, float aspect, float zNear, float zFar) {
	float sine, cotangent, deltaZ;
	float radians = fovy / 2 * GLU.PI / 180;

	deltaZ = zFar - zNear;
	sine = (float) Math.sin(radians);

	if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {
		return;
	}

	cotangent = (float) Math.cos(radians) / sine;

	__gluMakeIdentityf(matrix);

	matrix.put(0 * 4 + 0, cotangent / aspect);
	matrix.put(1 * 4 + 1, cotangent);
	matrix.put(2 * 4 + 2, - (zFar + zNear) / deltaZ);
	matrix.put(2 * 4 + 3, -1);
	matrix.put(3 * 4 + 2, -2 * zNear * zFar / deltaZ);
	matrix.put(3 * 4 + 3, 0);

	glMultMatrix(matrix);
}