// Fatory Methods
public static Matrix3 rotation(Vector3 axis, final float angle) {
if (angle == 0) return Identity;
axis = axis.unit();
if (!axis.isFinite()) throw new RuntimeException();
final float c = GMath.cos(angle), s = GMath.sin(angle);
return axis.mul(1 - c).mul(axis).add(Identity, c).add(axis.mul(s).tilda());
}
public static Quaternion makeRotation(Quaternion result, float theta, Vector axis) {
float halfTheta = theta / 2;
float sinHalfTheta = GMath.sin(halfTheta);
result.w = GMath.cos(halfTheta);
result.x = axis.getX() * sinHalfTheta;
result.y = axis.getY() * sinHalfTheta;
result.z = axis.getZ() * sinHalfTheta;
return result;
}
/**
* Creates a new GStar centered at the origin with the indicated horizontal width.
*
* @param width The width of the star
*/
public GStar(double width) {
double dx = width / 2;
double dy = dx * GMath.tanDegrees(18);
double edge = width / 2 - dy * GMath.tanDegrees(36);
addVertex(-dx, -dy);
int angle = 0;
for (int i = 0; i < 5; i++) {
addPolarEdge(edge, angle);
addPolarEdge(edge, angle + 72);
angle -= 72;
}
markAsComplete();
}
public float snap_cam_z_hud(float eye[], float center[], float up[]) {
float lookAt[] = new float[16];
float eye2[] = new float[3];
for (int a = 0; a < 3; a++) {
eye2[a] = eye[a];
}
for (float ez = 1; ez < 100; ez += 0.05) {
float cordx = mCanvasW;
float cordy = 0;
eye2[2] = ez;
float win[] = new float[3];
GMath.lookAtf(lookAt, eye2, center, up);
if (GLU.gluProject(cordx, cordy, 0.0f, lookAt, 0, mProjectionHud, 0, mViewport, 0, win, 0)
== GL10.GL_TRUE
&& win[0] > 0
&& win[0] < mViewport[2]) {
mCameraEyeHud[0] = 0;
mCameraEyeHud[1] = 0;
mCameraEyeHud[2] = ez;
saveLookAtHud(mCameraEyeHud, mCameraLookAtHud, mUpZHud);
return ez;
}
}
return 0;
}
public void screen2spaceVecHud(float x, float y, float[] vec) {
float c[] = new float[3];
y = mViewport[3] - y;
GMath.unProject(x, y, 1.0f, mLookAtHud, 0, mProjectionHud, 0, mViewport, 0, c, 0);
vec[0] = c[0] - this.mCameraEyeHud[0];
vec[1] = c[1] - this.mCameraEyeHud[1];
vec[2] = c[2] - this.mCameraEyeHud[2];
}
/** converts to quaternion */
public Quaternion quaternion() {
if (a.x + b.y + c.z >= 0) {
final float s = GMath.sqrt(1 + a.x + b.y + c.z) * 2;
return new Quaternion(s / 4, (c.y - b.z) / s, (a.z - c.x) / s, (b.x - a.y) / s);
}
if (a.x >= b.y && a.x >= c.z) {
final float s = GMath.sqrt(1 + a.x - b.y - c.z) * 2;
return new Quaternion((c.y - b.z) / s, s / 4, (a.y + b.x) / s, (c.x + a.z) / s);
}
if (b.y >= c.z) {
final float s = GMath.sqrt(1 - a.x + b.y - c.z) * 2;
return new Quaternion((a.z - c.x) / s, (a.y + b.x) / s, s / 4, (b.z + c.y) / s);
}
final float s = GMath.sqrt(1 - a.x - b.y + c.z) * 2;
return new Quaternion((b.x - a.y) / s, (c.x + a.z) / s, (b.z + c.y) / s, s / 4);
}
public void screen2space(float x, float y, float[] spacecoords) {
float c[] = new float[3];
float f[] = new float[3];
y = mViewport[3] - y;
GMath.unProject(x, y, 1.0f, mLookAt, 0, mProjection, 0, mViewport, 0, f, 0);
GMath.unProject(x, y, 0.0f, mLookAt, 0, mProjection, 0, mViewport, 0, c, 0);
f[0] -= c[0];
f[1] -= c[1];
f[2] -= c[2];
float rayLength = (float) Math.sqrt(c[0] * c[0] + c[1] * c[1] + c[2] * c[2]);
// normalize
f[0] /= rayLength;
f[1] /= rayLength;
f[2] /= rayLength;
float dot1, dot2;
float pointInPlaneX = 0;
float pointInPlaneY = 0;
float pointInPlaneZ = 0;
float planeNormalX = 0;
float planeNormalY = 0;
float planeNormalZ = -1;
pointInPlaneX -= c[0];
pointInPlaneY -= c[1];
pointInPlaneZ -= c[2];
dot1 =
(planeNormalX * pointInPlaneX)
+ (planeNormalY * pointInPlaneY)
+ (planeNormalZ * pointInPlaneZ);
dot2 = (planeNormalX * f[0]) + (planeNormalY * f[1]) + (planeNormalZ * f[2]);
float t = dot1 / dot2;
f[0] *= t;
f[1] *= t;
spacecoords[0] = f[0] + c[0];
spacecoords[1] = f[1] + c[1];
}
public float normalizeIfNot() {
float magSq = magnitudeSquared();
if (magSq != 1) {
float mag = GMath.sqrt(magSq);
this.w = w / mag;
this.x = x / mag;
this.y = y / mag;
this.z = z / mag;
return mag;
} else {
return 1;
}
}
public void saveLookAtHud(float[] eye, float[] center, float[] up) {
for (int a = 0; a < 16; a++) {
mLookAtHud[a] = 0;
}
GMath.lookAtf(mLookAtHud, eye, center, up);
}
public float magnitude() {
return GMath.sqrt(magnitudeSquared());
}
