void glutMotion(int x, int y)
{
if (gIsRotatingCamera)
{
static const double kTrackBallRadius = 0.8;
Vec3d lastPos;
lastPos[0] = gLastMouseX * 2.0 / gWindowWidth - 1.0;
lastPos[1] = (gWindowHeight - gLastMouseY) * 2.0 / gWindowHeight - 1.0;
lastPos[2] = projectToTrackball(kTrackBallRadius, lastPos[0], lastPos[1]);
Vec3d currPos;
currPos[0] = x * 2.0 / gWindowWidth - 1.0;
currPos[1] = (gWindowHeight - y) * 2.0 / gWindowHeight - 1.0;
currPos[2] = projectToTrackball(kTrackBallRadius, currPos[0], currPos[1]);
currPos.normalize();
lastPos.normalize();
Vec3d rotateVec = lastPos.cross(currPos);
double rotateAngle = asin(rotateVec.norm());
if (fabs(rotateAngle) > 1e-6)
{
double deltaRotation[16];
generateRotationMatrix(deltaRotation, rotateAngle, rotateVec[0], rotateVec[1], rotateVec[2]);
multRight(gCameraRotation, deltaRotation);
updateCamera();
}
}
else if (gIsScalingCamera)
{
float y1 = gWindowHeight - gLastMouseY;
float y2 = gWindowHeight - y;
gCameraScale *= 1 + (y1 - y2) / gWindowHeight;
updateCamera();
}
gLastMouseX = x;
gLastMouseY = y;
}
//! Right-multiply with the \a a_matrix matrix. \sa multRight().
matrix4<Type>& operator*=(const matrix4<Type>& a_matrix)
{
return multRight(a_matrix);
}