/*!
SLCurveBezier::findParamByDist gets parameter s distance in arc length from Q(t1).
Returns max SLfloat if can't find it.
*/
SLfloat SLCurveBezier::findParamByDist(SLfloat t1, SLfloat s)
{
// ensure that we remain within valid parameter space
if (s > arcLength(t1, _points[_points.size()-1].w))
return _points[_points.size()-1].w;
// make first guess
SLfloat p = t1 + s*(_points[_points.size()-1].w-_points[0].w)/_totalLength;
for (SLuint i = 0; i < 32; ++i)
{
// compute function value and test against zero
SLfloat func = arcLength(t1, p) - s;
if (SL_abs(func) < 1.0e-03f) return p;
// perform Newton-Raphson iteration step
SLfloat speed = velocity(p).length();
assert(SL_abs(speed) > FLT_EPSILON);
p -= func/speed;
}
// done iterating, return failure case
return FLT_MAX;
}
/*!
SLCamera::onTouch2Move gets called whenever two fingers move on a handheld
screen.
*/
SLbool SLCamera::onTouch2Move(const SLint x1, const SLint y1,
const SLint x2, const SLint y2)
{
SLScene* s = SLScene::current;
SLSceneView* sv = s->activeSV();
SLVec2f now1((SLfloat)x1, (SLfloat)y1);
SLVec2f now2((SLfloat)x2, (SLfloat)y2);
SLVec2f delta1(now1-_oldTouchPos1);
SLVec2f delta2(now2-_oldTouchPos2);
// Average out the deltas over the last 4 events for correct 1 pixel moves
static SLuint cnt=0;
static SLVec2f d1[4];
static SLVec2f d2[4];
d1[cnt%4] = delta1;
d2[cnt%4] = delta2;
SLVec2f avgDelta1(d1[0].x+d1[1].x+d1[2].x+d1[3].x, d1[0].y+d1[1].y+d1[2].y+d1[3].y);
SLVec2f avgDelta2(d2[0].x+d2[1].x+d2[2].x+d2[3].x, d2[0].y+d2[1].y+d2[2].y+d2[3].y);
avgDelta1 /= 4.0f;
avgDelta2 /= 4.0f;
cnt++;
SLfloat r1, phi1, r2, phi2;
avgDelta1.toPolar(r1, phi1);
avgDelta2.toPolar(r2, phi2);
// Scale the mouse delta by the lookAt distance
SLfloat lookAtDist;
if (_lookAtRay.length < FLT_MAX)
lookAtDist = _lookAtRay.length;
else lookAtDist = _focalDist;
// scale factor depending on the space sice at focal dist
SLfloat spaceH = tan(SL_DEG2RAD*_fov/2) * lookAtDist * 2.0f;
SLfloat spaceW = spaceH * sv->scrWdivH();
//SL_LOG("avgDelta1: (%05.2f,%05.2f), dPhi=%05.2f\n", avgDelta1.x, avgDelta1.y, SL_abs(phi1-phi2));
// if fingers move parallel slide camera vertically or horizontally
if (SL_abs(phi1-phi2) < 0.2f)
{
// Calculate center between finger points
SLVec2f nowCenter((now1+now2)*0.5f);
SLVec2f oldCenter((_oldTouchPos1+_oldTouchPos2)*0.5f);
// For first move set oldCenter = nowCenter
if (oldCenter == SLVec2f::ZERO) oldCenter = nowCenter;
SLVec2f delta(nowCenter - oldCenter);
// scale to 0-1
delta.x /= (SLfloat)sv->scrW();
delta.y /= (SLfloat)sv->scrH();
// scale to space size
delta.x *= spaceW;
delta.y *= spaceH;
if (_camAnim==turntableYUp || _camAnim==turntableZUp)
{
// apply delta to x- and y-position
_vm.translation(_vm.m(12) + delta.x,
_vm.m(13) - delta.y,
_vm.m(14));
setWMandState();
}
else if (_camAnim == walkingYUp || _camAnim == walkingZUp)
{
_maxSpeed.x = delta.x * 100.0f,
_maxSpeed.z = delta.y * 100.0f;
}
} else // Two finger pinch
{
// Calculate vector between fingers
SLVec2f nowDist(now2 - now1);
SLVec2f oldDist(_oldTouchPos2-_oldTouchPos1);
// For first move set oldDist = nowDist
if (oldDist == SLVec2f::ZERO) oldDist = nowDist;
SLfloat delta = oldDist.length() - nowDist.length();
if (_camAnim==turntableYUp)
{ // scale to 0-1
delta /= (SLfloat)sv->scrH();
// scale to space height
delta *= spaceH*2;
// apply delta to the z-position
_vm.translation(_vm.m(12),
_vm.m(13),
_vm.m(14) - delta);
setWMandState();
}
else if (_camAnim == walkingYUp)
{
// change field of view
_fov += SL_sign(delta) * 0.5f;
currentFOV = _fov;
}
}
_oldTouchPos1.set((SLfloat)x1, (SLfloat)y1);
_oldTouchPos2.set((SLfloat)x2, (SLfloat)y2);
return true;
}
