C++ LLVector2::normVec方法代码示例

F32 angle_between(const LLVector2& a, const LLVector2& b)
{
	LLVector2 an = a;
	LLVector2 bn = b;
	an.normVec();
	bn.normVec();
	F32 cosine = an * bn;
	F32 angle = (cosine >= 1.0f) ? 0.0f :
				(cosine <= -1.0f) ? F_PI :
				acos(cosine);
	return angle;
}

BOOL are_parallel(const LLVector2 &a, const LLVector2 &b, float epsilon)
{
	LLVector2 an = a;
	LLVector2 bn = b;
	an.normVec();
	bn.normVec();
	F32 dot = an * bn;
	if ( (1.0f - fabs(dot)) < epsilon)
	{
		return TRUE;
	}
	return FALSE;
}

void LLHUDNameTag::updateAll()
{
	// iterate over all text objects, calculate their restoration forces,
	// and add them to the visible set if they are on screen and close enough
	sVisibleTextObjects.clear();
	
	TextObjectIterator text_it;
	for (text_it = sTextObjects.begin(); text_it != sTextObjects.end(); ++text_it)
	{
		LLHUDNameTag* textp = (*text_it);
		textp->mTargetPositionOffset.clearVec();
		textp->updateSize();
		textp->updateVisibility();
	}
	
	// sort back to front for rendering purposes
	std::sort(sVisibleTextObjects.begin(), sVisibleTextObjects.end(), llhudnametag_further_away());

	// iterate from front to back, and set LOD based on current screen coverage
	F32 screen_area = (F32)(gViewerWindow->getWindowWidthScaled() * gViewerWindow->getWindowHeightScaled());
	F32 current_screen_area = 0.f;
	std::vector<LLPointer<LLHUDNameTag> >::reverse_iterator r_it;
	for (r_it = sVisibleTextObjects.rbegin(); r_it != sVisibleTextObjects.rend(); ++r_it)
	{
		LLHUDNameTag* textp = (*r_it);
		if (current_screen_area / screen_area > LOD_2_SCREEN_COVERAGE)
		{
			textp->setLOD(3);
		}
		else if (current_screen_area / screen_area > LOD_1_SCREEN_COVERAGE)
		{
			textp->setLOD(2);
		}
		else if (current_screen_area / screen_area > LOD_0_SCREEN_COVERAGE)
		{
			textp->setLOD(1);
		}
		else
		{
			textp->setLOD(0);
		}
		textp->updateSize();
		// find on-screen position and initialize collision rectangle
		textp->mTargetPositionOffset = textp->updateScreenPos(LLVector2::zero);
		current_screen_area += (F32)(textp->mSoftScreenRect.getWidth() * textp->mSoftScreenRect.getHeight());
	}

	LLTrace::CountStatHandle<>* camera_vel_stat = LLViewerCamera::getVelocityStat();
	F32 camera_vel = LLTrace::get_frame_recording().getLastRecording().getPerSec(*camera_vel_stat);
	if (camera_vel > MAX_STABLE_CAMERA_VELOCITY)
	{
		return;
	}

	VisibleTextObjectIterator src_it;

	for (S32 i = 0; i < NUM_OVERLAP_ITERATIONS; i++)
	{
		for (src_it = sVisibleTextObjects.begin(); src_it != sVisibleTextObjects.end(); ++src_it)
		{
			LLHUDNameTag* src_textp = (*src_it);

			VisibleTextObjectIterator dst_it = src_it;
			++dst_it;
			for (; dst_it != sVisibleTextObjects.end(); ++dst_it)
			{
				LLHUDNameTag* dst_textp = (*dst_it);

				if (src_textp->mSoftScreenRect.overlaps(dst_textp->mSoftScreenRect))
				{
					LLRectf intersect_rect = src_textp->mSoftScreenRect;
					intersect_rect.intersectWith(dst_textp->mSoftScreenRect);
					intersect_rect.stretch(-BUFFER_SIZE * 0.5f);
					
					F32 src_center_x = src_textp->mSoftScreenRect.getCenterX();
					F32 src_center_y = src_textp->mSoftScreenRect.getCenterY();
					F32 dst_center_x = dst_textp->mSoftScreenRect.getCenterX();
					F32 dst_center_y = dst_textp->mSoftScreenRect.getCenterY();
					F32 intersect_center_x = intersect_rect.getCenterX();
					F32 intersect_center_y = intersect_rect.getCenterY();
					LLVector2 force = lerp(LLVector2(dst_center_x - intersect_center_x, dst_center_y - intersect_center_y), 
										LLVector2(intersect_center_x - src_center_x, intersect_center_y - src_center_y),
										0.5f);
					force.setVec(dst_center_x - src_center_x, dst_center_y - src_center_y);
					force.normVec();

					LLVector2 src_force = -1.f * force;
					LLVector2 dst_force = force;

					LLVector2 force_strength;
					F32 src_mult = dst_textp->mMass / (dst_textp->mMass + src_textp->mMass); 
					F32 dst_mult = 1.f - src_mult;
					F32 src_aspect_ratio = src_textp->mSoftScreenRect.getWidth() / src_textp->mSoftScreenRect.getHeight();
					F32 dst_aspect_ratio = dst_textp->mSoftScreenRect.getWidth() / dst_textp->mSoftScreenRect.getHeight();
					src_force.mV[VY] *= src_aspect_ratio;
					src_force.normVec();
					dst_force.mV[VY] *= dst_aspect_ratio;
					dst_force.normVec();

					src_force.mV[VX] *= llmin(intersect_rect.getWidth() * src_mult, intersect_rect.getHeight() * SPRING_STRENGTH);
//.........这里部分代码省略.........