Method getRayTo

examples/SharedMemory/PhysicsServerExample.cpp:3240–3299

}

btVector3 PhysicsServerExample::getRayTo(int x, int y)
{
	CommonRenderInterface* renderer = m_guiHelper->getRenderInterface();

	if (!renderer)
	{
		btAssert(0);
		return btVector3(0, 0, 0);
	}

	float top = 1.f;
	float bottom = -1.f;
	float nearPlane = 1.f;
	float tanFov = (top - bottom) * 0.5f / nearPlane;
	float fov = btScalar(2.0) * btAtan(tanFov);

	btVector3 camPos, camTarget;
	renderer->getActiveCamera()->getCameraPosition(camPos);
	renderer->getActiveCamera()->getCameraTargetPosition(camTarget);

	btVector3 rayFrom = camPos;
	btVector3 rayForward = (camTarget - camPos);
	rayForward.normalize();
	float farPlane = 10000.f;
	rayForward *= farPlane;

	btVector3 rightOffset;
	btVector3 cameraUp = btVector3(0, 0, 0);
	cameraUp[m_guiHelper->getAppInterface()->getUpAxis()] = 1;

	btVector3 vertical = cameraUp;

	btVector3 hor;
	hor = rayForward.cross(vertical);
	hor.safeNormalize();
	vertical = hor.cross(rayForward);
	vertical.safeNormalize();

	float tanfov = tanf(0.5f * fov);

	hor *= 2.f * farPlane * tanfov;
	vertical *= 2.f * farPlane * tanfov;

	btScalar aspect;
	float width = float(renderer->getScreenWidth());
	float height = float(renderer->getScreenHeight());

	aspect = width / height;

	hor *= aspect;

	btVector3 rayToCenter = rayFrom + rayForward;
	btVector3 dHor = hor * 1.f / width;
	btVector3 dVert = vertical * 1.f / height;

	btVector3 rayTo = rayToCenter - 0.5f * hor + 0.5f * vertical;
	rayTo += btScalar(x) * dHor;
	rayTo -= btScalar(y) * dVert;