bool isCenterInViewport(const Frustum& frustum, const Boxf& worldBox,
const Viewport& viewport) const
{
Vector4f center = worldBox.getCenter();
center[3] = 1.0;
Vector4f mvpCenter = frustum.getMVPMatrix() * center;
Vector3f mvpCenterHom = mvpCenter / mvpCenter[3];
const bool isNegXBorder = viewport[0] == 0.0f; // left
const bool isPosXBorder =
viewport[0] + viewport[2] == 1.0f; // left + width
const bool isNegYBorder = viewport[1] == 0.0f; // top
const bool isPosYBorder =
viewport[1] + viewport[3] == 1.0f; // top + height
Vector3f minBox(-1.0f);
Vector3f maxBox(1.0f);
if (isNegXBorder)
minBox[0] = -infinite;
if (isPosXBorder)
maxBox[0] = infinite;
if (isNegYBorder)
minBox[1] = -infinite;
if (isPosYBorder)
maxBox[1] = infinite;
minBox[2] = -infinite;
maxBox[2] = infinite;
const Boxf ndcCube(minBox, maxBox);
return ndcCube.isIn(mvpCenterHom);
}
