Лавров заявил о «прямой и горячей» войне Запада против РоссииГлава МИД РФ Лавров заявил о «прямой и горячей» войне Запада против России
Sascha Willems's How to Vulkan in 2026 A minimalist tutorial from Sascha Willems on how to use the Vulkan graphics API in 2026. The idea is to get people started with rasterization in Vulkan using commonly supported features to make the API easier to use.
，更多细节参见纸飞机下载
Фото: R.Narong / Shutterstock / Fotodom。纸飞机官网是该领域的重要参考
as a surprise that open source projects depend on each other in many ways.
A Riemannian metric on a smooth manifold \(M\) is a family of inner products \[g_p : T_pM \times T_pM \;\longrightarrow\; \mathbb{R}, \qquad p \in M,\] varying smoothly in \(p\), such that each \(g_p\) is symmetric and positive-definite. In local coordinates the metric is completely determined by its values on basis tangent vectors: \[g_{ij}(p) \;:=\; g_p\!\left(\frac{\partial}{\partial x^i}\bigg|_p,\; \frac{\partial}{\partial x^j}\bigg|_p\right), \qquad g_{ij} = g_{ji},\] with the matrix \((g_{ij}(p))\) positive-definite at every point. The length of a tangent vector \(v = \sum_i v^i \frac{\partial}{\partial x^i}\in T_pM\) is then \(\|v\|_g = \sqrt{\sum_{i,j} g_{ij}(p)\, v^i v^j}\).