# 测试 Graphics View 的效率

Qt 说 Graphics View Framework 效率很高，到底有多高呢？来进行一个简单的测试，向 scene 中添加 10万，50万，100万个 items(修改程序中的 rowCount 和 colCount 即可)，进行缩放、旋转看看效率怎么样。

In computer science, binary space partitioning (BSP) is a method for recursively subdividing a space into convex sets by hyperplanes. This subdivision gives rise to a representation of objects within the space by means of a tree data structure known as a BSP tree.

Binary space partitioning was developed in the context of 3D computer graphics,[1][2] where the structure of a BSP tree allows spatial information about the objects in a scene that is useful in rendering, such as their ordering from front-to-back with respect to a viewer at a given location, to be accessed rapidly. Other applications include performing geometrical operations with shapes (constructive solid geometry) in CAD,[3] collision detection in robotics and 3-D video games, ray tracing and other computer applications that involve handling of complex spatial scenes.