Metal shader texture read vs sample

Question

在金属着色语言中，读取和示例函数之间用于访问纹理像素的确切区别是什么，以及何时应该使用哪一个？

Answer 1

A few differences:

• You can sample outside the bounds of the texture. But you should not read outside the texture.
• Sampling can use normalized coordinates (between 0 and 1). Reading always uses pixel coordinates.
• Samplers can interpolate between pixel values (for example if you're sampling in between two pixels). Reading always gives you the exact pixel value.