What's texture space and screen space in rendering pipeline?

Question

can anyone explain the difference of "texture space" and "screen space" When solving advanced Lighting in 3d rendering pipeline? I'm a newbee to shader. thanks in advance！

Answer 1

According to my knowledge, texture space in U, V coordinate system is: (0.0, 0.0) for bot left, (1.0, 1.0) for top right point of a texture to be sampled.

Screen space is the same thing, but it is (-0.5, 0.5) for top left and (0.5, -0.5) for bot right point of render target texture (0 0 is now in center), yet it is transformed by projection matrix, either perspective or orthographical, which makes it, for example, (-400, 300) to (400, -300) for a 2d game with open window 800x600, so you can operate with pixels precisely.

**

Actually in DirectX 11 texture space (0, 0) means top left point of texture

Screen space seems to be (-1, 1) for top left, (1, -1) for bot right.

But the idea is the same.