Imagination PowerVR SDK Blog

Will the fragments out of the rect defined by glScissor() be processed by Pixel Shader ?


#1

HI all

If I define a rect (x=0, y=0, w=300, h=300) using glScissor(), I want to know whether the clip operation executing before Pixel Shader or after it?



If a fragment represents the pixel(301, 301) on screen, it cannot be drawn on screen buffer surely. But I want to know if it is cut off before entering the Pixel Shader.







Thanks a lot!

Chris


#2

Sorry for “Pixel Shader” , I means “Fragments Shader”.


#3

Hi Chris,



The scissor is applied before fragment shaders execute. The only fragments that will be shaded are those that fall within the bounds of the scissor region.



Thanks,

Joe


#4

Thank you, Joe.