02. Scissor Test

The Scissor Test is used to limit drawing to a rectangular region of the viewport. When enabled, only fragments inside the rectangle are passed to later pipeline stages.

The ScissorTest can be enabled or disabled using EnableCap.ScissorTest

GL.Enable( EnableCap.ScissorTest );
GL.Disable( EnableCap.ScissorTest ); // default

Only a single command is related to the ScissorTest, GL.Scissor( x, y, width, height ). By default the parameters are set to cover the whole window.

  • X and Y are used to specify the lower-left corner of the rectangle.
  • Width is used to specify the horizontal extension of the rectangle.
  • Height is used to specify the vertical extension of the rectangle.

State Queries

To determine whether ScissorTest is enabled or disabled, use Result = GL.IsEnabled( EnableCap.ScissorTest );

The values set by GL.Scissor() can be queried by GL.GetInteger( GetPName.ScissorBox, ... ); // returns an array