In OpenGL, can I draw a pixel that exactly at the coordinates (5, 5)?

Question

By (5, 5) I mean exactly the fifth row and fifth column.

I found it very hard to draw things using screen coordinates, all the coordinates in OpenGL is relative, and usu

Answer 1

glEnable( GL_SCISSOR_TEST );
glScissor( 5, 5, 1, 1 ); /// position of pixel
glClearColor( 1.0f, 1.0f, 1.0f, 0.0f ); /// color of pixel
glClear( GL_COLOR_BUFFER_BIT );
glDisable( GL_SCISSOR_TEST );

By changing last 2 arguments of glScissor you can also draw pixel perfect rectangle.