Are you sure that draw_sprit
xt is for 3D rendering? If it's only for 2D drawing, then setting the projection to ortho shouldn't do anything. You could test that idea by setting the projection to perspective and seeing if the background is rendered appropriately.
Take a look at d3d_draw_wall. You could use that to draw the background with an appropriate Z depth along with an ortho projection. Note that in order to have the background static, either draw the background in a fixed position and use a static camera view matrix, or you can set the background's world position relative to the camera every game step along with making the background always face the camera (i.e. billboards). The first is the simplest approach.
xt is for 3D rendering? If it's only for 2D drawing, then setting the projection to ortho shouldn't do anything. You could test that idea by setting the projection to perspective and seeing if the background is rendered appropriately.Take a look at d3d_draw_wall. You could use that to draw the background with an appropriate Z depth along with an ortho projection. Note that in order to have the background static, either draw the background in a fixed position and use a static camera view matrix, or you can set the background's world position relative to the camera every game step along with making the background always face the camera (i.e. billboards). The first is the simplest approach.