r31 = r3
r28 = r4
r5 (mode variable)


r3 & 0x00000001		prm_triangle()
r3 & 0x00000002		prm_trianglestrip()
r3 & 0x00000004		prm_trianglefan()
r3 & 0x00000008		prm_line()
r3 & 0x00000010		prm_lines()
r3 & 0x00000020		prm_linestrip()
r3 & 0x00000040		prm_point
r3 & 0x00000080		prm_points
r3 & 0x00000100		prm_flashcolor
r3 & 0x00000200		prm_flashmisc

r4 & 0x00000001		mode_fog()
r4 & 0x00000002		mode_stipple()
r4 & 0x00000004		mode_viewclip()
r4 & 0x00000008		mode_scissor()
r4 & 0x00000010		mode_alphatest()
r4 & 0x00000020		mode_depthtest()
r4 & 0x00000040		mode_blend()
r4 & 0x00000080		mode_stenciltest()
r4 & 0x00000100		mode_stencilmod()
r4 & 0x00000200		mode_colormask()
r4 & 0x00000400		mode_depthmask()
r4 & 0x00000800		mode_stencilmask()
r4 & 0x00001000		mode_logicop()
r4 & 0x0007e000		any bit on -> enable_texture()
r4 & 0x00080000		1 -> texenter(), 0 -> mode_texmisc()