Starfield

program.ul

include "utils.ul"

loop:
   rand r1
   mulf r1, 255, r1
   f2i r1, r1
   or r1, 0xff000000, r1
   push r1
   call _gfx_clear
   call _gfx_show
   jmp loop

utils.ul

# The frame buffer, 320x240 pixels, RGBA
_gfx_buffer: reserve int x 320 * 240

jmp _utils_ul_end

#--------------------------------------------------
# Clears the frame buffer with the given color
#
# [SP + 0]: color
#--------------------------------------------------
_gfx_clear:
   pusha

   ld sp, 16 * 4, r1
   mov _gfx_buffer, r2   

   _gfx_clear_loop:
      sto r1, r2, 0 
      add r2, 4, r2
      cmp r2, _gfx_buffer + 320 * 240 * 4, r4
      jl r4, _gfx_clear_loop

   popa
   retn 1

#--------------------------------------------------
# Blits the frame buffer to the screen
#--------------------------------------------------
_gfx_show:
   push _gfx_buffer
   syscall 0x1
   ret

_utils_ul_end:
   nop