Find Unit at Coordinates (0x19d294)

# ROUTINE: FIND UNIT AT COORDINATES (0x19d294)                 ALTERNATIVE VERSION Get_unit_that_matches_coordinates
#    Parameters:
#        r4 = Integer byte array: [X Coordinate, Higher Elevation bit, Y Coordinate]
#    Returns:
#        r2 = Unit index of the unit found at the specified coordinates (0-20), or 21 if no unit found

0019d294: 00003021 addu r6,r0,r0                    #   [Unit index] = 0
0019d298: 340700ff ori r7,r0,0x00ff
0019d29c: 3c058019 lui r5,0x8019
0019d2a0: 24a508cc addiu r5,r5,0x08cc               #   Unit = UnitArray[0]

                                                    #   do {
0019d2a4: 90a20001 lbu r2,0x0001(r5)                #       [Unit ID]
0019d2a8: 00000000 nop
0019d2ac: 10470010 beq r2,r7,0x0019d2f0             #       If [Unit ID] == 0xFF (doesn't exist), continue (skip to next loop iteration)
0019d2b0: 00000000 nop
0019d2b4: 90a30047 lbu r3,0x0047(r5)                #       [Unit X Coordinate]
0019d2b8: 90820000 lbu r2,0x0000(r4)                #       ParameterArray[0]
0019d2bc: 00000000 nop
0019d2c0: 1462000b bne r3,r2,0x0019d2f0             #       If [Unit X Coordinate] != ParameterArray[0], continue (skip to next loop iteration)
0019d2c4: 00000000 nop
0019d2c8: 90a30048 lbu r3,0x0048(r5)                #       [Unit Y Coordinate]
0019d2cc: 90820002 lbu r2,0x0002(r4)                #       ParameterArray[2]
0019d2d0: 00000000 nop
0019d2d4: 14620006 bne r3,r2,0x0019d2f0             #       If [Unit Y Coordinate] != ParameterArray[0], continue (skip to next loop iteration)
0019d2d8: 00000000 nop
0019d2dc: 94a20048 lhu r2,0x0048(r5)                #       Load halfword with high byte = [Unit 0x49 flags], low byte = [Unit Y Coordinate]
0019d2e0: 90830001 lbu r3,0x0001(r4)                #       ParameterArray[1]
0019d2e4: 000213c2 srl r2,r2,0x0f                   #       [Higher Elevation] bit
0019d2e8: 10430005 beq r2,r3,0x0019d300             #       If [Higher Elevation] = ParameterArray[1], break out of the loop
0019d2ec: 00000000 nop 

0019d2f0: 24c60001 addiu r6,r6,0x0001               #       Increment [Unit index]
0019d2f4: 28c20015 slti r2,r6,0x0015                #       Check [Unit index] < 21
0019d2f8: 1440ffea bne r2,r0,0x0019d2a4
0019d2fc: 24a501c0 addiu r5,r5,0x01c0               #       Unit = UnitArray[Unit index + 1]
                                                    #   } while ([Unit index] < 21) 

0019d300: 03e00008 jr r31                           #   Return [Unit index]
0019d304: 00c01021 addu r2,r6,r0