View source for Check if another unit is on the same Tile

 Duplicated here [[Find_Unit_at_Specified_Coordinates]] (programmers friendly formatting)
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 Parameters : r4 = X coordinate
              r5 = Y coordinates
              r6 = Elevation (0x00 or 0x01)	
              r7 = Preset value - specify conditions to check
                    0x80 - check for mountable chocobo
                    0x41 - check for crystal and treasure
                    0x10 - check for transparent unit
                    0x00 - check for a unit without conditions	
 					
 Returns : r2 = -0x02 if coordinates are invalid			  
           r2 = -0x01 if there's no unit matching r7 at coordinates
           r2 = Unit ID if there's a unit matching r7
 ------------------------------------------------------------------------------
 r4 = X r5 = Y r6 = elevation r7 = preset value
 0017dca8: 27bdffd0 addiu r29,r29,0xffd0
 0017dcac: afb40020 sw r20,0x0020(r29)       |
 0017dcb0: 0080a021 addu r20,r4,r0           |{{f/std|<nowiki>r20 = Attacker current action target  X Coordinate</nowiki>}}
 0017dcb4: afb50024 sw r21,0x0024(r29)       |
 0017dcb8: 00a0a821 addu r21,r5,r0           |{{f/std|<nowiki>r21 = Attacker current action target  y Coordinate</nowiki>}}
 0017dcbc: afb60028 sw r22,0x0028(r29)       |
 0017dcc0: 00c0b021 addu r22,r6,r0           |{{f/std|<nowiki>r22 =  Attacker current action target map elevation</nowiki>}}
 0017dcc4: afb20018 sw r18,0x0018(r29)       |
 0017dcc8: 00e09021 addu r18,r7,r0           |{{f/std|<nowiki>r18 = Preset Value</nowiki>}}
 0017dccc: afbf002c sw r31,0x002c(r29)       |
 0017dcd0: afb3001c sw r19,0x001c(r29)       |
 0017dcd4: afb10014 sw r17,0x0014(r29)       |
 0017dcd8: 0680002c bltz r20,0x0017dd8c      {{f/Cond|<nowiki>If Target X coordinate >= 0</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}}  {{f/std|<nowiki>(branch to a jump to end with r2 = -0x02)</nowiki>}}
 0017dcdc: afb00010 sw r16,0x0010(r29)            |{{f/store|<nowiki>  </nowiki>}}
 0017dce0: 3c03800e lui r3,0x800e                 |
 0017dce4: 90634e9c lbu r3,0x4e9c(r3)             |{{f/load|<nowiki>r3 = Map Max X Coordinate</nowiki>}}
 0017dce8: 00000000 nop                           |
 0017dcec: 0283102a slt r2,r20,r3                 |{{f/std|<nowiki>r2 = 0x01 if Unit X coord. < Map max X</nowiki>}}
 0017dcf0: 10400026 beq r2,r0,0x0017dd8c          {{f/Cond|<nowiki>If Unit X is in the map</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}} {{f/std|<nowiki>(branch to a jump to end with r2 = -0x02)</nowiki>}}
 0017dcf4: 00000000 nop                               |{{f/std|<nowiki> </nowiki>}}
 0017dcf8: 06a0006a bltz r21,0x0017dea4               {{f/Cond|<nowiki>If Unit Y coord. >= 0x00</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}} with r2 = -0x02
 0017dcfc: 2402fffe addiu r2,r0,-0x0002               |{{f/std|<nowiki>r2 = -0x02</nowiki>}}
 0017dd00: 3c02800e lui r2,0x800e                         |{{f/std|<nowiki> </nowiki>}}
 0017dd04: 90424ea0 lbu r2,0x4ea0(r2)                     |{{f/load|<nowiki>r4 =Map Max Y Coordinate</nowiki>}}
 0017dd08: 00000000 nop                                   |
 0017dd0c: 02a2102a slt r2,r21,r2                         |{{f/std|<nowiki>r2 = 0x01 if Unit Y coord < map max Y</nowiki>}}
 0017dd10: 1040001e beq r2,r0,0x0017dd8c                  {{f/Cond|<nowiki>If unit is in the map</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}} {{f/std|<nowiki>(branch to a jump to end with r2 = -0x02)</nowiki>}}
 0017dd14: 2ec20002 sltiu r2,r22,0x0002                       |{{f/std|<nowiki>r2 = 0x01 if Unit Map elevation < 0x02</nowiki>}}
 0017dd18: 1040001c beq r2,r0,0x0017dd8c                      {{f/Cond|<nowiki>If Unit Map Elevation  < 0x02</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}} {{f/std|<nowiki>(branch to a jump to end with r2 = -0x02)</nowiki>}}
 0017dd1c: 02a30018 mult r21,r3                                   |{{f/std|<nowiki>Max X * Y</nowiki>}}
 0017dd20: 00161200 sll r2,r22,0x08                               |{{f/std|<nowiki>r2 = Map elevation * 0x100</nowiki>}}
 0017dd24: 00001812 mflo r3                                       |{{f/std|<nowiki>r3 = Map Max X *Unit  Y coord (Y modified)</nowiki>}}
 0017dd28: 00431021 addu r2,r2,r3                                 |{{f/std|<nowiki>r2 = Y modified + Map elevation * 0x100</nowiki>}}
 0017dd2c: 00541021 addu r2,r2,r20                                |{{f/std|<nowiki>r2 = Tile ID</nowiki>}} {{f/std|<nowiki>r2 = Y modified + X + Map elevation * 0x100</nowiki>}}
 0017dd30: 000210c0 sll r2,r2,0x03                                |{{f/std|<nowiki>r2=Tile ID * 8 (size of tiles data)</nowiki>}}
 0017dd34: 3c038019 lui r3,0x8019                                 |
 0017dd38: 2463f8cc addiu r3,r3,-0x0734                           |{{f/std|<nowiki>r3 = 0x8018f8cc (start of tiles data)</nowiki>}}
 0017dd3c: 00431821 addu r3,r2,r3                                 |{{f/adr|<nowiki>r3 = Target tile data</nowiki>}}
 0017dd40: 90620006 lbu r2,0x0006(r3)                             |{{f/load|<nowiki>r2 = Tile data byte 0x06 (shadow and targetable)</nowiki>}}
 0017dd44: 00000000 nop                                           |
 0017dd48: 30420003 andi r2,r2,0x0003                             |{{f/std|<nowiki>r2 <> 0x00 if tile is unselectable and/or not targetable</nowiki>}}
 0017dd4c: 14400055 bne r2,r0,0x0017dea4                          {{f/Cond|<nowiki>If tile is targetable/selectable</nowiki>}} /Else branch to {{f/loc|<nowiki>End</nowiki>}} With r2 = -0x02
 0017dd50: 2402fffe addiu r2,r0,0xfffe                            |{{f/std|<nowiki>r2 = -0x02</nowiki>}}
 0017dd54: 30e20002 andi r2,r7,0x0002                                 |{{f/std|<nowiki> r2 <> 0x00 if preset value has 0x02 enabled</nowiki>}} {{f/std|<nowiki>Slope check ? </nowiki>}}
 0017dd58: 10400010 beq r2,r0,0x0017dd9c                              {{f/Cond|<nowiki>if r7 contains 0x02 flag</nowiki>}} /Else branch to loop
 0017dd5c: 00008821 addu r17,r0,r0                                    |{{f/std|<nowiki>r17 = 0x00 (counter for next loop)</nowiki>}}
 0017dd60: 90620003 lbu r2,0x0003(r3)                                     |{{f/load|<nowiki>r2 = Load Tile Height + Depth byte</nowiki>}}
 0017dd64: 00000000 nop                                                   |
 0017dd68: 304200e0 andi r2,r2,0x00e0                                     |{{f/std|<nowiki>r2 <> 0 if tile has depth</nowiki>}}
 0017dd6c: 1440004d bne r2,r0,0x0017dea4                                  {{f/Cond|<nowiki>If tile has no depth</nowiki>}} /Else Branch to {{f/loc|<nowiki>End</nowiki>}} if Tile has water (with r2 = -0x02)
 0017dd70: 2402fffe addiu r2,r0,0xfffe                                    |{{f/std|<nowiki>r2 = -0x02</nowiki>}}
 0017dd74: 90620003 lbu r2,0x0003(r3)                                         |{{f/load|<nowiki>r2 = Load Tile Height + Depth byte</nowiki>}}
 0017dd78: 00000000 nop                                                       |
 0017dd7c: 3042001f andi r2,r2,0x001f                                         |{{f/std|<nowiki>r2 = Target height/2 only</nowiki>}}
 0017dd80: 28420003 slti r2,r2,0x0003                                         |{{f/std|<nowiki>r2 = 0x01 if slope < 0x03</nowiki>}}
 0017dd84: 14400006 bne r2,r0,0x0017dda0                                      {{f/Cond|<nowiki>If slope >= 0x03 (not reachable ?)</nowiki>}} /Else branch to unit loop
 0017dd88: 00009821 addu r19,r0,r0                                            |{{f/std|<nowiki>r19 = 0x00 (some counter for next loop)</nowiki>}}
 0017dd8c: 0805f7a9 j 0x0017dea4                  {{f/Cond|<nowiki>E</nowiki>}}     {{f/Cond|<nowiki>E</nowiki>}} {{f/Cond|<nowiki>E</nowiki>}}                {{f/jump|<nowiki>Jump to end (r2 = -0x02)</nowiki>}}
 0017dd90: 2402fffe addiu r2,r0,-0x0002                                           |{{f/std|<nowiki>r2 = -0x02</nowiki>}}
 0017dd94: 0805f7a9 j 0x0017dea4                  {{f/std|<nowiki> Weird section - landing site of a branch command at 0x17dd94</nowiki>}}
 0017dd98: 3082001f andi r2,r4,0x001f             {{f/std|<nowiki> routine will return r2 = ridden unit</nowiki>}}
 0017dd9c: 00009821 addu r19,r0,r0                                {{f/Cond|<nowiki>Else</nowiki>}} {{f/std|<nowiki>r19 =0x00 (loop counter, refers to unit ID)</nowiki>}}
 0017dda0: 3c028019 lui r2,0x8019                                     {{f/bloop|<nowiki>LOOP (Each unit) </nowiki>}}
 0017dda4: 244208cc addiu r2,r2,0x08cc                                    |{{f/std|<nowiki>r2 = 0x801908cc (start of unit ID)</nowiki>}}
 0017dda8: 02628021 addu r16,r19,r2                                       |{{f/std|<nowiki>r16 = Start of unit data + unit offset</nowiki>}}
 0017ddac: 92030001 lbu r3,0x0001(r16)                                    |{{f/load|<nowiki>r3 = Unit ID</nowiki>}}
 0017ddb0: 340200ff ori r2,r0,0x00ff                                      |{{f/std|<nowiki>r2 = 0xff</nowiki>}}
 0017ddb4: 10620036 beq r3,r2,0x0017de90                                  {{f/Cond|<nowiki>If unit Exist</nowiki>}} {{f/Cond|<nowiki>Else branch to </nowiki>{{f/loc|<nowiki>next unit</nowiki>}}<nowiki> (loop)</nowiki>}}
 0017ddb8: 32420051 andi r2,r18,0x0051                                        |{{f/std|<nowiki>r2 = Preset and 0x51 (0x40 crystal, 0x10 transparent, 0x01 treasure)</nowiki>}}
 0017ddbc: 10400018 beq r2,r0,0x0017de20                                      {{f/Cond|<nowiki>If Preset checks crystal/transparent treasure</nowiki>}} /Else Branch to chocobo section
 0017ddc0: 32420040 andi r2,r18,0x0040                                            |{{f/std|<nowiki>r2 = Preset and 0x40 (crystal check)</nowiki>}}
 0017ddc4: 10400007 beq r2,r0,0x0017dde4                                          {{f/Cond|<nowiki>If preset checks crystal</nowiki>}} /Else branch to treasure section
 0017ddc8: 32420001 andi r2,r18,0x0001                                            |{{f/std|<nowiki>r2 = preset and 0x01 (treasure check)</nowiki>}}
 0017ddcc: 92020058 lbu r2,0x0058(r16)                                                |{{f/load|<nowiki>r2 = Units current status set 1</nowiki>}}
 0017ddd0: 00000000 nop                                                               |
 0017ddd4: 30420040 andi r2,r2,0x0040                                                 |{{f/std|<nowiki>r2 = 0x40 if unit has crystal</nowiki>}}
 0017ddd8: 14400012 bne r2,r0,0x0017de24                                              {{f/Cond|<nowiki>If unit don't have crystal </nowiki>}} /Else branch to chocobo section
 0017dddc: 32420080 andi r2,r18,0x0080                                                |{{f/std|<nowiki>r2 =  0x80 if preset check chocobo / Else 0x00</nowiki>}}
 0017dde0: 32420001 andi r2,r18,0x0001                                                    |{{f/std|<nowiki>r2 = 0x01 if preset contains treasure check</nowiki>}}
 0017dde4: 10400007 beq r2,r0,0x0017de04                                          {{f/Cond|<nowiki>Else if preset check Treasure</nowiki>}} /Else branch to transparent section
 0017dde8: 32420010 andi r2,r18,0x0010                                            |{{f/std|<nowiki>r2 = 0x10 if preset checks transparent</nowiki>}}
 0017ddec: 92020059 lbu r2,0x0059(r16)                                                |{{f/load|<nowiki>r2 = Unit status set 2</nowiki>}}
 0017ddf0: 00000000 nop                                                               |
 0017ddf4: 30420001 andi r2,r2,0x0001                                                 |{{f/std|<nowiki>r2 = 0x01 if unit is treasure</nowiki>}}
 0017ddf8: 1440000a bne r2,r0,0x0017de24                                              {{f/Cond|<nowiki>If unit is not treasure</nowiki>}} /Else branch to chocobo section
 0017ddfc: 32420080 andi r2,r18,0x0080                                                |{{f/std|<nowiki>r2 =  0x80 if preset check chocobo / Else 0x00</nowiki>}}
 0017de00: 32420010 andi r2,r18,0x0010                                                    |{{f/std|<nowiki>r2 = 0x10 if preset checks transparent</nowiki>}}
 0017de04: 10400022 beq r2,r0,0x0017de90                                          {{f/Cond|<nowiki>Else if preset check transparent</nowiki>}} /Else goto {{f/loc|<nowiki>next unit</nowiki>}} (loop) - fail to find crystal/treasure while looking for it
 0017de08: 00000000 nop                                                               |
 0017de0c: 9202005a lbu r2,0x005a(r16)                                                |{{f/load|<nowiki>r2 = units current status set 3</nowiki>}}
 0017de10: 00000000 nop                                                               |
 0017de14: 30420010 andi r2,r2,0x0010                                                 |{{f/std|<nowiki>r2 = 0x10 is unit has transparent /else 0x00</nowiki>}}
 0017de18: 1040001d beq r2,r0,0x0017de90                                              {{f/Cond|<nowiki>If unit has transparent</nowiki>}} /Else goto {{f/loc|<nowiki>next unit</nowiki>}} (loop) - fail to find transparent  while looking for it
 0017de1c: 00000000 nop                                                               |
 0017de20: 32420080 andi r2,r18,0x0080                                        {{f/Cond|<nowiki>ELSE  - Not checking for status or Unit has the status checked for</nowiki>}} {{f/std|<nowiki> r2 = 0x80 if checking chocobo</nowiki>}}
 0017de24: 10400005 beq r2,r0,0x0017de3c                                      {{f/Cond|<nowiki>If Checking for chocobo</nowiki>}} /Else branch to 
 0017de28: 00000000 nop                                                           |{{f/std|<nowiki> </nowiki>}}
 0017de2c: 0c05d0f2 jal 0x001743c8                                                |{{f/jal|Chocobo_Check|<nowiki>Chocobo_Check</nowiki>}}  returns r2 = 0x00 if not chocobo/not mountable
 0017de30: 02002021 addu r4,r16,r0                                                |{{f/std|<nowiki>r4 = unit data pointer</nowiki>}}
 0017de34: 10400016 beq r2,r0,0x0017de90                                          {{f/Cond|<nowiki>If unit is a mountable chocobo (may be already ridden)</nowiki>}} /Else Go to {{f/loc|<nowiki>next unit</nowiki>}} (loop)
 0017de38: 00000000 nop                                                               |{{f/std|<nowiki> </nowiki>}}
 0017de3c: 92020047 lbu r2,0x0047(r16)                                        {{f/Cond|<nowiki>Else</nowiki>}} {{f/load|<nowiki>r2 = Unit X coord.</nowiki>}}  (You're here if you check nothing or have found what you're checking)
 0017de40: 00000000 nop                                                       |
 0017de44: 14540012 bne r2,r20,0x0017de90                                     {{f/Cond|<nowiki>If Unit X coord = Attacker X target coord.</nowiki>}} /Else goto {{f/loc|<nowiki>next unit</nowiki>}} (loop) 
 0017de48: 00000000 nop                                                           |{{f/std|<nowiki> </nowiki>}}
 0017de4c: 92020048 lbu r2,0x0048(r16)                                            |{{f/load|<nowiki>r2 = Units Y coord.</nowiki>}}
 0017de50: 00000000 nop                                                           |
 0017de54: 1455000e bne r2,r21,0x0017de90                                         {{f/Cond|<nowiki>If Unit Y coord = Attacker Y target coord.</nowiki>}} /Else goto {{f/loc|<nowiki>next unit</nowiki>}} (loop) 
 0017de58: 00000000 nop                                                               |{{f/std|<nowiki> </nowiki>}}
 0017de5c: 96020048 lhu r2,0x0048(r16)                                                |{{f/load|<nowiki>r2 = Unit's Y + Map elevation/Facing (halfword)</nowiki>}}
 0017de60: 00000000 nop                                                               |
 0017de64: 000213c2 srl r2,r2,0x0f                                                    |{{f/std|<nowiki>r2 = higher bit of the halfword (elevation)</nowiki>}}
 0017de68: 14560009 bne r2,r22,0x0017de90                                             {{f/Cond|<nowiki> If unit elevation = Attacker target elevation</nowiki>}} /Else goto {{f/loc|<nowiki>next unit</nowiki>}} (loop) 
 0017de6c: 00000000 nop                                                                   |{{f/std|<nowiki> </nowiki>}}
 0017de70: 92040182 lbu r4,0x0182(r16)                                                    |{{f/load|<nowiki>r4 = Unit's mount data</nowiki>}}
 0017de74: 00000000 nop                                                                   |
 0017de78: 308200ff andi r2,r4,0x00ff                                                     |{{f/std|<nowiki>r4 = last byte of r4 (security check ?)</nowiki>}}
 0017de7c: 2c420080 sltiu r2,r2,0x0080                                                    |{{f/std|<nowiki>r2 = 0x01 if mount info < 0x80 - everything but "is riding")</nowiki>}}
 0017de80: 1040ffc4 beq r2,r0,0x0017dd94                                                  {{f/Cond|<nowiki>If Unit is not riding</nowiki>}} /Else branch (above) then jump to end with r2 = ID of ridden unit
 0017de84: 02201021 addu r2,r17,r0                                                            |{{f/std|<nowiki>r2 = counter (unit ID)</nowiki>}}
 0017de88: 0805f7a9 j 0x0017dea4                                                              {{f/jump|<nowiki>Jump to </nowiki>{{f/loc|<nowiki>End</nowiki>}}<nowiki> - abort looping</nowiki>}}
 0017de8c: 00000000 nop                                                                       |
 0017de90: 26310001 addiu r17,r17,0x0001                                  {{f/Cond|<nowiki>Else (unit don' exist or none of the checks find the good unit)</nowiki>}}
 0017de94: 2a220015 slti r2,r17,0x0015                                    |
 0017de98: 1440ffc1 bne r2,r0,0x0017dda0                              {{f/eloop|<nowiki>Loop (next unit)</nowiki>}}
 0017de9c: 267301c0 addiu r19,r19,0x01c0                                  |{{f/std|<nowiki>r19 = next unit data pointer</nowiki>}}
 0017dea0: 2402ffff addiu r2,r0,0xffff                                |{{f/std|<nowiki>r2 = -1 (unit doesn't exist)</nowiki>}}
 0017dea4: 8fbf002c lw r31,0x002c(r29)        END
 0017dea8: 8fb60028 lw r22,0x0028(r29)                                
 0017deac: 8fb50024 lw r21,0x0024(r29)                                
 0017deb0: 8fb40020 lw r20,0x0020(r29)                                
 0017deb4: 8fb3001c lw r19,0x001c(r29)                                
 0017deb8: 8fb20018 lw r18,0x0018(r29)                                
 0017debc: 8fb10014 lw r17,0x0014(r29)                                
 0017dec0: 8fb00010 lw r16,0x0010(r29)                                
 0017dec4: 27bd0030 addiu r29,r29,0x0030                              
 0017dec8: 03e00008 jr r31                                            
 0017decc: 00000000 nop
=== Return locations ===
 0017dc98: [[Get_ID_of_Unit_if_Tile_is_Targetable]]              r7 = 0x00 (just looking for Unit ID at location)
 0017fe48: [[Set_Rider/Mount%27s_X/Y_Data]]                        r7 = 0x80 (chocobo)
 0017fff0: [[Set_target_for_mounted_unit,_move_find_item/trap]]  r7 = 0x41 (Crystal - treasure)
 00180314: [[Set_map_Item/trap_data]]                            r7 = 0x10 (transparent) 
 00180578: [[Generate_Crystal_or_Treasure]]                      r7 = 0x41 (crystal - treasure)