Routines
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24967: Describe Location
Used by the routines at GameLoop, ObeyCommand, OfferAnotherGame and RedrawLocation.
Prints where the player is, what is here, and which ways lead out. Bank 6 supplies the long text for rooms below 102, and it opens "welcome to Blizzard Pass by Alan Cox. This program is dedicated to Hawkwind. Any resemblance between the characters in the game and your mother in law is total coincidence". A dark room says so and lists nothing. The text is underlined before the cursor is put back for the prompt.
Remember the cursor, and choose a row. Pictures use row 13 so the text sits under the illustration.
DescribeLocation 24967 LD A,255 The description pauses at the bottom of the picture.
24969 LD (24966),A
24972 LD A,46 A full stop makes the first letter a capital.
24974 LD (23451),A
24977 LD HL,(23433) Save the cursor so it can be restored under the rule.
24980 PUSH HL
24981 LD HL,(23431)
24984 PUSH HL
24985 CALL ClearLowerRows Call ClearLowerRows to clear the text rows.
24988 LD A,(26326) Pictures off forces row 0.
24991 OR A
24992 LD A,13 Pictures on use row 13.
24994 JR NZ,DescribeLocation_Row
24996 XOR A
DescribeLocation_Row 24997 LD (23433),A Remember that row.
25000 CALL HomeRow Call HomeRow and home the cursor.
25003 XOR A
25004 LD (23434),A
25007 LD A,(23944) Darkness skips the description.
25010 OR A
25011 JR Z,DescribeLocation_Text
25013 LD A,25 Message 25: it is dark, you cannot see.
25015 CALL PrintSystemMessage
25018 JP DescribeLocation_Rule Jump to DescribeLocation_Rule to underline the description.
Rooms under 102 with pictures switched off are read from bank 6. Every other room uses the tokenised text at TokenisedLocations.
DescribeLocation_Text 25021 LD HL,30158 The default text is the tokenised list at TokenisedLocations.
25024 LD A,(23943) Rooms at or above 102 have no long description.
25027 CP 102
25029 JR NC,DescribeLocation_Print
25031 LD A,(26326) Pictures on also keep the short text.
25034 OR A
25035 LD A,(23943)
25038 JR NZ,DescribeLocation_Print
DescribeLocation_Page 25040 PUSH AF page RAM bank 6 in at 49152, keeping the 48K ROM.
25041 LD A,6
25043 CALL PageBank
25046 LD HL,49152 The long description starts at 49152.
25049 POP AF
DescribeLocation_Print 25050 LD (23439),A Store the room as the message number.
25053 CALL PrintMessage Call PrintMessage to print that description.
25056 XOR A page RAM bank 0 in at 49152, keeping the 48K ROM.
25057 CALL PageBank
25060 XOR A No object has been listed yet. Start the scan at ObjectLocations.
25061 LD (23418),A
25064 LD HL,24010
25067 LD B,A
List every object whose location byte is this room. The first one is introduced with a colon.
DescribeLocation_Objects 25068 LD A,(23943) This object is in the current room.
25071 CP (HL)
25072 JR NZ,DescribeLocation_Next
25074 LD A,(23418) Another object in the same room skips the introduction.
25077 OR A
25078 JR NZ,DescribeLocation_Seen
25080 LD A,B An index below 70 is named without the introduction.
25081 CP 70
25083 JR C,DescribeLocation_Name
25085 XOR A Message 0: ". You can see ".
25086 PUSH BC
25087 CALL PrintSystemMessage
25090 POP BC
25091 LD A,32 Print a space and a colon.
25093 CALL PlotCharacter
25096 LD A,58
25098 CALL PlotCharacter
25101 LD A,45 Print a dash and a space.
25103 CALL PlotCharacter
25106 LD A,32
25108 CALL PlotCharacter
DescribeLocation_Seen 25111 LD A,1 Remember that an object was listed.
25113 LD (23418),A
DescribeLocation_Name 25116 LD A,B Call PrintObjectName to print this object's name.
25117 CALL PrintObjectName
DescribeLocation_Next 25120 LD A,(23949) Stop at the object total.
25123 CP B
25124 JR Z,DescribeLocation_Exits
25126 INC B The next location byte belongs to the next object.
25127 INC HL
25128 JR DescribeLocation_Objects
After the objects, list the directions that leave this room.
DescribeLocation_Exits 25130 LD A,(23418) An empty list needs no tidy-up.
25133 OR A
25134 JR Z,DescribeLocation_Moves
25136 LD A,12 Two backspaces remove the comma after the last object.
25138 CALL PlotCharacter
25141 LD A,12
25143 CALL PlotCharacter
DescribeLocation_Moves 25146 CALL FindExits Call FindExits to find this room's exits.
25149 INC HL No exits means no "you can go" line.
25150 BIT 7,(HL)
25152 JR NZ,DescribeLocation_Rule
25154 LD A,13 Message 13: ". You can go".
25156 CALL PrintSystemMessage
DescribeLocation_Exit 25159 LD A,(HL) Bit 7 ends the list of directions.
25160 BIT 7,A
25162 JR NZ,DescribeLocation_Stop
25164 CALL PrintSystemMessage Print the direction and step to the next exit.
25167 INC HL
25168 INC HL
25169 JR DescribeLocation_Exit
DescribeLocation_Stop 25171 LD A,12 Rub out the last comma.
25173 CALL PlotCharacter
25176 LD A,12
25178 CALL PlotCharacter
25181 LD A,46 Finish with a full stop.
25183 CALL PlotCharacter
Underline the description and restore the cursor the caller had saved.
DescribeLocation_Rule 25186 XOR A The description is finished, so scrolling may resume.
25187 LD (24966),A
25190 LD A,13 Start the rule on a new line.
25192 CALL PrintCharacter
25195 LD A,(26326) Pictures on keep the row the text already reached.
25198 OR A
25199 LD A,(23433)
25202 JR NZ,DescribeLocation_Bottom
25204 LD A,15 Pictures off force row 15.
25206 LD (23433),A
25209 XOR A Home the cursor and keep that row.
25210 LD (23434),A
25213 CALL HomeRow
25216 LD A,15
DescribeLocation_Bottom 25218 INC A The rule sits on the row under the text.
25219 LD (23447),A
25222 LD B,42 Forty-two underscores fill the row.
DescribeLocation_Bar 25224 LD A,95 Print one underscore.
25226 CALL PlotCharacter
25229 DJNZ DescribeLocation_Bar
25231 LD A,13 Close the rule with ENTER.
25233 CALL PrintCharacter
25236 POP HL Restore the cursor saved before the description from the stack.
25237 LD (23431),HL
25240 POP HL
25241 LD (23433),HL
25244 RET Return.
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