Routines
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42635: Run Game
Used by the routine at LeaveRoomToWest.
The main game loop. The first call builds the objects of the room. Every pass through RunGame_Frame is one frame: each object is updated, the visible objects are sorted and drawn, the screen is refreshed and the panel is updated.
After the first pass
run-game
Build the objects of the room.
RunGame 42635 CALL BuildRoomObjects Call BuildRoomObjects.
This entry point is used by the routine at GameOver.
Give every object a chance to update itself.
RunGame_Frame 42638 LD IX,23432 Point IX at PlayerBottomObject.
RunGame_NextObject 42642 LD SP,61696 Set the stack pointer to ReversedByteTable.
42645 LD HL,42688 Point HL at RunGame_ObjectUpdated.
42648 PUSH HL Stash the return address on the stack.
42649 LD A,(IX+24) Fetch the width of the sprite.
42652 LD (IX+28),A Store it as the previous width.
42655 LD A,(IX+25) Fetch the height of the sprite.
42658 LD (IX+29),A Store it as the previous height.
42661 LD A,(IX+26) Fetch the pixel x position of the sprite.
42664 LD (IX+30),A Store it as the previous x position.
42667 LD A,(IX+27) Fetch the pixel y position of the sprite.
42670 LD (IX+31),A Store it as the previous y position.
This entry point is used by the routine at HandleLastAppearingSparkle.
Jump to the update routine for the sprite.
RunGame_UpdateObject 42673 LD L,(IX+0) Fetch the sprite number into L.
42676 LD BC,42986 Point BC at ObjectUpdateRoutines.
This entry point is used by the routines at SetPlayerSpeed and DrawObjectsInOrder.
RunGame_JumpToHandler 42679 LD H,0 Clear the high byte of HL.
42681 ADD HL,HL Double the sprite number.
42682 ADD HL,BC Add the address of the table.
42683 LD A,(HL) Fetch the low byte of the routine.
42684 INC HL Move on to the high byte.
42685 LD H,(HL) Fetch the high byte of the routine.
42686 LD L,A Put the low byte in L.
42687 JP (HL) Jump to the update routine.
Stir RandomSeed2 from the refresh register.
RunGame_ObjectUpdated 42688 LD A,R Fetch the refresh register.
42690 LD C,A Copy it to C.
42691 LD A,(23301) Fetch RandomSeed2.
42694 ADD A,C Add the refresh register to it.
42695 LD (23301),A Set RandomSeed2.
Move on to the next object.
42698 LD BC,32 Move IX on by 0032 bytes.
42701 ADD IX,BC
42703 PUSH IX Copy IX to HL (using the stack).
42705 POP HL
42706 LD BC,25224 Point BC at UnusedAfterObjects.
42709 AND A Subtract UnusedAfterObjects from HL.
42710 SBC HL,BC
42712 JR NC,RunGame_FinishFrame Jump to RunGame_FinishFrame if there are no more objects.
42714 JR RunGame_NextObject Jump to RunGame_NextObject.
Stir RandomSeed2 from the ROM byte at FrameCounter.
RunGame_FinishFrame 42716 LD HL,(23298) Fetch FrameCounter.
42719 INC HL Move on to the next address.
42720 LD (23298),HL Set FrameCounter.
42723 LD A,(23301) Fetch RandomSeed2.
42726 ADD A,(HL) Add the byte of ROM.
42727 ADD A,L Add the low byte of the address.
42728 ADD A,H Add the high byte of the address.
42729 LD (23301),A Set RandomSeed2.
42732 LD HL,23314 Point HL at RoomFlags.
42735 SET 0,(HL) Set bit 0 of RoomFlags.
Draw the room into the screen buffer.
42737 CALL ListObjectsToDraw Call ListObjectsToDraw.
42740 CALL DrawChangedObjects Call DrawChangedObjects.
42743 LD A,(23332) Fetch GameOverFlag.
42746 AND A Jump to RunGame_GameOver if it is set.
42747 JP NZ,RunGame_GameOver
Slow the game down when few objects are drawn.
42750 LD A,(23326) Fetch ObjectsDrawn.
42753 NEG Negate it.
42755 ADD A,6 Add 6.
42757 LD B,A Keep the number of delay loops in B.
42758 JP M,RunGame_UpdateDisplay Jump to RunGame_UpdateDisplay if there were more than 6 objects.
42761 JR Z,RunGame_UpdateDisplay Jump to RunGame_UpdateDisplay if there were exactly 6 objects.
RunGame_Delay 42763 LD HL,768 Set the delay counter to 768.
RunGame_DelayLoop 42766 DEC HL Decrease the delay counter.
42767 LD A,L Jump to RunGame_DelayLoop until the delay counter is zero.
42768 OR H
42769 JR NZ,RunGame_DelayLoop
42771 DJNZ RunGame_Delay Jump to RunGame_Delay until all of the delay loops are done.
Update the status panel.
RunGame_UpdateDisplay 42773 CALL UpdateLightYears Call UpdateLightYears.
42776 LD A,(23319) Fetch RedrawPanelFlag.
42779 AND A Jump to RunGame_Continue if it is not set.
42780 JR Z,RunGame_Continue
42782 CALL DrawPanel Call DrawPanel.
42785 CALL UpdatePanel Call UpdatePanel.
RunGame_RefreshScreen 42788 XOR A Write 0 to RedrawPanelFlag.
42789 LD (23319),A
42792 CALL UpdateScreen Call UpdateScreen.
42795 CALL ResetWipeFlags Call ResetWipeFlags.
Check whether the game is paused and whether the player is alive.
RunGame_Continue 42798 CALL PauseGame Call PauseGame.
42801 LD IX,23432 Point IX at PlayerBottomObject.
42805 LD A,(IX+0) Fetch the sprite number of the player.
42808 OR (IX+32) Combine it with the sprite number of PlayerTopObject.
42811 JP Z,StartLife Jump to StartLife if both are zero.
42814 JP RunGame_Frame Jump to RunGame_Frame.
Only refresh the screen if the panel needs to be redrawn.
RunGame_GameOver 42817 LD A,(23319) Fetch RedrawPanelFlag.
42820 AND A Jump to RunGame_Continue if it is not set.
42821 JR Z,RunGame_Continue
42823 JR RunGame_RefreshScreen Jump to RunGame_RefreshScreen.
View the equivalent code in;
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