Routines
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D307: Action Controls
Used by the routine at D2D9.
On entry A will contain one of;
Value Bits Door
10 00010000 Door 2
11 00010001 Door 3
12 00010010 Door 1
This is written to Controls_Byte, and then decoded into writing a 01 02 or 03 to Hit to represent which door has been shot at. This routine also writes 01 to One, Two and Three to represent the same thing. Before returning, HL is set to the screen location for displaying the shot mask/ shot image in the centre of the door.
Action_Controls D307 LD HL,$D306 Writes A to Controls_Byte and sets HL=Hit.
D30A LD (HL),A
D30B LD HL,$D300
D30E LD A,C
D30F BIT 0,A If "3" was pressed then jump to Shot_Three (a check for if bit 0 is set).
D311 JR NZ,Shot_Three
D313 BIT 1,A If "1" was pressed then jump to Shot_One (a check for if bit 1 is set).
D315 JR NZ,Shot_One
Handles settings flags and shot drawing location for door 2.
Shot_Two D317 LD A,($D303) If Two is not zero then return.
D31A AND A
D31B RET NZ
D31C LD ($D304),A Sets the other two door flags to zero (Three and One).
D31F LD ($D305),A
D322 INC A Indicate the the middle door is being shot at (write 01 to Two and 02 to Hit).
D323 LD ($D303),A
D326 LD A,$02
D328 LD (HL),A
D329 LD HL,$D8AC Increase D8AC by one.
D32C INC (HL)
D32D LD HL,$482F Sets the screen location for this shot to 482F and stash it.
D330 PUSH HL
D331 CALL Draw_GunShot_Mask Draw the shot mask.
D334 POP HL Grab the screen location again, and now draw the shot.
D335 CALL Draw_GunShot
D338 JP Shot_Sound_01_Alias Jump to Shot_Sound_01_Alias.
Handles settings flags and shot drawing location for door 3.
Shot_Three D33B LD A,($D304) If Three is not zero then return.
D33E AND A
D33F RET NZ
D340 LD ($D303),A Sets the other two door flags to zero (Two and One).
D343 LD ($D305),A
D346 INC A Indicate the the right door is being shot at (write 01 to Three and 03 to Hit).
D347 LD ($D304),A
D34A LD A,$03
D34C LD (HL),A
D34D LD HL,$D8AC Shifts the value at D8AC to the left with bit 7 moved to the carry flag and bit 0 reset (zeroed).
D350 SLA (HL)
D352 LD HL,$483A Sets the screen location for this shot to 483A and stash it.
D355 PUSH HL
D356 CALL Draw_GunShot_Mask Draw the shot mask.
D359 POP HL Grab the screen location again, and now draw the shot.
D35A CALL Draw_GunShot
D35D JP Shot_Sound_02_Alias Jump to Shot_Sound_02_Alias.
Handles settings flags and shot drawing location for door 1.
Shot_One D360 LD A,($D305) If One is not zero then return.
D363 AND A
D364 RET NZ
D365 LD ($D303),A Sets the other two door flags to zero (Two and Three).
D368 LD ($D304),A
D36B INC A Indicate the the left door is being shot at (write 01 to One and 01 to Hit).
D36C LD ($D305),A
D36F LD A,$01
D371 LD (HL),A
D372 LD HL,$D8AC Shifts the value at D8AC to the left with bit 7 moved to the carry flag and bit 0 reset (zeroed).
D375 SLA (HL)
D377 LD HL,$4824 Sets the screen location for this shot to 4824 and stash it.
D37A PUSH HL
D37B CALL Draw_GunShot_Mask Draw the shot mask.
D37E POP HL Grab the screen location again, and now draw the shot.
D37F CALL Draw_GunShot
D382 CALL Shot_Sound_03_Alias Jump to Shot_Sound_03_Alias.
D385 RET Return.
Sets the flag for indicating "right" has been pressed by the player.
Set_Right D386 LD HL,$D301 Write 01 to Right and return.
D389 LD (HL),$01
D38B RET
Sets the flag for indicating "left" has been pressed by the player.
Set_Left D38C LD HL,$D302 Write 01 to Left and return.
D38F LD (HL),$01
D391 RET
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