Routines
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36692: Damage Ship
Used by the routine at ApplyCollisionEffects.
Damages the player's ship. A ship that has just been hit cannot be hit again for a few frames. Each hit changes the colour of the damage indicator, and the third hit destroys the ship.
Input
IX Address of the object that was hit
DamageShip 36692 LD A,(IX+23) Fetch the second set of flags of the object.
36695 AND %11110000 Keep the top four bits.
36697 RET NZ Return if they are not zero.
36698 LD A,(IX+23) Fetch the second set of flags again.
36701 ADD A,240 Set the top four bits.
36703 LD (IX+23),A Store them.
36706 LD A,(35183) Fetch the flag from 35183.
36709 AND A Test it.
36710 JR Z,DamageShip_Hit Jump to DamageShip_Hit if it is zero.
36712 LD A,C Fetch the collision effects.
36713 AND %11111110 Clear bit 0.
36715 CP 80 Jump to DamageShip_Hit if the remaining effects are not 80.
36717 JR NZ,DamageShip_Hit
36719 SET 5,(IX+16) Set bit 5 of the flags of the object.
36723 CALL PlayHitSound Play the explosion sound.
This entry point is used by the routines at CheckBeamHit and CheckMapObjectCollisions.
DamageShip_Hit 36726 LD A,(35183) Fetch the flag from 35183.
36729 AND A Test it.
36730 RET NZ Return if it is set.
36731 LD A,(36691) Fetch the explosion counter from 36691.
36734 AND A Test it.
36735 RET NZ Return if the ship is exploding.
36736 CALL PlayHitSound Play the explosion sound.
36739 LD A,(36803) Fetch the damage counter from 36803.
36742 INC A Add one and store it.
36743 LD (36803),A
36746 PUSH BC Stash BC on the stack.
36747 LD B,71 Use bright white for the first hit...
36749 AND A Test the counter.
36750 JR Z,DamageShip_Colour Jump to DamageShip_Colour if it is zero.
36752 LD B,70 Use bright yellow for the second hit...
36754 CP 1 Jump to DamageShip_Colour if the counter is one.
36756 JR Z,DamageShip_Colour
36758 LD B,67 Otherwise use bright magenta.
DamageShip_Colour 36760 CP 3 Jump to DamageShip_Indicator if the counter is not three.
36762 JR NZ,DamageShip_Indicator
36764 LD A,1 Set the explosion counter to one.
36766 LD (36691),A
36769 LD B,0 Use black for the damage indicator.
DamageShip_Indicator 36771 LD A,B Store the attribute in the data at DamageShip_Attribute.
36772 LD (36801),A
36775 LD HL,3888 Set the position of the damage indicator.
36778 LD A,(51740) Fetch the flag from 51740.
36781 AND A Test it.
36782 JR Z,DamageShip_Draw Jump to DamageShip_Draw if it is zero.
36784 LD HL,4016 Move the damage indicator.
DamageShip_Draw 36787 LD DE,36799 Use the data at DamageShip_Attribute.
36790 CALL FillAttributes Draw the damage indicator.
36793 POP BC Bring BC back off the stack.
36794 RET Return.
36795 DEFB 48,15,176,15
DamageShip_Attribute 36799 DEFB 4,2,0,201,0
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