Robotron: 2084: Routine at 52532

52532: Clear Colour Bar Column

Used by the routines at Handle_Homing_Enemy, Process_Entity_Record_Fast, Kill_Tracked_Enemy_Entity, Process_Cluster_Entity, Kill_Wall_Bouncing_Enemy and Process_Final_Phase_Enemy_Entity. Clears a seven-column, six-pixel-row strip from the screen pixel area at the column position held in Colour_Bar_Column, then jumps to PrintPlayerScore to redraw the column.
Clear_Colour_Bar_Column	52532	LD B,6	Prepare to clear six pixel rows of the colour bar column.
	52534	LD H,66	Prepare to clear six pixel rows of the colour bar column.
For each row, point to the target column and zero seven pixel cells.
Clear_Colour_Bar_Column_Row	52536	LD A,(50208)	Point to the colour bar column in the current pixel row.
	52539	LD L,A	Point to the colour bar column in the current pixel row.
	52540	XOR A	Zero seven pixel cells at the column position.
	52541	LD (HL),A
	52542	INC HL
	52543	LD (HL),A
	52544	INC HL
	52545	LD (HL),A
	52546	INC HL
	52547	LD (HL),A
	52548	INC HL
	52549	LD (HL),A
	52550	INC HL
	52551	LD (HL),A
	52552	INC HL
	52553	LD (HL),A
	52554	INC H	Advance to the next pixel row and repeat until all six are cleared.
	52555	DJNZ Clear_Colour_Bar_Column_Row
	52557	JP PrintPlayerScore	Jump to PrintPlayerScore to redraw the score display column.