Sherlock: Routine at 62608

62608: Drawing Fill

Used by the routine at Drawing. Flood-fills from the pen and stores the ink at 62987.
DrawingFill	62608	LD (62987),A	Store the ink, save the pen and the picture pointer, and push the 176 end marker.
	62611	PUSH DE
	62612	PUSH HL
	62613	LD HL,176
	62616	PUSH HL	Save the end marker and read the pixel under the pen.
DrawingFill_0	62617	CALL KeepOnlyBitsThatAreSet	Save the end marker and read the pixel under the pen.
	62620	JR NZ,DrawingFill_Next	Go to DrawingFill_Next if the pixel under the pen is already set.
	62622	CALL StepPenLeft	Step the pen left and try that pixel again until the left edge.
	62625	JR NZ,DrawingFill_0
	62627	JR DrawingFill_RecordDrawingPen	No set pixel to the left, so start filling from DrawingFill_RecordDrawingPen.
Plot this pixel and step the pen right.
DrawingFill_Next	62629	CALL PlotPixel	Plot this pixel, then step the pen right.
	62632	CALL StepPenRight	Plot this pixel, then step the pen right.
DrawingFill_RecordDrawingPen	62635	LD HL,0	Clear the two bytes that remember a seed.
	62638	LD (62606),HL	Clear the two bytes that remember a seed.
DrawingFill_Loop	62641	CALL StepPenUp	Go to DrawingFill_DrawingPenStep if the pen is already at the top edge.
	62644	LD A,0
	62646	JR Z,DrawingFill_DrawingPenStep
	62648	CALL KeepOnlyBitsThatAreSet	Jump ahead to DrawingFill_StepPen if the pixel under the pen is already set.
	62651	LD A,0
	62653	JR NZ,DrawingFill_StepPen
	62655	LD A,(62606)	Jump to DrawingFill_StepPen if a seed is already saved for this row.
	62658	AND A
	62659	JR NZ,DrawingFill_StepPen
	62661	PUSH DE	Save this spot as a seed and note it in A.
	62662	LD A,1	Save this spot as a seed and note it in A.
DrawingFill_StepPen	62664	PUSH AF	Save that note, step the pen down.
	62665	CALL StepPenDown	Save that note, step the pen down.
	62668	POP AF	Restore the note from the stack.
DrawingFill_DrawingPenStep	62669	LD (62606),A	Store the note and step the pen down.
	62672	CALL StepPenDown	Store the note and step the pen down.
	62675	LD A,0	Go to DrawingFill_DrawingPenDrawing, with A=0 if the pen could not step down.
	62677	JR Z,DrawingFill_DrawingPenDrawing
	62679	CALL KeepOnlyBitsThatAreSet	Jump ahead to DrawingFill_StepPenUp if the pixel under the pen is already set.
	62682	LD A,0
	62684	JR NZ,DrawingFill_StepPenUp
	62686	LD A,(62607)	Jump to DrawingFill_StepPenUp if a seed is already saved for this row.
	62689	AND A
	62690	JR NZ,DrawingFill_StepPenUp
	62692	PUSH DE	Save this spot as a seed and note it in A.
	62693	LD A,1	Save this spot as a seed and note it in A.
DrawingFill_StepPenUp	62695	PUSH AF	Save the note, step the pen up.
	62696	CALL StepPenUp	Save the note, step the pen up.
	62699	POP AF	Restore the note from the stack.
DrawingFill_DrawingPenDrawing	62700	LD (62607),A	Store the note in the other pen byte and plot this pixel.
	62703	CALL PlotPixel	Store the note in the other pen byte and plot this pixel.
	62706	CALL StepPenRight	Go to DrawingFill_ByteMatchesMarker if the pen is already at the right edge.
	62709	JR Z,DrawingFill_ByteMatchesMarker
	62711	CALL KeepOnlyBitsThatAreSet	Jump back to DrawingFill_Loop if the pixel under the pen is clear.
	62714	JR Z,DrawingFill_Loop
	62716	CALL PlotPixel	Plot this pixel.
DrawingFill_ByteMatchesMarker	62719	POP DE	Take the next seed off the stack, and go back to DrawingFill_0 until the 176 end marker, pushed at the start of the fill, comes off.
	62720	LD A,E
	62721	CP 176
	62723	JR NZ,DrawingFill_0
	62725	LD A,0	Clear the drawing ink.
	62727	LD (62987),A	Clear the drawing ink.
	62730	POP HL	Restore the picture pointer and the pen from the stack.
	62731	POP DE	Restore the picture pointer and the pen from the stack.
	62732	RET	Return.