Bubbler: Routine at 50200

Used by the routine at DrawBlockShape.

Draws a block whose shape number is 9 to 16. DrawBlockShape has already copied the shape's steps into this routine. The shape number chooses the edges: shapes below 11 use one edge, 11 and 12 leave the edges alone, 13 and 14 use two, and 15 and 16 lengthen the row count by 14 as well. Each column is drawn a row at a time by DrawBlockRow.

Used by the routine at DrawBlockShape. Draws a block whose shape number is 9 to 16. DrawBlockShape has already copied the shape's steps into this routine. The shape number chooses the edges: shapes below 11 use one edge, 11 and 12 leave the edges alone, 13 and 14 use two, and 15 and 16 lengthen the row count by 14 as well. Each column is drawn a row at a time by DrawBlockRow.
The shape number is in A. It chooses how many edge steps this column adds, and which edges are written before a single-row column.
DrawBlockShapeThree	50200	PUSH HL	Remember the screen address.
	50201	LD L,1	One edge step for a shape below 11.
	50203	LD H,L
	50204	CP 11
	50206	JR C,DrawBlockShapeThree_Steps
	50208	INC H	Two edge steps for shape 13 or 14.
	50209	CP 13
	50211	JR Z,DrawBlockShapeThree_Steps
	50213	CP 14
	50215	JR Z,DrawBlockShapeThree_Steps
	50217	INC L	None for shape 11 or 12 and three for a higher shape.
	50218	INC H
	50219	CP 14
	50221	JR NC,DrawBlockShapeThree_Steps
	50223	LD H,0
DrawBlockShapeThree_Steps	50225	LD A,L	Remember how many steps this column adds.
	50226	LD (50436),A	Remember how many steps this column adds.
	50229	LD A,H	Remember the edge choice.
	50230	LD (50287),A
	50233	LD (50417),A
	50236	XOR A	Clear the running total of steps.
	50237	LD (50434),A	Clear the running total of steps.
	50240	LD A,(50133)	Copy the row count into the row loop.
	50243	LD (50281),A	Copy the row count into the row loop.
	50246	LD HL,(50136)	Copy the row routine and the four steps from the shape.
	50249	LD (50379),HL
	50252	LD HL,(50140)
	50255	LD (50383),HL
	50258	LD HL,(50145)
	50261	LD (50388),HL
	50264	LD HL,(50154)
	50267	LD (50451),HL
	50270	LD HL,(50160)
	50273	LD (50457),HL
	50276	POP HL	Restore the screen address.
DrawBlockShapeThree_Rows	50277	PUSH BC	Remember the column count and both addresses.
	50278	PUSH HL
	50279	PUSH DE
	50280	LD B,0	Take the row count.
The edges are changed only when a single row remains, and only for an edge choice other than zero.
DrawBlockShapeThree_Columns	50282	PUSH BC	Remember the row count.
	50283	DEC B	Change the edges only when a single row remains.
	50284	JR NZ,DrawBlockShapeThree_Draw	Change the edges only when a single row remains.
	50286	LD A,0	Read the edge choice.
	50288	AND A	Leave the edges as they are when the choice is zero.
	50289	JR Z,DrawBlockShapeThree_Draw	Leave the edges as they are when the choice is zero.
	50291	RRA	The low bit of the choice selects the wide edges.
	50292	JR C,DrawBlockShapeThree_Wide	The low bit of the choice selects the wide edges.
	50294	LD A,(50434)	Read the running total of steps.
	50297	RRA	Use the narrow edges only when that total is odd.
	50298	JR NC,DrawBlockShapeThree_Draw	Use the narrow edges only when that total is odd.
	50300	LD (IY+6),8	Set the edges to 8.
	50304	LD A,8
	50306	LD (50824),A
	50309	LD (50842),A
	50312	LD (50869),A
	50315	ADD A,6
	50317	LD (50986),A
	50320	JR DrawBlockShapeThree_Draw
DrawBlockShapeThree_Wide	50322	LD (IY+6),24	Set the edges to 24.
	50326	LD B,A
	50327	LD A,24
	50329	LD (50824),A
	50332	LD (50842),A
	50335	LD (50869),A
	50338	ADD A,6
	50340	LD (50986),A
	50343	RR B	A choice of three also sets the edges to 16 and lengthens the rows.
	50345	JR NC,DrawBlockShapeThree_Draw
	50347	LD (IY+6),16
	50351	LD A,16
	50353	LD (50824),A
	50356	LD (50842),A
	50359	LD (50869),A
	50362	ADD A,6
	50364	LD (50986),A
	50367	LD A,(50665)
	50370	ADD A,14
	50372	LD (50665),A
	50375	LD (51001),A
DrawBlockShapeThree_Draw	50378	CALL DrawBlockRow	Draw this row. The routine is patched.
	50381	EXX	Step both addresses on by the shape's row steps.
	50382	LD BC,0
	50385	ADD HL,BC
	50386	EX DE,HL
	50387	LD BC,0
	50390	ADD HL,BC
	50391	EX DE,HL
	50392	POP BC	Repeat for the remaining rows.
	50393	DJNZ DrawBlockShapeThree_Columns	Repeat for the remaining rows.
	50395	POP HL	Restore the screen address.
	50396	LD (IY+6),24	Put the edges back to 24.
	50400	LD A,24
	50402	LD (50869),A
	50405	LD (50824),A
	50408	LD (50842),A
	50411	ADD A,6
	50413	LD (50986),A
	50416	LD A,0	A choice of three shortens the row count again.
	50418	CP 3
	50420	JR NZ,DrawBlockShapeThree_0
	50422	LD A,(50665)
	50425	SUB 14
	50427	LD (50665),A
	50430	LD (51001),A
DrawBlockShapeThree_0	50433	LD A,0	Add this column's steps to the running total.
	50435	ADD A,0
	50437	LD (50434),A
	50440	RRA	Shorten the remaining rows when the total overflows.
	50441	JR C,DrawBlockShapeThree_1
	50443	LD A,(50281)
	50446	DEC A
	50447	LD (50281),A
DrawBlockShapeThree_1	50450	LD BC,0	Step the screen address on by the column step.
	50453	ADD HL,BC
	50454	EX DE,HL
	50455	POP HL	Restore the sprite address and step it on too.
	50456	LD BC,0
	50459	ADD HL,BC
	50460	POP BC	Repeat for the remaining columns.
	50461	DEC B
	50462	JP NZ,DrawBlockShapeThree_Rows
	50465	RET	Return.