Avalon: Routine at 56612

56612: Draw the spell pointer arrow, spell charge icons and energy bar on the scroll

Used by the routines at 58945, 59130 and 59219.

Input
DE	Screen display address location to draw at

Draws the scroll arrow (called from 58945), the spell 'charge' icons (called from 59130) or the energy bar (called from 59246)

56612

LD HL,(60241)

Get graphics address pointer from 38851

56615

LD A,(HL)

Get the graphics address pointer low byte for the arrow (44966), the scroll charge icons (44775), or the energy bar (44787)

56616

INC HL

High byte of the graphics address pointer

56617

LD H,(HL)

56618

LD L,A

...HL register pair now contains the graphics address pointer for the relevant graphic

56619

LD C,(HL)

Number of tiles that make up the graphic

56620

INC HL

Move graphics address pointer along to start of first tile graphic

56621

INC HL

56622

INC HL

56623

LD B,(HL)

Number of bytes in the graphics tile to draw

56624

INC HL

Move pointer to start of tile graphics

56625

LD (60126),DE

Store screen display address position

Draw graphic tile on screen

56629

LD A,(HL)

Copy graphic byte onto screen:

56630

LD (DE),A

56631

INC HL

Move to next graphic byte

56632

LD A,D

Get pixel row

56633

AND 7

56635

INC A

Move down to next pixel row

56636

CP 8

Are we crossing a pixel/character boundary?

56638

JR C,56656

...If not, move down 1 pixel row and continue drawing the graphic

56640

LD A,D

...If so, recalculate screen display address. Get high byte of screen address

56641

AND 248

Reset the low 3 bits (pixel row number) to zero

56643

LD D,A

56644

LD A,E

Get the low byte of the screen address

56645

ADD A,32

Increment column by 32 to move down to next screen row

56647

LD E,A

56648

JR NC,56657

Crossing a 1/3 screen boundary? ...If not, skip next 3 instructions

56650

LD A,D

...If so, adjust high byte of screen address accordingly

56651

ADD A,8

56653

LD D,A

Store correct screen address high byte back in D register

56654

JR 56657

56656

INC D

Move down 1 pixel row

56657

DJNZ 56629

Repeat for all pixel rows of this graphics tile

Continue to draw the remaining tiles in the graphic

56659

LD DE,(60126)

Retrieve screen display address

56663

INC E

Move right one character square

56664

DEC C

Decrement tile graphic counter

56665

JR NZ,56621

If there are tiles left in the graphic, draw the next one.

56667

RET