Bubbler: Routine at 58301

58301: Draw Frame Bar

Used by the routine at DrawFrame.

Draws a horizontal bar of four rows for the frame, with each row as wide as the frame.

Input
H	The vertical position
IX	The entry of the frame

DrawFrameBar

58301

LD L,(IX+0)

Fetch the x position of the frame into L.

58304

LD C,4

Set the number of pixel lines in the bar to 4.

58306

CALL GetScreenAddress

Convert the position into a screen address.

DrawFrameBar_Loop

58309

LD B,(IX+2)

Fetch the width of the frame in bytes.

DrawFrameBar_Loop2

58312

LD (HL),255

Draw a byte of the bar.

58314

INC L

Move onto the next byte.

58315

DJNZ DrawFrameBar_Loop2

Repeat until the line is drawn.

58317

LD A,L

Copy the screen address into A.

58318

SUB (IX+2)

Subtract the width of the frame.

58321

LD L,A

Copy it back into L, to return to the start of the line.

58322

DEC H

Move up a pixel line.

58323

DEC C

Decrease the number of pixel lines by one.

58324

JR NZ,DrawFrameBar_Loop

Repeat until the bar is drawn.

58326

RET

Return.