Krakout: Draw the KRAKOUT title logo

BE03: Draw the KRAKOUT title logo

Draws the KRAKOUT title logo, a 14-by-3 block of glyph cells with its own per-cell attribute block.
draw_title_logo	BE03	LD HL,SCREEN_BASE+$49	Pass 1 destination: the logo's top-left display cell, character row 2 column 9.
	BE06	LD DE,title_logo_glyphs	Glyph bitmaps: 8 bytes per cell, cell after cell.
	BE09	LD B,$03	Walk the logo's character rows (rows 2–4).
logo_row	BE0B	PUSH BC	Hold the row counter and this row's first cell across the columns below.
	BE0C	PUSH HL
	BE0D	LD B,$0E	Walk this row's cells (columns 9–22).
logo_col	BE0F	PUSH BC	Hold the column counter and this cell's address across the glyph copy.
	BE10	PUSH HL
	BE11	LD C,$46	Draw this cell's glyph with a throwaway attribute. Pass 2 repaints every cell's color.
	BE13	CALL draw_glyph
	BE16	POP HL
	BE17	INC L	Step to the next column in the same row. After the 14th column, take the row's start cell back, step down one character row and repeat.
	BE18	POP BC
	BE19	DJNZ logo_col
	BE1B	POP HL
	BE1C	CALL advance_buffer_row
	BE1F	POP BC
	BE20	DJNZ logo_row
Pass 2 copies the attribute block into the attribute file, cell for cell, which is what gives the logo its multicolor look. Pass 1 left every cell a throwaway attribute.
	BE22	LD HL,ATTR_BASE+$49	Pass 2 destination: the attribute cell for character row 2 column 9.
	BE25	LD DE,title_logo_attrs	Per-cell attribute block: the logo's final colors. They replace the throwaway attributes that pass 1 wrote.
	BE28	LD B,$03
logo_attr_row	BE2A	PUSH BC	Hold the row counter and this row's first attribute cell across the columns below.
	BE2B	PUSH HL
	BE2C	LD B,$0E
logo_attr_col	BE2E	LD A,(DE)	Copy one cell's final attribute into the attribute file.
	BE2F	LD (HL),A
	BE30	INC DE
	BE31	INC HL
	BE32	DJNZ logo_attr_col
	BE34	POP HL	Take the row's start cell back, step down one character row and repeat.
	BE35	CALL advance_buffer_row
	BE38	POP BC
	BE39	DJNZ logo_attr_row
	BE3B	RET

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