pt3: oops forgot the most important file

add awful framebuffer copy code

pt3_player/fire.s

@@ -0,0 +1,173 @@
+; Lo-res fire animation, size-optimized
+
+; by deater (Vince Weaver) <vince@deater.net>
+
+; based on code described here http://fabiensanglard.net/doom_fire_psx/
+
+FIRE_YSIZE=20
+
+fire_init:
+	lda	#<fire_framebuffer
+	sta	FIRE_FB_L
+
+	lda	#>fire_framebuffer
+	sta	FIRE_FB_H
+
+	ldx	#FIRE_YSIZE
+clear_fire_loop:
+
+	lda	#0
+	ldy	#40
+clear_fire_line_loop:
+	beq	done_fire_line_loop
+	sta	(FIRE_FB_L),Y
+	dey
+	jmp	clear_fire_line_loop
+done_fire_line_loop:
+
+	clc
+	lda	FIRE_FB_L
+	adc	#40
+	sta	FIRE_FB_L
+	lda	FIRE_FB_H
+	adc	#0
+	sta	FIRE_FB_H
+
+	dex
+	bne	clear_fire_loop
+
+	lda	#7
+	jsr	fire_setline
+
+	rts
+
+
+
+	;======================================
+	; set bottom line to color in A
+	;======================================
+	;
+fire_setline:
+
+	ldx	#<(fire_framebuffer+(FIRE_YSIZE-1)*40)
+	stx	FIRE_FB_L
+
+	ldx	#>(fire_framebuffer+(FIRE_YSIZE-1)*40)
+	stx	FIRE_FB_H
+
+	ldy	#39
+set_fire_line:
+	sta	(FIRE_FB_L),Y
+	dey
+	bpl	set_fire_line
+done_set_fire_line:
+
+	rts
+
+
+	;===============================
+	;===============================
+	; Draw fire frame
+	;===============================
+	;===============================
+
+draw_fire_frame:
+
+	;===============================
+	; Update fire frame
+	;===============================
+
+	;===============================
+	; copy framebuffer to low-res screen
+
+
+	lda	#<fire_framebuffer
+	sta	FIRE_FB_L
+
+	lda	#>fire_framebuffer
+	sta	FIRE_FB_H
+
+	lda	#<(fire_framebuffer+40)
+	sta	FIRE_FB2_L
+
+	lda	#>(fire_framebuffer+40)
+	sta	FIRE_FB2_H
+
+	lda	#16
+	sta	FIRE_FB_LINE
+
+	ldx	#(FIRE_YSIZE/2)
+
+fire_fb_copy:
+	lda	FIRE_FB_LINE
+	clc
+	adc	#$2
+	sta	FIRE_FB_LINE
+	tay
+
+	lda	gr_offsets,Y
+	sta	OUTL
+	lda	gr_offsets+1,Y
+	clc
+	adc	DRAW_PAGE
+	sta	OUTH
+
+	; FIXME: below, can we do this better?  self-modifying code?
+
+	ldy	#39
+fire_fb_copy_loop:
+	txa
+	pha
+
+	; get top byte
+	lda	(FIRE_FB_L),Y
+	tax
+	lda	fire_colors_high,X
+	pha
+
+	; get bottom byte
+	lda	(FIRE_FB2_L),Y
+	tax
+	pla
+	ora	fire_colors_low,X
+	sta	(OUTL),Y		; store out
+	pla
+	tax
+
+	dey
+	bpl	fire_fb_copy_loop
+done_fire_fb_copy_loop:
+
+	; complicated adjustment
+	clc
+	lda	FIRE_FB_L
+	adc	#80
+	sta	FIRE_FB_L
+	lda	FIRE_FB_H
+	adc	#0
+	sta	FIRE_FB_H
+
+	clc
+	lda	FIRE_FB2_L
+	adc	#80
+	sta	FIRE_FB2_L
+	lda	FIRE_FB2_H
+	adc	#0
+	sta	FIRE_FB2_H
+
+
+	dex
+	bne	fire_fb_copy
+
+
+	rts
+
+fire_colors_low:	.byte	$00,$00,$03,$02,$06,$07,$0E,$0F
+fire_colors_high:	.byte	$00,$00,$30,$20,$60,$70,$E0,$F0
+
+
+
+	; FIXME: just reserve space in our memory map
+fire_framebuffer:
+	.res    40*FIRE_YSIZE, $00
+