second: chessboard falling

a hack but maybe good enough for now

demos/second/hgr_clear_screen.s

@@ -1,3 +1,8 @@
+hgr_clear_screen:
+	lda	DRAW_PAGE
+	beq	hgr_page1_clearscreen
+	lda	#0
+	beq	hgr_page2_clearscreen
 
 hgr_page1_clearscreen:
 

demos/second/part04_chess_shapes/Makefile

@@ -21,6 +21,7 @@ chess.o:	chess.s \
 	circles.s \
 	falling_bars.s \
 	sierzoom.s \
+	hgr_partial.s \
 	../irq_wait.s \
 	../zp.inc ../hardware.inc ../qload.inc \
 	graphics/chess_object2.hgr.zx02 \

demos/second/part04_chess_shapes/chess.s

@@ -35,6 +35,22 @@ chess_start:
 	; Load graphics
 	;===================
 
+
+
+	;=============================
+	; load chessboard image offscreen $6000
+	;=============================
+
+	lda	#<chess_data
+	sta	zx_src_l+1
+	lda	#>chess_data
+	sta	zx_src_h+1
+	lda	#$60
+	jsr	zx02_full_decomp
+
+
+
+
 	; wait until pattern1
 pattern2_loop:
 	lda	#2
@@ -118,7 +134,43 @@ compact_inner_loop:
 	bne	compact_loop
 
 
+	;=============================
+	; dropping board
+	;=============================
 
+	ldx	#0
+	stx	BOARD_COUNT
+
+drop_board_loop:
+	jsr	hgr_clear_screen
+
+	ldx	BOARD_COUNT
+	lda	board_y,X
+	sta	HGR_DEST
+
+	lda	board_starty,X
+	sta	HGR_Y1
+
+	lda	#0
+	sta	HGR_X1
+	lda	#40
+	sta	HGR_X2
+	lda	#192
+	sta	HGR_Y2
+
+	jsr	hgr_partial
+
+	jsr	hgr_page_flip
+
+;	jsr	wait_until_keypress
+
+	lda	#10
+	jsr	wait_ticks
+
+	inc	BOARD_COUNT
+	lda	BOARD_COUNT
+	cmp	#7
+	bne	drop_board_loop
 
 
 	;=============================
@@ -130,16 +182,6 @@ compact_inner_loop:
 
 	bit	PAGE2
 
-	; load image offscreen $6000
-
-	lda	#<chess_data
-	sta	zx_src_l+1
-	lda	#>chess_data
-	sta	zx_src_h+1
-	lda	#$60
-	jsr	zx02_full_decomp
-
-
 	lda	#0
 	sta	COUNT
 	sta	DRAW_PAGE
@@ -403,6 +445,7 @@ main_interference_done:
 	.include	"sierzoom.s"
 	.include	"../hgr_page_flip.s"
 	.include	"falling_bars.s"
+	.include	"hgr_partial.s"
 
 	; wait A * 1/50s
 wait_irq:
@@ -461,5 +504,15 @@ bounce_coords_y:
 	.byte	4, 20, 35, 45, 60, 70, 82, 102, 115
 	.byte 115,102, 82, 70, 60, 45, 35,  20,   4
 
+	; 148-192 = full = 44
 
+	; 0 frames in = 0 high,			bottom=125+13	Y=125
+	; 4 frames in, 130-138 = 8 high		bottom=138+17	Y=130
+	; 8 frames in, from 135-155 = 20	bottom=155+25	Y=135
+	;12 frames in, from 145-180 = 35	bottom=180	Y=145
 
+board_y:
+	.byte 125,130,135,145,139,145,139
+
+board_starty:
+	.byte 184,184,172,157,139,157,139

demos/second/part04_chess_shapes/hgr_partial.s

@@ -0,0 +1,46 @@
+; copy partial part of screen from $6000 to DRAW_PAGE
+	; HGR_X1,HGR_Y1 to HGR_X2,HGR_Y2 source
+	; destination = Y at HGR_DEST
+
+hgr_partial:
+	lda	HGR_DEST
+	sta	dest_y_smc+1
+
+	ldx	HGR_Y1		; Y1
+hgr_partial_outer_loop:
+	lda	hposn_low,X
+	sta	INL
+	lda	hposn_high,X
+	ora	#$40		; convert to $6000
+	sta	INH
+
+	txa
+	pha
+
+dest_y_smc:
+	ldx	#100		; DEST_Y
+	lda	hposn_low,X
+	sta	OUTL
+	lda	hposn_high,X
+	clc
+	adc	DRAW_PAGE
+	sta	OUTH
+
+	pla
+	tax
+
+	ldy	HGR_X1		; X1
+hgr_partial_inner_loop:
+	lda	(INL),Y
+	sta	(OUTL),Y
+	iny
+	cpy	HGR_X2		; X2
+	bne	hgr_partial_inner_loop
+
+	inc	dest_y_smc+1
+
+	inx
+	cpx	HGR_Y2		; Y2
+	bne	hgr_partial_outer_loop
+
+	rts

demos/second/zp.inc

@@ -95,8 +95,14 @@ TOTAL_RAM       = $8F
 ;=============================
 
 ;=============================
-; $D0-$DA = ?
+; $D0-$D9 = hgr move
 ;=============================
+HGR_X1	= $D0
+HGR_X2	= $D1
+HGR_Y1	= $D2
+HGR_Y2	= $D3
+HGR_DEST= $D4
+BOARD_COUNT	= $D5
 
 
 WHICH_SLOT = $DA		; from boot sector
@@ -176,7 +182,6 @@ Y2		= $F7
 SCENE_COUNT	= $F8
 LAST_TYPE	= $F9
 
-
 ; lens
 LENS_X		= $F0
 LENS_Y		= $F1