peasant: try to keep peasant Y at a multiple of 4

also initial bg priority support

games/peasant/hgr_7x28_sprite_mask.s

@@ -15,6 +15,9 @@
 
 hgr_draw_sprite_7x28:
 
+	lda	#0
+	sta	MASK_COUNTDOWN
+
 	; set up pointers
 	lda	INL
 	sta	h728_smc1+1
@@ -31,6 +34,30 @@ hgr_draw_sprite_7x28:
 
 	ldx	#0			; X is row counter
 hgr_7x28_sprite_yloop:
+	lda	MASK_COUNTDOWN
+	and	#$3			; only update every 4th
+	bne	mask_good
+
+	txa
+	pha				; save X
+
+	; recalculate mask
+	txa
+	clc
+	adc	CURSOR_Y
+	tax
+	ldy	CURSOR_X
+	jsr	update_bg_mask
+
+
+        pla				; restore X
+	tax
+
+mask_good:
+	lda	MASK
+	bne	draw_sprite_skip
+
+
 	txa				; X is current row
 
 	clc
@@ -53,6 +80,11 @@ h728_smc1:
 	ora	$d000,X		; or in sprite
 	sta	(GBASL),Y	; store out
 
+
+draw_sprite_skip:
+
+	inc	MASK_COUNTDOWN
+
 	inx
 	cpx	#28
 	bne	hgr_7x28_sprite_yloop
@@ -129,6 +161,73 @@ restore_yloop:
 	rts
 
 
+	;===================
+	; update_bg_mask
+	;===================
+	; newx/7 in Y
+	; newy in X
+	; updates MASK
+update_bg_mask:
+
+			; rrrr rtii	top 5 bits row, bit 2 top/bottom
+
+	txa
+	and	#$04	; see if odd/even
+	beq	bg_mask_even
+
+bg_mask_odd:
+	lda	#$f0
+	bne	bg_mask_mask		; bra
+
+bg_mask_even:
+	lda	#$0f
+bg_mask_mask:
+
+	sta	MASK
+
+	txa
+	lsr
+	lsr		; need to divide by 8 then * 2
+	lsr		; can't just div by 4 as we need to mask bottom bit
+	asl
+	tax
+
+	lda	gr_offsets,X
+	sta	BASL
+	lda	gr_offsets+1,X
+	sta	BASH
+
+	lda	(BASL),Y
+	and	MASK
+
+	cmp	#$30
+	beq	mask_false		; true if color 3
+
+	cmp	#$03
+	beq	mask_false
+
+	;bne	mask_false
+
+mask_true:
+	lda	#$ff
+	sta	MASK
+	rts
+
+mask_false:
+	lda	#$00
+	sta	MASK
+	rts
+
+
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+
+	rts
+
+
 ;====================
 ; save area
 ;====================

games/peasant/intro.s

@@ -106,11 +106,11 @@ escape_handler:
 
 	;=========================
 	; init peasant position
-	; draw at 18,107
+	; draw at 18,108
 
 	lda	#18
 	sta	PEASANT_X
-	lda	#107
+	lda	#108
 	sta	PEASANT_Y
 
 	lda	#PEASANT_DIR_RIGHT

games/peasant/peasant3.s

@@ -165,7 +165,7 @@ score_text:
 .include "hgr_font.s"
 .include "draw_box.s"
 .include "hgr_rectangle.s"
-.include "hgr_7x28_sprite.s"
+.include "hgr_7x28_sprite_mask.s"
 .include "hgr_1x5_sprite.s"
 ;.include "hgr_save_restore.s"
 .include "hgr_partial_save.s"

games/peasant/peasant4.s

@@ -166,7 +166,7 @@ score_text:
 .include "hgr_font.s"
 .include "draw_box.s"
 .include "hgr_rectangle.s"
-.include "hgr_7x28_sprite.s"
+.include "hgr_7x28_sprite_mask.s"
 .include "hgr_1x5_sprite.s"
 ;.include "hgr_save_restore.s"
 .include "hgr_partial_save.s"

games/peasant/peasant_move.s

@@ -85,7 +85,7 @@ done_movex:
 	cmp	#45				; if <45 then off screen
 	bcc	peasant_y_negative		; blt
 
-	cmp	#150				; if >=150 then off screen
+	cmp	#160				; if >=150 then off screen
 	bcs	peasant_y_toobig		; bge
 
 	; check collide
@@ -126,7 +126,7 @@ peasant_y_negative:
 
 	jsr	new_map_location
 
-	lda	#150		; new X location
+	lda	#160		; new X location
 
 	jmp	done_movey
 

games/peasant/zp.inc

@@ -11,7 +11,10 @@ HGR_BITS	= $1C
 
 GBASL		= $26
 GBASH		= $27
+BASL		= $28
+BASH		= $29
 MASK		= $2E
+MASK_COUNTDOWN	= $2F
 
 PEASANT_X	= $60
 PEASANT_Y	= $61