git.y1.nz

commit 729e040c557228fa592178b388f10dd47a498bc5
parent 0b16757feeffbfd0f4e0ab2db562a970cd8e6a7f
Author: toxa <untoxa@mail.ru>
Date:   Tue, 24 Nov 2020 23:03:53 +0300

safer copy-to-VRAM functions

Diffstat:
M
gbdk-lib/libc/gb/init_tt.s
26
++++++++------------------
M
gbdk-lib/libc/gb/set_1bit_data.s
31
++++++-------------------------
M
gbdk-lib/libc/gb/set_data.s
21
++++++---------------

3 files changed, 20 insertions(+), 58 deletions(-)
diff --git a/gbdk-lib/libc/gb/init_tt.s b/gbdk-lib/libc/gb/init_tt.s
@@ -24,40 +24,30 @@
 	LD	DE,#0x0400	; One whole GB Screen
 
 .init_vram::
-1$:
-	SRL	D
-	RR	E
-	JR	NC, 2$
-	WAIT_STAT
-	LD	A, B
-	LD	(HL+),A
-2$:
 	SRL	D
 	RR	E
-	JR	NC, 3$
+	JR	NC, 1$
+
 	WAIT_STAT
 	LD	A, B
 	LD	(HL+),A
-	LD	(HL+),A
-3$:
+1$:
 	LD	A, D
 	OR	E
 	RET	Z
 	
 	INC	D
 	INC	E
-	JR	5$
-4$:
+	JR	2$
+3$:
 	WAIT_STAT
 	LD	A, B
 	LD	(HL+),A
 	LD	(HL+),A
-	LD	(HL+),A
-	LD	(HL+),A
-5$:
+2$:
 	DEC	E
-	JR	NZ, 4$
+	JR	NZ, 3$
 	DEC	D
-	JR	NZ, 4$
+	JR	NZ, 3$
 	
 	RET
diff --git a/gbdk-lib/libc/gb/set_1bit_data.s b/gbdk-lib/libc/gb/set_1bit_data.s
@@ -1,7 +1,5 @@
 	.include	"global.s"
 
-	.globl	.copy_vram
-
 	.area	_BASE
 
 _set_bkg_1bit_data::
@@ -39,32 +37,15 @@ _set_sprite_1bit_data::
 	jr z, 2$
 	res 4, d
 2$:
-	.rept 3		; Repeat this 3 times to copy 12 bytes...
-		WAIT_STAT
-		; We have 16 cycles free to access VRAM, during which we can expand 2 bytes into 4 bytes
-		ld a, (hl+)
-		ld (de), a
-		inc e ; inc de
-		ld (de), a
-		inc e ; inc de
-		ld a, (hl+)
-		ld (de), a
-		inc e ; inc de
-		ld (de), a
-		inc e ; inc de
-	.endm
+	ld b, #16
+3$:
 	WAIT_STAT
-	; We have 16 cycles free to access VRAM, during which we can expand 2 bytes into 4 byte
-	ld a, (hl+)
-	ld (de), a
-	inc e ; inc de
-	ld (de), a
-	inc e ; inc de
 	ld a, (hl+)
 	ld (de), a
-	inc e ; inc de
-	ld (de), a
-	inc de ; This actually can overflow into the high byte
+	inc de
+	
+	dec b
+	jr nz, 3$
 
 	dec c
 	jr nz, 1$
diff --git a/gbdk-lib/libc/gb/set_data.s b/gbdk-lib/libc/gb/set_data.s
@@ -1,7 +1,5 @@
 	.include	"global.s"
 
-	.globl	.copy_vram
-
 	;; BANKED:	checked
 	.area	_BASE
 
@@ -40,22 +38,15 @@ _set_sprite_data::
 	jr z, 1$
 	res 4, d
 1$:
-	.rept 5
-		WAIT_STAT
-		ld a, (hl+)
-		ld (de), a
-		inc e ; inc de
-		ld a, (hl+)
-		ld (de), a
-		inc e ; inc de
-		ld a, (hl+)
-		ld (de), a
-		inc e ; inc de
-	.endm
+	ld b, #16
+3$:
 	WAIT_STAT
 	ld a, (hl+)
 	ld (de), a
-	inc de ; This actually can overflow into the high byte
+	inc de
+	
+	dec b
+	jr nz, 3$
 
 	dec c
 	jr nz, 2$

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