git.y1.nz

commit 484f0765338441549574b7aa4c97e567ab02892b
parent e06edf4e324ede3d804dfac7f97864c07d65f4e6
Author: toxa <untoxa@mail.ru>
Date:   Fri,  6 Nov 2020 00:58:53 +0300

fix wrapping maps when base address is 0x9c00

Diffstat:
M
gbdk-lib/libc/gb/fill_rect.s
10
+++++++---
M
gbdk-lib/libc/gb/get_xy_t.s
10
+++++++---
M
gbdk-lib/libc/gb/set_xy_t.s
10
+++++++---

3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/gbdk-lib/libc/gb/fill_rect.s b/gbdk-lib/libc/gb/fill_rect.s
@@ -67,8 +67,12 @@
 	PUSH	DE
 
 	LD	A, B		; next row and wrap around
-	AND	#0xF8
-	LD 	E, A
+	AND	#0xFC
+	LD 	E, A		; save high bits
+
+	LD	A, B		; make map zero-based 
+	AND	#0x03
+	LD	B, A
 
 	LD	A,#0x20
 
@@ -77,7 +81,7 @@
 	ADC	A, B
 	SUB	C
 	AND	#0x03
-	OR	E
+	OR	E		; restore high bits
 	LD	B, A
 
 	PUSH	BC
diff --git a/gbdk-lib/libc/gb/get_xy_t.s b/gbdk-lib/libc/gb/get_xy_t.s
@@ -69,8 +69,12 @@
 	PUSH	DE
 
 	LD	A, B		; next row and wrap around
-	AND	#0xF8
-	LD 	E, A
+	AND	#0xFC
+	LD 	E, A		; save high bits
+
+	LD	A, B		; make map zero-based 
+	AND	#0x03
+	LD	B, A
 
 	LD	A,#0x20
 
@@ -79,7 +83,7 @@
 	ADC	A, B
 	SUB	C
 	AND	#0x03
-	OR	E
+	OR	E		; restore high bits
 	LD	B, A
 
 	PUSH	BC
diff --git a/gbdk-lib/libc/gb/set_xy_t.s b/gbdk-lib/libc/gb/set_xy_t.s
@@ -67,8 +67,12 @@
 	PUSH	DE
 
 	LD	A, B		; next row and wrap around
-	AND	#0xF8
-	LD 	E, A
+	AND	#0xFC
+	LD 	E, A		; save high bits
+
+	LD	A, B		; make map zero-based 
+	AND	#0x03
+	LD	B, A
 
 	LD	A,#0x20
 
@@ -77,7 +81,7 @@
 	ADC	A, B
 	SUB	C
 	AND	#0x03
-	OR	E
+	OR	E		; restore high bits
 	LD	B, A
 
 	PUSH	BC

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