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diff vdp.h @ 471:f065769836e8

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Implement FIFO as a ring buffer so the behavior of reads from invalid CRAM and VSRAM bits can be implemented properly
author Mike Pavone <pavone@retrodev.com>
date Sun, 15 Sep 2013 22:20:43 -0700
parents 541c1ae8abf3
children 2e4a4188cfb0
line wrap: on
line diff
--- a/vdp.h	Fri Sep 13 19:22:46 2013 -0700
+++ b/vdp.h	Sun Sep 15 22:20:43 2013 -0700
@@ -110,6 +110,8 @@
 	int16_t y;
 } sprite_info;
 
+#define FIFO_SIZE 4
+
 typedef struct {
 	uint32_t cycle;
 	uint16_t address;
@@ -119,8 +121,9 @@
 } fifo_entry;
 
 typedef struct {
-	fifo_entry  *fifo_cur;
-	fifo_entry  *fifo_end;
+	fifo_entry  fifo[FIFO_SIZE];
+	int32_t     fifo_write;
+	int32_t     fifo_read;
 	uint16_t    address;
 	uint8_t     cd;
 	uint8_t	    flags;