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48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
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#ifndef _VRAMBUF_H
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#define _VRAMBUF_H
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#include "neslib.h"
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// VBUFSIZE = maximum update buffer bytes
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#define VBUFSIZE 128
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// update buffer starts at $100 (stack page)
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#define updbuf ((byte* const)0x100)
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// index to end of buffer
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extern byte updptr;
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// macro to add a multibyte header
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#define VRAMBUF_PUT(addr,len,flags)\
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VRAMBUF_ADD(((addr) >> 8) | (flags));\
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VRAMBUF_ADD(addr);\
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VRAMBUF_ADD(len);
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// macro to set a single byte in buffer
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#define VRAMBUF_SET(b)\
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__A__ = (b);\
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asm("ldy %v", updptr);\
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asm("sta $100,y");
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// macro to set a single byte to buffer, then increment
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#define VRAMBUF_ADD(b)\
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VRAMBUF_SET(b)\
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asm("inc %v", updptr);
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// add EOF marker to buffer (but don't increment pointer)
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void cendbuf(void);
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// clear vram buffer and place EOF marker
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void cclearbuf(void);
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// wait for next frame, then clear buffer
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// this assumes the NMI will call flush_vram_update()
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void cflushnow(void);
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// add multiple characters to update buffer
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// using horizontal increment
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void putbytes(word addr, const char* str, byte len);
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#endif // vrambuf.h
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