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/*
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 * GUSEMU32 - API
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 *
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 * Copyright (C) 2000-2007 Tibor "TS" Schütz
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * of this software and associated documentation files (the "Software"), to deal
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 * in the Software without restriction, including without limitation the rights
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the Software is
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 * furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice shall be included in
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 * all copies or substantial portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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 * THE SOFTWARE.
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 */
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#ifndef GUSEMU_H
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#define GUSEMU_H
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/* data types (need to be adjusted if neither a VC6 nor a C99 compatible compiler is used) */
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#if defined _WIN32 && defined _MSC_VER /* doesnt support other win32 compilers yet, do it yourself... */
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 typedef unsigned char GUSbyte;
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 typedef unsigned short GUSword;
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 typedef unsigned int GUSdword;
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 typedef signed char GUSchar;
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 typedef signed short GUSsample;
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#else
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 #include <stdint.h>
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 typedef int8_t GUSchar;
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 typedef uint8_t GUSbyte;
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 typedef uint16_t GUSword;
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 typedef uint32_t GUSdword;
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 typedef int16_t GUSsample;
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#endif
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typedef struct _GUSEmuState
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{
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 GUSbyte *himemaddr; /* 1024*1024 bytes used for storing uploaded samples (+32 additional bytes for read padding) */
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 GUSbyte *gusdatapos; /* (gusdataend-gusdata) bytes used for storing emulated GF1/mixer register states (32*32+4 bytes in initial GUSemu32 version) */
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 uint32_t gusirq;
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 uint32_t gusdma;
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 unsigned int timer1fraction;
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 unsigned int timer2fraction;
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 void *opaque;
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} GUSEmuState;
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/* ** Callback functions needed: */
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/* NMI is defined as hwirq=-1 (not supported (yet?)) */
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/* GUS_irqrequest returns the number of IRQs actually scheduled into the virtual machine */
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/* Level triggered IRQ simulations normally return 1 */
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/* Event triggered IRQ simulation can safely ignore GUS_irqclear calls */
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int  GUS_irqrequest(GUSEmuState *state, int hwirq, int num);/* needed in both mixer and bus emulation functions. */
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void GUS_irqclear(  GUSEmuState *state, int hwirq); /* used by gus_write() only - can be left empty for mixer functions */
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void GUS_dmarequest(GUSEmuState *state);            /* used by gus_write() only - can be left empty for mixer functions */
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/* ** ISA bus interface functions: */
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/* Port I/O handlers */
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/* support the following ports: */
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/* 2x0,2x6,2x8...2xF,3x0...3x7;  */
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/* optional: 388,389 (at least writes should be forwarded or some GUS detection algorithms will fail) */
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/* data is passed in host byte order */
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unsigned int gus_read( GUSEmuState *state, int port, int size);
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void         gus_write(GUSEmuState *state, int port, int size, unsigned int data);
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/* size is given in bytes (1 for byte, 2 for word) */
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/* DMA data transfer function */
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/* data pointed to is passed in native x86 order */
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void gus_dma_transferdata(GUSEmuState *state, char *dma_addr, unsigned int count, int TC);
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/* Called back by GUS_start_DMA as soon as the emulated DMA controller is ready for a transfer to or from GUS */
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/* (might be immediately if the DMA controller was programmed first) */
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/* dma_addr is an already translated address directly pointing to the beginning of the memory block */
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/* do not forget to update DMA states after the call, including the DREQ and TC flags */
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/* it is possible to break down a single transfer into multiple ones, but take care that: */
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/* -dma_count is actually count-1 */
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/* -before and during a transfer, DREQ is set and TC cleared */
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/* -when calling gus_dma_transferdata(), TC is only set true for call transfering the last byte */
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/* -after the last transfer, DREQ is cleared and TC is set */
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/* ** GF1 mixer emulation functions: */
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/* Usually, gus_irqgen should be called directly after gus_mixvoices if you can meet the recommended ranges. */
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/* If the interrupts are executed immediately (i.e., are synchronous), it may be useful to break this */
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/* down into a sequence of gus_mixvoice();gus_irqgen(); calls while mixing an audio block. */
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/* If the interrupts are asynchronous, it may be needed to use a separate thread mixing into a temporary */
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/* audio buffer in order to avoid quality loss caused by large numsamples and elapsed_time values. */
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void gus_mixvoices(GUSEmuState *state, unsigned int playback_freq, unsigned int numsamples, GUSsample *bufferpos);
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/* recommended range: 10 < numsamples < 100 */
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/* lower values may result in increased rounding error, higher values often cause audible timing delays */
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void gus_irqgen(GUSEmuState *state, unsigned int elapsed_time);
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/* recommended range: 80us < elapsed_time < max(1000us, numsamples/playback_freq) */
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/* lower values won´t provide any benefit at all, higher values can cause audible timing delays */
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/* note: masked timers are also calculated by this function, thus it might be needed even without any IRQs in use! */
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#endif  /* gusemu.h */