/*

 * GUSEMU32 - API

 *

 * Copyright (C) 2000-2007 Tibor "TS" Schütz

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef GUSEMU_H

#define GUSEMU_H

/* data types (need to be adjusted if neither a VC6 nor a C99 compatible compiler is used) */

#if defined _WIN32 && defined _MSC_VER /* doesnt support other win32 compilers yet, do it yourself... */

 typedef unsigned char GUSbyte;

 typedef unsigned short GUSword;

 typedef unsigned int GUSdword;

 typedef signed char GUSchar;

 typedef signed short GUSsample;

#else

 #include <stdint.h>

 typedef int8_t GUSchar;

 typedef uint8_t GUSbyte;

 typedef uint16_t GUSword;

 typedef uint32_t GUSdword;

 typedef int16_t GUSsample;

#endif

typedef struct _GUSEmuState

{

 GUSbyte *himemaddr; /* 1024*1024 bytes used for storing uploaded samples (+32 additional bytes for read padding) */

 GUSbyte *gusdatapos; /* (gusdataend-gusdata) bytes used for storing emulated GF1/mixer register states (32*32+4 bytes in initial GUSemu32 version) */

 int gusirq;

 int gusdma;

 unsigned int timer1fraction;

 unsigned int timer2fraction;

 void *opaque;

} GUSEmuState;

/* ** Callback functions needed: */

/* NMI is defined as hwirq=-1 (not supported (yet?)) */

/* GUS_irqrequest returns the number of IRQs actually scheduled into the virtual machine */

/* Level triggered IRQ simulations normally return 1 */

/* Event triggered IRQ simulation can safely ignore GUS_irqclear calls */

int  GUS_irqrequest(GUSEmuState *state, int hwirq, int num);/* needed in both mixer and bus emulation functions. */

void GUS_irqclear(  GUSEmuState *state, int hwirq); /* used by gus_write() only - can be left empty for mixer functions */

void GUS_dmarequest(GUSEmuState *state);            /* used by gus_write() only - can be left empty for mixer functions */

/* ** ISA bus interface functions: */

/* Port I/O handlers */

/* support the following ports: */

/* 2x0,2x6,2x8...2xF,3x0...3x7;  */

/* optional: 388,389 (at least writes should be forwarded or some GUS detection algorithms will fail) */

/* data is passed in host byte order */

unsigned int gus_read( GUSEmuState *state, int port, int size);

void         gus_write(GUSEmuState *state, int port, int size, unsigned int data);

/* size is given in bytes (1 for byte, 2 for word) */

/* DMA data transfer function */

/* data pointed to is passed in native x86 order */

void gus_dma_transferdata(GUSEmuState *state, char *dma_addr, unsigned int count, int TC);

/* Called back by GUS_start_DMA as soon as the emulated DMA controller is ready for a transfer to or from GUS */

/* (might be immediately if the DMA controller was programmed first) */

/* dma_addr is an already translated address directly pointing to the beginning of the memory block */

/* do not forget to update DMA states after the call, including the DREQ and TC flags */

/* it is possible to break down a single transfer into multiple ones, but take care that: */

/* -dma_count is actually count-1 */

/* -before and during a transfer, DREQ is set and TC cleared */

/* -when calling gus_dma_transferdata(), TC is only set true for call transfering the last byte */

/* -after the last transfer, DREQ is cleared and TC is set */

/* ** GF1 mixer emulation functions: */

/* Usually, gus_irqgen should be called directly after gus_mixvoices if you can meet the recommended ranges. */

/* If the interrupts are executed immediately (i.e., are synchronous), it may be useful to break this */

/* down into a sequence of gus_mixvoice();gus_irqgen(); calls while mixing an audio block. */

/* If the interrupts are asynchronous, it may be needed to use a separate thread mixing into a temporary */

/* audio buffer in order to avoid quality loss caused by large numsamples and elapsed_time values. */

void gus_mixvoices(GUSEmuState *state, unsigned int playback_freq, unsigned int numsamples, GUSsample *bufferpos);

/* recommended range: 10 < numsamples < 100 */

/* lower values may result in increased rounding error, higher values often cause audible timing delays */

void gus_irqgen(GUSEmuState *state, unsigned int elapsed_time);

/* recommended range: 80us < elapsed_time < max(1000us, numsamples/playback_freq) */

/* lower values won´t provide any benefit at all, higher values can cause audible timing delays */

/* note: masked timers are also calculated by this function, thus it might be needed even without any IRQs in use! */

#endif  /* gusemu.h */