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+/*
+ * 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 /* doesn't 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) */
+ uint32_t gusirq;
+ uint32_t 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 transferring 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 */