#ifndef VB_H_
#define VB_H_

#ifdef __cplusplus
extern "C" {
#endif

#ifndef VBAPI
#define VBAPI extern
#endif

/* Header includes */
#include <stddef.h>
#include <stdint.h>



/**************************** Compilation Control ****************************/

/*
  VB_DIRECT_EXCEPTION
  VB_DIRECT_EXECUTE
  VB_DIRECT_FETCH
  VB_DIRECT_FRAME
  VB_DIRECT_READ
  VB_DIRECT_SAMPLES
  VB_DIRECT_WRITE

  Implements callbacks as direct function calls with names given by the above
  symbols in their respective situations. If left undefined, the function
  pointer in the simulation state is used. Whether or not to call the callback
  is still determined by whether the function pointer is NULL.
*/

/*
  VB_DIV_GENERIC

  Provides a generic implementation for the DIV instruction that guarantees the
  correct results for quotient and remainder. If left undefined, an accelerated
  implementation is used that depends on the compiler's behavior.
*/

/*
  VB_LITTLE_ENDIAN

  Accelerates simulated memory reads and writes on hosts with little-endian
  byte ordering. If left undefined, a generic implementation is used instead.
*/

/*
  VB_SIGNED_PROPAGATE

  Accelerates sign extension by assuming the >> operator propagates the sign
  bit for signed types and does not for unsigned types. If left undefined, a
  generic implementation is used instead.
*/




/********************************* Constants *********************************/

/* System registers */
#define VB_ADTRE 25
#define VB_CHCW  24
#define VB_ECR    4
#define VB_EIPC   0
#define VB_EIPSW  1
#define VB_FEPC   2
#define VB_FEPSW  3
#define VB_PIR    6
#define VB_PSW    5
#define VB_TKCW   7

/* Memory access data types */
#define VB_S8  0
#define VB_U8  1
#define VB_S16 2
#define VB_U16 3
#define VB_S32 4



/*********************************** Types ***********************************/

/* Simulation state */
typedef struct VB VB;

/* Callbacks */
typedef int  (*vbOnException)(VB *sim, uint16_t *cause);
typedef int  (*vbOnExecute  )(VB *sim, uint32_t address, const uint16_t *code, int length);
typedef int  (*vbOnFetch    )(VB *sim, int fetch, uint32_t address, int32_t *value, uint32_t *cycles);
typedef int  (*vbOnFrame    )(VB *sim);
typedef int  (*vbOnRead     )(VB *sim, uint32_t address, int type, int32_t *value, uint32_t *cycles);
typedef void (*vbOnSamples  )(VB *sim, int16_t *buffer, uint32_t capacity);
typedef int  (*vbOnWrite    )(VB *sim, uint32_t address, int type, int32_t *value, uint32_t *cycles, int *cancel);




/******************************* API Commands ********************************/

VBAPI int           vbEmulate             (VB *sim, uint32_t *clocks);
VBAPI int           vbEmulateEx           (VB **sims, int count, uint32_t *clocks);
VBAPI void*         vbGetCallback         (VB *sim, int id);
VBAPI void*         vbGetCartRAM          (VB *sim, uint32_t *size);
VBAPI void*         vbGetCartROM          (VB *sim, uint32_t *size);
VBAPI vbOnException vbGetExceptionCallback(VB *sim);
VBAPI vbOnExecute   vbGetExecuteCallback  (VB *sim);
VBAPI vbOnFetch     vbGetFetchCallback    (VB *sim);
VBAPI vbOnFrame     vbGetFrameCallback    (VB *sim);
VBAPI uint16_t      vbGetKeys             (VB *sim);
VBAPI void          vbGetPixels           (VB *sim, void *left, int leftStrideX, int leftStrideY, void *right, int rightStrideX, int rightStrideY);
VBAPI uint32_t      vbGetProgramCounter   (VB *sim);
VBAPI int32_t       vbGetProgramRegister  (VB *sim, int index);
VBAPI vbOnRead      vbGetReadCallback     (VB *sim);
VBAPI void*         vbGetSamples          (VB *sim, uint32_t *capacity, uint32_t *position);
VBAPI vbOnSamples   vbGetSamplesCallback  (VB *sim);
VBAPI uint32_t      vbGetSystemRegister   (VB *sim, int index);
VBAPI void*         vbGetUserData         (VB *sim);
VBAPI vbOnWrite     vbGetWriteCallback    (VB *sim);
VBAPI VB*           vbInit                (VB *sim);
VBAPI int32_t       vbRead                (VB *sim, uint32_t address, int type);
VBAPI VB*           vbReset               (VB *sim);
VBAPI int           vbSetCartRAM          (VB *sim, void *sram, uint32_t size);
VBAPI int           vbSetCartROM          (VB *sim, void *rom, uint32_t size);
VBAPI vbOnException vbSetExceptionCallback(VB *sim, vbOnException callback);
VBAPI vbOnExecute   vbSetExecuteCallback  (VB *sim, vbOnExecute callback);
VBAPI vbOnFetch     vbSetFetchCallback    (VB *sim, vbOnFetch callback);
VBAPI vbOnFrame     vbSetFrameCallback    (VB *sim, vbOnFrame callback);
VBAPI uint16_t      vbSetKeys             (VB *sim, uint16_t keys);
VBAPI uint32_t      vbSetProgramCounter   (VB *sim, uint32_t value);
VBAPI int32_t       vbSetProgramRegister  (VB *sim, int index, int32_t value);
VBAPI vbOnRead      vbSetReadCallback     (VB *sim, vbOnRead callback);
VBAPI int           vbSetSamples          (VB *sim, void *samples, uint32_t capacity);
VBAPI vbOnSamples   vbSetSamplesCallback  (VB *sim, vbOnSamples callback);
VBAPI uint32_t      vbSetSystemRegister   (VB *sim, int index, uint32_t value);
VBAPI void*         vbSetUserData         (VB *sim, void *tag);
VBAPI vbOnWrite     vbSetWriteCallback    (VB *sim, vbOnWrite callback);
VBAPI size_t        vbSizeOf              ();
VBAPI int32_t       vbWrite               (VB *sim, uint32_t address, int type, int32_t value);



#ifdef __cplusplus
}
#endif

#endif /* VB_H_ */