cog/Frameworks/GME/vgmplay/chips/sn76489.h

109 lines
3.5 KiB
C

#ifndef _SN76489_H_
#define _SN76489_H_
// all these defines are defined in mamedef.h, but GCC's #ifdef doesn't seem to know typedefs
/*#ifndef INT32
#define INT32 signed long
#endif
#ifndef UINT16
#define UINT16 unsigned short
#endif
#ifndef INT16
#define INT16 signed short
#endif
#ifndef INT8
#define INT8 signed char
#endif*/
#ifndef uint8
#define uint8 signed char
#endif
/*#define MAX_SN76489 4*/
/*
More testing is needed to find and confirm feedback patterns for
SN76489 variants and compatible chips.
*/
enum feedback_patterns {
FB_BBCMICRO = 0x8005, /* Texas Instruments TMS SN76489N (original) from BBC Micro computer */
FB_SC3000 = 0x0006, /* Texas Instruments TMS SN76489AN (rev. A) from SC-3000H computer */
FB_SEGAVDP = 0x0009, /* SN76489 clone in Sega's VDP chips (315-5124, 315-5246, 315-5313, Game Gear) */
};
enum sr_widths {
SRW_SC3000BBCMICRO = 15,
SRW_SEGAVDP = 16
};
enum volume_modes {
VOL_TRUNC = 0, /* Volume levels 13-15 are identical */
VOL_FULL = 1, /* Volume levels 13-15 are unique */
};
enum mute_values {
MUTE_ALLOFF = 0, /* All channels muted */
MUTE_TONE1 = 1, /* Tone 1 mute control */
MUTE_TONE2 = 2, /* Tone 2 mute control */
MUTE_TONE3 = 4, /* Tone 3 mute control */
MUTE_NOISE = 8, /* Noise mute control */
MUTE_ALLON = 15, /* All channels enabled */
};
typedef struct
{
int Mute; // per-channel muting
int BoostNoise; // double noise volume when non-zero
/* Variables */
float Clock;
float dClock;
int PSGStereo;
int NumClocksForSample;
int WhiteNoiseFeedback;
int SRWidth;
/* PSG registers: */
int Registers[8]; /* Tone, vol x4 */
int LatchedRegister;
int NoiseShiftRegister;
int NoiseFreq; /* Noise channel signal generator frequency */
/* Output calculation variables */
int ToneFreqVals[4]; /* Frequency register values (counters) */
int ToneFreqPos[4]; /* Frequency channel flip-flops */
int Channels[4]; /* Value of each channel, before stereo is applied */
float IntermediatePos[4]; /* intermediate values used at boundaries between + and - (does not need double accuracy)*/
float panning[4][2]; /* fake stereo */
int NgpFlags; /* bit 7 - NGP Mode on/off, bit 0 - is 2nd NGP chip */
void* NgpChip2;
} SN76489_Context;
/* Function prototypes */
SN76489_Context* SN76489_Init(int PSGClockValue, int SamplingRate);
void SN76489_Reset(SN76489_Context* chip);
void SN76489_Shutdown(SN76489_Context* chip);
void SN76489_Config(SN76489_Context* chip, /*int mute,*/ int feedback, int sw_width, int boost_noise);
/*
void SN76489_SetContext(SN76489_Context* chip, uint8 *data);
void SN76489_GetContext(SN76489_Context* chip, uint8 *data);
uint8 *SN76489_GetContextPtr(int chip);
int SN76489_GetContextSize(void);*/
void SN76489_Write(SN76489_Context* chip, int data);
void SN76489_GGStereoWrite(SN76489_Context* chip, int data);
//void SN76489_Update(SN76489_Context* chip, INT16 **buffer, int length);
void SN76489_Update(SN76489_Context* chip, INT32 **buffer, int length);
/* Non-standard getters and setters */
//int SN76489_GetMute(SN76489_Context* chip);
void SN76489_SetMute(SN76489_Context* chip, int val);
void SN76489_SetPanning(SN76489_Context* chip, int ch0, int ch1, int ch2, int ch3);
/* and a non-standard data getter */
//void SN76489_UpdateOne(SN76489_Context* chip, int *l, int *r);
#endif /* _SN76489_H_ */