view snes_spc/dsp.h @ 0:e38dacceb958

initial import
author Robert McIntyre <rlm@mit.edu>
date Fri, 21 Oct 2011 05:53:11 -0700
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1 /* SNES SPC-700 DSP emulator C interface (also usable from C++) */
3 /* snes_spc 0.9.0 */
4 #ifndef DSP_H
5 #define DSP_H
7 #include <stddef.h>
9 #ifdef __cplusplus
10 extern "C" {
11 #endif
13 typedef struct SPC_DSP SPC_DSP;
15 /* Creates new DSP emulator. NULL if out of memory. */
16 SPC_DSP* spc_dsp_new( void );
18 /* Frees DSP emulator */
19 void spc_dsp_delete( SPC_DSP* );
21 /* Initializes DSP and has it use the 64K RAM provided */
22 void spc_dsp_init( SPC_DSP*, void* ram_64k );
24 /* Sets destination for output samples. If out is NULL or out_size is 0,
25 doesn't generate any. */
26 typedef short spc_dsp_sample_t;
27 void spc_dsp_set_output( SPC_DSP*, spc_dsp_sample_t* out, int out_size );
29 /* Number of samples written to output since it was last set, always
30 a multiple of 2. Undefined if more samples were generated than
31 output buffer could hold. */
32 int spc_dsp_sample_count( SPC_DSP const* );
35 /**** Emulation *****/
37 /* Resets DSP to power-on state */
38 void spc_dsp_reset( SPC_DSP* );
40 /* Emulates pressing reset switch on SNES */
41 void spc_dsp_soft_reset( SPC_DSP* );
43 /* Reads/writes DSP registers. For accuracy, you must first call spc_dsp_run() */
44 /* to catch the DSP up to present. */
45 int spc_dsp_read ( SPC_DSP const*, int addr );
46 void spc_dsp_write( SPC_DSP*, int addr, int data );
48 /* Runs DSP for specified number of clocks (~1024000 per second). Every 32 clocks */
49 /* a pair of samples is be generated. */
50 void spc_dsp_run( SPC_DSP*, int clock_count );
53 /**** Sound control *****/
55 /* Mutes voices corresponding to non-zero bits in mask. Reduces emulation accuracy. */
56 enum { spc_dsp_voice_count = 8 };
57 void spc_dsp_mute_voices( SPC_DSP*, int mask );
59 /* If true, prevents channels and global volumes from being phase-negated.
60 Only supported by fast DSP; has no effect on accurate DSP. */
61 void spc_dsp_disable_surround( SPC_DSP*, int disable );
64 /**** State save/load *****/
66 /* Resets DSP and uses supplied values to initialize registers */
67 enum { spc_dsp_register_count = 128 };
68 void spc_dsp_load( SPC_DSP*, unsigned char const regs [spc_dsp_register_count] );
70 /* Saves/loads exact emulator state (accurate DSP only) */
71 enum { spc_dsp_state_size = 640 }; /* maximum space needed when saving */
72 typedef void (*spc_dsp_copy_func_t)( unsigned char** io, void* state, size_t );
73 void spc_dsp_copy_state( SPC_DSP*, unsigned char** io, spc_dsp_copy_func_t );
75 /* Returns non-zero if new key-on events occurred since last call (accurate DSP only) */
76 int spc_dsp_check_kon( SPC_DSP* );
79 #ifdef __cplusplus
80 }
81 #endif
83 #endif