Classic_Emu.h

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// Common aspects of emulators which use Blip_Buffer for sound output
 
// Game_Music_Emu https://bitbucket.org/mpyne/game-music-emu/
#ifndef CLASSIC_EMU_H
#define CLASSIC_EMU_H
 
#include "blargg_common.h"
#include "Blip_Buffer.h"
#include "Music_Emu.h"
 
class Classic_Emu : public Music_Emu {
public:
        Classic_Emu();
        ~Classic_Emu();
        void set_buffer( Multi_Buffer* );
        blargg_err_t set_multi_channel( bool is_enabled ) override;
protected:
        // Services
        enum { wave_type = 0x100, noise_type = 0x200, mixed_type = wave_type | noise_type };
        void set_voice_types( int const* t ) { voice_types = t; }
        blargg_err_t setup_buffer( long clock_rate );
        long clock_rate() const { return clock_rate_; }
        void change_clock_rate( long ); // experimental
        
        // Overridable
        virtual void set_voice( int index, Blip_Buffer* center,
                        Blip_Buffer* left, Blip_Buffer* right ) = 0;
        virtual void update_eq( blip_eq_t const& ) = 0;
        virtual blargg_err_t start_track_( int track ) = 0;
        virtual blargg_err_t run_clocks( blip_time_t& time_io, int msec ) = 0;
protected:
        blargg_err_t set_sample_rate_( long sample_rate );
        void mute_voices_( int );
        void set_equalizer_( equalizer_t const& );
        blargg_err_t play_( long, sample_t* );
private:
        Multi_Buffer* buf;
        Multi_Buffer* stereo_buffer; // NULL if using custom buffer
        long clock_rate_;
        unsigned buf_changed_count;
        int const* voice_types;
};
 
inline void Classic_Emu::set_buffer( Multi_Buffer* new_buf )
{
        assert( !buf && new_buf );
        buf = new_buf;
}
 
// ROM data handler, used by several Classic_Emu derivitives. Loads file data
// with padding on both sides, allowing direct use in bank mapping. The main purpose
// is to allow all file data to be loaded with only one read() call (for efficiency).
 
class Rom_Data_ {
public:
        typedef unsigned char byte;
protected:
        enum { pad_extra = 8 };
        blargg_vector<byte> rom;
        long file_size_;
        blargg_long rom_addr;
        blargg_long mask;
        blargg_long size_; // TODO: eliminate
        
        blargg_err_t load_rom_data_( Data_Reader& in, int header_size, void* header_out,
                        int fill, long pad_size );
        void set_addr_( long addr, int unit );
};
 
template<int unit>
class Rom_Data : public Rom_Data_ {
        enum { pad_size = unit + pad_extra };
public:
        // Load file data, using already-loaded header 'h' if not NULL. Copy header
        // from loaded file data into *out and fill unmapped bytes with 'fill'.
        blargg_err_t load( Data_Reader& in, int header_size, void* header_out, int fill )
        {
                return load_rom_data_( in, header_size, header_out, fill, pad_size );
        }
        
        // Size of file data read in (excluding header)
        long file_size() const { return file_size_; }
        
        // Pointer to beginning of file data
        byte* begin() const { return rom.begin() + pad_size; }
        
        // Set address that file data should start at
        void set_addr( long addr ) { set_addr_( addr, unit ); }
        
        // Free data
        void clear() { rom.clear(); }
        
        // Size of data + start addr, rounded to a multiple of unit
        long size() const { return size_; }
        
        // Pointer to unmapped page filled with same value
        byte* unmapped() { return rom.begin(); }
        
        // Mask address to nearest power of two greater than size()
        blargg_long mask_addr( blargg_long addr ) const
        {
                #ifdef check
                        check( addr <= mask );
                #endif
                return addr & mask;
        }
        
        // Pointer to page starting at addr. Returns unmapped() if outside data.
        byte* at_addr( blargg_long addr )
        {
                blargg_ulong offset = mask_addr( addr ) - rom_addr;
                if ( offset > blargg_ulong (rom.size() - pad_size) )
                        offset = 0; // unmapped
                return &rom [offset];
        }
};
 
#ifndef GME_APU_HOOK
        #define GME_APU_HOOK( emu, addr, data ) ((void) 0)
#endif
 
#ifndef GME_FRAME_HOOK
        #define GME_FRAME_HOOK( emu ) ((void) 0)
#else
        #define GME_FRAME_HOOK_DEFINED 1
#endif
 
#endif