1 files changed, 132 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/hes_cpu.h b/lib/rbcodec/codecs/libgme/hes_cpu.h
new file mode 100644
index 0000000000..0429eeaba0
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/hes_cpu.h
@@ -0,0 +1,132 @@
+// PC Engine CPU emulator for use with HES music files
+
+// Game_Music_Emu 0.6-pre
+#ifndef HES_CPU_H
+#define HES_CPU_H
+
+#include "blargg_common.h"
+#include "blargg_source.h"
+
+typedef int hes_time_t; // clock cycle count
+typedef int hes_addr_t; // 16-bit address
+
+struct Hes_Emu;
+
+enum { future_time = INT_MAX/2 + 1 };
+enum { page_bits = 13 };
+enum { page_size = 1 << page_bits };
+enum { page_count = 0x10000 / page_size };
+
+// Can read this many bytes past end of a page
+enum { cpu_padding = 8 };
+enum { irq_inhibit_mask = 0x04 };
+enum { idle_addr = 0x1FFF };
+
+// Cpu state
+struct cpu_state_t {
+        byte const* code_map [page_count + 1];
+        hes_time_t base;
+        int time;
+};
+
+// NOT kept updated during emulation.
+struct registers_t {
+        uint16_t pc;
+        byte a;
+        byte x;
+        byte y;
+        byte flags;
+        byte sp;
+};
+
+struct Hes_Cpu {
+        struct registers_t r;
+
+        hes_time_t irq_time_;
+        hes_time_t end_time_;
+        
+        struct cpu_state_t* cpu_state; // points to state_ or a local copy within run()
+        struct cpu_state_t cpu_state_;
+        
+        // page mapping registers
+        uint8_t mmr [page_count + 1];
+        uint8_t ram [page_size];
+};
+
+// Init cpu state
+static inline void Cpu_init( struct Hes_Cpu* this )
+{
+        this->cpu_state = &this->cpu_state_;
+}
+
+// Reset hes cpu
+void Cpu_reset( struct Hes_Cpu* this );
+
+// Set end_time and run CPU from current time. Returns true if any illegal
+// instructions were encountered.
+bool Cpu_run( struct Hes_Emu* this, hes_time_t end_time );
+
+// Time of ning of next instruction to be executed
+static inline hes_time_t Cpu_time( struct Hes_Cpu* this )
+{
+        return this->cpu_state->time + this->cpu_state->base;
+}
+
+static inline void Cpu_set_time( struct Hes_Cpu* this, hes_time_t t )    { this->cpu_state->time = t - this->cpu_state->base; }
+static inline void Cpu_adjust_time( struct Hes_Cpu* this, int delta )    { this->cpu_state->time += delta; }
+
+#define HES_CPU_PAGE( addr ) ((unsigned) (addr) >> page_bits)
+
+#ifdef BLARGG_NONPORTABLE
+        #define HES_CPU_OFFSET( addr ) (addr)
+#else
+        #define HES_CPU_OFFSET( addr ) ((addr) & (page_size - 1))
+#endif
+
+static inline uint8_t const* Cpu_get_code( struct Hes_Cpu* this, hes_addr_t addr )
+{
+        return this->cpu_state_.code_map [HES_CPU_PAGE( addr )] + HES_CPU_OFFSET( addr );
+}
+
+static inline void update_end_time( struct Hes_Cpu* this, hes_time_t end, hes_time_t irq )
+{
+        if ( end > irq && !(this->r.flags & irq_inhibit_mask) )
+                end = irq;
+        
+        this->cpu_state->time += this->cpu_state->base - end;
+        this->cpu_state->base = end;
+}
+
+static inline hes_time_t Cpu_end_time( struct Hes_Cpu* this ) { return this->end_time_; }
+
+static inline void Cpu_set_irq_time( struct Hes_Cpu* this, hes_time_t t )
+{
+        this->irq_time_ = t;
+        update_end_time( this, this->end_time_, t );
+}
+
+static inline void Cpu_set_end_time( struct Hes_Cpu* this, hes_time_t t )
+{
+        this->end_time_ = t;
+        update_end_time( this, t, this->irq_time_ );
+}
+
+static inline void Cpu_end_frame( struct Hes_Cpu* this, hes_time_t t )
+{
+        assert( this->cpu_state == &this->cpu_state_ );
+        this->cpu_state_.base -= t;
+        if ( this->irq_time_ < future_time ) this->irq_time_ -= t;
+        if ( this->end_time_ < future_time ) this->end_time_ -= t;
+}
+
+static inline void Cpu_set_mmr( struct Hes_Cpu* this, int reg, int bank, void const* code )
+{
+        assert( (unsigned) reg <= page_count ); // allow page past end to be set
+        assert( (unsigned) bank < 0x100 );
+        this->mmr [reg] = bank;
+        byte const* p = STATIC_CAST(byte const*,code) - HES_CPU_OFFSET( reg << page_bits );
+        this->cpu_state->code_map [reg] = p;
+        this->cpu_state_.code_map [reg] = p;
+}
+
+#endif