o cleanup

tools/bsnes/chip/spc7110/decomp.hpp

@@ -0,0 +1,45 @@
+class SPC7110Decomp {
+public:
+  uint8 read();
+  void init(unsigned mode, unsigned offset, unsigned index);
+  void reset();
+
+  SPC7110Decomp();
+  ~SPC7110Decomp();
+
+private:
+  unsigned decomp_mode;
+  unsigned decomp_offset;
+
+  //read() will spool chunks half the size of decomp_buffer_size
+  enum { decomp_buffer_size = 64 }; //must be >= 64, and must be a power of two
+  uint8 *decomp_buffer;
+  unsigned decomp_buffer_rdoffset;
+  unsigned decomp_buffer_wroffset;
+  unsigned decomp_buffer_length;
+
+  void write(uint8 data);
+  uint8 dataread();
+
+  void mode0(bool init);
+  void mode1(bool init);
+  void mode2(bool init);
+
+  static const uint8 evolution_table[53][4];
+  static const uint8 mode2_context_table[32][2];
+
+  struct ContextState {
+    uint8 index;
+    uint8 invert;
+  } context[32];
+
+  uint8 probability(unsigned n);
+  uint8 next_lps(unsigned n);
+  uint8 next_mps(unsigned n);
+  bool toggle_invert(unsigned n);
+
+  unsigned morton16[2][256];
+  unsigned morton32[4][256];
+  unsigned morton_2x8(unsigned data);
+  unsigned morton_4x8(unsigned data);
+};