start implementing the libretro interface. (not working yet)

1 files changed, 291 insertions, 0 deletions

diff --git a/libretro.c b/libretro.c
new file mode 100644
index 0000000..56a4ccf
--- /dev/null
+++ b/libretro.c
@@ -0,0 +1,291 @@
+
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include "common.h"
+#include "libco.h"
+
+static retro_log_printf_t log_cb;
+static retro_video_refresh_t video_cb;
+static retro_input_poll_t input_poll_cb;
+static retro_environment_t environ_cb;
+
+struct retro_perf_callback perf_cb;
+
+static cothread_t main_thread;
+static cothread_t cpu_thread;
+
+void switch_to_main_thread(void)
+{
+   co_switch(main_thread);
+}
+
+static inline void switch_to_cpu_thread(void)
+{
+   co_switch(cpu_thread);
+}
+
+static void cpu_thread_entry(void)
+{
+   execute_arm_translate(reg[EXECUTE_CYCLES]);
+}
+
+static inline void init_context_switch(void)
+{
+   main_thread = co_active();
+   cpu_thread = co_create(0x20000, cpu_thread_entry);
+}
+
+static inline void deinit_context_switch(void)
+{
+   co_delete(cpu_thread);
+}
+
+void retro_get_system_info(struct retro_system_info *info)
+{
+   info->library_name = "TempGBA";
+   info->library_version = "v0.0.1";
+   info->need_fullpath = true;
+   info->block_extract = false;
+   info->valid_extensions = "gba|bin|agb|gbz" ;
+}
+
+
+void retro_get_system_av_info(struct retro_system_av_info *info)
+{
+   info->geometry.base_width = GBA_SCREEN_WIDTH;
+   info->geometry.base_height = GBA_SCREEN_HEIGHT;
+   info->geometry.max_width = GBA_SCREEN_WIDTH;
+   info->geometry.max_height = GBA_SCREEN_HEIGHT;
+   info->geometry.aspect_ratio = 0;
+   info->timing.fps = ((float) CPU_FREQUENCY) / (308 * 228 * 4); // 59.72750057 hz
+   info->timing.sample_rate = SOUND_FREQUENCY;
+//   info->timing.sample_rate = 32 * 1024;
+}
+
+
+void retro_init()
+{
+   init_gamepak_buffer();
+   init_sound();
+}
+
+void retro_deinit()
+{
+   perf_cb.perf_log();
+   quit_gba();
+}
+
+void retro_set_environment(retro_environment_t cb)
+{
+   struct retro_log_callback log;
+
+   environ_cb = cb;
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log))
+      log_cb = log.log;
+   else
+      log_cb = NULL;
+
+   environ_cb(RETRO_ENVIRONMENT_GET_PERF_INTERFACE, &perf_cb);
+
+}
+
+void retro_set_video_refresh(retro_video_refresh_t cb) { video_cb = cb; }
+void retro_set_input_poll(retro_input_poll_t cb) { input_poll_cb = cb; }
+
+void retro_set_controller_port_device(unsigned port, unsigned device) {}
+
+void retro_reset()
+{
+   deinit_context_switch();
+
+   update_backup();
+   reset_gba();
+
+   init_context_switch();
+}
+
+
+size_t retro_serialize_size()
+{
+   return SAVESTATE_SIZE;
+}
+
+bool retro_serialize(void *data, size_t size)
+{
+   if (size < SAVESTATE_SIZE)
+      return false;
+
+   gba_save_state(data);
+
+   return true;
+}
+
+bool retro_unserialize(const void *data, size_t size)
+{
+   if (size < SAVESTATE_SIZE)
+      return false;
+
+   gba_load_state(data);
+
+   return true;
+}
+
+void retro_cheat_reset() {}
+void retro_cheat_set(unsigned index, bool enabled, const char *code) {}
+
+void error_msg(const char *text)
+{
+   if (log_cb)
+      log_cb(RETRO_LOG_ERROR, text);
+}
+
+void info_msg(const char *text)
+{
+   if (log_cb)
+      log_cb(RETRO_LOG_INFO, text);
+}
+
+static void extract_directory(char *buf, const char *path, size_t size)
+{
+   strncpy(buf, path, size - 1);
+   buf[size - 1] = '\0';
+
+   char *base = strrchr(buf, '/');
+
+   if (base)
+      *base = '\0';
+   else
+      strncpy(buf, ".", size);
+}
+
+bool retro_load_game(const struct retro_game_info *info)
+{
+   char filename_bios[MAX_PATH];
+   const char *dir = NULL;
+
+   enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
+   if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
+   {
+      if (log_cb)
+         log_cb(RETRO_LOG_INFO, "[TempGBA]: 0RGB1555 is not supported.\n");
+      return false;
+   }
+
+   extract_directory(main_path,info->path,sizeof(main_path));
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &dir) && dir)
+      strncpy(filename_bios, dir, sizeof(filename_bios));
+   else
+      strncpy(filename_bios, main_path, sizeof(filename_bios));
+
+   strncat(filename_bios, "/gba_bios.bin",sizeof(filename_bios));
+
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY, &dir) && dir)
+      strncpy(dir_save, dir, sizeof(dir_save));
+   else
+      strncpy(dir_save, main_path, sizeof(dir_save));
+
+   strncat(dir_save, "/",sizeof(dir_save));
+
+   strncat(main_path, "/",sizeof(main_path));
+
+   if (load_bios(filename_bios) < 0)
+   {
+     error_msg("Could not load BIOS image file.\n");
+     return false;
+   }
+
+   gamepak_filename[0] = 0;
+
+   if (load_gamepak(info->path) < 0)
+   {
+     error_msg("Could not load the game file.\n");
+     return false;
+   }
+
+   reset_gba();
+
+   init_context_switch();
+
+   return true;
+}
+
+
+bool retro_load_game_special(unsigned game_type, const struct retro_game_info *info, size_t num_info)
+{ return false; }
+
+void retro_unload_game()
+{
+   deinit_context_switch();
+   update_backup();
+}
+
+unsigned retro_get_region() { return RETRO_REGION_NTSC; }
+
+void *retro_get_memory_data(unsigned id)
+{
+//   switch (id)
+//   {
+//   case RETRO_MEMORY_SAVE_RAM:
+//      return gamepak_backup;
+//   }
+
+   return 0;
+}
+
+size_t retro_get_memory_size(unsigned id)
+{
+//   switch (id)
+//   {
+//   case RETRO_MEMORY_SAVE_RAM:
+//      switch(backup_type)
+//      {
+//      case BACKUP_SRAM:
+//         return sram_size;
+
+//      case BACKUP_FLASH:
+//         return flash_size;
+
+//      case BACKUP_EEPROM:
+//         return eeprom_size;
+
+//      case BACKUP_NONE:
+//         return 0x0;
+
+//      default:
+//         return 0x8000;
+//      }
+//   }
+
+   return 0;
+}
+
+static void check_variables(void)
+{
+
+}
+
+void retro_run()
+{
+   bool updated = false;
+
+   input_poll_cb();
+
+   switch_to_cpu_thread();
+
+   update_input();
+
+   render_audio();
+
+   video_cb(GBA_FRAME_TEXTURE, GBA_SCREEN_WIDTH, GBA_SCREEN_HEIGHT, 512);
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated)
+       check_variables();
+
+}
+
+unsigned retro_api_version() { return RETRO_API_VERSION; }