From: notaz <notasas@gmail.com>
Date: Tue, 30 Jul 2013 23:18:34 +0000 (+0300)
Subject: libretro: add savestate support
X-Git-Tag: v1.85~17
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?p=picodrive.git;a=commitdiff_plain;h=86b38dc46d93354418faf5aecd430f8661adb4b3

libretro: add savestate support
---

diff --git a/pico/state.c b/pico/state.c
index 11eee6f..3969e18 100644
--- a/pico/state.c
+++ b/pico/state.c
@@ -11,15 +11,11 @@
 
 #include "../cpu/sh2/sh2.h"
 #include "sound/ym2612.h"
+#include "state.h"
 
 // sn76496
 extern int *sn76496_regs;
 
-typedef size_t (arearw)(void *p, size_t _size, size_t _n, void *file);
-typedef size_t (areaeof)(void *file);
-typedef int    (areaseek)(void *file, long offset, int whence);
-typedef int    (areaclose)(void *file);
-
 static arearw    *areaRead;
 static arearw    *areaWrite;
 static areaeof   *areaEof;
@@ -594,15 +590,10 @@ readend:
   return 0;
 }
 
-int PicoState(const char *fname, int is_save)
+static int pico_state_internal(void *afile, int is_save)
 {
-  void *afile = NULL;
   int ret;
 
-  afile = open_save_file(fname, is_save);
-  if (afile == NULL)
-    return -1;
-
   if (is_save)
     ret = state_save(afile);
   else {
@@ -617,10 +608,35 @@ int PicoState(const char *fname, int is_save)
     Pico.m.dirtyPal = 1;
   }
 
+  return ret;
+}
+
+int PicoState(const char *fname, int is_save)
+{
+  void *afile = NULL;
+  int ret;
+
+  afile = open_save_file(fname, is_save);
+  if (afile == NULL)
+    return -1;
+
+  ret = pico_state_internal(afile, is_save);
   areaClose(afile);
   return ret;
 }
 
+int PicoStateFP(void *afile, int is_save,
+  arearw *read, arearw *write, areaeof *eof, areaseek *seek)
+{
+  areaRead  = read;
+  areaWrite = write;
+  areaEof   = eof;
+  areaSeek  = seek;
+  areaClose = NULL;
+
+  return pico_state_internal(afile, is_save);
+}
+
 int PicoStateLoadGfx(const char *fname)
 {
   void *afile;
diff --git a/pico/state.h b/pico/state.h
new file mode 100644
index 0000000..1d38022
--- /dev/null
+++ b/pico/state.h
@@ -0,0 +1,9 @@
+#include <stdlib.h>
+
+typedef size_t (arearw)(void *p, size_t _size, size_t _n, void *file);
+typedef size_t (areaeof)(void *file);
+typedef int    (areaseek)(void *file, long offset, int whence);
+typedef int    (areaclose)(void *file);
+
+int PicoStateFP(void *afile, int is_save,
+  arearw *read, arearw *write, areaeof *eof, areaseek *seek);
diff --git a/platform/libretro.c b/platform/libretro.c
index 15a83ba..d46cc4a 100644
--- a/platform/libretro.c
+++ b/platform/libretro.c
@@ -17,6 +17,7 @@
 #endif
 
 #include <pico/pico_int.h>
+#include <pico/state.h>
 #include "common/input_pico.h"
 #include "common/version.h"
 #include "libretro.h"
@@ -226,20 +227,124 @@ void retro_get_system_av_info(struct retro_system_av_info *info)
 	info->geometry.aspect_ratio = 4.0 / 3.0;
 }
 
-/* savestates - TODO */
+/* savestates */
+struct savestate_state {
+	const char *load_buf;
+	char *save_buf;
+	size_t size;
+	size_t pos;
+};
+
+size_t state_read(void *p, size_t size, size_t nmemb, void *file)
+{
+	struct savestate_state *state = file;
+	size_t bsize = size * nmemb;
+
+	if (state->pos + bsize > state->size) {
+		lprintf("savestate error: %u/%u\n",
+			state->pos + bsize, state->size);
+		bsize = state->size - state->pos;
+		if ((int)bsize <= 0)
+			return 0;
+	}
+
+	memcpy(p, state->load_buf + state->pos, bsize);
+	state->pos += bsize;
+	return bsize;
+}
+
+size_t state_write(void *p, size_t size, size_t nmemb, void *file)
+{
+	struct savestate_state *state = file;
+	size_t bsize = size * nmemb;
+
+	if (state->pos + bsize > state->size) {
+		lprintf("savestate error: %u/%u\n",
+			state->pos + bsize, state->size);
+		bsize = state->size - state->pos;
+		if ((int)bsize <= 0)
+			return 0;
+	}
+
+	memcpy(state->save_buf + state->pos, p, bsize);
+	state->pos += bsize;
+	return bsize;
+}
+
+size_t state_skip(void *p, size_t size, size_t nmemb, void *file)
+{
+	struct savestate_state *state = file;
+	size_t bsize = size * nmemb;
+
+	state->pos += bsize;
+	return bsize;
+}
+
+size_t state_eof(void *file)
+{
+	struct savestate_state *state = file;
+
+	return state->pos >= state->size;
+}
+
+int state_fseek(void *file, long offset, int whence)
+{
+	struct savestate_state *state = file;
+
+	switch (whence) {
+	case SEEK_SET:
+		state->pos = offset;
+		break;
+	case SEEK_CUR:
+		state->pos += offset;
+		break;
+	case SEEK_END:
+		state->pos = state->size + offset;
+		break;
+	}
+	return (int)state->pos;
+}
+
+/* savestate sizes vary wildly depending if cd/32x or
+ * carthw is active, so run the whole thing to get size */
 size_t retro_serialize_size(void) 
 { 
-       return 0;
+	struct savestate_state state = { 0, };
+	int ret;
+
+	ret = PicoStateFP(&state, 1, NULL, state_skip, NULL, state_fseek);
+	if (ret != 0)
+		return 0;
+
+	return state.pos;
 }
 
 bool retro_serialize(void *data, size_t size)
 { 
-       return false;
+	struct savestate_state state = { 0, };
+	int ret;
+
+	state.save_buf = data;
+	state.size = size;
+	state.pos = 0;
+
+	ret = PicoStateFP(&state, 1, NULL, state_write,
+		NULL, state_fseek);
+	return ret == 0;
 }
 
 bool retro_unserialize(const void *data, size_t size)
 {
-       return false;
+	struct savestate_state state = { 0, };
+	int ret;
+
+	state.load_buf = data;
+	state.size = size;
+	state.pos = 0;
+
+	ret = PicoStateFP(&state, 0, state_read, NULL,
+		state_eof, state_fseek);
+	return ret == 0;
 }
 
 /* cheats - TODO */