libretro: support disk control interface

2 files changed, 271 insertions, 4 deletions

diff --git a/frontend/libretro.c b/frontend/libretro.c
index c6d113f..e22ef5b 100644
--- a/frontend/libretro.c
+++ b/frontend/libretro.c
@@ -13,6 +13,8 @@
 #include "../libpcsxcore/psxcounters.h"
 #include "../libpcsxcore/psxmem_map.h"
 #include "../libpcsxcore/new_dynarec/new_dynarec.h"
+#include "../libpcsxcore/cdrom.h"
+#include "../libpcsxcore/cdriso.h"
 #include "../libpcsxcore/cheat.h"
 #include "../plugins/dfsound/out.h"
 #include "cspace.h"
@@ -363,6 +365,7 @@ bool retro_unserialize(const void *data, size_t size)
 	return ret == 0 ? true : false;
 }
 
+/* cheats */
 void retro_cheat_reset(void)
 {
 	ClearAllCheats();
@@ -388,8 +391,132 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
 		Cheats[index].Enabled = enabled;
 }
 
+/* multidisk support */
+static bool disk_ejected;
+static unsigned int disk_current_index;
+static struct disks_state {
+	char *fname;
+	int internal_index; // for multidisk eboots
+} disks[8];
+
+static bool disk_set_eject_state(bool ejected)
+{
+	// weird PCSX API..
+	SetCdOpenCaseTime(ejected ? -1 : (time(NULL) + 2));
+	LidInterrupt();
+
+	disk_ejected = ejected;
+	return true;
+}
+
+static bool disk_get_eject_state(void)
+{
+	/* can't be controlled by emulated software */
+	return disk_ejected;
+}
+
+static unsigned int disk_get_image_index(void)
+{
+	return disk_current_index;
+}
+
+static bool disk_set_image_index(unsigned int index)
+{
+	if (index >= sizeof(disks) / sizeof(disks[0]))
+		return false;
+
+	CdromId[0] = '\0';
+	CdromLabel[0] = '\0';
+
+	if (disks[index].fname == NULL) {
+		SysPrintf("missing disk #%u\n", index);
+		CDR_shutdown();
+
+		// RetroArch specifies "no disk" with index == count,
+		// so don't fail here..
+		disk_current_index = index;
+		return true;
+	}
+
+	SysPrintf("switching to disk %u: \"%s\" #%d\n", index,
+		disks[index].fname, disks[index].internal_index);
+
+	cdrIsoMultidiskSelect = disks[index].internal_index;
+	set_cd_image(disks[index].fname);
+	if (ReloadCdromPlugin() < 0) {
+		SysPrintf("failed to load cdr plugin\n");
+		return false;
+	}
+	if (CDR_open() < 0) {
+		SysPrintf("failed to open cdr plugin\n");
+		return false;
+	}
+
+	if (!disk_ejected) {
+		SetCdOpenCaseTime(time(NULL) + 2);
+		LidInterrupt();
+	}
+
+	disk_current_index = index;
+	return true;
+}
+
+static unsigned int disk_get_num_images(void)
+{
+	unsigned int count = 0;
+	size_t i;
+
+	for (i = 0; i < sizeof(disks) / sizeof(disks[0]); i++)
+		if (disks[i].fname != NULL)
+			count++;
+
+	return count;
+}
+
+static bool disk_replace_image_index(unsigned index,
+	const struct retro_game_info *info)
+{
+	char *old_fname;
+	bool ret = true;
+
+	if (index >= sizeof(disks) / sizeof(disks[0]))
+		return false;
+
+	old_fname = disks[index].fname;
+	disks[index].fname = NULL;
+	disks[index].internal_index = 0;
+
+	if (info != NULL) {
+		disks[index].fname = strdup(info->path);
+		if (index == disk_current_index)
+			ret = disk_set_image_index(index);
+	}
+
+	if (old_fname != NULL)
+		free(old_fname);
+
+	return ret;
+}
+
+static bool disk_add_image_index(void)
+{
+	// TODO??
+	return true;
+}
+
+static struct retro_disk_control_callback disk_control = {
+	.set_eject_state = disk_set_eject_state,
+	.get_eject_state = disk_get_eject_state,
+	.get_image_index = disk_get_image_index,
+	.set_image_index = disk_set_image_index,
+	.get_num_images = disk_get_num_images,
+	.replace_image_index = disk_replace_image_index,
+	.add_image_index = disk_add_image_index,
+};
+
 bool retro_load_game(const struct retro_game_info *info)
 {
+	size_t i;
 #ifdef FRONTEND_SUPPORTS_RGB565
 	enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
 	if (environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt)) {
@@ -397,12 +524,28 @@ bool retro_load_game(const struct retro_game_info *info)
 	}
 #endif
 
+	if (info == NULL || info->path == NULL) {
+		SysPrintf("info->path required\n");
+		return false;
+	}
+
 	if (plugins_opened) {
 		ClosePlugins();
 		plugins_opened = 0;
 	}
 
-	set_cd_image(info->path);
+	for (i = 0; i < sizeof(disks) / sizeof(disks[0]); i++) {
+		if (disks[i].fname != NULL) {
+			free(disks[i].fname);
+			disks[i].fname = NULL;
+		}
+		disks[i].internal_index = 0;
+	}
+
+	disk_current_index = 0;
+	disks[0].fname = strdup(info->path);
+
+	set_cd_image(disks[0].fname);
 
 	/* have to reload after set_cd_image for correct cdr plugin */
 	if (LoadPlugins() == -1) {
@@ -434,6 +577,12 @@ bool retro_load_game(const struct retro_game_info *info)
 	}
 	emu_on_new_cd(0);
 
+	// multidisk images
+	for (i = 1; i < sizeof(disks) / sizeof(disks[0]) && i < cdrIsoMultidiskCount; i++) {
+		disks[i].fname = strdup(info->path);
+		disks[i].internal_index = i;
+	}
+
 	return true;
 }
 
@@ -551,6 +700,7 @@ void retro_init(void)
 	environ_cb(RETRO_ENVIRONMENT_SET_PERFORMANCE_LEVEL, &level);
 
 	environ_cb(RETRO_ENVIRONMENT_GET_CAN_DUPE, &vout_can_dupe);
+	environ_cb(RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE, &disk_control);
 
 	/* Set how much slower PSX CPU runs * 100 (so that 200 is 2 times)
 	 * we have to do this because cache misses and some IO penalties
diff --git a/frontend/libretro.h b/frontend/libretro.h
index 3eef758..0c39e6e 100644
--- a/frontend/libretro.h
+++ b/frontend/libretro.h
@@ -19,7 +19,7 @@ extern "C" {
 #endif
 
 // Used for checking API/ABI mismatches that can break libretro implementations.
-// It is not incremented for compatible changes.
+// It is not incremented for compatible changes to the API.
 #define RETRO_API_VERSION         1
 
 // Libretro's fundamental device abstractions.
@@ -50,6 +50,28 @@ extern "C" {
 // Only use ANALOG type when polling for analog values of the axes.
 #define RETRO_DEVICE_ANALOG       5
 
+// Abstracts the concept of a pointing mechanism, e.g. touch.
+// This allows libretro to query in absolute coordinates where on the screen a mouse (or something similar) is being placed.
+// For a touch centric device, coordinates reported are the coordinates of the press.
+//
+// Coordinates in X and Y are reported as:
+// [-0x7fff, 0x7fff]: -0x7fff corresponds to the far left/top of the screen,
+// and 0x7fff corresponds to the far right/bottom of the screen.
+// The "screen" is here defined as area that is passed to the frontend and later displayed on the monitor.
+// The frontend is free to scale/resize this screen as it sees fit, however,
+// (X, Y) = (-0x7fff, -0x7fff) will correspond to the top-left pixel of the game image, etc.
+//
+// To check if the pointer coordinates are valid (e.g. a touch display actually being touched),
+// PRESSED returns 1 or 0.
+// If using a mouse, PRESSED will usually correspond to the left mouse button.
+// PRESSED will only return 1 if the pointer is inside the game screen.
+//
+// For multi-touch, the index variable can be used to successively query more presses.
+// If index = 0 returns true for _PRESSED, coordinates can be extracted
+// with _X, _Y for index = 0. One can then query _PRESSED, _X, _Y with index = 1, and so on.
+// Eventually _PRESSED will return false for an index. No further presses are registered at this point.
+#define RETRO_DEVICE_POINTER      6
+
 // These device types are specializations of the base types above.
 // They should only be used in retro_set_controller_type() to inform libretro implementations
 // about use of a very specific device type.
@@ -101,6 +123,11 @@ extern "C" {
 #define RETRO_DEVICE_ID_LIGHTGUN_PAUSE    5
 #define RETRO_DEVICE_ID_LIGHTGUN_START    6
 
+// Id values for POINTER.
+#define RETRO_DEVICE_ID_POINTER_X         0
+#define RETRO_DEVICE_ID_POINTER_Y         1
+#define RETRO_DEVICE_ID_POINTER_PRESSED   2
+
 // Returned from retro_get_region().
 #define RETRO_REGION_NTSC  0
 #define RETRO_REGION_PAL   1
@@ -285,9 +312,28 @@ enum retro_key
    RETROK_EURO           = 321,
    RETROK_UNDO           = 322,
 
-   RETROK_LAST
+   RETROK_LAST,
+
+   RETROK_DUMMY          = INT_MAX // Ensure sizeof(enum) == sizeof(int)
+};
+
+enum retro_mod
+{
+   RETROKMOD_NONE       = 0x0000,
+
+   RETROKMOD_SHIFT      = 0x01,
+   RETROKMOD_CTRL       = 0x02,
+   RETROKMOD_ALT        = 0x04,
+   RETROKMOD_META       = 0x08,
+
+   RETROKMOD_NUMLOCK    = 0x10,
+   RETROKMOD_CAPSLOCK   = 0x20,
+   RETROKMOD_SCROLLOCK  = 0x40,
+
+   RETROKMOD_DUMMY = INT_MAX // Ensure sizeof(enum) == sizeof(int)
 };
 
+
 // Environment commands.
 #define RETRO_ENVIRONMENT_SET_ROTATION  1  // const unsigned * --
                                            // Sets screen rotation of graphics.
@@ -331,7 +377,7 @@ enum retro_key
                                            //
                                            // It can be used by the frontend to potentially warn
                                            // about too demanding implementations.
-                                           // 
+                                           //
                                            // The levels are "floating", but roughly defined as:
                                            // 0: Low-powered embedded devices such as Raspberry Pi
                                            // 1: 6th generation consoles, such as Wii/Xbox 1, and phones, tablets, etc.
@@ -366,7 +412,78 @@ enum retro_key
                                            // It is up to the frontend to present this in a usable way.
                                            // The array is terminated by retro_input_descriptor::description being set to NULL.
                                            // This function can be called at any time, but it is recommended to call it as early as possible.
+#define RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK 12
+                                           // const struct retro_keyboard_callback * --
+                                           // Sets a callback function used to notify core about keyboard events.
+                                           //
+#define RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE 13
+                                           // const struct retro_disk_control_callback * --
+                                           // Sets an interface which frontend can use to eject and insert disk images.
+                                           // This is used for games which consist of multiple images and must be manually
+                                           // swapped out by the user (e.g. PSX).
+
 
+// Callback type passed in RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK. Called by the frontend in response to keyboard events.
+// down is set if the key is being pressed, or false if it is being released.
+// keycode is the RETROK value of the char.
+// character is the text character of the pressed key. (UTF-32).
+// key_modifiers is a set of RETROKMOD values or'ed together.
+typedef void (*retro_keyboard_event_t)(bool down, unsigned keycode, uint32_t character, uint16_t key_modifiers);
+
+struct retro_keyboard_callback
+{
+    retro_keyboard_event_t callback;
+};
+
+// Callbacks for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
+// Should be set for implementations which can swap out multiple disk images in runtime.
+// If the implementation can do this automatically, it should strive to do so.
+// However, there are cases where the user must manually do so.
+//
+// Overview: To swap a disk image, eject the disk image with set_eject_state(true).
+// Set the disk index with set_image_index(index). Insert the disk again with set_eject_state(false).
+
+// If ejected is true, "ejects" the virtual disk tray.
+// When ejected, the disk image index can be set.
+typedef bool (*retro_set_eject_state_t)(bool ejected);
+// Gets current eject state. The initial state is 'not ejected'.
+typedef bool (*retro_get_eject_state_t)(void);
+// Gets current disk index. First disk is index 0.
+// If return value is >= get_num_images(), no disk is currently inserted.
+typedef unsigned (*retro_get_image_index_t)(void);
+// Sets image index. Can only be called when disk is ejected.
+// The implementation supports setting "no disk" by using an index >= get_num_images().
+typedef bool (*retro_set_image_index_t)(unsigned index);
+// Gets total number of images which are available to use.
+typedef unsigned (*retro_get_num_images_t)(void);
+//
+// Replaces the disk image associated with index.
+// Arguments to pass in info have same requirements as retro_load_game().
+// Virtual disk tray must be ejected when calling this.
+// Replacing a disk image with info = NULL will remove the disk image from the internal list.
+// As a result, calls to get_image_index() can change.
+//
+// E.g. replace_image_index(1, NULL), and previous get_image_index() returned 4 before.
+// Index 1 will be removed, and the new index is 3.
+struct retro_game_info;
+typedef bool (*retro_replace_image_index_t)(unsigned index, const struct retro_game_info *info);
+// Adds a new valid index (get_num_images()) to the internal disk list.
+// This will increment subsequent return values from get_num_images() by 1.
+// This image index cannot be used until a disk image has been set with replace_image_index.
+typedef bool (*retro_add_image_index_t)(void);
+
+struct retro_disk_control_callback
+{
+   retro_set_eject_state_t set_eject_state;
+   retro_get_eject_state_t get_eject_state;
+
+   retro_get_image_index_t get_image_index;
+   retro_set_image_index_t set_image_index;
+   retro_get_num_images_t  get_num_images;
+
+   retro_replace_image_index_t replace_image_index;
+   retro_add_image_index_t add_image_index;
+};
 
 enum retro_pixel_format
 {