From aa5575826830ed953e8bc4d5e3fe17baf34d7feb Mon Sep 17 00:00:00 2001
From: trinitou <debuggleburger@gmail.com>
Date: Wed, 15 Mar 2023 04:27:27 +0100
Subject: [PATCH 01/29] gui extension: use !floating tag for some more
 embedded-only methods

---
 include/clap/ext/gui.h | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/include/clap/ext/gui.h b/include/clap/ext/gui.h
index 893d620c..b43aabb3 100644
--- a/include/clap/ext/gui.h
+++ b/include/clap/ext/gui.h
@@ -147,8 +147,7 @@ typedef struct clap_plugin_gui {
    bool(CLAP_ABI *get_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
 
    // Returns true if the window is resizeable (mouse drag).
-   // Only for embedded windows.
-   // [main-thread]
+   // [main-thread & !floating]
    bool(CLAP_ABI *can_resize)(const clap_plugin_t *plugin);
 
    // Returns true if the plugin can provide hints on how to resize the window.
@@ -159,16 +158,14 @@ typedef struct clap_plugin_gui {
    // usable size which fits in the given size.
    // This method does not change the size.
    //
-   // Only for embedded windows.
-   //
    // Returns true if the plugin could adjust the given size.
-   // [main-thread]
+   // [main-thread & !floating]
    bool(CLAP_ABI *adjust_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
 
-   // Sets the window size. Only for embedded windows.
+   // Sets the window size.
    //
    // Returns true if the plugin could resize its window to the given size.
-   // [main-thread]
+   // [main-thread & !floating]
    bool(CLAP_ABI *set_size)(const clap_plugin_t *plugin, uint32_t width, uint32_t height);
 
    // Embeds the plugin window into the given window.
@@ -215,7 +212,7 @@ typedef struct clap_host_gui {
     * acknowledged the request and will process it asynchronously. If the request then can't be
     * satisfied then the host will call set_size() to revert the operation.
     *
-    * [thread-safe] */
+    * [thread-safe & !floating] */
    bool(CLAP_ABI *request_resize)(const clap_host_t *host, uint32_t width, uint32_t height);
 
    /* Request the host to show the plugin gui.

From d8f2f33fe3394e466bf1cfe69c65efe5376d79b4 Mon Sep 17 00:00:00 2001
From: trinitou <debuggleburger@gmail.com>
Date: Wed, 15 Mar 2023 04:32:12 +0100
Subject: [PATCH 02/29] gui extension: use !floating tag for resize_hints
 methods as well

---
 include/clap/ext/gui.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/clap/ext/gui.h b/include/clap/ext/gui.h
index b43aabb3..e2d2d24a 100644
--- a/include/clap/ext/gui.h
+++ b/include/clap/ext/gui.h
@@ -151,7 +151,7 @@ typedef struct clap_plugin_gui {
    bool(CLAP_ABI *can_resize)(const clap_plugin_t *plugin);
 
    // Returns true if the plugin can provide hints on how to resize the window.
-   // [main-thread]
+   // [main-thread & !floating]
    bool(CLAP_ABI *get_resize_hints)(const clap_plugin_t *plugin, clap_gui_resize_hints_t *hints);
 
    // If the plugin gui is resizable, then the plugin will calculate the closest
@@ -201,7 +201,7 @@ typedef struct clap_plugin_gui {
 
 typedef struct clap_host_gui {
    // The host should call get_resize_hints() again.
-   // [thread-safe]
+   // [thread-safe & !floating]
    void(CLAP_ABI *resize_hints_changed)(const clap_host_t *host);
 
    /* Request the host to resize the client area to width, height.

From f6d86a7e7c9cd3da233cb9ffa8e54396000ecabf Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Fri, 24 Mar 2023 12:31:45 +0100
Subject: [PATCH 03/29] clarify what the `plugin_path` is on macOS

---
 ChangeLog.md         | 4 ++++
 include/clap/entry.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index cfd44bcd..75260c83 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+# Changes in 1.1.9
+
+* [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS
+
 # Changes in 1.1.8
 
 * [params.h](include/clap/ext/params.h): document how persisting parameter values between sessions should be implemented
diff --git a/include/clap/entry.h b/include/clap/entry.h
index 33f07948..c1f9d9c3 100644
--- a/include/clap/entry.h
+++ b/include/clap/entry.h
@@ -48,6 +48,8 @@ typedef struct clap_plugin_entry {
    //
    // If init() returns false, then the host must not call deinit() nor any other clap
    // related symbols from the DSO.
+   //
+   // plugin_path is the path to the DSO (Linux, Windows), or the bundle (macOS).
    bool(CLAP_ABI *init)(const char *plugin_path);
 
    // No more calls into the DSO must be made after calling deinit().

From 111858ded845bdbfd86eaf7e95b0d88115ed722e Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 23 May 2023 17:21:06 +0200
Subject: [PATCH 04/29] Rework audio ports configuration and surround /
 ambisonic

---
 include/clap/ext/draft/ambisonic.h            | 19 +++++++-----
 .../clap/ext/draft/configurable-audio-ports.h | 30 ++++++-------------
 include/clap/ext/draft/surround.h             | 18 +++++------
 3 files changed, 30 insertions(+), 37 deletions(-)

diff --git a/include/clap/ext/draft/ambisonic.h b/include/clap/ext/draft/ambisonic.h
index 285a2979..26936023 100644
--- a/include/clap/ext/draft/ambisonic.h
+++ b/include/clap/ext/draft/ambisonic.h
@@ -4,7 +4,7 @@
 
 // This extension can be used to specify the channel mapping used by the plugin.
 
-static CLAP_CONSTEXPR const char CLAP_EXT_AMBISONIC[] = "clap.ambisonic.draft/2";
+static CLAP_CONSTEXPR const char CLAP_EXT_AMBISONIC[] = "clap.ambisonic.draft/3";
 
 static CLAP_CONSTEXPR const char CLAP_PORT_AMBISONIC[] = "ambisonic";
 
@@ -28,21 +28,26 @@ enum {
    CLAP_AMBISONIC_NORMALIZATION_N2D = 4,
 };
 
-typedef struct clap_ambisonic_info {
+typedef struct clap_ambisonic_config {
    uint32_t ordering;
    uint32_t normalization;
-} clap_ambisonic_info_t;
+} clap_ambisonic_config_t;
 
 typedef struct clap_plugin_ambisonic {
+   // Returns true if the given configuration is supported.
+   // [main-thread]
+   bool(CLAP_ABI *is_config_supported)(const clap_plugin_t           *plugin,
+                                       const clap_ambisonic_config_t *config);
+
    // Returns true on success
    //
    // config_id: the configuration id, see clap_plugin_audio_ports_config.
    // If config_id is CLAP_INVALID_ID, then this function queries the current port info.
    // [main-thread]
-   bool(CLAP_ABI *get_info)(const clap_plugin_t   *plugin,
-                            bool                   is_input,
-                            uint32_t               port_index,
-                            clap_ambisonic_info_t *info);
+   bool(CLAP_ABI *get_config)(const clap_plugin_t     *plugin,
+                              bool                     is_input,
+                              uint32_t                 port_index,
+                              clap_ambisonic_config_t *config);
 
 } clap_plugin_ambisonic_t;
 
diff --git a/include/clap/ext/draft/configurable-audio-ports.h b/include/clap/ext/draft/configurable-audio-ports.h
index 57de8057..431363af 100644
--- a/include/clap/ext/draft/configurable-audio-ports.h
+++ b/include/clap/ext/draft/configurable-audio-ports.h
@@ -9,13 +9,9 @@ extern "C" {
 // This extension lets the host configure the plugin's input and output audio ports.
 // This is a "push" approach to audio ports configuration.
 static CLAP_CONSTEXPR const char CLAP_EXT_CONFIGURABLE_AUDIO_PORTS[] =
-   "clap.configurable-audio-ports.draft0";
+   "clap.configurable-audio-ports.draft1";
 
 typedef struct clap_audio_port_configuration_request {
-   // When true, allows the plugin to pick a similar port configuration instead
-   // if the requested one can't be applied.
-   bool is_best_effort;
-
    // Identifies the port by is_input and port_index
    bool     is_input;
    uint32_t port_index;
@@ -30,27 +26,19 @@ typedef struct clap_audio_port_configuration_request {
    // - CLAP_PORT_MONO: (discard)
    // - CLAP_PORT_STEREO: (discard)
    // - CLAP_PORT_SURROUND: const uint8_t *channel_map
-   // - CLAP_PORT_AMBISONIC: const clap_ambisonic_info_t *info
+   // - CLAP_PORT_AMBISONIC: const clap_ambisonic_config_t *info
    const void *port_details;
 } clap_audio_port_configuration_request_t;
 
 typedef struct clap_plugin_configurable_audio_ports {
-   // Some ports may not be configurable, or simply the result of another port configuration.
-   // For example if you have a simple delay plugin, then the output port must have the exact
-   // same type as the input port; in that example, we consider the output port type to be a
-   // function (identity) of the input port type.
-   // [main-thread && !active]
-   bool(CLAP_ABI *is_port_configurable)(const clap_plugin_t *plugin,
-                                        bool                 is_input,
-                                        uint32_t             port_index);
-
-   // Submit a bunch of configuration requests which will atomically be applied together,
-   // or discarded together.
+   // If is_dry_run is true, then checks if the configuration can be applied.
+   // If is_dry_run is true, then applies the configuration.
+   // Returns true if applied.
    // [main-thread && !active]
-   bool(CLAP_ABI *request_configuration)(
-      const clap_plugin_t                                *plugin,
-      const struct clap_audio_port_configuration_request *requests,
-      uint32_t                                            request_count);
+   bool(CLAP_ABI *apply_configuration)(const clap_plugin_t                                *plugin,
+                                       const struct clap_audio_port_configuration_request *requests,
+                                       uint32_t request_count,
+                                       bool     is_dry_run);
 } clap_plugin_configurable_audio_ports_t;
 
 #ifdef __cplusplus
diff --git a/include/clap/ext/draft/surround.h b/include/clap/ext/draft/surround.h
index 0f612653..b54156c9 100644
--- a/include/clap/ext/draft/surround.h
+++ b/include/clap/ext/draft/surround.h
@@ -24,7 +24,7 @@
 // 3. host calls clap_plugin_surround->get_channel_map()
 // 4. host activates the plugin and can start processing audio
 
-static CLAP_CONSTEXPR const char CLAP_EXT_SURROUND[] = "clap.surround.draft/3";
+static CLAP_CONSTEXPR const char CLAP_EXT_SURROUND[] = "clap.surround.draft/4";
 
 static CLAP_CONSTEXPR const char CLAP_PORT_SURROUND[] = "surround";
 
@@ -54,21 +54,21 @@ enum {
 };
 
 typedef struct clap_plugin_surround {
-   // Stores into the channel_map array, the surround identifier of each channel.
+   // Checks if a given channel mask is supported.
+   // The channel mask is a bitmask, for example:
+   //   (1 << CLAP_SURROUND_FL) | (1 << CLAP_SURROUND_FR) | ...
+   // [main-thread]
+   bool(CLAP_ABI *is_channel_mask_supported)(const clap_plugin_t *plugin, uint64_t channel_mask);
+
+   // Stores the surround identifier of each channel into the channel_map array.
    // Returns the number of elements stored in channel_map.
-   //
-   // config_id: the configuration id, see clap_plugin_audio_ports_config.
-   // If config_id is CLAP_INVALID_ID, then this function queries the current port info.
+   // channel_map_capacity should be greater or equal to the channel count of the given port.
    // [main-thread]
    uint32_t(CLAP_ABI *get_channel_map)(const clap_plugin_t *plugin,
                                        bool                 is_input,
                                        uint32_t             port_index,
                                        uint8_t             *channel_map,
                                        uint32_t             channel_map_capacity);
-
-   // Informs the plugin that the host preferred channel map has changed.
-   // [main-thread]
-   void(CLAP_ABI *changed)(const clap_plugin_t *plugin);
 } clap_plugin_surround_t;
 
 typedef struct clap_host_surround {

From c04dae56296e79558c046f56b68137e6e0d710b8 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 23 May 2023 17:23:02 +0200
Subject: [PATCH 05/29] Update changelog

---
 ChangeLog.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index 75260c83..5c0392f2 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,9 @@
+# Changes in 1.1.10
+
+* [surround.h](include/clap/ext/draft/surround.h): simplify the design
+* [ambisonic.h](include/clap/ext/draft/ambisonic.h): simplify the design
+* [configurable-audio-ports.h](include/clap/ext/draft/configurable-audio-ports.h): simplify the design
+
 # Changes in 1.1.9
 
 * [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS

From 007a10765b744c61641be242c3a8f42dfc757cd0 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 23 May 2023 17:26:31 +0200
Subject: [PATCH 06/29] update changelog

---
 ChangeLog.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index 5c0392f2..8e3c01dd 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,6 +3,8 @@
 * [surround.h](include/clap/ext/draft/surround.h): simplify the design
 * [ambisonic.h](include/clap/ext/draft/ambisonic.h): simplify the design
 * [configurable-audio-ports.h](include/clap/ext/draft/configurable-audio-ports.h): simplify the design
+* [gui.h](include/clap/ext/gui.h): documentation clarifications
+* [entry.h](include/clap/entry.h): documentation clarifications
 
 # Changes in 1.1.9
 

From d2cf8b1d26ba3509de52980523a4a7f2f2a62206 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Wed, 24 May 2023 00:48:35 +0200
Subject: [PATCH 07/29] Update
 include/clap/ext/draft/configurable-audio-ports.h

Co-authored-by: Robbert van der Helm <mail@robbertvanderhelm.nl>
---
 include/clap/ext/draft/configurable-audio-ports.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/clap/ext/draft/configurable-audio-ports.h b/include/clap/ext/draft/configurable-audio-ports.h
index 431363af..dcee8f18 100644
--- a/include/clap/ext/draft/configurable-audio-ports.h
+++ b/include/clap/ext/draft/configurable-audio-ports.h
@@ -32,7 +32,7 @@ typedef struct clap_audio_port_configuration_request {
 
 typedef struct clap_plugin_configurable_audio_ports {
    // If is_dry_run is true, then checks if the configuration can be applied.
-   // If is_dry_run is true, then applies the configuration.
+   // If is_dry_run is false, then applies the configuration.
    // Returns true if applied.
    // [main-thread && !active]
    bool(CLAP_ABI *apply_configuration)(const clap_plugin_t                                *plugin,

From a4e1605d37dae9c6943b288ea6a73bbbccb53f7e Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Fri, 7 Jul 2023 16:07:04 +0200
Subject: [PATCH 08/29] Introduce incremental state

---
 ChangeLog.md                               |  4 ++
 include/clap/clap.h                        |  1 +
 include/clap/ext/draft/incremental-state.h | 50 ++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 include/clap/ext/draft/incremental-state.h

diff --git a/ChangeLog.md b/ChangeLog.md
index 8e3c01dd..a7832091 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -6,6 +6,10 @@
 * [gui.h](include/clap/ext/gui.h): documentation clarifications
 * [entry.h](include/clap/entry.h): documentation clarifications
 
+## Draft Extensions
+
+* [incremental-state.h](include/clap/ext/draft/incremental-state.h): incremental state
+
 # Changes in 1.1.9
 
 * [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS
diff --git a/include/clap/clap.h b/include/clap/clap.h
index e57dbf44..b33579ee 100644
--- a/include/clap/clap.h
+++ b/include/clap/clap.h
@@ -69,3 +69,4 @@
 #include "ext/draft/tuning.h"
 #include "ext/draft/configurable-audio-ports.h"
 #include "ext/draft/extensible-audio-ports.h"
+#include "ext/draft/incremental-state.h"
diff --git a/include/clap/ext/draft/incremental-state.h b/include/clap/ext/draft/incremental-state.h
new file mode 100644
index 00000000..a62cef24
--- /dev/null
+++ b/include/clap/ext/draft/incremental-state.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include "../../plugin.h"
+
+static CLAP_CONSTEXPR const char CLAP_EXT_INCREMENTAL_STATE[] = "clap.incremental-state.draft/0";
+
+// This extension is useful for the host to collect incremental changes instead of saving the plugin
+// state after each changes.
+//
+// The typical use case is for crash recovery:
+// 1. the host saves the entire project (expensive)
+// 2. many things, happens and the host saves little delta operations to disk (cheap)
+// 3. the application crashes
+//
+// Then once the application is restarted, the user can decide to recover the project which will
+// work as follow:
+// 1. open the last project state
+// 2. apply all the deltas in sequence
+// 3. project is ready and should be in the same state as it was before the crash
+//
+// Saving a project, can be an expensive task especially for large project and can
+// cause playback performance issues.
+// This is why saving deltas is interesting because it is lightweight.
+//
+// This interface is not meant to replace saving the entire project.
+//
+// If the plugin decides to implement this interface, it should then be able to encode
+// the deltas in a space efficient way.
+//
+// The plugin can assume that the delta will be applied on the same computer as the
+// one used to produce it. Meaning that it doesn't have to take care of endianness
+// and can store path to files on the computer.
+
+typedef struct clap_plugin_incremental_state {
+   // [main-thread]
+   bool (*apply_delta)(clap_plugin_t *plugin, const char *data, size_t size);
+} clap_plugin_incremental_state_t;
+
+typedef struct clap_host_incremental_state {
+   // Adds a delta, its size should be reasonably small.
+   //
+   // [main-thread]
+   void (*add_delta)(clap_host_t *host, const char *data, size_t size);
+
+   // One change happened which can't be encoded as a delta, and requires
+   // the host to save the entire state again.
+   //
+   // [main-thread]
+   void (*save_is_required)(clap_host_t *host);
+} clap_host_incremental_state_t;

From cc53c04c389bfe26575a8b169dbe7fca7fdf80ef Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Fri, 7 Jul 2023 16:07:04 +0200
Subject: [PATCH 09/29] Initial take on undo support

---
 ChangeLog.md                  |  4 +++
 include/clap/clap.h           |  1 +
 include/clap/ext/draft/undo.h | 63 +++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 include/clap/ext/draft/undo.h

diff --git a/ChangeLog.md b/ChangeLog.md
index 8e3c01dd..62926cc6 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -6,6 +6,10 @@
 * [gui.h](include/clap/ext/gui.h): documentation clarifications
 * [entry.h](include/clap/entry.h): documentation clarifications
 
+## Draft extensions
+
+* [undo.h](include/clap/ext/draft/undo.h): undo support
+
 # Changes in 1.1.9
 
 * [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS
diff --git a/include/clap/clap.h b/include/clap/clap.h
index e57dbf44..16aebba2 100644
--- a/include/clap/clap.h
+++ b/include/clap/clap.h
@@ -69,3 +69,4 @@
 #include "ext/draft/tuning.h"
 #include "ext/draft/configurable-audio-ports.h"
 #include "ext/draft/extensible-audio-ports.h"
+#include "ext/draft/undo.h"
diff --git a/include/clap/ext/draft/undo.h b/include/clap/ext/draft/undo.h
new file mode 100644
index 00000000..d5975e51
--- /dev/null
+++ b/include/clap/ext/draft/undo.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include "../../plugin.h"
+#include "../../string-sizes.h"
+
+static CLAP_CONSTEXPR const char CLAP_EXT_UNDO[] = "clap.undo.draft/0";
+
+// Describes an undo step
+typedef struct clap_undo_info {
+   // This is the unique identifier of this undo step.
+   // It is valid until loading a state or destroying the plugin.
+   clap_id id;
+
+   // A short string which describes the corresponding change.
+   char description[CLAP_NAME_SIZE];
+} clap_undo_info_t;
+
+typedef struct clap_plugin_undo {
+   // returns true if an undo/redo step exists and the info were provided
+   // [main-thread]
+   bool (*get_current_undo_info)(clap_plugin_t *plugin, clap_undo_info_t *info);
+   bool (*get_current_redo_info)(clap_plugin_t *plugin, clap_undo_info_t *info);
+
+   // request the plugin to perform an undo operation (async)
+   // returns true if the request is being processed, false otherwise.
+   // when returning true, the plugin must call clap_host_undo->after_undo_request() once the
+   // request is completed or failed.
+   //
+   // The plugin should only perform the operation if the current
+   // undo/redo operation matches the given id; this is because of the asynchronous nature of the
+   // task and to avoid race conditions if the plugin's undo manager lives in a different thread.
+   //
+   // [main-thread]
+   bool (*request_undo)(clap_plugin_t *plugin, clap_id id);
+   bool (*request_redo)(clap_plugin_t *plugin, clap_id id);
+} clap_plugin_undo_t;
+
+typedef struct clap_host_undo {
+   // Marks the begining and end of a change which will lead to the creation of an undo step.
+   // [main-thread]
+   void (*begin_changes)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*end_changes)(clap_host_t *host, const clap_undo_info_t *info);
+
+   // Marks the beginning and end of processing an undo change.
+   // [main-thread]
+   void (*begin_undo)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*end_undo)(clap_host_t *host, const clap_undo_info_t *info);
+
+   // Marks the beginning and end of processing a redo change.
+   // [main-thread]
+   void (*begin_redo)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*end_redo)(clap_host_t *host, const clap_undo_info_t *info);
+
+   // A destructive change happened which makes it impossible to perform an undo.
+   // The entire plugin's undo/redo stack has been cleared.
+   // [main-thread]
+   void (*after_destructive_change)(clap_host_t *host);
+
+   // Callbacks for clap_plugin_undo->request_*()
+   // [main-thread]
+   void (*after_undo_request)(clap_host_t *host, clap_id id, bool succeed, const char *error_msg);
+   void (*after_redo_request)(clap_host_t *host, clap_id id, bool succeed, const char *error_msg);
+} clap_host_undo_t;

From 5c9612d19af69f1af8542a3e79870ca3900329e3 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Mon, 10 Jul 2023 12:46:03 +0200
Subject: [PATCH 10/29] undo: try to clarify the call sequence and use
 change_id instead of id

---
 include/clap/ext/draft/undo.h | 56 +++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 22 deletions(-)

diff --git a/include/clap/ext/draft/undo.h b/include/clap/ext/draft/undo.h
index d5975e51..e39e4daf 100644
--- a/include/clap/ext/draft/undo.h
+++ b/include/clap/ext/draft/undo.h
@@ -5,51 +5,56 @@
 
 static CLAP_CONSTEXPR const char CLAP_EXT_UNDO[] = "clap.undo.draft/0";
 
-// Describes an undo step
-typedef struct clap_undo_info {
+// Describes a change which can be undone or redone
+typedef struct clap_undo_change_info {
    // This is the unique identifier of this undo step.
    // It is valid until loading a state or destroying the plugin.
-   clap_id id;
+   clap_id change_id;
 
    // A short string which describes the corresponding change.
    char description[CLAP_NAME_SIZE];
-} clap_undo_info_t;
+} clap_undo_change_info_t;
 
 typedef struct clap_plugin_undo {
    // returns true if an undo/redo step exists and the info were provided
    // [main-thread]
-   bool (*get_current_undo_info)(clap_plugin_t *plugin, clap_undo_info_t *info);
-   bool (*get_current_redo_info)(clap_plugin_t *plugin, clap_undo_info_t *info);
+   bool (*get_current_undo_info)(clap_plugin_t *plugin, clap_undo_change_info_t *info);
+   bool (*get_current_redo_info)(clap_plugin_t *plugin, clap_undo_change_info_t *info);
 
-   // request the plugin to perform an undo operation (async)
-   // returns true if the request is being processed, false otherwise.
-   // when returning true, the plugin must call clap_host_undo->after_undo_request() once the
+   // Request the plugin to perform an undo operation (async).
+   //
+   // Returns true if the request is being processed, false otherwise.
+   // When returning true, the plugin **must** call clap_host_undo->after_undo_request() once the
    // request is completed or failed.
    //
-   // The plugin should only perform the operation if the current
-   // undo/redo operation matches the given id; this is because of the asynchronous nature of the
-   // task and to avoid race conditions if the plugin's undo manager lives in a different thread.
+   // The plugin should only perform the operation if the current undo/redo operation matches the
+   // given id; this is because of the asynchronous nature of the task and to avoid race conditions
+   // if the plugin's undo manager lives in a different thread.
    //
+   // Call sequence:
+   // 1. plugin->request_undo(change_id=X) -> returns true
+   // 2. later on host->begin_undo(change_id=X)
+   // 3. later on host->end_undo(change_id=X), host->after_undo(change_id=X, true, nullptr)
    // [main-thread]
-   bool (*request_undo)(clap_plugin_t *plugin, clap_id id);
-   bool (*request_redo)(clap_plugin_t *plugin, clap_id id);
+   bool (*request_undo)(clap_plugin_t *plugin, clap_id change_id);
+   bool (*request_redo)(clap_plugin_t *plugin, clap_id change_id);
 } clap_plugin_undo_t;
 
 typedef struct clap_host_undo {
    // Marks the begining and end of a change which will lead to the creation of an undo step.
    // [main-thread]
-   void (*begin_changes)(clap_host_t *host, const clap_undo_info_t *info);
-   void (*end_changes)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*begin_changes)(clap_host_t *host, const clap_undo_change_info_t *info);
+   void (*end_changes)(clap_host_t *host, const clap_undo_change_info_t *info);
 
    // Marks the beginning and end of processing an undo change.
    // [main-thread]
-   void (*begin_undo)(clap_host_t *host, const clap_undo_info_t *info);
-   void (*end_undo)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*begin_undo)(clap_host_t *host, const clap_undo_change_info_t *info);
+   void (*end_undo)(clap_host_t *host, const clap_undo_change_info_t *info);
 
    // Marks the beginning and end of processing a redo change.
    // [main-thread]
-   void (*begin_redo)(clap_host_t *host, const clap_undo_info_t *info);
-   void (*end_redo)(clap_host_t *host, const clap_undo_info_t *info);
+   void (*begin_redo)(clap_host_t *host, const clap_undo_change_info_t *info);
+   void (*end_redo)(clap_host_t *host, const clap_undo_change_info_t *info);
 
    // A destructive change happened which makes it impossible to perform an undo.
    // The entire plugin's undo/redo stack has been cleared.
@@ -57,7 +62,14 @@ typedef struct clap_host_undo {
    void (*after_destructive_change)(clap_host_t *host);
 
    // Callbacks for clap_plugin_undo->request_*()
+   // If succeed is true, then error_msg is ignored and may be null.
    // [main-thread]
-   void (*after_undo_request)(clap_host_t *host, clap_id id, bool succeed, const char *error_msg);
-   void (*after_redo_request)(clap_host_t *host, clap_id id, bool succeed, const char *error_msg);
+   void (*after_undo_request)(clap_host_t *host,
+                              clap_id      change_id,
+                              bool         succeed,
+                              const char  *error_msg);
+   void (*after_redo_request)(clap_host_t *host,
+                              clap_id      change_id,
+                              bool         succeed,
+                              const char  *error_msg);
 } clap_host_undo_t;

From b768df6fe2a21780f453bf7f822192011739e076 Mon Sep 17 00:00:00 2001
From: jatin <jatinchowdhury18@gmail.com>
Date: Mon, 10 Jul 2023 13:58:36 -0700
Subject: [PATCH 11/29] Adding compile test for version macros

---
 CMakeLists.txt |  4 ++++
 src/main.cc    | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c386acf0..8773c35f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -60,6 +60,10 @@ if (${CLAP_BUILD_TESTS})
         add_test(NAME test-clap-compile-${SUFFIX} COMMAND clap-compile-${SUFFIX})
         add_dependencies(clap-tests clap-compile-${SUFFIX})
 
+        if (${EXT} STREQUAL "cc")
+            target_compile_definitions(clap-compile-${SUFFIX} PRIVATE CLAP_COMPILE_TEST_CXX_VERSION=${STDCPP})
+        endif()
+
         if (${CMAKE_C_COMPILER_ID} STREQUAL "GNU" OR ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
             target_compile_options(clap-compile-${SUFFIX} PRIVATE -Wall -Wextra -pedantic)
         endif()
diff --git a/src/main.cc b/src/main.cc
index 949d0bb8..80febfba 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -48,6 +48,18 @@
 #error CLAP_VERSION_LT is inconsistent (REVISION)
 #endif
 
+#if (CLAP_COMPILE_TEST_CXX_VERSION >= 11) && ! defined(CLAP_HAS_CXX11)
+#error CLAP_HAS_CXX11 is not defined correctly
+#endif
+
+#if (CLAP_COMPILE_TEST_CXX_VERSION >= 17) && ! defined(CLAP_HAS_CXX17)
+#error CLAP_HAS_CXX17 is not defined correctly
+#endif
+
+#if (CLAP_COMPILE_TEST_CXX_VERSION >= 20) && ! defined(CLAP_HAS_CXX20)
+#error CLAP_HAS_CXX20 is not defined correctly
+#endif
+
 static const CLAP_CONSTEXPR clap_version m = CLAP_VERSION;
 
 int main(int, char **) {

From 5c8b26d06ff67f580c9d0449bf697cba50d87a43 Mon Sep 17 00:00:00 2001
From: jatin <jatinchowdhury18@gmail.com>
Date: Mon, 10 Jul 2023 14:05:22 -0700
Subject: [PATCH 12/29] Trying to get msvc build happening on CI

---
 .github/workflows/cmake.yml | 11 ++++++++++-
 CMakePresets.json           | 30 ++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index 88040a96..7b9ccd9a 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -39,8 +39,17 @@ jobs:
 
       - name: Run CMake+Ninja+CTest to generate/build/test.
         uses: lukka/run-cmake@v10
-        id: runcmake
+        id: runcmake-ninja
         with:
           configurePreset: 'ninja'
           buildPreset: 'ninja-release'
           testPreset: 'ninja-release'
+
+      - name: Run CMake+MSVC+CTest to generate/build/test.
+        uses: lukka/run-cmake@v10
+        if: startsWith(matrix.os, 'win')
+        id: runcmake-msvc
+        with:
+          configurePreset: 'msvc'
+          buildPreset: 'msvc-release'
+          testPreset: 'msvc-release'
diff --git a/CMakePresets.json b/CMakePresets.json
index d707bfb9..bd0b1c51 100644
--- a/CMakePresets.json
+++ b/CMakePresets.json
@@ -22,6 +22,23 @@
           "value": true
         }
       }
+    },
+    {
+      "name": "msvc",
+      "displayName": "MSVC",
+      "description": "Configure and generate MSVC project files for all configurations",
+      "binaryDir": "${sourceDir}/builds/${presetName}",
+      "generator": "Visual Studio 17 2022",
+      "cacheVariables": {
+        "CMAKE_EXPORT_COMPILE_COMMANDS": {
+          "type": "boolean",
+          "value": true
+        },
+        "CLAP_BUILD_TESTS": {
+          "type": "boolean",
+          "value": true
+        }
+      }
     }
   ],
   "buildPresets": [
@@ -32,6 +49,14 @@
       "description": "Build ninja Release configuration",
       "configuration": "RelWithDebInfo",
       "targets": ["clap-tests"]
+    },
+    {
+      "name": "msvc-release",
+      "configurePreset": "msvc",
+      "displayName": "Build msvc-release",
+      "description": "Build msvc Release configuration",
+      "configuration": "RelWithDebInfo",
+      "targets": ["clap-tests"]
     }
   ],
   "testPresets": [
@@ -39,6 +64,11 @@
       "name": "ninja-release",
       "configurePreset": "ninja",
       "configuration": "RelWithDebInfo"
+    },
+    {
+      "name": "msvc-release",
+      "configurePreset": "msvc",
+      "configuration": "RelWithDebInfo"
     }
   ]
 }
\ No newline at end of file

From d23d576a9d96f23c58b529d803053333ac127918 Mon Sep 17 00:00:00 2001
From: jatin <jatinchowdhury18@gmail.com>
Date: Mon, 10 Jul 2023 14:12:37 -0700
Subject: [PATCH 13/29] Add MSVC bypass for getting C++ version macro

---
 include/clap/private/macros.h | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/clap/private/macros.h b/include/clap/private/macros.h
index 15b6b1b3..0281de23 100644
--- a/include/clap/private/macros.h
+++ b/include/clap/private/macros.h
@@ -25,20 +25,28 @@
 #   endif
 #endif
 
-#if defined(__cplusplus) && __cplusplus >= 201103L
+#if defined(__cplusplus)
+#   if MSVC
+#      define CLAP_CPLUSPLUS _MSVC_LANG
+#   else
+#      define CLAP_CPLUSPLUS __cplusplus
+#   endif
+#endif
+
+#if defined(CLAP_CPLUSPLUS) && CLAP_CPLUSPLUS >= 201103L
 #   define CLAP_HAS_CXX11
 #   define CLAP_CONSTEXPR constexpr
 #else
 #   define CLAP_CONSTEXPR
 #endif
 
-#if defined(__cplusplus) && __cplusplus >= 201703L
+#if defined(CLAP_CPLUSPLUS) && CLAP_CPLUSPLUS >= 201703L
 #   define CLAP_HAS_CXX17
 #   define CLAP_NODISCARD [[nodiscard]]
 #else
 #   define CLAP_NODISCARD
 #endif
 
-#if defined(__cplusplus) && __cplusplus >= 202002L
+#if defined(CLAP_CPLUSPLUS) && CLAP_CPLUSPLUS >= 202002L
 #   define CLAP_HAS_CXX20
 #endif

From e661d1caa56deac3dc207af2445738b93e84e5a0 Mon Sep 17 00:00:00 2001
From: Jatin Chowdhury <jatinchowdhury18@gmail.com>
Date: Mon, 10 Jul 2023 14:32:43 -0700
Subject: [PATCH 14/29] Different strategy for definitions check

---
 include/clap/private/macros.h | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/include/clap/private/macros.h b/include/clap/private/macros.h
index 0281de23..ba1d6656 100644
--- a/include/clap/private/macros.h
+++ b/include/clap/private/macros.h
@@ -25,12 +25,10 @@
 #   endif
 #endif
 
-#if defined(__cplusplus)
-#   if MSVC
-#      define CLAP_CPLUSPLUS _MSVC_LANG
-#   else
-#      define CLAP_CPLUSPLUS __cplusplus
-#   endif
+#if defined(_MSVC_LANG)
+#   define CLAP_CPLUSPLUS _MSVC_LANG
+#elif defined(__cplusplus)
+#   define CLAP_CPLUSPLUS __cplusplus
 #endif
 
 #if defined(CLAP_CPLUSPLUS) && CLAP_CPLUSPLUS >= 201103L

From 92f4a63502b91a610d060ae0e498d914cf49602b Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 11 Jul 2023 16:37:40 +0200
Subject: [PATCH 15/29] Update include/clap/ext/draft/undo.h

Co-authored-by: Trinitou <106991375+Trinitou@users.noreply.github.com>
---
 include/clap/ext/draft/undo.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/clap/ext/draft/undo.h b/include/clap/ext/draft/undo.h
index e39e4daf..84204e6e 100644
--- a/include/clap/ext/draft/undo.h
+++ b/include/clap/ext/draft/undo.h
@@ -43,8 +43,8 @@ typedef struct clap_plugin_undo {
 typedef struct clap_host_undo {
    // Marks the begining and end of a change which will lead to the creation of an undo step.
    // [main-thread]
-   void (*begin_changes)(clap_host_t *host, const clap_undo_change_info_t *info);
-   void (*end_changes)(clap_host_t *host, const clap_undo_change_info_t *info);
+   void (*begin_change)(clap_host_t *host, const clap_undo_change_info_t *info);
+   void (*end_change)(clap_host_t *host, const clap_undo_change_info_t *info);
 
    // Marks the beginning and end of processing an undo change.
    // [main-thread]

From fe8d233c1275ee5d665fe75c438f7fd14b9dd3e6 Mon Sep 17 00:00:00 2001
From: xris1658 <chris1658@foxmail.com>
Date: Wed, 19 Jul 2023 12:09:31 +0800
Subject: [PATCH 16/29] Fix typo

filed -> field
---
 include/clap/ext/audio-ports.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/clap/ext/audio-ports.h b/include/clap/ext/audio-ports.h
index d5b4a040..46186e76 100644
--- a/include/clap/ext/audio-ports.h
+++ b/include/clap/ext/audio-ports.h
@@ -49,7 +49,7 @@ typedef struct clap_audio_port_info {
    uint32_t channel_count;
 
    // If null or empty then it is unspecified (arbitrary audio).
-   // This filed can be compared against:
+   // This field can be compared against:
    // - CLAP_PORT_MONO
    // - CLAP_PORT_STEREO
    // - CLAP_PORT_SURROUND (defined in the surround extension)

From 6062f41198fc42d9fe197345f0a5f64edbdca92a Mon Sep 17 00:00:00 2001
From: luzpaz <luzpaz@users.noreply.github.com>
Date: Sun, 6 Aug 2023 09:23:22 -0400
Subject: [PATCH 17/29] Fix various typos

---
 ChangeLog.md                                  | 2 +-
 include/clap/ext/draft/resource-directory.h   | 2 +-
 include/clap/ext/gui.h                        | 2 +-
 include/clap/factory/draft/preset-discovery.h | 2 +-
 include/clap/plugin.h                         | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index cfd44bcd..63979c5a 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -126,7 +126,7 @@
   it is now **required** to deactivate the plugin before destroying it.
 * [params.h](include/clap/ext/params.h): improve documentation for `clap_host_params->request_flush()`.
 * [entry.h](include/clap/entry.h): improve documentation regarding `init()`, `deinit()` and CLAP search path.
-* [gui.h](inclued/clap/gui.h): fix typo `clap_gui_resize_hints.preserve_aspect_ratio`
+* [gui.h](include/clap/gui.h): fix typo `clap_gui_resize_hints.preserve_aspect_ratio`
 * [plugin-template](src/plugin-template.c): missing impl of plugin destroy.
 * various documentation improvements
 
diff --git a/include/clap/ext/draft/resource-directory.h b/include/clap/ext/draft/resource-directory.h
index 1d96da5f..fc65eaa8 100644
--- a/include/clap/ext/draft/resource-directory.h
+++ b/include/clap/ext/draft/resource-directory.h
@@ -44,7 +44,7 @@ extern "C" {
 
 typedef struct clap_plugin_resource_directory {
    // Sets the directory in which the plugin can save its resources.
-   // The directory remains valid until it is overriden or the plugin is destroyed.
+   // The directory remains valid until it is overridden or the plugin is destroyed.
    // If path is null or blank, it clears the directory location.
    // path must be absolute.
    // [main-thread]
diff --git a/include/clap/ext/gui.h b/include/clap/ext/gui.h
index 893d620c..13bb591c 100644
--- a/include/clap/ext/gui.h
+++ b/include/clap/ext/gui.h
@@ -118,7 +118,7 @@ typedef struct clap_plugin_gui {
    //
    // After this call, the GUI may not be visible yet; don't forget to call show().
    //
-   // Returns true if the GUI is successfuly created.
+   // Returns true if the GUI is successfully created.
    // [main-thread]
    bool(CLAP_ABI *create)(const clap_plugin_t *plugin, const char *api, bool is_floating);
 
diff --git a/include/clap/factory/draft/preset-discovery.h b/include/clap/factory/draft/preset-discovery.h
index 76a2e6ac..db26f1e9 100644
--- a/include/clap/factory/draft/preset-discovery.h
+++ b/include/clap/factory/draft/preset-discovery.h
@@ -61,7 +61,7 @@ enum clap_preset_discovery_location_kind {
    CLAP_PRESET_DISCOVERY_LOCATION_FILE = 0,
 
    // The preset is bundled within the plugin DSO itself.
-   // The location must then be null, as the preset are within the plugin itsel and then the plugin
+   // The location must then be null, as the preset are within the plugin itself and then the plugin
    // will act as a preset container.
    CLAP_PRESET_DISCOVERY_LOCATION_PLUGIN = 1,
 };
diff --git a/include/clap/plugin.h b/include/clap/plugin.h
index e366e051..2fd6530d 100644
--- a/include/clap/plugin.h
+++ b/include/clap/plugin.h
@@ -16,7 +16,7 @@ typedef struct clap_plugin_descriptor {
    // Otherwise the fields can be null or blank, though it is safer to make them blank.
    //
    // Some indications regarding id and version
-   // - id is an arbritrary string which should be unique to your plugin,
+   // - id is an arbitrary string which should be unique to your plugin,
    //   we encourage you to use a reverse URI eg: "com.u-he.diva"
    // - version is an arbitrary string which describes a plugin,
    //   it is useful for the host to understand and be able to compare two different

From c56eaa9aee042031ebb31f073a416f13d5d12bb2 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 15 Aug 2023 11:13:40 +0200
Subject: [PATCH 18/29] specify the sample size to be used when activating the
 audio port

Fixes #321
---
 ChangeLog.md                                    | 1 +
 include/clap/ext/draft/audio-ports-activation.h | 8 ++++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 4c450dcf..fde73e30 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -5,6 +5,7 @@
 * [configurable-audio-ports.h](include/clap/ext/draft/configurable-audio-ports.h): simplify the design
 * [gui.h](include/clap/ext/gui.h): documentation clarifications
 * [entry.h](include/clap/entry.h): documentation clarifications
+* [audio-ports-activation.h](include/clap/ext/draft/audio-ports-activation.h): specify the sample size to be used when activating the audio port.
 
 ## Draft extensions
 
diff --git a/include/clap/ext/draft/audio-ports-activation.h b/include/clap/ext/draft/audio-ports-activation.h
index 63fb31e8..f451c005 100644
--- a/include/clap/ext/draft/audio-ports-activation.h
+++ b/include/clap/ext/draft/audio-ports-activation.h
@@ -26,7 +26,7 @@
 /// clap_host_audio_ports.rescan(CLAP_AUDIO_PORTS_RESCAN_LIST).
 
 static CLAP_CONSTEXPR const char CLAP_EXT_AUDIO_PORTS_ACTIVATION[] =
-   "clap.audio-ports-activation/draft-1";
+   "clap.audio-ports-activation/draft-2";
 
 #ifdef __cplusplus
 extern "C" {
@@ -42,12 +42,16 @@ typedef struct clap_plugin_audio_ports_activation {
    // It is only possible to activate and de-activate on the audio-thread if
    // can_activate_while_processing() returns true.
    //
+   // sample_size indicate if the host will provide 32 bit audio buffers or 64 bits one.
+   // Possible values are: 32, 64 or 0 if unspecified.
+   //
    // returns false if failed, or invalid parameters
    // [active ? audio-thread : main-thread]
    bool(CLAP_ABI *set_active)(const clap_plugin_t *plugin,
                               bool                 is_input,
                               uint32_t             port_index,
-                              bool                 is_active);
+                              bool                 is_active,
+                              uint32_t             sample_size);
 } clap_plugin_audio_ports_activation_t;
 
 #ifdef __cplusplus

From 48803fe177db696f982a19339ed9899bc98ecf4c Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 15 Aug 2023 11:27:56 +0200
Subject: [PATCH 19/29] Cleanup changelog

---
 ChangeLog.md | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 5e9ead22..26a20f83 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,6 @@
-# Changes in 1.1.10
+# Changes in 1.1.9
 
+* [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS
 * [surround.h](include/clap/ext/draft/surround.h): simplify the design
 * [ambisonic.h](include/clap/ext/draft/ambisonic.h): simplify the design
 * [configurable-audio-ports.h](include/clap/ext/draft/configurable-audio-ports.h): simplify the design
@@ -10,15 +11,8 @@
 ## Draft extensions
 
 * [undo.h](include/clap/ext/draft/undo.h): undo support
-
-## Draft Extensions
-
 * [incremental-state.h](include/clap/ext/draft/incremental-state.h): incremental state
 
-# Changes in 1.1.9
-
-* [entry.h](include/clap/entry.h): clarify what the `plugin_path` is on macOS
-
 # Changes in 1.1.8
 
 * [params.h](include/clap/ext/params.h): document how persisting parameter values between sessions should be implemented

From dcd29e318c87915263a62bc8b53df1725f71ddd9 Mon Sep 17 00:00:00 2001
From: defiantnerd <97224712+defiantnerd@users.noreply.github.com>
Date: Wed, 11 Oct 2023 14:24:25 +0200
Subject: [PATCH 20/29] clarify latency is defined in samples

using the same wording as in tail extension to clarify details.
---
 include/clap/ext/latency.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/clap/ext/latency.h b/include/clap/ext/latency.h
index ca068cab..862b3341 100644
--- a/include/clap/ext/latency.h
+++ b/include/clap/ext/latency.h
@@ -10,7 +10,7 @@ extern "C" {
 
 // The audio ports scan has to be done while the plugin is deactivated.
 typedef struct clap_plugin_latency {
-   // Returns the plugin latency.
+   // Returns the plugin latency in samples.
    // [main-thread]
    uint32_t(CLAP_ABI *get)(const clap_plugin_t *plugin);
 } clap_plugin_latency_t;

From f9dffddcdc08b7f889ac1bf3d747963c6c619186 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 17 Oct 2023 10:22:04 +0200
Subject: [PATCH 21/29] Remove undo and incremental state as the design isn't
 ready yet and needs more work

---
 ChangeLog.md                               |  5 --
 include/clap/ext/draft/incremental-state.h | 50 ---------------
 include/clap/ext/draft/undo.h              | 75 ----------------------
 3 files changed, 130 deletions(-)
 delete mode 100644 include/clap/ext/draft/incremental-state.h
 delete mode 100644 include/clap/ext/draft/undo.h

diff --git a/ChangeLog.md b/ChangeLog.md
index 26a20f83..cce7a328 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -8,11 +8,6 @@
 * [entry.h](include/clap/entry.h): documentation clarifications
 * [audio-ports-activation.h](include/clap/ext/draft/audio-ports-activation.h): specify the sample size to be used when activating the audio port.
 
-## Draft extensions
-
-* [undo.h](include/clap/ext/draft/undo.h): undo support
-* [incremental-state.h](include/clap/ext/draft/incremental-state.h): incremental state
-
 # Changes in 1.1.8
 
 * [params.h](include/clap/ext/params.h): document how persisting parameter values between sessions should be implemented
diff --git a/include/clap/ext/draft/incremental-state.h b/include/clap/ext/draft/incremental-state.h
deleted file mode 100644
index a62cef24..00000000
--- a/include/clap/ext/draft/incremental-state.h
+++ /dev/null
@@ -1,50 +0,0 @@
-#pragma once
-
-#include "../../plugin.h"
-
-static CLAP_CONSTEXPR const char CLAP_EXT_INCREMENTAL_STATE[] = "clap.incremental-state.draft/0";
-
-// This extension is useful for the host to collect incremental changes instead of saving the plugin
-// state after each changes.
-//
-// The typical use case is for crash recovery:
-// 1. the host saves the entire project (expensive)
-// 2. many things, happens and the host saves little delta operations to disk (cheap)
-// 3. the application crashes
-//
-// Then once the application is restarted, the user can decide to recover the project which will
-// work as follow:
-// 1. open the last project state
-// 2. apply all the deltas in sequence
-// 3. project is ready and should be in the same state as it was before the crash
-//
-// Saving a project, can be an expensive task especially for large project and can
-// cause playback performance issues.
-// This is why saving deltas is interesting because it is lightweight.
-//
-// This interface is not meant to replace saving the entire project.
-//
-// If the plugin decides to implement this interface, it should then be able to encode
-// the deltas in a space efficient way.
-//
-// The plugin can assume that the delta will be applied on the same computer as the
-// one used to produce it. Meaning that it doesn't have to take care of endianness
-// and can store path to files on the computer.
-
-typedef struct clap_plugin_incremental_state {
-   // [main-thread]
-   bool (*apply_delta)(clap_plugin_t *plugin, const char *data, size_t size);
-} clap_plugin_incremental_state_t;
-
-typedef struct clap_host_incremental_state {
-   // Adds a delta, its size should be reasonably small.
-   //
-   // [main-thread]
-   void (*add_delta)(clap_host_t *host, const char *data, size_t size);
-
-   // One change happened which can't be encoded as a delta, and requires
-   // the host to save the entire state again.
-   //
-   // [main-thread]
-   void (*save_is_required)(clap_host_t *host);
-} clap_host_incremental_state_t;
diff --git a/include/clap/ext/draft/undo.h b/include/clap/ext/draft/undo.h
deleted file mode 100644
index 84204e6e..00000000
--- a/include/clap/ext/draft/undo.h
+++ /dev/null
@@ -1,75 +0,0 @@
-#pragma once
-
-#include "../../plugin.h"
-#include "../../string-sizes.h"
-
-static CLAP_CONSTEXPR const char CLAP_EXT_UNDO[] = "clap.undo.draft/0";
-
-// Describes a change which can be undone or redone
-typedef struct clap_undo_change_info {
-   // This is the unique identifier of this undo step.
-   // It is valid until loading a state or destroying the plugin.
-   clap_id change_id;
-
-   // A short string which describes the corresponding change.
-   char description[CLAP_NAME_SIZE];
-} clap_undo_change_info_t;
-
-typedef struct clap_plugin_undo {
-   // returns true if an undo/redo step exists and the info were provided
-   // [main-thread]
-   bool (*get_current_undo_info)(clap_plugin_t *plugin, clap_undo_change_info_t *info);
-   bool (*get_current_redo_info)(clap_plugin_t *plugin, clap_undo_change_info_t *info);
-
-   // Request the plugin to perform an undo operation (async).
-   //
-   // Returns true if the request is being processed, false otherwise.
-   // When returning true, the plugin **must** call clap_host_undo->after_undo_request() once the
-   // request is completed or failed.
-   //
-   // The plugin should only perform the operation if the current undo/redo operation matches the
-   // given id; this is because of the asynchronous nature of the task and to avoid race conditions
-   // if the plugin's undo manager lives in a different thread.
-   //
-   // Call sequence:
-   // 1. plugin->request_undo(change_id=X) -> returns true
-   // 2. later on host->begin_undo(change_id=X)
-   // 3. later on host->end_undo(change_id=X), host->after_undo(change_id=X, true, nullptr)
-   // [main-thread]
-   bool (*request_undo)(clap_plugin_t *plugin, clap_id change_id);
-   bool (*request_redo)(clap_plugin_t *plugin, clap_id change_id);
-} clap_plugin_undo_t;
-
-typedef struct clap_host_undo {
-   // Marks the begining and end of a change which will lead to the creation of an undo step.
-   // [main-thread]
-   void (*begin_change)(clap_host_t *host, const clap_undo_change_info_t *info);
-   void (*end_change)(clap_host_t *host, const clap_undo_change_info_t *info);
-
-   // Marks the beginning and end of processing an undo change.
-   // [main-thread]
-   void (*begin_undo)(clap_host_t *host, const clap_undo_change_info_t *info);
-   void (*end_undo)(clap_host_t *host, const clap_undo_change_info_t *info);
-
-   // Marks the beginning and end of processing a redo change.
-   // [main-thread]
-   void (*begin_redo)(clap_host_t *host, const clap_undo_change_info_t *info);
-   void (*end_redo)(clap_host_t *host, const clap_undo_change_info_t *info);
-
-   // A destructive change happened which makes it impossible to perform an undo.
-   // The entire plugin's undo/redo stack has been cleared.
-   // [main-thread]
-   void (*after_destructive_change)(clap_host_t *host);
-
-   // Callbacks for clap_plugin_undo->request_*()
-   // If succeed is true, then error_msg is ignored and may be null.
-   // [main-thread]
-   void (*after_undo_request)(clap_host_t *host,
-                              clap_id      change_id,
-                              bool         succeed,
-                              const char  *error_msg);
-   void (*after_redo_request)(clap_host_t *host,
-                              clap_id      change_id,
-                              bool         succeed,
-                              const char  *error_msg);
-} clap_host_undo_t;

From 92d7ebe55dafa47c20b9b5d5543b35abc21c4600 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 17 Oct 2023 10:23:39 +0200
Subject: [PATCH 22/29] Forgot to remove this include

---
 include/clap/clap.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/include/clap/clap.h b/include/clap/clap.h
index 72fab306..e57dbf44 100644
--- a/include/clap/clap.h
+++ b/include/clap/clap.h
@@ -69,5 +69,3 @@
 #include "ext/draft/tuning.h"
 #include "ext/draft/configurable-audio-ports.h"
 #include "ext/draft/extensible-audio-ports.h"
-#include "ext/draft/incremental-state.h"
-#include "ext/draft/undo.h"

From 18922fad9d7e378721433904dbabf100f4f841b1 Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Tue, 17 Oct 2023 13:43:47 +0200
Subject: [PATCH 23/29] Update version.h to 1.1.9

---
 include/clap/version.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/clap/version.h b/include/clap/version.h
index ff45ddf5..1b9cc234 100644
--- a/include/clap/version.h
+++ b/include/clap/version.h
@@ -22,7 +22,7 @@ typedef struct clap_version {
 
 #define CLAP_VERSION_MAJOR 1
 #define CLAP_VERSION_MINOR 1
-#define CLAP_VERSION_REVISION 8
+#define CLAP_VERSION_REVISION 9
 
 #define CLAP_VERSION_INIT                                                                          \
    { (uint32_t)CLAP_VERSION_MAJOR, (uint32_t)CLAP_VERSION_MINOR, (uint32_t)CLAP_VERSION_REVISION }

From 4a2aefc0963afd3dccd55b1ae2ccdce0b34391ed Mon Sep 17 00:00:00 2001
From: trinitou <debuggleburger@gmail.com>
Date: Tue, 17 Oct 2023 22:32:06 +0200
Subject: [PATCH 24/29] Clarify ambisonic enums

---
 include/clap/ext/draft/ambisonic.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/clap/ext/draft/ambisonic.h b/include/clap/ext/draft/ambisonic.h
index 26936023..556af9a6 100644
--- a/include/clap/ext/draft/ambisonic.h
+++ b/include/clap/ext/draft/ambisonic.h
@@ -12,15 +12,15 @@ static CLAP_CONSTEXPR const char CLAP_PORT_AMBISONIC[] = "ambisonic";
 extern "C" {
 #endif
 
-enum {
+enum clap_ambisonic_ordering {
    // FuMa channel ordering
-   CLAP_AMBISONIC_FUMA = 0,
+   CLAP_AMBISONIC_ORDERING_FUMA = 0,
 
    // ACN channel ordering
-   CLAP_AMBISONIC_ACN = 1,
+   CLAP_AMBISONIC_ORDERING_ACN = 1,
 };
 
-enum {
+enum clap_ambisonic_normalization {
    CLAP_AMBISONIC_NORMALIZATION_MAXN = 0,
    CLAP_AMBISONIC_NORMALIZATION_SN3D = 1,
    CLAP_AMBISONIC_NORMALIZATION_N3D = 2,
@@ -29,8 +29,8 @@ enum {
 };
 
 typedef struct clap_ambisonic_config {
-   uint32_t ordering;
-   uint32_t normalization;
+   uint32_t ordering;      // see clap_ambisonic_ordering
+   uint32_t normalization; // see clap_ambisonic_normalization
 } clap_ambisonic_config_t;
 
 typedef struct clap_plugin_ambisonic {

From b31b26a0a1532115e08dc48b6c5c29519f76573c Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Wed, 18 Oct 2023 10:13:10 +0200
Subject: [PATCH 25/29] Update include/clap/ext/draft/surround.h

Co-authored-by: Trinitou <106991375+Trinitou@users.noreply.github.com>
---
 include/clap/ext/draft/surround.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/clap/ext/draft/surround.h b/include/clap/ext/draft/surround.h
index b54156c9..82f4e888 100644
--- a/include/clap/ext/draft/surround.h
+++ b/include/clap/ext/draft/surround.h
@@ -62,7 +62,7 @@ typedef struct clap_plugin_surround {
 
    // Stores the surround identifier of each channel into the channel_map array.
    // Returns the number of elements stored in channel_map.
-   // channel_map_capacity should be greater or equal to the channel count of the given port.
+   // channel_map_capacity must be greater or equal to the channel count of the given port.
    // [main-thread]
    uint32_t(CLAP_ABI *get_channel_map)(const clap_plugin_t *plugin,
                                        bool                 is_input,

From 98df4531c92b99e53bd62cc9c5b4d5c92712d97c Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Wed, 18 Oct 2023 12:57:29 +0200
Subject: [PATCH 26/29] Doc.

---
 include/clap/ext/draft/configurable-audio-ports.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/clap/ext/draft/configurable-audio-ports.h b/include/clap/ext/draft/configurable-audio-ports.h
index dcee8f18..58c382a8 100644
--- a/include/clap/ext/draft/configurable-audio-ports.h
+++ b/include/clap/ext/draft/configurable-audio-ports.h
@@ -31,6 +31,9 @@ typedef struct clap_audio_port_configuration_request {
 } clap_audio_port_configuration_request_t;
 
 typedef struct clap_plugin_configurable_audio_ports {
+   // Submit a bunch of configuration requests which will atomically be applied together,
+   // or discarded together.
+   //
    // If is_dry_run is true, then checks if the configuration can be applied.
    // If is_dry_run is false, then applies the configuration.
    // Returns true if applied.

From 093141f6eb25ded8dce095f067d6086f06bd59de Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Wed, 18 Oct 2023 13:01:13 +0200
Subject: [PATCH 27/29] remove is_dry_run and make two functions instead

---
 include/clap/ext/draft/configurable-audio-ports.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/clap/ext/draft/configurable-audio-ports.h b/include/clap/ext/draft/configurable-audio-ports.h
index 58c382a8..8a709d9c 100644
--- a/include/clap/ext/draft/configurable-audio-ports.h
+++ b/include/clap/ext/draft/configurable-audio-ports.h
@@ -31,17 +31,21 @@ typedef struct clap_audio_port_configuration_request {
 } clap_audio_port_configuration_request_t;
 
 typedef struct clap_plugin_configurable_audio_ports {
+   // Returns true if the given configurations can be applied using apply_configuration().
+   // [main-thread && !active]
+   bool(CLAP_ABI *can_apply_configuration)(
+      const clap_plugin_t                                *plugin,
+      const struct clap_audio_port_configuration_request *requests,
+      uint32_t                                            request_count);
+
    // Submit a bunch of configuration requests which will atomically be applied together,
    // or discarded together.
    //
-   // If is_dry_run is true, then checks if the configuration can be applied.
-   // If is_dry_run is false, then applies the configuration.
    // Returns true if applied.
    // [main-thread && !active]
    bool(CLAP_ABI *apply_configuration)(const clap_plugin_t                                *plugin,
                                        const struct clap_audio_port_configuration_request *requests,
-                                       uint32_t request_count,
-                                       bool     is_dry_run);
+                                       uint32_t request_count);
 } clap_plugin_configurable_audio_ports_t;
 
 #ifdef __cplusplus

From 08d6b5efab0753838a95b600c90f36e1fffc78fd Mon Sep 17 00:00:00 2001
From: Alexandre Bique <bique.alexandre@gmail.com>
Date: Wed, 18 Oct 2023 13:06:51 +0200
Subject: [PATCH 28/29] Doc.

---
 include/clap/ext/draft/configurable-audio-ports.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/clap/ext/draft/configurable-audio-ports.h b/include/clap/ext/draft/configurable-audio-ports.h
index 8a709d9c..4fe60cd1 100644
--- a/include/clap/ext/draft/configurable-audio-ports.h
+++ b/include/clap/ext/draft/configurable-audio-ports.h
@@ -41,6 +41,10 @@ typedef struct clap_plugin_configurable_audio_ports {
    // Submit a bunch of configuration requests which will atomically be applied together,
    // or discarded together.
    //
+   // Once the configuration is successfully applied, it isn't necessary for the plugin to call
+   // clap_host_audio_ports->changed(); and it isn't necessary for the host to scan the
+   // audio ports.
+   //
    // Returns true if applied.
    // [main-thread && !active]
    bool(CLAP_ABI *apply_configuration)(const clap_plugin_t                                *plugin,

From 548f6fbf8733b86c1ebd57f8c92e56a9dd876feb Mon Sep 17 00:00:00 2001
From: deeedob <dennis.ob@protonmail.com>
Date: Thu, 19 Oct 2023 12:55:31 +0200
Subject: [PATCH 29/29] README: Re-phrase the mentioning of ABI

ABI (Application Binary Interface), can be a confusing term for
people who stumble over it. What we want to achieve is to let people
know that the interface is stable and backwards compatible.
---
 README.md | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index ddf6369a..52dc263c 100644
--- a/README.md
+++ b/README.md
@@ -22,8 +22,14 @@
 
 # Learn about CLAP
 
-CLAP stands for **CL**ever **A**udio **P**lugin.
-It is an audio plugin ABI which defines a standard for *Digital Audio Workstations* and audio plugins (synthesizers, audio effects, ...) to work together.
+CLAP stands for **CL**ever **A**udio **P**lugin. It is an interface that
+provides a stable ABI to define a standard for *Digital Audio Workstations* and
+audio plugins (synthesizers, audio effects, ...) to work together.
+
+The ABI, or **A**pplication **B**inary **I**nterface, serves as a means of
+communication between a host and a plugin. It provides backwards compatibility,
+that is, a plugin binary compiled with CLAP 1.x can be loaded by any other
+CLAP 1.y.
 
 To work with CLAP, include [clap/clap.h](include/clap/clap.h).