commit 6b71d8b9c73fed2bfe6900d0b64a10e2ad13136a
parent b6b0df4b4c97c6ddb589e2f125366c81b27ef410
Author: defiantnerd <97224712+defiantnerd@users.noreply.github.com>
Date: Fri, 24 Jun 2022 12:01:54 +0200
Initial proposal for ext-state2
Diffstat:
1 file changed, 88 insertions(+), 0 deletions(-)
diff --git a/include/clap/ext/state2.h b/include/clap/ext/state2.h
@@ -0,0 +1,88 @@
+#pragma once
+
+#include "../plugin.h"
+#include "../stream.h"
+
+/// @page state2 extension
+/// @brief extended state handling
+///
+/// Main idea:
+///
+/// Sometimes it is desirable to add additional information about a plugin state
+/// depending on context. The extension is designed to be a full replacement
+/// of the ext-state extensions of CLAP.
+///
+/// An example could be a plugin that also interacts with an external hardware.
+/// Each instance would be connected to a device that is probably using external connections.
+///
+/// To restore this information, the hardware's id is being stored in the plugin state stream.
+///
+/// But if a 'preset' is saved (and restored later via load()) there shouldn't be such an
+/// information. This would create presets that are tied to a given hardware id.
+///
+/// Therefore the host should give a context hint for the operation it executes.
+///
+/// Scenarios for the save() function:
+///
+/// - Context `clap_state_context_preset`: The plugin stores all sound settings into the stream
+/// and would NOT include any project specific settings (like the hardware's id)
+/// - Context `clap_state_context_project`: The plugin stores all aound settings including
+/// the project specific settings (like the hardware's id)
+/// - Context `clap_state_context_clone`: The plugin stores all relevant settings that allow
+/// a new instance of the plugin to be presented as 'duplicate' effectively, like
+/// using the next index of an enumeration, a channel etc.
+///
+/// Scenarios for the load() function:
+///
+/// - Context `clap_state_context_preset`: The plugin restores all sound settings from the stream
+/// and would IGNORE any project specific settings (like the hardware's id) which possibly
+/// is in the stream.
+/// - Context `clap_state_context_project`: The plugin restores all aound settings including
+/// the project specific settings (like the hardware's id). If no project specific settings
+/// are in the stream, those should go to default
+/// - Context `clap_state_context_clone`: The plugin restores all relevant settings that allow
+/// this instance of the plugin to be presented as 'duplicate' effectively, but probably
+/// changing settings in a useful way (like using the next channel, sidechain or whatever)
+///
+/// The plugin is responsible to ignore data that makes not sense in the given context or provide
+/// useful settings in case such a data is not contained in the stream.
+///
+/// The host is responsible to declare the context the state operation in which it is happening.
+///
+/// @note if the `ext-state2` extension is not available, the fallback is always the `ext-state`
+/// extension, so a plugin MUST implement both interfaces and handle the stream of `ext-state`
+/// like `clap_context_state_preset`.
+///
+/// @note if an unknown context index is provided, it should be handled as `context_state_preset`.
+///
+/// 2022 Timo Kaluza / defiant nerd
+
+static CLAP_CONSTEXPR const char CLAP_EXT_STATE2[] = "clap.state2";
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct clap_plugin_state2 {
+
+ // the state context
+ typedef enum {
+ clap_state_context_preset = 1,
+ clap_state_context_project = 2,
+ clap_state_context_clone = 3
+ } clap_plugin_state_context_t;
+
+ // Saves the plugin state for a given context into stream.
+ // Returns true if the state was correctly saved.
+ // [main-thread]
+ bool (*save)(const clap_plugin_t *plugin, clap_plugin_state_context_t context, const clap_ostream_t *stream);
+
+ // Loads the plugin state from stream in a given context
+ // Returns true if the state was correctly restored.
+ // [main-thread]
+ bool (*load)(const clap_plugin_t *plugin, clap_plugin_state_context_t context, const clap_istream_t *stream);
+} clap_plugin_state2_t;
+
+#ifdef __cplusplus
+}
+#endif
