commit ac13daa043289d71b74891ae9f780a4f41186987
parent 8ee4edf00950b2c064a56499ae7840dec550d186
Author: defiantnerd <97224712+defiantnerd@users.noreply.github.com>
Date: Thu, 30 Jun 2022 19:49:29 +0200
moved state-context to draft
in #ext-clone the decision was to move it to draft
Diffstat:
1 file changed, 82 insertions(+), 0 deletions(-)
diff --git a/include/clap/ext/draft/state-context.h b/include/clap/ext/draft/state-context.h
@@ -0,0 +1,82 @@
+#pragma once
+
+#include "../../plugin.h"
+#include "../../stream.h"
+
+/// @page state-context 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 extension for the
+/// ext-state extension 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 save() function:
+///
+/// - 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_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_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_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_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_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 or the host did not implement
+/// the usage of ext-state-context.
+///
+/// The host is responsible to declare the context the state operation in which it is happening.
+///
+/// @note if an unknown context index is provided, it should be handled as
+/// `CLAP_STATE_CONTEXT_PROJECT`.
+///
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static CLAP_CONSTEXPR const char CLAP_EXT_STATE_CONTEXT[] = "clap.state-context.draft/0";
+
+enum clap_plugin_state_context_type {
+ CLAP_STATE_CONTEXT_PROJECT = 1,
+ CLAP_STATE_CONTEXT_PRESET = 2,
+ CLAP_STATE_CONTEXT_CLONE = 3
+};
+
+typedef struct clap_plugin_state_context {
+ // Hosts that use the set_state_context() function should *always* call it directly before
+ // ->save() or load(). Plugins that implement the set_state_context() function should
+ // keep the last assigned context around, regardless of the frequency of invocations.
+
+ // Assign the context for subsequent calls to ->save() or load() of the
+ // clap_plugin_state extension.
+ // [main-thread]
+ void (*set_state_context)(const clap_plugin_t *plugin, uint32_t context);
+} clap_plugin_state_context_t;
+
+#ifdef __cplusplus
+}
+#endif
