Add protoview

https://github.com/antirez/protoview

applications/plugins/protoview/app_buffer.h

@@ -0,0 +1,31 @@
+/* Copyright (C) 2022-2023 Salvatore Sanfilippo -- All Rights Reserved
+ * See the LICENSE file for information about the license. */
+
+/* Our circular buffer of raw samples, used in order to display
+ * the signal. */
+
+#define RAW_SAMPLES_NUM 2048 /* Use a power of two: we take the modulo
+                                of the index quite often to normalize inside
+                                the range, and division is slow. */
+typedef struct RawSamplesBuffer {
+    FuriMutex *mutex;
+    struct {
+        uint16_t level:1;
+        uint16_t dur:15;
+    } samples[RAW_SAMPLES_NUM];
+    uint32_t idx;   /* Current idx (next to write). */
+    uint32_t total; /* Total samples: same as RAW_SAMPLES_NUM, we provide
+                       this field for a cleaner interface with the user, but
+                       we always use RAW_SAMPLES_NUM when taking the modulo so
+                       the compiler can optimize % as bit masking. */
+    /* Signal features. */
+    uint32_t short_pulse_dur; /* Duration of the shortest pulse. */
+} RawSamplesBuffer;
+
+RawSamplesBuffer *raw_samples_alloc(void);
+void raw_samples_reset(RawSamplesBuffer *s);
+void raw_samples_center(RawSamplesBuffer *s, uint32_t offset);
+void raw_samples_add(RawSamplesBuffer *s, bool level, uint32_t dur);
+void raw_samples_get(RawSamplesBuffer *s, uint32_t idx, bool *level, uint32_t *dur);
+void raw_samples_copy(RawSamplesBuffer *dst, RawSamplesBuffer *src);
+void raw_samples_free(RawSamplesBuffer *s);