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engines/glk/scott/ring_buffer.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * Based on ScottFree interpreter version 1.14 developed by Swansea
+ * University Computer Society without disassembly of any other game
+ * drivers, only of game databases as permitted by EEC law (for purposes
+ * of compatibility).
+ *
+ * Licensed under GPLv2
+ *
+ * https://github.com/angstsmurf/spatterlight/tree/master/terps/scott
+ */
+
+#ifndef GLK_SCOTT_RINGBUFFER_H
+#define GLK_SCOTT_RINGBUFFER_H
+
+#include "glk/scott/types.h"
+
+namespace Glk {
+namespace Scott {
+
+// Opaque circular buffer structure
+struct CircularBuf;
+// Handle type, the way users interact with the API
+typedef CircularBuf *cbuf_handle_t;
+
+/// Pass in a storage buffer and size
+/// Returns a circular buffer handle
+cbuf_handle_t circularBufInit(uint8_t *buffer, size_t size);
+
+/// Free a circular buffer structure.
+/// Does not free data buffer; owner is responsible for that
+void circularBufFree(cbuf_handle_t me);
+
+/// Reset the circular buffer to empty, head == tail
+void circularBufReset(cbuf_handle_t me);
+
+/// Rejects new data if the buffer is full
+/// Returns 0 on success, -1 if buffer is full
+int circularBufPut(cbuf_handle_t me, uint8_t x, uint8_t y);
+
+/// Retrieve a value from the buffer
+/// Returns 0 on success, -1 if the buffer is empty
+int circularBufGet(cbuf_handle_t me, int *x, int *y);
+
+/// Returns true if the buffer is empty
+bool circularBufEmpty(cbuf_handle_t me);
+
+/// Returns true if the buffer is full
+bool circularBufFull(cbuf_handle_t me);
+
+/// Returns the maximum capacity of the buffer
+size_t circularBufCapacity(cbuf_handle_t me);
+
+/// Returns the current number of elements in the buffer
+size_t circularBufSize(cbuf_handle_t me);
+
+} // End of namespace Scott
+} // End of namespace Glk
+
+#endif