Initial commit

graphics/tinygl/specbuf.cpp

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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/>.
+ *
+ */
+
+/*
+ * This file is based on, or a modified version of code from TinyGL (C) 1997-2022 Fabrice Bellard,
+ * which is licensed under the MIT license (see LICENSE).
+ * It also has modifications by the ResidualVM-team, which are covered under the GPLv2 (or later).
+ */
+
+#include "graphics/tinygl/zgl.h"
+
+namespace TinyGL {
+
+static void calc_buf(GLSpecBuf *buf, const float shininess) {
+	float val, inc;
+	val = 0.0f;
+	inc = 1.0f / SPECULAR_BUFFER_SIZE;
+	for (int i = 0; i <= SPECULAR_BUFFER_SIZE; i++) {
+		buf->buf[i] = pow(val, shininess);
+		val += inc;
+	}
+}
+
+GLSpecBuf *GLContext::specbuf_get_buffer(const int shininess_i, const float shininess) {
+	GLSpecBuf *found, *oldest;
+	found = oldest = specbuf_first;
+	while (found && found->shininess_i != shininess_i) {
+		if (found->last_used < oldest->last_used) {
+			oldest = found;
+		}
+		found = found->next;
+	}
+	if (found) {
+		found->last_used = specbuf_used_counter++;
+		return found;
+	}
+	if (!oldest || specbuf_num_buffers < MAX_SPECULAR_BUFFERS) {
+		// create new buffer
+		GLSpecBuf *buf = (GLSpecBuf *)gl_malloc(sizeof(GLSpecBuf));
+		if (!buf)
+			error("could not allocate specular buffer");
+		specbuf_num_buffers++;
+		buf->next = specbuf_first;
+		specbuf_first = buf;
+		buf->last_used = specbuf_used_counter++;
+		buf->shininess_i = shininess_i;
+		calc_buf(buf, shininess);
+		return buf;
+	}
+	//overwrite the lru buffer
+	oldest->shininess_i = shininess_i;
+	oldest->last_used = specbuf_used_counter++;
+	calc_buf(oldest, shininess);
+	return oldest;
+}
+
+void GLContext::specbuf_cleanup() {
+	GLSpecBuf *buf, *next;
+	buf = specbuf_first;
+	for (int i = 0; i < specbuf_num_buffers; ++i) {
+		next = buf->next;
+		gl_free(buf);
+		buf = next;
+	}
+}
+
+} // end of namespace TinyGL