scummvm/graphics/tinygl/specbuf.cpp
2014-08-13 18:52:52 +02:00

87 lines
2.6 KiB
C++

/* ResidualVM - A 3D game interpreter
*
* ResidualVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the AUTHORS
* 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
/*
* This file is based on, or a modified version of code from TinyGL (C) 1997-1998 Fabrice Bellard,
* which is licensed under the zlib-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 *specbuf_get_buffer(GLContext *c, const int shininess_i, const float shininess) {
GLSpecBuf *found, *oldest;
found = oldest = c->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 = c->specbuf_used_counter++;
return found;
}
if (!oldest || c->specbuf_num_buffers < MAX_SPECULAR_BUFFERS) {
// create new buffer
GLSpecBuf *buf = (GLSpecBuf *)gl_malloc(sizeof(GLSpecBuf));
if (!buf)
error("could not allocate specular buffer");
c->specbuf_num_buffers++;
buf->next = c->specbuf_first;
c->specbuf_first = buf;
buf->last_used = c->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 = c->specbuf_used_counter++;
calc_buf(oldest, shininess);
return oldest;
}
void specbuf_cleanup(GLContext *c) {
GLSpecBuf *buf, *next;
buf = c->specbuf_first;
for (int i = 0; i < c->specbuf_num_buffers; ++i) {
next = buf->next;
gl_free(buf);
buf = next;
}
}
} // end of namespace TinyGL