00001 #include "zgl.h"
00002 #include <math.h>
00003 #include <stdlib.h>
00004
00005 static void calc_buf(GLSpecBuf *buf, const PN_stdfloat shininess)
00006 {
00007 int i;
00008 PN_stdfloat val, inc;
00009 val = 0.0f;
00010 inc = 1.0f/SPECULAR_BUFFER_SIZE;
00011 for (i = 0; i <= SPECULAR_BUFFER_SIZE; i++) {
00012 buf->buf[i] = pow(val, shininess);
00013 val += inc;
00014 }
00015 }
00016
00017 GLSpecBuf *
00018 specbuf_get_buffer(GLContext *c, const int shininess_i,
00019 const PN_stdfloat shininess)
00020 {
00021 GLSpecBuf *found, *oldest;
00022 found = oldest = c->specbuf_first;
00023 while (found && found->shininess_i != shininess_i) {
00024 if (found->last_used < oldest->last_used) {
00025 oldest = found;
00026 }
00027 found = found->next;
00028 }
00029 if (found) {
00030 found->last_used = c->specbuf_used_counter++;
00031 return found;
00032 }
00033 if (oldest == NULL || c->specbuf_num_buffers < MAX_SPECULAR_BUFFERS) {
00034
00035 GLSpecBuf *buf = (GLSpecBuf *)gl_malloc(sizeof(GLSpecBuf));
00036 if (!buf) gl_fatal_error("could not allocate specular buffer");
00037 c->specbuf_num_buffers++;
00038 buf->next = c->specbuf_first;
00039 c->specbuf_first = buf;
00040 buf->last_used = c->specbuf_used_counter++;
00041 buf->shininess_i = shininess_i;
00042 calc_buf(buf, shininess);
00043 return buf;
00044 }
00045
00046 oldest->shininess_i = shininess_i;
00047 oldest->last_used = c->specbuf_used_counter++;
00048 calc_buf(oldest, shininess);
00049 return oldest;
00050 }