version 2.8
specbuf.c
1 #include "zgl.h"
2 #include "msghandling.h"
3 #include <math.h>
4 #include <stdlib.h>
5 
6 static void calc_buf(GLSpecBuf *buf, const float shininess)
7 {
8  int i;
9  float val, inc;
10  val = 0.0f;
11  inc = 1.0f/SPECULAR_BUFFER_SIZE;
12  for (i = 0; i <= SPECULAR_BUFFER_SIZE; i++) {
13  buf->buf[i] = pow(val, shininess);
14  val += inc;
15  }
16 }
17 
18 GLSpecBuf *
19 specbuf_get_buffer(GLContext *c, const int shininess_i,
20  const float shininess)
21 {
22  GLSpecBuf *found, *oldest;
23  found = oldest = c->specbuf_first;
24  while (found && found->shininess_i != shininess_i) {
25  if (found->last_used < oldest->last_used) {
26  oldest = found;
27  }
28  found = found->next;
29  }
30  if (found) { /* hey, found one! */
31  found->last_used = c->specbuf_used_counter++;
32  return found;
33  }
34  if (oldest == NULL || c->specbuf_num_buffers < MAX_SPECULAR_BUFFERS) {
35  /* create new buffer */
36  GLSpecBuf *buf = gl_malloc(sizeof(GLSpecBuf));
37  if (!buf) gl_fatal_error("could not allocate specular buffer");
38  c->specbuf_num_buffers++;
39  buf->next = c->specbuf_first;
40  c->specbuf_first = buf;
41  buf->last_used = c->specbuf_used_counter++;
42  buf->shininess_i = shininess_i;
43  calc_buf(buf, shininess);
44  return buf;
45  }
46  /* overwrite the lru buffer */
47  /*tgl_trace("overwriting spec buffer :(\n");*/
48  oldest->shininess_i = shininess_i;
49  oldest->last_used = c->specbuf_used_counter++;
50  calc_buf(oldest, shininess);
51  return oldest;
52 }