src/graphics/lighting.c

   1 /************************************************************************
   2 * lighting.c
   3 * voxelands - 3d voxel world sandbox game
   4 * Copyright (C) Lisa 'darkrose' Milne 2016 <lisa@ltmnet.com>
   5 *
   6 * This program is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14 * See the GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program.  If not, see <http://www.gnu.org/licenses/>
  18 ************************************************************************/
  19
  20 #include "common.h"
  21 #include "graphics.h"
  22 #include "array.h"
  23 #include "list.h"
  24
  25 static struct {
  26         int ids;
  27         array_t lights;
  28 } light_data = {
  29         -1
  30 };
  31
  32 /* comparison functions:
  33  * return 0 to insert
  34  * return 1 to insert later
  35  * return -1 to not insert at all
  36  */
  37 static int light_insert_cmp(void *e1, void *e2)
  38 {
  39         light_t *l1;
  40         light_t *l2;
  41
  42         l1 = e1;
  43         l2 = e2;
  44
  45         if (l1->d < l2->d)
  46                 return 0;
  47         return 1;
  48 }
  49
  50 int light_add(colour_t *colour, v3_t *pos, v3_t *att)
  51 {
  52         light_t *l;
  53         if (light_data.ids < 0)
  54                 array_init(&light_data.lights,ARRAY_TYPE_PTR);
  55
  56         l = malloc(sizeof(light_t));
  57         if (!l)
  58                 return -1;
  59
  60         l->pos.x = pos->x;
  61         l->pos.y = pos->y;
  62         l->pos.z = pos->z;
  63
  64         l->colour.r = colour->r;
  65         l->colour.g = colour->g;
  66         l->colour.b = colour->b;
  67         l->colour.a = colour->a;
  68
  69         if (att) {
  70                 l->att.x = att->x;
  71                 l->att.y = att->y;
  72                 l->att.z = att->z;
  73         }else{
  74                 l->att.x = 1.0;
  75                 l->att.y = 0.0;
  76                 l->att.z = 0.0;
  77         }
  78
  79         l->id = ++light_data.ids;
  80
  81         array_push_ptr(&light_data.lights,l);
  82
  83         return -1;
  84 }
  85
  86 void light_remove(int id)
  87 {
  88 }
  89
  90 void light_bind_near(shader_t *s, v3_t *pos)
  91 {
  92         int i;
  93         light_t *l;
  94         light_t *nearby = NULL;
  95
  96         if (light_data.ids < 0)
  97                 return;
  98
  99         for (i=0; i<light_data.lights.length; i++) {
 100                 l = array_get_ptr(&light_data.lights,i);
 101                 if (!l)
 102                         continue;
 103                 l->d = math_distance(pos,&l->pos);
 104                 nearby = list_insert_cmp(&nearby,l,light_insert_cmp);
 105         }
 106
 107         l = nearby;
 108         for (i=0; l; i++) {
 109                 shader_uniform_light(s,i,l);
 110                 l = l->next;
 111         }
 112         for (; i<8; i++) {
 113                 shader_uniform_light(s,i,NULL);
 114         }
 115 }