+ world_global.in_volume = in_volume;
+
+#if 0
+ if( k_debug_light_indices )
+ {
+ for( int i=0; i<world->light_count; i++ ){
+ struct world_light *light = &world->lights[i];
+ struct classtype_world_light *inf = light->inf;
+
+ u32 colour = 0xff000000;
+ u8 r = inf->colour[0] * 255.0f,
+ g = inf->colour[1] * 255.0f,
+ b = inf->colour[2] * 255.0f;
+
+ colour |= r;
+ colour |= g << 8;
+ colour |= b << 16;
+
+ vg_line_pt3( light->node->co, 0.25f, colour );
+ }
+ }
+
+#endif
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * API implementation
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void ray_world_get_tri( world_instance *world,
+ ray_hit *hit, v3f tri[3] )
+{
+ for( int i=0; i<3; i++ )
+ v3_copy( world->scene_geo.arrvertices[ hit->tri[i] ].co, tri[i] );
+}
+
+VG_STATIC int ray_world( world_instance *world,
+ v3f pos, v3f dir, ray_hit *hit )
+{
+ return scene_raycast( &world->scene_geo, world->geo_bh, pos, dir, hit );
+}
+
+/*
+ * Cast a sphere from a to b and see what time it hits
+ */
+VG_STATIC int spherecast_world( world_instance *world,
+ v3f pa, v3f pb, float r, float *t, v3f n )
+{
+ bh_iter it;
+ bh_iter_init( 0, &it );
+
+ boxf region;
+ box_init_inf( region );
+ box_addpt( region, pa );
+ box_addpt( region, pb );
+
+ v3_add( (v3f){ r, r, r}, region[1], region[1] );
+ v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
+
+ v3f dir;
+ v3_sub( pb, pa, dir );
+
+ v3f dir_inv;
+ dir_inv[0] = 1.0f/dir[0];
+ dir_inv[1] = 1.0f/dir[1];
+ dir_inv[2] = 1.0f/dir[2];
+
+ int hit = -1;
+ float min_t = 1.0f;
+
+ int idx;
+ while( bh_next( world->geo_bh, &it, region, &idx ) ){
+ u32 *ptri = &world->scene_geo.arrindices[ idx*3 ];
+ v3f tri[3];
+
+ boxf box;
+ box_init_inf( box );
+
+ for( int j=0; j<3; j++ ){
+ v3_copy( world->scene_geo.arrvertices[ptri[j]].co, tri[j] );
+ box_addpt( box, tri[j] );
+ }
+
+ v3_add( (v3f){ r, r, r}, box[1], box[1] );
+ v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
+
+ if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
+ continue;
+
+ float t;
+ v3f n1;
+ if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
+ if( t < min_t ){
+ min_t = t;
+ hit = idx;
+ v3_copy( n1, n );
+ }
+ }
+ }
+
+ *t = min_t;
+ return hit;
+}
+
+VG_STATIC
+struct world_surface *world_tri_index_surface( world_instance *world,
+ u32 index )
+{
+ for( int i=1; i<world->surface_count; i++ ){
+ struct world_surface *surf = &world->surfaces[i];
+
+ if( (index >= surf->sm_geo.vertex_start) &&
+ (index < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
+ {
+ return surf;
+ }
+ }
+
+ return &world->surfaces[0];
+}
+
+VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
+ rb_ct *ct )
+{
+ return world_tri_index_surface( world, ct->element_id );
+}
+
+VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
+ ray_hit *hit )
+{
+ return world_tri_index_surface( world, hit->tri[0] );
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Audio sampling
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC
+enum audio_sprite_type world_audio_sample_sprite_kandom(v3f origin, v3f output);
+VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
+
+#include "audio.h"
+
+/*
+ * Trace out a random point, near the player to try and determine water areas
+ */
+VG_STATIC
+enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
+{
+ v3f chance = { (vg_randf64()-0.5f) * 30.0f,
+ 8.0f,
+ (vg_randf64()-0.5f) * 30.0f };
+
+ v3f pos;
+ v3_add( chance, origin, pos );
+
+ ray_hit contact;
+ contact.dist = vg_minf( 16.0f, pos[1] );
+
+ world_instance *world = get_active_world();
+
+ if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
+ struct world_surface *mat = ray_hit_surface( world, &contact );
+
+ if( mat->info.surface_prop == k_surface_prop_grass){
+ v3_copy( contact.pos, output );
+ return k_audio_sprite_type_grass;
+ }
+ else{
+ return k_audio_sprite_type_none;
+ }
+ }
+
+ output[0] = pos[0];
+ output[1] = 0.0f;
+ output[2] = pos[2];
+
+ float dist = fabsf(output[1] - origin[1]);
+
+ if( world->water.enabled && dist<=40.0f )
+ return k_audio_sprite_type_water;
+ else
+ return k_audio_sprite_type_none;
+}
+
+VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
+{
+ float inr3 = 0.57735027,
+ inr2 = 0.70710678118;
+
+ v3f sample_directions[] = {
+ { -1.0f, 0.0f, 0.0f },
+ { 1.0f, 0.0f, 0.0f },
+ { 0.0f, 0.0f, 1.0f },
+ { 0.0f, 0.0f, -1.0f },
+ { 0.0f, 1.0f, 0.0f },
+ { 0.0f, -1.0f, 0.0f },
+ { -inr3, inr3, inr3 },
+ { inr3, inr3, inr3 },
+ { -inr3, inr3, -inr3 },
+ { inr3, inr3, -inr3 },
+ { -inr2, 0.0f, inr2 },
+ { inr2, 0.0f, inr2 },
+ { -inr2, 0.0f, -inr2 },
+ { inr2, 0.0f, -inr2 },
+ };
+
+ static int si = 0;
+ static float distances[16];
+
+ ray_hit ray;
+ ray.dist = 5.0f;
+
+ v3f rc, rd, ro;
+ v3_copy( sample_directions[ si ], rd );
+ v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
+ v3_copy( ro, rc );
+
+ float dist = 200.0f;
+
+ for( int i=0; i<10; i++ ){
+ if( ray_world( get_active_world(), rc, rd, &ray ) ){
+ dist = (float)i*5.0f + ray.dist;
+ break;
+ }
+ else{
+ v3_muladds( rc, rd, ray.dist, rc );
+ }
+ }
+
+ distances[si] = dist;
+
+ if( vg_lines.draw ){
+ for( int i=0; i<14; i++ ){
+ if( distances[i] != 200.0f ){
+ u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
+ VG__CYAN, VG__YELOW, VG__PINK,
+ VG__WHITE };
+
+ u32 colour = colours[i%7];
+
+ v3f p1;
+ v3_muladds( ro, sample_directions[i], distances[i], p1 );
+ vg_line( ro, p1, colour );
+ vg_line_pt3( p1, 0.1f, colour );
+ }
+ }
+ }
+
+ *index = si;
+ *value = dist;