X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=scene.c;fp=scene.c;h=f472f2cafde666817ffc502b12289a5a8002b83a;hb=5f6a4f9df6c8accc89f1920bfe9ace3cbac4c4b6;hp=0000000000000000000000000000000000000000;hpb=a109f126d8adab622e38fbcc2d4281e75255246a;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/scene.c b/scene.c
new file mode 100644
index 0000000..f472f2c
--- /dev/null
+++ b/scene.c
@@ -0,0 +1,404 @@
+#include "scene.h"
+
+u32 scene_mem_required( scene_context *ctx )
+{
+   u32 vertex_length = vg_align8(ctx->max_vertices * sizeof(scene_vert)),
+       index_length  = vg_align8(ctx->max_indices  * sizeof(u32));
+
+   return vertex_length + index_length;
+}
+
+void scene_init( scene_context *ctx, u32 max_vertices, u32 max_indices )
+{
+   ctx->vertex_count = 0;
+   ctx->indice_count = 0;
+   ctx->max_vertices = max_vertices;
+   ctx->max_indices = max_indices;
+   ctx->arrindices = NULL; /* must be filled out by user */
+   ctx->arrvertices = NULL;
+
+   memset( &ctx->submesh, 0, sizeof(mdl_submesh) );
+
+   v3_fill( ctx->bbx[0],  999999.9f );
+   v3_fill( ctx->bbx[1], -999999.9f );
+}
+
+void scene_supply_buffer( scene_context *ctx, void *buffer )
+{
+   u32 vertex_length = vg_align8( ctx->max_vertices * sizeof(scene_vert) );
+
+   ctx->arrvertices = buffer;
+   ctx->arrindices  = (u32*)(((u8*)buffer) + vertex_length);
+}
+
+void scene_vert_pack_norm( scene_vert *vert, v3f norm, f32 blend )
+{
+   v3f n;
+   v3_muls( norm, 127.0f, n );
+   v3_minv( n, (v3f){  127.0f,  127.0f,  127.0f }, n );
+   v3_maxv( n, (v3f){ -127.0f, -127.0f, -127.0f }, n );
+   vert->norm[0] = n[0];
+   vert->norm[1] = n[1];
+   vert->norm[2] = n[2];
+   vert->norm[3] = blend * 127.0f;
+}
+
+/* 
+ * Append a model into the scene with a given transform
+ */
+void scene_add_mdl_submesh( scene_context *ctx, mdl_context *mdl, 
+                            mdl_submesh *sm, m4x3f transform )
+{
+   if( ctx->vertex_count + sm->vertex_count > ctx->max_vertices ){
+      vg_fatal_error( "Scene vertex buffer overflow (%u exceeds %u)\n",
+                        ctx->vertex_count + sm->vertex_count, 
+                        ctx->max_vertices );
+   }
+
+   if( ctx->indice_count + sm->indice_count > ctx->max_indices ){
+      vg_fatal_error( "Scene index buffer overflow (%u exceeds %u)\n",
+                        ctx->indice_count + sm->indice_count,
+                        ctx->max_indices );
+   }
+
+   mdl_vert   *src_verts = mdl_arritm( &mdl->verts, sm->vertex_start );
+   scene_vert *dst_verts = &ctx->arrvertices[ ctx->vertex_count ];
+
+   u32 *src_indices    =  mdl_arritm( &mdl->indices, sm->indice_start ),
+       *dst_indices    = &ctx->arrindices[ ctx->indice_count ];
+   
+   /* Transform and place vertices */
+   boxf bbxnew;
+   box_init_inf( bbxnew );
+   m4x3_expand_aabb_aabb( transform, bbxnew, sm->bbx );
+   box_concat( ctx->bbx, bbxnew );
+
+   m3x3f normal_matrix;
+   m3x3_copy( transform, normal_matrix );
+   v3_normalize( normal_matrix[0] );
+   v3_normalize( normal_matrix[1] );
+   v3_normalize( normal_matrix[2] );
+   
+   for( u32 i=0; i<sm->vertex_count; i++ ){
+      mdl_vert   *src   = &src_verts[i];
+      scene_vert *pvert = &dst_verts[i];
+
+      m4x3_mulv( transform, src->co, pvert->co );
+
+      v3f normal;
+      m3x3_mulv( normal_matrix, src->norm, normal );
+      scene_vert_pack_norm( pvert, normal, src->colour[0]*(1.0f/255.0f) );
+      
+      v2_copy( src->uv, pvert->uv );
+   }
+
+   u32 real_indices = 0;
+   for( u32 i=0; i<sm->indice_count/3; i++ ){
+      u32 *src = &src_indices[i*3],
+          *dst = &dst_indices[real_indices];
+
+      v3f ab, ac, tn;
+      v3_sub( src_verts[src[2]].co, src_verts[src[0]].co, ab );
+      v3_sub( src_verts[src[1]].co, src_verts[src[0]].co, ac );
+      v3_cross( ac, ab, tn );
+
+#if 0
+      if( v3_length2( tn ) <= 0.00001f )
+         continue;
+#endif
+
+      dst[0] = src[0] + ctx->vertex_count;
+      dst[1] = src[1] + ctx->vertex_count;
+      dst[2] = src[2] + ctx->vertex_count;
+
+      real_indices += 3;
+   }
+
+   if( real_indices != sm->indice_count )
+      vg_warn( "Zero area triangles in model\n" );
+
+   ctx->vertex_count += sm->vertex_count;
+   ctx->indice_count += real_indices;
+}
+
+/*
+ * One by one adders for simplified access (mostly procedural stuff)
+ */
+void scene_push_tri( scene_context *ctx, u32 tri[3] )
+{
+   if( ctx->indice_count + 3 > ctx->max_indices )
+      vg_fatal_error( "Scene indice buffer overflow (%u exceeds %u)\n",
+                        ctx->indice_count+3, ctx->max_indices );
+
+   u32 *dst = &ctx->arrindices[ ctx->indice_count ];
+
+   dst[0] = tri[0];
+   dst[1] = tri[1];
+   dst[2] = tri[2];
+
+   ctx->indice_count += 3;
+}
+
+void scene_push_vert( scene_context *ctx, scene_vert *v )
+{
+   if( ctx->vertex_count + 1 > ctx->max_vertices )
+      vg_fatal_error( "Scene vertex buffer overflow (%u exceeds %u)\n",
+                        ctx->vertex_count+1, ctx->max_vertices );
+
+   scene_vert *dst = &ctx->arrvertices[ ctx->vertex_count ];
+   *dst = *v;
+
+   ctx->vertex_count ++;
+}
+
+void scene_copy_slice( scene_context *ctx, mdl_submesh *sm )
+{
+   sm->indice_start = ctx->submesh.indice_start;
+   sm->indice_count = ctx->indice_count - sm->indice_start;
+
+   sm->vertex_start = ctx->submesh.vertex_start;
+   sm->vertex_count = ctx->vertex_count - sm->vertex_start;
+   
+   ctx->submesh.indice_start = ctx->indice_count;
+   ctx->submesh.vertex_start = ctx->vertex_count;
+}
+
+void scene_set_vertex_flags( scene_context *ctx, 
+                             u32 start, u32 count, u16 flags )
+{
+   for( u32 i=0; i<count; i++ )
+      ctx->arrvertices[ start + i ].flags = flags;
+}
+
+struct scene_upload_info{
+   scene_context *ctx;
+   glmesh *mesh;
+};
+
+void async_scene_upload( void *payload, u32 size )
+{
+   struct scene_upload_info *info = payload;
+
+   //assert( mesh->loaded == 0 );
+   
+   glmesh *mesh = info->mesh;
+   scene_context *ctx = info->ctx;
+
+   glGenVertexArrays( 1, &mesh->vao );
+   glGenBuffers( 1, &mesh->vbo );
+   glGenBuffers( 1, &mesh->ebo );
+   glBindVertexArray( mesh->vao );
+
+   size_t stride = sizeof(scene_vert);
+
+   glBindBuffer( GL_ARRAY_BUFFER, mesh->vbo );
+   glBufferData( GL_ARRAY_BUFFER, ctx->vertex_count*stride, 
+                 ctx->arrvertices, GL_STATIC_DRAW );
+
+   glBindVertexArray( mesh->vao );
+   glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, mesh->ebo );
+   glBufferData( GL_ELEMENT_ARRAY_BUFFER, ctx->indice_count*sizeof(u32),
+                 ctx->arrindices, GL_STATIC_DRAW );
+   
+   /* 0: coordinates */
+   glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, stride, (void*)0 );
+   glEnableVertexAttribArray( 0 );
+
+   /* 1: normal */
+   glVertexAttribPointer( 1, 4, GL_BYTE, GL_TRUE,
+         stride, (void *)offsetof(scene_vert, norm) );
+   glEnableVertexAttribArray( 1 );
+
+   /* 2: uv */
+   glVertexAttribPointer( 2, 2, GL_FLOAT, GL_FALSE, 
+         stride, (void *)offsetof(scene_vert, uv) );
+   glEnableVertexAttribArray( 2 );
+
+   VG_CHECK_GL_ERR();
+
+   mesh->indice_count = ctx->indice_count;
+   mesh->loaded = 1;
+
+   vg_info( "Scene upload ( XYZ_f32 UV_f32 XYZW_i8 )[ u32 ]\n" );
+   vg_info( "   indices:%u\n", ctx->indice_count );
+   vg_info( "   verts:%u\n",   ctx->vertex_count );
+}
+
+void scene_upload_async( scene_context *ctx, glmesh *mesh )
+{
+   vg_async_item *call = vg_async_alloc( sizeof(struct scene_upload_info) );
+
+   struct scene_upload_info *info = call->payload;
+   info->mesh = mesh;
+   info->ctx = ctx;
+
+   vg_async_dispatch( call, async_scene_upload );
+}
+
+vg_async_item *scene_alloc_async( scene_context *scene, glmesh *mesh,
+                                  u32 max_vertices, u32 max_indices )
+{
+   scene_init( scene, max_vertices, max_indices );
+   u32 buf_size = scene_mem_required( scene );
+
+   u32 hdr_size = vg_align8(sizeof(struct scene_upload_info));
+   vg_async_item *call = vg_async_alloc( hdr_size + buf_size );
+
+   struct scene_upload_info *info = call->payload;
+
+   info->mesh = mesh;
+   info->ctx = scene;
+
+   void *buffer = ((u8*)call->payload)+hdr_size;
+   scene_supply_buffer( scene, buffer );
+
+   return call;
+}
+
+
+/*
+ * BVH implementation
+ */
+
+static void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
+{
+   scene_context *s = user;
+   scene_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
+              *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
+              *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
+   
+  box_addpt( bound, pa->co );
+  box_addpt( bound, pb->co );
+  box_addpt( bound, pc->co );
+}
+
+static float scene_bh_centroid( void *user, u32 item_index, int axis )
+{
+   scene_context *s = user;
+   scene_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
+              *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
+              *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
+
+   #if 0
+
+   float min, max;
+
+   min = vg_minf( pa->co[axis], pb->co[axis] );
+   max = vg_maxf( pa->co[axis], pb->co[axis] );
+   min = vg_minf( min, pc->co[axis] );
+   max = vg_maxf( max, pc->co[axis] );
+
+   return (min+max) * 0.5f;
+
+   #else
+   return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
+   #endif
+}
+
+static void scene_bh_swap( void *user, u32 ia, u32 ib )
+{
+   scene_context *s = user;
+
+   u32 *ti = &s->arrindices[ia*3];
+   u32 *tj = &s->arrindices[ib*3];
+
+   u32 temp[3];
+   temp[0] = ti[0];
+   temp[1] = ti[1];
+   temp[2] = ti[2];
+
+   ti[0] = tj[0];
+   ti[1] = tj[1];
+   ti[2] = tj[2];
+
+   tj[0] = temp[0];
+   tj[1] = temp[1];
+   tj[2] = temp[2];
+}
+
+static void scene_bh_debug( void *user, u32 item_index )
+{
+   scene_context *s = user;
+   u32 idx = item_index*3;
+   scene_vert *pa = &s->arrvertices[ s->arrindices[ idx+0 ] ],
+              *pb = &s->arrvertices[ s->arrindices[ idx+1 ] ],
+              *pc = &s->arrvertices[ s->arrindices[ idx+2 ] ];
+
+   vg_line( pa->co, pb->co, 0xff0000ff );
+   vg_line( pb->co, pc->co, 0xff0000ff );
+   vg_line( pc->co, pa->co, 0xff0000ff );
+}
+
+static void scene_bh_closest( void *user, u32 index, v3f point, v3f closest )
+{
+   scene_context *s = user;
+
+   v3f positions[3];
+   u32 *tri = &s->arrindices[ index*3 ];
+   for( int i=0; i<3; i++ )
+      v3_copy( s->arrvertices[tri[i]].co, positions[i] );
+
+   closest_on_triangle_1( point, positions, closest );
+}
+
+bh_system bh_system_scene = 
+{
+   .expand_bound = scene_bh_expand_bound,
+   .item_centroid = scene_bh_centroid,
+   .item_closest = scene_bh_closest,
+   .item_swap = scene_bh_swap,
+   .item_debug = scene_bh_debug,
+};
+
+/*
+ * An extra step is added onto the end to calculate the hit normal
+ */
+int scene_raycast( scene_context *s, bh_tree *bh, 
+                   v3f co, v3f dir, ray_hit *hit, u16 ignore )
+{
+   hit->tri = NULL;
+
+   bh_iter it;
+   bh_iter_init_ray( 0, &it, co, dir, hit->dist );
+   i32 idx;
+
+   while( bh_next( bh, &it, &idx ) ){
+      u32 *tri = &s->arrindices[ idx*3 ];
+
+      if( s->arrvertices[tri[0]].flags & ignore )  continue;
+
+      v3f vs[3];
+      for( u32 i=0; i<3; i++ )
+         v3_copy( s->arrvertices[tri[i]].co, vs[i] );
+      
+      f32 t;
+      if( ray_tri( vs, co, dir, &t, 0 ) ){
+         if( t < hit->dist ){
+            hit->dist = t;
+            hit->tri = tri;
+         }
+      }
+   }
+
+   if( hit->tri ){
+      v3f v0, v1;
+      
+      float *pa = s->arrvertices[hit->tri[0]].co,
+            *pb = s->arrvertices[hit->tri[1]].co,
+            *pc = s->arrvertices[hit->tri[2]].co;
+
+      v3_sub( pa, pb, v0 );
+      v3_sub( pc, pb, v1 );
+      v3_cross( v1, v0, hit->normal );
+      v3_normalize( hit->normal );
+      v3_muladds( co, dir, hit->dist, hit->pos );
+   }
+
+   return hit->tri?1:0;
+}
+
+bh_tree *scene_bh_create( void *lin_alloc, scene_context *s )
+{
+   u32 triangle_count = s->indice_count / 3;
+   return bh_create( lin_alloc, &bh_system_scene, s, triangle_count, 2 );
+}