csrDraw.h

   1 typedef struct csr_frag csr_frag;
   2 typedef struct csr_target csr_target;
   3
   4 struct csr_frag
   5 {
   6         u32 id; // Triangle index
   7         float depth;    // 'depth testing'
   8
   9         v3f co;
  10         v3f nrm;
  11 };
  12
  13 struct csr_target
  14 {
  15         csr_frag *fragments;
  16         u32 x, y;
  17         v4f bounds;
  18 };
  19
  20 void csr_rt_clear( csr_target *rt )
  21 {
  22         for( u32 i = 0; i < rt->x*rt->y; i ++ )
  23         {
  24                 rt->fragments[ i ].depth = 0.f;
  25         }
  26 }
  27
  28 void simple_raster( csr_target *rt, vmf_vert tri[3], int id )
  29 {
  30         // Very simplified tracing algorithm
  31         float tqa = 0.f, tqb = 0.f;
  32
  33         v2f bmin = { 0.f, 0.f };
  34         v2f bmax = { rt->x, rt->y };
  35
  36         v2_minv( tri[0].co, tri[1].co, bmin );
  37         v2_minv( tri[2].co, bmin, bmin );
  38
  39         v2_maxv( tri[0].co, tri[1].co, bmax );
  40         v2_maxv( tri[2].co, bmax, bmax );
  41
  42         float range_x = (rt->bounds[2]-rt->bounds[0])/(float)rt->x;
  43         float range_y = (rt->bounds[3]-rt->bounds[1])/(float)rt->y;
  44
  45         int start_x = csr_min( rt->x-1, csr_max( 0,     floorf( (bmin[0]-rt->bounds[0])/range_x)));
  46         int end_x =   csr_max( 0,       csr_min( rt->x-1, floorf( (bmax[0]-rt->bounds[0])/range_x )));
  47         int start_y = csr_min( rt->y-1, csr_max( 0,      ceilf( (bmin[1]-rt->bounds[1])/range_y )));
  48         int end_y =   csr_max( 0,       csr_min( rt->y-1,  ceilf( (bmax[1]-rt->bounds[1])/range_y )));
  49
  50         v3f trace_dir = { 0.f, 0.f, 1.f };
  51         v3f trace_origin = { 0.f, 0.f, -16385.f };
  52
  53         for( u32 py = start_y; py <= end_y; py ++ )
  54         {
  55                 trace_origin[1] = csr_lerpf( rt->bounds[1], rt->bounds[3], (float)py/(float)rt->y );
  56
  57                 for( u32 px = start_x; px <= end_x; px ++ )
  58                 {
  59                         csr_frag *frag = &rt->fragments[ py * rt->y + px ];
  60
  61                         trace_origin[0] = csr_lerpf( rt->bounds[0], rt->bounds[2], (float)px/(float)rt->x );
  62                         float tdepth = csr_ray_tri( trace_origin, trace_dir, tri[0].co, tri[1].co, tri[2].co, &tqa, &tqb );
  63
  64                         if( tdepth > frag->depth )
  65                         {
  66                                 frag->depth = tdepth;
  67
  68                                 v3_muls( tri[1].co, tqa, frag->co );
  69                                 v3_muladds( frag->co, tri[2].co, tqb, frag->co );
  70                                 v3_muladds( frag->co, tri[0].co, 1.f - tqa - tqb, frag->co );
  71                         }
  72                 }
  73         }
  74 }
  75
  76 void csr_draw( csr_target *rt, vmf_vert *triangles, u32 triangle_count, m4x3f transform )
  77 {
  78         m3x3f normal;
  79         vmf_vert new_tri[3];
  80
  81         // Derive normal matrix
  82         m4x3_to_3x3( transform, normal );
  83         m3x3_inv_transpose( normal, normal );
  84
  85         for( u32 i = 0; i < triangle_count; i ++ )
  86         {
  87                 vmf_vert *triangle = triangles + i*3;
  88
  89                 m4x3_mulv( transform, triangle[0].co, new_tri[0].co );
  90                 m4x3_mulv( transform, triangle[1].co, new_tri[1].co );
  91                 m4x3_mulv( transform, triangle[2].co, new_tri[2].co );
  92                 m3x3_mulv( normal, triangle[0].nrm, new_tri[0].nrm );
  93                 m3x3_mulv( normal, triangle[1].nrm, new_tri[1].nrm );
  94                 m3x3_mulv( normal, triangle[2].nrm, new_tri[2].nrm );
  95
  96                 simple_raster( rt, new_tri, 0 );
  97         }
  98 }
  99
 100 void draw_vmf_group( csr_target *rt, vmf_map *map, vdf_node *root, int const group, m4x3f prev, m4x3f inst )
 101 {
 102         m4x3f transform = M4X3_IDENTITY;
 103         vmf_solid solid;
 104         vmf_vert tri[3];
 105
 106         // Multiply previous transform with instance transform to create basis
 107         if( prev )
 108         {
 109                 m4x3_mul( prev, inst, transform );
 110         }
 111
 112         // Draw brushes
 113         solidgen_ctx_init( &solid );
 114         vdf_node *world = vdf_next( root, "world", NULL );
 115
 116         vdf_foreach( world, "solid", brush )
 117         {
 118                 solidgen_push( &solid, brush );
 119         }
 120
 121         for( int i = 0; i < csr_sb_count( solid.indices )/3; i ++ )
 122         {
 123                 u32 * base = solid.indices + i*3;
 124
 125                 tri[0] = solid.verts[ base[0] ];
 126                 tri[1] = solid.verts[ base[1] ];
 127                 tri[2] = solid.verts[ base[2] ];
 128
 129                 csr_draw( rt, tri, 1, transform );
 130         }
 131
 132         solidgen_ctx_reset( &solid );
 133
 134         // Actual entity loop
 135         m4x3f model;
 136
 137         vdf_foreach( root, "entity", ent )
 138         {
 139                 if( ent->user & VMF_FLAG_IS_PROP )
 140                 {
 141                         // Create model transform
 142                         m4x3_identity( model );
 143
 144                         vmf_entity_transform( ent, model );
 145                         m4x3_mul( transform, model, model );
 146
 147                         // Draw model
 148                         mdl_mesh_t *mdl = &map->models[ ent->user1 ].mdl;
 149                         for( int i = 0; i < mdl->num_indices/3; i ++ )
 150                         {
 151                                 for( int j = 0; j < 3; j ++ )
 152                                 {
 153                                         v3_copy( &mdl->vertices[ mdl->indices[ i*3+j ] *8 ],   tri[j].co );
 154                                         v3_copy( &mdl->vertices[ mdl->indices[ i*3+j ] *8+3 ], tri[j].nrm );
 155                                         tri[j].xy[0] = 0.f;
 156                                         tri[j].xy[1] = 0.f;
 157                                 }
 158
 159                                 csr_draw( rt, tri, 1, model );
 160                         }
 161                 }
 162                 else if( ent->user & VMF_FLAG_IS_INSTANCE )
 163                 {
 164                         m4x3_identity( model );
 165                         vmf_entity_transform( ent, model );
 166
 167                         draw_vmf_group( rt, map, map->cache[ ent->user1 ].root, group, transform, model );
 168                 }
 169                 else if( ent->user & VMF_FLAG_BRUSH_ENT )
 170                 {
 171                         // ...
 172                 }
 173         }
 174
 175         solidgen_ctx_free( &solid );
 176 }