1.1 --- a/src/pvr2/scene.c	Sun Aug 24 02:57:15 2008 +0000
     1.2 +++ b/src/pvr2/scene.c	Mon Sep 08 11:23:32 2008 +0000
     1.3 @@ -55,8 +55,15 @@
     1.4      return temp.f;
     1.5  }
     1.6  
     1.7 -
     1.8 -
     1.9 +static float parse_fog_density( uint32_t value )
    1.10 +{
    1.11 +    union {
    1.12 +        uint32_t i;
    1.13 +        float f;
    1.14 +    } u;
    1.15 +    u.i = (((value+127)&0xFF)<<23)|((value & 0xFF00)<<7);
    1.16 +    return u.f;
    1.17 +}
    1.18  
    1.19  
    1.20  struct pvr2_scene_struct pvr2_scene;
    1.21 @@ -245,7 +252,6 @@
    1.22      unpack_bgra(*data.ival++, vert->rgba);
    1.23      if( POLY1_SPECULAR(poly1) ) {
    1.24          unpack_bgra(*data.ival++, vert->offset_rgba);
    1.25 -        vert->offset_rgba[3] = 1.0;
    1.26      } else {
    1.27          vert->offset_rgba[0] = 0.0;
    1.28          vert->offset_rgba[1] = 0.0;
    1.29 @@ -255,7 +261,6 @@
    1.30  
    1.31      if( force_alpha ) {
    1.32          vert->rgba[3] = 1.0;
    1.33 -        vert->offset_rgba[3] = 1.0;
    1.34      }
    1.35  }
    1.36  
    1.37 @@ -329,6 +334,61 @@
    1.38      }
    1.39  }
    1.40  
    1.41 +static float scene_compute_lut_fog_vertex( float z, float fog_density, float fog_table[][2] )
    1.42 +{
    1.43 +    union {
    1.44 +        uint32_t i;
    1.45 +        float f;
    1.46 +    } v;
    1.47 +    v.f = z * fog_density;
    1.48 +    if( v.f < 1.0 ) v.f = 1.0;
    1.49 +    else if( v.f > 255.9999 ) v.f = 255.9999;
    1.50 +    
    1.51 +    uint32_t index = ((v.i >> 18) & 0x0F)|((v.i>>19)&0x70);
    1.52 +    return fog_table[index][0];
    1.53 +}
    1.54 +
    1.55 +/**
    1.56 + * Compute the fog coefficients for all polygons using lookup-table fog. It's 
    1.57 + * a little more convenient to do this as a separate pass, since we don't have
    1.58 + * to worry about computed vertexes.
    1.59 + */
    1.60 +static void scene_compute_lut_fog( )
    1.61 +{
    1.62 +    int i,j;
    1.63 +
    1.64 +    float fog_density = parse_fog_density(MMIO_READ( PVR2, RENDER_FOGCOEFF ));
    1.65 +    float fog_table[128][2];
    1.66 +    
    1.67 +    /* Parse fog table out into floating-point format */
    1.68 +    for( i=0; i<128; i++ ) {
    1.69 +        uint32_t ent = MMIO_READ( PVR2, RENDER_FOGTABLE + (i<<2) );
    1.70 +        fog_table[i][0] = ((float)(((ent&0x0000FF00)>>8) + 1)) / 256.0;
    1.71 +        fog_table[i][1] = ((float)((ent&0x000000FF) + 1)) / 256.0;
    1.72 +    }
    1.73 +    
    1.74 +    
    1.75 +    for( i=0; i<pvr2_scene.poly_count; i++ ) {
    1.76 +        int mode = POLY2_FOG_MODE(pvr2_scene.poly_array[i].context[1]);
    1.77 +        if( mode == PVR2_POLY_FOG_LOOKUP ) {
    1.78 +            uint32_t index = pvr2_scene.poly_array[i].vertex_index;
    1.79 +            for( j=0; j<=pvr2_scene.poly_array[i].vertex_count; j++ ) {
    1.80 +                pvr2_scene.vertex_array[index+j].offset_rgba[3] = 
    1.81 +                    scene_compute_lut_fog_vertex( pvr2_scene.vertex_array[index+j].z, fog_density, fog_table );
    1.82 +            }
    1.83 +        } else if( mode == PVR2_POLY_FOG_LOOKUP2 ) {
    1.84 +            uint32_t index = pvr2_scene.poly_array[i].vertex_index;
    1.85 +            for( j=0; j<=pvr2_scene.poly_array[i].vertex_count; j++ ) {
    1.86 +                pvr2_scene.vertex_array[index+j].rgba[0] = pvr2_scene.fog_lut_colour[0];
    1.87 +                pvr2_scene.vertex_array[index+j].rgba[1] = pvr2_scene.fog_lut_colour[1];
    1.88 +                pvr2_scene.vertex_array[index+j].rgba[2] = pvr2_scene.fog_lut_colour[2];
    1.89 +                pvr2_scene.vertex_array[index+j].rgba[3] = 
    1.90 +                    scene_compute_lut_fog_vertex( pvr2_scene.vertex_array[index+j].z, fog_density, fog_table );
    1.91 +            }
    1.92 +        }
    1.93 +    }    
    1.94 +}
    1.95 +
    1.96  static void scene_add_vertexes( pvraddr_t poly_idx, int vertex_length,
    1.97                                  gboolean is_modified )
    1.98  {
    1.99 @@ -628,6 +688,12 @@
   1.100      	 */
   1.101      	pvr2_scene.bounds[1] *= 2;
   1.102      }
   1.103 +    
   1.104 +    uint32_t fog_col = MMIO_READ( PVR2, RENDER_FOGTBLCOL );
   1.105 +    unpack_bgra( fog_col, pvr2_scene.fog_lut_colour );
   1.106 +    fog_col = MMIO_READ( PVR2, RENDER_FOGVRTCOL );
   1.107 +    unpack_bgra( fog_col, pvr2_scene.fog_vert_colour );
   1.108 +    
   1.109      uint32_t *tilebuffer = (uint32_t *)(video_base + MMIO_READ( PVR2, RENDER_TILEBASE ));
   1.110      uint32_t *segment = tilebuffer;
   1.111      pvr2_scene.segment_list = (struct tile_segment *)tilebuffer;
   1.112 @@ -688,6 +754,7 @@
   1.113      } while( (control & SEGMENT_END) == 0 );
   1.114  
   1.115      scene_extract_background();
   1.116 +    scene_compute_lut_fog();
   1.117  
   1.118      vertex_buffer_unmap();
   1.119  }