1.1 --- a/src/pvr2/glrender.c	Sun Sep 28 01:09:51 2008 +0000
     1.2 +++ b/src/pvr2/glrender.c	Mon Sep 29 05:55:33 2008 +0000
     1.3 @@ -122,15 +122,8 @@
     1.4      glClearStencil(0);
     1.5  }
     1.6  
     1.7 -/**
     1.8 - * Setup the basic context that's shared between normal and modified modes -
     1.9 - * depth, culling, shade model, and color sum
    1.10 - */
    1.11 -static void render_set_base_context( uint32_t poly1 )
    1.12 +static void render_set_cull( uint32_t poly1 )
    1.13  {
    1.14 -    glDepthFunc( POLY1_DEPTH_MODE(poly1) );
    1.15 -    glDepthMask( POLY1_DEPTH_WRITE(poly1) ? GL_TRUE : GL_FALSE );
    1.16 -
    1.17      switch( POLY1_CULL_MODE(poly1) ) {
    1.18      case CULL_NONE:
    1.19      case CULL_SMALL:
    1.20 @@ -144,8 +137,20 @@
    1.21          glEnable( GL_CULL_FACE );
    1.22          glFrontFace( GL_CCW );
    1.23          break;
    1.24 -    }
    1.25 +    }   
    1.26 +}    
    1.27  
    1.28 +/**
    1.29 + * Setup the basic context that's shared between normal and modified modes -
    1.30 + * depth, culling
    1.31 + */
    1.32 +static void render_set_base_context( uint32_t poly1 )
    1.33 +{
    1.34 +    glDepthFunc( POLY1_DEPTH_MODE(poly1) );
    1.35 +    glDepthMask( POLY1_DEPTH_WRITE(poly1) ? GL_TRUE : GL_FALSE );
    1.36 +
    1.37 +    render_set_cull( poly1 );
    1.38 +    
    1.39      glShadeModel( POLY1_SHADE_MODEL(poly1) );
    1.40  
    1.41      if( POLY1_SPECULAR(poly1) ) {
    1.42 @@ -233,12 +238,14 @@
    1.43          glBindTexture(GL_TEXTURE_2D, poly->tex_id);
    1.44      }
    1.45      if( poly->mod_vertex_index == -1 ) {
    1.46 +        glDisable( GL_STENCIL_TEST );
    1.47          render_set_context( poly->context, RENDER_NORMAL );
    1.48          glDrawArrays(GL_TRIANGLE_STRIP, poly->vertex_index, poly->vertex_count );
    1.49 -    } else {
    1.50 +    }  else {
    1.51 +        glEnable( GL_STENCIL_TEST );
    1.52          render_set_base_context( poly->context[0] );
    1.53          render_set_tsp_context( poly->context[0], poly->context[1], poly->context[2] );
    1.54 -        glStencilFunc(GL_EQUAL, 0, 1);
    1.55 +        glStencilFunc(GL_EQUAL, 0, 2);
    1.56          glDrawArrays(GL_TRIANGLE_STRIP, poly->vertex_index, poly->vertex_count );
    1.57  
    1.58          if( pvr2_scene.shadow_mode == SHADOW_FULL ) {
    1.59 @@ -247,7 +254,7 @@
    1.60              }
    1.61              render_set_tsp_context( poly->context[0], poly->context[3], poly->context[4] );
    1.62          }
    1.63 -        glStencilFunc(GL_EQUAL, 1, 1);
    1.64 +        glStencilFunc(GL_EQUAL, 2, 2);
    1.65          glDrawArrays(GL_TRIANGLE_STRIP, poly->mod_vertex_index, poly->vertex_count );
    1.66      }
    1.67  }
    1.68 @@ -346,7 +353,81 @@
    1.69      }           
    1.70  }
    1.71  
    1.72 -void gl_render_modifier_tilelist( pvraddr_t tile_entry )
    1.73 +static void drawrect2d( uint32_t tile_bounds[], float z )
    1.74 +{
    1.75 +    glBegin( GL_QUADS );
    1.76 +    glVertex3f( tile_bounds[0], tile_bounds[2], z );
    1.77 +    glVertex3f( tile_bounds[1], tile_bounds[2], z );
    1.78 +    glVertex3f( tile_bounds[1], tile_bounds[3], z );
    1.79 +    glVertex3f( tile_bounds[0], tile_bounds[3], z );
    1.80 +    glEnd();
    1.81 +}
    1.82 +
    1.83 +void gl_render_modifier_polygon( struct polygon_struct *poly, uint32_t tile_bounds[] )
    1.84 +{
    1.85 +    /* A bit of explanation:
    1.86 +     * In theory it works like this: generate a 1-bit stencil for each polygon
    1.87 +     * volume, and then AND or OR it against the overall 1-bit tile stencil at 
    1.88 +     * the end of the volume. 
    1.89 +     * 
    1.90 +     * The implementation here uses a 2-bit stencil buffer, where each volume
    1.91 +     * is drawn using only stencil bit 0, and then a 'flush' polygon is drawn
    1.92 +     * to update bit 1 accordingly and clear bit 0.
    1.93 +     * 
    1.94 +     * This could probably be more efficient, but at least it works correctly 
    1.95 +     * now :)
    1.96 +     */
    1.97 +    
    1.98 +    render_set_cull(poly->context[0]);
    1.99 +    glDrawArrays(GL_TRIANGLE_STRIP, poly->vertex_index, poly->vertex_count );
   1.100 +    
   1.101 +    int poly_type = POLY1_VOLUME_MODE(poly->context[0]);
   1.102 +    if( poly_type == PVR2_VOLUME_REGION0 ) {
   1.103 +        /* 00 => 00
   1.104 +         * 01 => 00
   1.105 +         * 10 => 10
   1.106 +         * 11 => 00
   1.107 +         */
   1.108 +        glStencilMask( 0x03 );
   1.109 +        glStencilFunc(GL_EQUAL, 0x02, 0x03);
   1.110 +        glStencilOp(GL_ZERO, GL_KEEP, GL_KEEP);
   1.111 +        glDisable( GL_CULL_FACE );
   1.112 +        glDisable( GL_DEPTH_TEST );
   1.113 +
   1.114 +        drawrect2d( tile_bounds, pvr2_scene.bounds[4] );
   1.115 +        
   1.116 +        glEnable( GL_DEPTH_TEST );
   1.117 +        glStencilMask( 0x01 );
   1.118 +        glStencilFunc( GL_ALWAYS, 0, 1 );
   1.119 +        glStencilOp( GL_KEEP,GL_INVERT, GL_KEEP ); 
   1.120 +    } else if( poly_type == PVR2_VOLUME_REGION1 ) {
   1.121 +        /* This is harder with the standard stencil ops - do it in two passes
   1.122 +         * 00 => 00 | 00 => 10
   1.123 +         * 01 => 10 | 01 => 10
   1.124 +         * 10 => 10 | 10 => 00
   1.125 +         * 11 => 10 | 11 => 10
   1.126 +         */
   1.127 +        glStencilMask( 0x02 );
   1.128 +        glStencilOp( GL_INVERT, GL_INVERT, GL_INVERT );
   1.129 +        glDisable( GL_CULL_FACE );
   1.130 +        glDisable( GL_DEPTH_TEST );
   1.131 +        
   1.132 +        drawrect2d( tile_bounds, pvr2_scene.bounds[4] );
   1.133 +        
   1.134 +        glStencilMask( 0x03 );
   1.135 +        glStencilFunc( GL_NOTEQUAL,0x02, 0x03);
   1.136 +        glStencilOp( GL_ZERO, GL_REPLACE, GL_REPLACE );
   1.137 +        
   1.138 +        drawrect2d( tile_bounds, pvr2_scene.bounds[4] );
   1.139 +        
   1.140 +        glEnable( GL_DEPTH_TEST );
   1.141 +        glStencilMask( 0x01 );
   1.142 +        glStencilFunc( GL_ALWAYS, 0, 1 );
   1.143 +        glStencilOp( GL_KEEP,GL_INVERT, GL_KEEP );         
   1.144 +    }
   1.145 +}
   1.146 +
   1.147 +void gl_render_modifier_tilelist( pvraddr_t tile_entry, uint32_t tile_bounds[] )
   1.148  {
   1.149      uint32_t *tile_list = (uint32_t *)(video_base+tile_entry);
   1.150      int strip_count;
   1.151 @@ -365,7 +446,7 @@
   1.152      
   1.153      glStencilFunc( GL_ALWAYS, 0, 1 );
   1.154      glStencilOp( GL_KEEP,GL_INVERT, GL_KEEP ); 
   1.155 -
   1.156 +    glStencilMask( 0x01 );
   1.157      glDepthMask( GL_FALSE );
   1.158      
   1.159      while(1) {
   1.160 @@ -382,7 +463,7 @@
   1.161              strip_count = ((entry >> 25) & 0x0F)+1;
   1.162              poly = pvr2_scene.buf_to_poly_map[entry&0x000FFFFF];
   1.163              while( strip_count > 0 ) {
   1.164 -                glDrawArrays(GL_TRIANGLE_STRIP, poly->vertex_index, poly->vertex_count );
   1.165 +                gl_render_modifier_polygon( poly, tile_bounds );
   1.166                  poly = poly->next;
   1.167                  strip_count--;
   1.168              }
   1.169 @@ -390,7 +471,7 @@
   1.170          default:
   1.171              if( entry & 0x7E000000 ) {
   1.172                  poly = pvr2_scene.buf_to_poly_map[entry&0x000FFFFF];
   1.173 -                glDrawArrays(GL_TRIANGLE_STRIP, poly->vertex_index, poly->vertex_count );
   1.174 +                gl_render_modifier_polygon( poly, tile_bounds );
   1.175              }
   1.176          }
   1.177      }
   1.178 @@ -432,6 +513,7 @@
   1.179      /* Clear the buffer (FIXME: May not want always want to do this) */
   1.180      glDisable( GL_SCISSOR_TEST );
   1.181      glDepthMask( GL_TRUE );
   1.182 +    glStencilMask( 0x03 );
   1.183      glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
   1.184  
   1.185      /* Setup vertex array pointers */
   1.186 @@ -466,7 +548,7 @@
   1.187          /* Clip to the visible part of the tile */
   1.188          glScissor( tile_bounds[0], pvr2_scene.buffer_height-tile_bounds[3], 
   1.189                     tile_bounds[1]-tile_bounds[0], tile_bounds[3] - tile_bounds[2] );
   1.190 -        if( display_driver->capabilities.stencil_bits != 0 && 
   1.191 +        if( display_driver->capabilities.stencil_bits >= 2 && 
   1.192                  IS_TILE_PTR(segment->opaquemod_ptr) &&
   1.193                  !IS_EMPTY_TILE_LIST(segment->opaquemod_ptr) ) {
   1.194              /* Don't do this unless there's actually some shadow polygons */
   1.195 @@ -474,7 +556,7 @@
   1.196              /* Use colormask instead of drawbuffer for simplicity */
   1.197              glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
   1.198              gl_render_tilelist_depthonly(segment->opaque_ptr);
   1.199 -            gl_render_modifier_tilelist(segment->opaquemod_ptr);
   1.200 +            gl_render_modifier_tilelist(segment->opaquemod_ptr, tile_bounds);
   1.201              glClear( GL_DEPTH_BUFFER_BIT );
   1.202              glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );
   1.203          }