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/**************************************************************************

 *

 * Copyright 2007 VMware, Inc.

 * All Rights Reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sub license, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice (including the

 * next paragraph) shall be included in all copies or substantial portions

 * of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.

 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR

 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 *

 **************************************************************************/

/**

 * \brief  Drawing stage for handling glPolygonMode(line/point).

 * Convert triangles to points or lines as needed.

 */

/* Authors:  Keith Whitwell 

 */

#include "util/u_memory.h"

#include "pipe/p_defines.h"

#include "draw_private.h"

#include "draw_pipe.h"

#include "draw_fs.h"

struct unfilled_stage {

   struct draw_stage stage;

   /** [0] = front face, [1] = back face.

    * legal values:  PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,

    * and PIPE_POLYGON_MODE_POINT,

    */

   unsigned mode[2];

   int face_slot;

};

static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )

{

   return (struct unfilled_stage *)stage;

}

static void

inject_front_face_info(struct draw_stage *stage,

                       struct prim_header *header)

{

   struct unfilled_stage *unfilled = unfilled_stage(stage);

   unsigned ccw = header->det < 0.0;

   boolean is_front_face = (

      (stage->draw->rasterizer->front_ccw && ccw) ||

      (!stage->draw->rasterizer->front_ccw && !ccw));

   int slot = unfilled->face_slot;

   unsigned i;

   /* In case the backend doesn't care about it */

   if (slot < 0) {

      return;

   }

   for (i = 0; i < 3; ++i) {

      struct vertex_header *v = header->v[i];

      v->data[slot][0] = is_front_face;

      v->data[slot][1] = is_front_face;

      v->data[slot][2] = is_front_face;

      v->data[slot][3] = is_front_face;

      v->vertex_id = UNDEFINED_VERTEX_ID;

   }

}

static void point( struct draw_stage *stage,

		   struct vertex_header *v0 )

{

   struct prim_header tmp;

   tmp.v[0] = v0;

   stage->next->point( stage->next, &tmp );

}

static void line( struct draw_stage *stage,

		  struct vertex_header *v0,

		  struct vertex_header *v1 )

{

   struct prim_header tmp;

   tmp.v[0] = v0;

   tmp.v[1] = v1;

   stage->next->line( stage->next, &tmp );

}

static void points( struct draw_stage *stage,

		    struct prim_header *header )

{

   struct vertex_header *v0 = header->v[0];

   struct vertex_header *v1 = header->v[1];

   struct vertex_header *v2 = header->v[2];

   inject_front_face_info(stage, header);

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) point( stage, v0 );

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) point( stage, v1 );

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) point( stage, v2 );

}

static void lines( struct draw_stage *stage,

		   struct prim_header *header )

{

   struct vertex_header *v0 = header->v[0];

   struct vertex_header *v1 = header->v[1];

   struct vertex_header *v2 = header->v[2];

   if (header->flags & DRAW_PIPE_RESET_STIPPLE)

      stage->next->reset_stipple_counter( stage->next );

   inject_front_face_info(stage, header);

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) line( stage, v2, v0 );

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) line( stage, v0, v1 );

   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) line( stage, v1, v2 );

}

/** For debugging */

static void

print_header_flags(unsigned flags)

{

   debug_printf("header->flags = ");

   if (flags & DRAW_PIPE_RESET_STIPPLE)

      debug_printf("RESET_STIPPLE ");

   if (flags & DRAW_PIPE_EDGE_FLAG_0)

      debug_printf("EDGE_FLAG_0 ");

   if (flags & DRAW_PIPE_EDGE_FLAG_1)

      debug_printf("EDGE_FLAG_1 ");

   if (flags & DRAW_PIPE_EDGE_FLAG_2)

      debug_printf("EDGE_FLAG_2 ");

   debug_printf("\n");

}

/* Unfilled tri:

 *

 * Note edgeflags in the vertex struct is not sufficient as we will

 * need to manipulate them when decomposing primitives.

 *

 * We currently keep the vertex edgeflag and primitive edgeflag mask

 * separate until the last possible moment.

 */

static void unfilled_tri( struct draw_stage *stage,

			  struct prim_header *header )

{

   struct unfilled_stage *unfilled = unfilled_stage(stage);

   unsigned cw = header->det >= 0.0;

   unsigned mode = unfilled->mode[cw];

   if (0)

      print_header_flags(header->flags);

   switch (mode) {

   case PIPE_POLYGON_MODE_FILL:

      stage->next->tri( stage->next, header );

      break;

   case PIPE_POLYGON_MODE_LINE:

      lines( stage, header );

      break;

   case PIPE_POLYGON_MODE_POINT:

      points( stage, header );

      break;

   default:

      assert(0);

   }

}

static void unfilled_first_tri( struct draw_stage *stage,

				struct prim_header *header )

{

   struct unfilled_stage *unfilled = unfilled_stage(stage);

   const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;

   unfilled->mode[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;

   unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;

   stage->tri = unfilled_tri;

   stage->tri( stage, header );

}

static void unfilled_flush( struct draw_stage *stage,

			    unsigned flags )

{

   stage->next->flush( stage->next, flags );

   stage->tri = unfilled_first_tri;

}

static void unfilled_reset_stipple_counter( struct draw_stage *stage )

{

   stage->next->reset_stipple_counter( stage->next );

}

static void unfilled_destroy( struct draw_stage *stage )

{

   draw_free_temp_verts( stage );

   FREE( stage );

}

/*

 * Try to allocate an output slot which we can use

 * to preserve the front face information.

 */

void

draw_unfilled_prepare_outputs( struct draw_context *draw,

                               struct draw_stage *stage )

{

   struct unfilled_stage *unfilled = unfilled_stage(stage);

   const struct pipe_rasterizer_state *rast = draw ? draw->rasterizer : 0;

   boolean is_unfilled = (rast &&

                          (rast->fill_front != PIPE_POLYGON_MODE_FILL ||

                           rast->fill_back != PIPE_POLYGON_MODE_FILL));

   const struct draw_fragment_shader *fs = draw ? draw->fs.fragment_shader : 0;

   if (is_unfilled && fs && fs->info.uses_frontface)  {

      unfilled->face_slot = draw_alloc_extra_vertex_attrib(

         stage->draw, TGSI_SEMANTIC_FACE, 0);

   } else {

      unfilled->face_slot = -1;

   }

}

/**

 * Create unfilled triangle stage.

 */

struct draw_stage *draw_unfilled_stage( struct draw_context *draw )

{

   struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);

   if (unfilled == NULL)

      goto fail;

   unfilled->stage.draw = draw;

   unfilled->stage.name = "unfilled";

   unfilled->stage.next = NULL;

   unfilled->stage.tmp = NULL;

   unfilled->stage.point = draw_pipe_passthrough_point;

   unfilled->stage.line = draw_pipe_passthrough_line;

   unfilled->stage.tri = unfilled_first_tri;

   unfilled->stage.flush = unfilled_flush;

   unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;

   unfilled->stage.destroy = unfilled_destroy;

   unfilled->face_slot = -1;

   if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))

      goto fail;

   return &unfilled->stage;

 fail:

   if (unfilled)

      unfilled->stage.destroy( &unfilled->stage );

   return NULL;

}