third_party_mesa3d/src/mesa/state_tracker/st_atom_setup.c

/**************************************************************************
 * 
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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 TUNGSTEN GRAPHICS 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.
 * 
 **************************************************************************/

 /*
  * Authors:
  *   Keith Whitwell <keith@tungstengraphics.com>
  */
 

#include "st_context.h"
#include "pipe/p_context.h"
#include "st_atom.h"

static GLuint translate_fill( GLenum mode )
{
   switch (mode) {
   case GL_POINT: return FILL_POINT;
   case GL_LINE: return FILL_LINE;
   case GL_FILL: return FILL_TRI;
   default: assert(0); return 0;
   }
}

static GLboolean get_offset_flag( GLuint fill_mode, 
				  const struct gl_polygon_attrib *Polygon )
{
   switch (fill_mode) {
   case FILL_POINT: return Polygon->OffsetPoint;
   case FILL_LINE: return Polygon->OffsetLine;
   case FILL_TRI: return Polygon->OffsetFill;
   default: assert(0); return 0;
   }
}


static void update_setup_state( struct st_context *st )
{
   GLcontext *ctx = st->ctx;
   struct pipe_setup_state setup;

   memset(&setup, 0, sizeof(setup));
   
   /* _NEW_POLYGON, _NEW_BUFFERS
    */
   {
      setup.front_winding = WINDING_CW;
	
      if (ctx->DrawBuffer && ctx->DrawBuffer->Name != 0)
	 setup.front_winding ^= WINDING_BOTH;

      if (ctx->Polygon.FrontFace != GL_CCW)
	 setup.front_winding ^= WINDING_BOTH;
   }

   /* _NEW_LIGHT
    */
   if (ctx->Light.ShadeModel == GL_FLAT)
      setup.flatshade = 1;

   /* _NEW_LIGHT 
    *
    * Not sure about the light->enabled requirement - does this still
    * apply??
    */
   if (ctx->Light.Enabled && 
       ctx->Light.Model.TwoSide)
      setup.light_twoside = 1;


   /* _NEW_POLYGON
    */
   if (ctx->Polygon.CullFlag) {
      if (ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK) {
	 setup.cull_mode = WINDING_BOTH;
      }
      else if (ctx->Polygon.CullFaceMode == GL_FRONT) {
	 setup.cull_mode = setup.front_winding;
      }
      else {
	 setup.cull_mode = setup.front_winding ^ WINDING_BOTH;
      }
   }

   /* _NEW_POLYGON
    */
   {
      GLuint fill_front = translate_fill( ctx->Polygon.FrontMode );
      GLuint fill_back = translate_fill( ctx->Polygon.BackMode );
      
      if (setup.front_winding == WINDING_CW) {
	 setup.fill_cw = fill_front;
	 setup.fill_ccw = fill_back;
      }
      else {
	 setup.fill_cw = fill_back;
	 setup.fill_ccw = fill_front;
      }

      /* Simplify when culling is active:
       */
      if (setup.cull_mode & WINDING_CW) {
	 setup.fill_cw = setup.fill_ccw;
      }
      
      if (setup.cull_mode & WINDING_CCW) {
	 setup.fill_ccw = setup.fill_cw;
      }
   }

   /* Hardware does offset for filled prims, but need to do it in
    * software for unfilled.
    *
    * _NEW_POLYGON 
    */
   if (setup.fill_cw != FILL_TRI)
      setup.offset_cw = get_offset_flag( setup.fill_cw, 
					 &ctx->Polygon );
   
   if (setup.fill_ccw != FILL_TRI)
      setup.offset_ccw = get_offset_flag( setup.fill_ccw, 
					  &ctx->Polygon );


   /* _NEW_BUFFERS, _NEW_POLYGON
    */
   if (setup.fill_cw != FILL_TRI ||
       setup.fill_ccw != FILL_TRI)
   {
      GLfloat mrd = (ctx->DrawBuffer ? 
		     ctx->DrawBuffer->_MRD : 
		     1.0);

      setup.offset_units = ctx->Polygon.OffsetFactor * mrd;
      setup.offset_scale = (ctx->Polygon.OffsetUnits * mrd *
			    st->polygon_offset_scale);
   }
      

   if (memcmp(&setup, &st->state.setup, sizeof(setup)) != 0) {
      st->state.setup = setup;
      st->pipe->set_setup_state( st->pipe, &setup );
   }
}

const struct st_tracked_state st_update_setup = {
   .dirty = {
      .mesa = (_NEW_LIGHT | _NEW_POLYGON | _NEW_BUFFERS),
      .st  = 0,
   },
   .update = update_setup_state
};