t_dd_dmatmp.h

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

      GLuint j, nr;
      int dmasz = GET_SUBSEQUENT_VB_MAX_VERTS();
      int currentsz;

      INIT(GL_QUAD_STRIP);

      currentsz = GET_CURRENT_VB_MAX_VERTS();
      if (currentsz < 8) {
	 currentsz = dmasz;
      }

      dmasz -= (dmasz & 2);
      currentsz -= (currentsz & 2);

      for (j = start ; j + 3 < count; j += nr - 2 ) {
	 nr = MIN2( currentsz, count - j );
	 TAG(emit_verts)( ctx, j, nr, ALLOC_VERTS(nr) );
	 currentsz = dmasz;
      }

      FLUSH();

   } else if (HAVE_TRI_STRIPS && 
	      (ctx->_TriangleCaps & DD_FLATSHADE) &&
	      TNL_CONTEXT(ctx)->vb.ColorPtr[0]->stride) {
      if (HAVE_ELTS) {
	 LOCAL_VARS;
	 int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
	 int currentsz;
	 GLuint j, nr;

         EMIT_INDEXED_VERTS( ctx, start, count );

	 /* Simulate flat-shaded quadstrips using indexed vertices:
	  */
	 ELT_INIT( GL_TRIANGLES );

	 currentsz = GET_CURRENT_VB_MAX_ELTS();

	 /* Emit whole number of quads in total, and in each buffer.
	  */
	 dmasz -= dmasz & 1;
	 count -= (count-start) & 1;
	 currentsz -= currentsz & 1;

	 if (currentsz < 12)
	    currentsz = dmasz;

	 currentsz = currentsz/6*2;
	 dmasz = dmasz/6*2;

	 for (j = start; j + 3 < count; j += nr - 2 ) {
	    nr = MIN2( currentsz, count - j );
	    if (nr >= 4) {
	       GLint quads = (nr/2)-1;
	       GLint i;
	       ELTS_VARS( ALLOC_ELTS( quads*6 ) );

	       for ( i = j-start ; i < j-start+quads*2 ; i+=2 ) {
		  EMIT_TWO_ELTS( 0, (i+0), (i+1) );
		  EMIT_TWO_ELTS( 2, (i+2), (i+1) );
		  EMIT_TWO_ELTS( 4, (i+3), (i+2) );
		  INCR_ELTS( 6 );
	       }

	       FLUSH();
	    }
	    currentsz = dmasz;
	 }

	 RELEASE_ELT_VERTS();
	 FLUSH();
      }
      else {
	 /* Vertices won't fit in a single buffer or elts not
	  * available - should never happen.
	  */
	 fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
	 return;
      }
   }
   else if (HAVE_TRI_STRIPS) {
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_VERTS();
      int currentsz;

      /* Emit smooth-shaded quadstrips as tristrips:
       */
      FLUSH();
      INIT( GL_TRIANGLE_STRIP );

      /* Emit whole number of quads in total, and in each buffer.
       */
      dmasz -= dmasz & 1;
      currentsz = GET_CURRENT_VB_MAX_VERTS();
      currentsz -= currentsz & 1;
      count -= (count-start) & 1;

      if (currentsz < 8) {
	 currentsz = dmasz;
      }

      for (j = start; j + 3 < count; j += nr - 2 ) {
	 nr = MIN2( currentsz, count - j );
	 TAG(emit_verts)( ctx, j, nr, ALLOC_VERTS(nr) );
	 currentsz = dmasz;
      }

      FLUSH();

   } else {
      fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
      return;
   }
}


static void TAG(render_quads_verts)( GLcontext *ctx,
				     GLuint start,
				     GLuint count,
				     GLuint flags )
{
   if (HAVE_QUADS) {
      LOCAL_VARS;
      int dmasz = (GET_SUBSEQUENT_VB_MAX_VERTS()/4) * 4;
      int currentsz;
      GLuint j, nr;

      INIT(GL_QUADS);

      /* Emit whole number of quads in total.  dmasz is already a multiple
       * of 4.
       */
      count -= (count-start)%4;

      currentsz = (GET_CURRENT_VB_MAX_VERTS()/4) * 4;
      if (currentsz < 8)
         currentsz = dmasz;

      for (j = start; j < count; j += nr) {
         nr = MIN2( currentsz, count - j );
         TAG(emit_verts)( ctx, j, nr, ALLOC_VERTS(nr) );
         currentsz = dmasz;
      }
   }
   else if (HAVE_ELTS) {
      /* Hardware doesn't have a quad primitive type -- try to
       * simulate it using indexed vertices and the triangle
       * primitive:
       */
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
      int currentsz;
      GLuint j, nr;

      EMIT_INDEXED_VERTS( ctx, start, count );

      FLUSH();
      ELT_INIT( GL_TRIANGLES );
      currentsz = GET_CURRENT_VB_MAX_ELTS();

      /* Emit whole number of quads in total, and in each buffer.
       */
      dmasz -= dmasz & 3;
      count -= (count-start) & 3;
      currentsz -= currentsz & 3;

      /* Adjust for rendering as triangles:
       */
      currentsz = currentsz/6*4;
      dmasz = dmasz/6*4;

      if (currentsz < 8)
	 currentsz = dmasz;

      for (j = start; j < count; j += nr ) {
	 nr = MIN2( currentsz, count - j );
	 if (nr >= 4) {
	    GLint quads = nr/4;
	    GLint i;
	    ELTS_VARS( ALLOC_ELTS( quads*6 ) );

	    for ( i = j-start ; i < j-start+quads*4 ; i+=4 ) {
	       EMIT_TWO_ELTS( 0, (i+0), (i+1) );
	       EMIT_TWO_ELTS( 2, (i+3), (i+1) );
	       EMIT_TWO_ELTS( 4, (i+2), (i+3) );
	       INCR_ELTS( 6 );
	    }

	    FLUSH();
	 }
	 currentsz = dmasz;
      }

      RELEASE_ELT_VERTS();
   }
   else if (HAVE_TRIANGLES) {
      /* Hardware doesn't have a quad primitive type -- try to
       * simulate it using triangle primitive.  This is a win for
       * gears, but is it useful in the broader world?
       */
      LOCAL_VARS;
      GLuint j;

      INIT(GL_TRIANGLES);

      for (j = start; j < count-3; j += 4) {
	 void *tmp = ALLOC_VERTS( 6 );
	 /* Send v0, v1, v3
	  */
	 tmp = EMIT_VERTS(ctx, j,     2, tmp);
	 tmp = EMIT_VERTS(ctx, j + 3, 1, tmp);
	 /* Send v1, v2, v3
	  */
	 tmp = EMIT_VERTS(ctx, j + 1, 3, tmp);
      }
   }
   else {
      /* Vertices won't fit in a single buffer, should never happen.
       */
      fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
      return;
   }
}

static void TAG(render_noop)( GLcontext *ctx,
			      GLuint start,
			      GLuint count,
			      GLuint flags )
{
}




static tnl_render_func TAG(render_tab_verts)[GL_POLYGON+2] =
{
   TAG(render_points_verts),
   TAG(render_lines_verts),
   TAG(render_line_loop_verts),
   TAG(render_line_strip_verts),
   TAG(render_triangles_verts),
   TAG(render_tri_strip_verts),
   TAG(render_tri_fan_verts),
   TAG(render_quads_verts),
   TAG(render_quad_strip_verts),
   TAG(render_poly_verts),
   TAG(render_noop),
};


/****************************************************************************
 *                 Render elts using hardware indexed verts                 *
 ****************************************************************************/

#if (HAVE_ELTS)
static void TAG(render_points_elts)( GLcontext *ctx,
				     GLuint start,
				     GLuint count,
				     GLuint flags )
{
   if (HAVE_POINTS) {
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
      int currentsz;
      GLuint *elts = TNL_CONTEXT(ctx)->vb.Elts;
      GLuint j, nr;

      ELT_INIT( GL_POINTS );

      currentsz = GET_CURRENT_VB_MAX_ELTS();
      if (currentsz < 8)
	 currentsz = dmasz;

      for (j = start; j < count; j += nr ) {
	 nr = MIN2( currentsz, count - j );
	 TAG(emit_elts)( ctx, elts+j, nr, ALLOC_ELTS(nr) );
	 FLUSH();
	 currentsz = dmasz;
      }
   } else {
      fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
      return;
   }
}



static void TAG(render_lines_elts)( GLcontext *ctx,
				    GLuint start,
				    GLuint count,
				    GLuint flags )
{
   if (HAVE_LINES) {
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
      int currentsz;
      GLuint *elts = TNL_CONTEXT(ctx)->vb.Elts;
      GLuint j, nr;

      ELT_INIT( GL_LINES );

      /* Emit whole number of lines in total and in each buffer:
       */
      count -= (count-start) & 1;
      currentsz -= currentsz & 1;
      dmasz -= dmasz & 1;

      currentsz = GET_CURRENT_VB_MAX_ELTS();
      if (currentsz < 8)
	 currentsz = dmasz;

      for (j = start; j < count; j += nr ) {
	 nr = MIN2( currentsz, count - j );
	 TAG(emit_elts)( ctx, elts+j, nr, ALLOC_ELTS(nr) );
	 FLUSH();
	 currentsz = dmasz;
      }
   } else {
      fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
      return;
   }
}


static void TAG(render_line_strip_elts)( GLcontext *ctx,
					 GLuint start,
					 GLuint count,
					 GLuint flags )
{
   if (HAVE_LINE_STRIPS) {
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
      int currentsz;
      GLuint *elts = TNL_CONTEXT(ctx)->vb.Elts;
      GLuint j, nr;

      FLUSH(); /* always a new primitive */
      ELT_INIT( GL_LINE_STRIP );

      currentsz = GET_CURRENT_VB_MAX_ELTS();
      if (currentsz < 8)
	 currentsz = dmasz;

      for (j = start; j + 1 < count; j += nr - 1 ) {
	 nr = MIN2( currentsz, count - j );
	 TAG(emit_elts)( ctx, elts+j, nr, ALLOC_ELTS(nr) );
	 FLUSH();
	 currentsz = dmasz;
      }
   } else {
      /* TODO: Try to emit as indexed lines.
       */
      fprintf(stderr, "%s - cannot draw primitive\n", __FUNCTION__);
      return;
   }
}


static void TAG(render_line_loop_elts)( GLcontext *ctx,
					GLuint start,
					GLuint count,
					GLuint flags )
{
   if (HAVE_LINE_STRIPS) {
      LOCAL_VARS;
      int dmasz = GET_SUBSEQUENT_VB_MAX_ELTS();
      int currentsz;
      GLuint *elts = TNL_CONTEXT(ctx)->vb.Elts;
      GLuint j, nr;

      FLUSH();
      ELT_INIT( GL_LINE_STRIP );

      if (flags & PRIM_BEGIN)
	 j = start;
      else
	 j = start + 1;

      currentsz = GET_CURRENT_VB_MAX_ELTS();
      if (currentsz < 8) {
	 currentsz = dmasz;
      }

      /* Ensure last vertex doesn't wrap:
       */
      currentsz--;
      dmasz--;

      if (j + 1 < count) {
	 for ( ; j + 1 < count; j += nr - 1 ) {
	    nr = MIN2( currentsz, count - j );

	    if (j + nr >= count &&
		start < count - 1 && 
		(flags & PRIM_END)) 
	    {
	       void *tmp;
	       tmp = ALLOC_ELTS(nr+1);
	       tmp = TAG(emit_elts)( ctx, elts+j, nr, tmp );
	       tmp = TAG(emit_elts)( ctx, elts+start, 1, tmp );
	    }
	    else {
	       TAG(emit_elts)( ctx, elts+j, nr, ALLOC_ELTS(nr) );
	       currentsz = dmasz;
	    }
	 }

      }
      else if (start + 1 < count && (flags & PRIM_END)) {
	 void *tmp;
	 tmp = ALLOC_ELTS(2);
	 tmp = TAG(emit_elts)( ctx, elts+start+1, 1, tmp );
	 tmp = TAG(emit_elts)( ctx, elts+start, 1, tmp );
      }

      FLUSH();
   } else {
      /* TODO: Try to emit as indexed lines */