source: branches/swt/src/opengl/mesa/cull_tmp.h

/* $Id: cull_tmp.h,v 1.1 2000-02-29 00:48:28 sandervl Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  3.1
 *
 * Copyright (C) 1999  Brian Paul   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, sublicense,
 * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL 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.
 */

/*
 * New (3.1) transformation code written by Keith Whitwell.
 */


static GLuint TAG(gl_cull_triangles)( struct vertex_buffer *VB,
                                      GLuint start,
                                      GLuint count,
                                      GLuint parity,
                                      CONST GLfloat (*proj)[4])
{
   const GLcontext *ctx = VB->ctx;
   const GLubyte face_bit = ctx->Polygon.FrontBit;
   const GLubyte cull_faces = ctx->Polygon.CullBits;
   GLubyte *cullmask = VB->CullMask;
   GLint i,cullcount = 0;
   GLint last = count - 3;

   (void) parity;
   for (i=start; i <= last ; i+=3 ) {
      CULL_TRI(DO_CLIP, DO_AREA, i, i+1, i+2, face_bit, 3);
   }

   if (i != count)
      cullcount += count - i;

   return cullcount;
}

                        




static GLuint TAG(gl_cull_triangle_fan)( struct vertex_buffer *VB,
                                         GLuint start,
                                         GLuint count,
                                         GLuint parity,
                                         CONST GLfloat (*proj)[4])
{
   const GLcontext *ctx = VB->ctx;
   const GLubyte face_bit = ctx->Polygon.FrontBit;
   const GLubyte cull_faces = ctx->Polygon.CullBits;
   GLubyte *cullmask = VB->CullMask;
   GLint cullcount = 0;
   GLint i;
   GLint last = count - 3;
   GLint nr = 3;

   (void) parity;
   for (i=start; i <= last ; i++, nr = 1) {
      CULL_TRI(DO_CLIP, DO_AREA, start, i+1, i+2, face_bit, nr);
   }

   if (i != last + 1)
      cullcount += count - i;

   return cullcount;
}



static GLuint TAG(gl_cull_triangle_strip)( struct vertex_buffer *VB,
                                           GLuint start,
                                           GLuint count,
                                           GLuint parity,
                                           CONST GLfloat (*proj)[4])
{
   const GLcontext *ctx = VB->ctx;
   const GLubyte face_bit = ctx->Polygon.FrontBit;
   const GLubyte cull_faces = ctx->Polygon.CullBits;
   GLubyte *cullmask = VB->CullMask;
   GLint i;
   GLint cullcount = 0;
   GLint last = count - 3;
   GLint nr = 2;

   parity ^= face_bit;

   for (i = start; i <= last ; i++, parity ^= 1, nr = 1 ) {
      CULL_TRI(DO_CLIP, DO_AREA, i, i+1, i+2, parity, nr);
   }

   if (i != last + 1)
      cullcount += count - i;

   return cullcount;
}





static GLuint TAG(gl_cull_quads)( struct vertex_buffer *VB,
                                  GLuint start,
                                  GLuint count,
                                  GLuint parity,
                                  CONST GLfloat (*proj)[4])
{
   const GLcontext *ctx = VB->ctx;
   const GLubyte face_bit = ctx->Polygon.FrontBit;
   const GLubyte cull_faces = ctx->Polygon.CullBits;
   GLubyte *cullmask = VB->CullMask;
   GLint i,cullcount = 0;
   GLint last = count - 4;

   (void) parity;

   for (i = start; i <= last ; i += 4) {
      CULL_QUAD(DO_CLIP, DO_AREA, i, i+1, i+2, i+3, 4);
   }

   if (i != count)
      cullcount += count - i;

   return cullcount;
}


static GLuint TAG(gl_cull_quad_strip)( struct vertex_buffer *VB,
                                       GLuint start,
                                       GLuint count,
                                       GLuint parity,
                                       CONST GLfloat (*proj)[4])
{
   const GLcontext *ctx = VB->ctx;
   const GLubyte face_bit = ctx->Polygon.FrontBit;
   const GLubyte cull_faces = ctx->Polygon.CullBits;
   GLubyte *cullmask = VB->CullMask;
   GLint i,cullcount = 0;
   GLint last = count - 4;
   GLint nr = 4;

   (void) parity;

   for (i = start ; i <= last ; i += 2, nr = 2) {
      CULL_QUAD(DO_CLIP, DO_AREA, i, i+1, i+3, i+2, nr);
   }

   if (i != last + 2)
      cullcount += count - i;

   return cullcount;
}




#undef DO_CLIP
#undef DO_AREA
#undef TAG