/*
   Copyright (C) 1999-2007 id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "stdafx.h"
#include "winding.h"
#include "filters.h"

/*
   =============
   CSG_MakeHollow
   =============
 */

void Brush_Scale( brush_t* b ){
	for ( face_t* f = b->brush_faces ; f ; f = f->next )
	{
		for ( int i = 0 ; i < 3 ; i++ )
		{
			VectorScale( f->planepts[i], g_qeglobals.d_gridsize, f->planepts[i] );
		}
	}
}

void CSG_MakeHollow( void ){
	brush_t     *b, *front, *back, *next;
	face_t      *f;
	face_t split;
	vec3_t move;
	int i;

	for ( b = selected_brushes.next ; b != &selected_brushes ; b = next )
	{
		next = b->next;

		if ( b->owner->eclass->fixedsize || b->patchBrush || b->bFiltered ) {
			continue;
		}

		for ( f = b->brush_faces ; f ; f = f->next )
		{
			split = *f;
			VectorScale( f->plane.normal, g_qeglobals.d_gridsize, move );
			for ( i = 0 ; i < 3 ; i++ )
				VectorSubtract( split.planepts[i], move, split.planepts[i] );

			Brush_SplitBrushByFace( b, &split, &front, &back );
			if ( back ) {
				Brush_Free( back );
			}
			if ( front ) {
				Brush_AddToList( front, &selected_brushes );
			}
		}
		Brush_Free( b );
	}
	Sys_UpdateWindows( W_ALL );
}

/*
   =============
   Brush_Merge

   Returns a new brush that is created by merging brush1 and brush2.
   May return NULL if brush1 and brush2 do not create a convex brush when merged.
   The input brushes brush1 and brush2 stay intact.

   if onlyshape is true then the merge is allowed based on the shape only
   otherwise the texture/shader references of faces in the same plane have to
   be the same as well.
   =============
 */
brush_t *Brush_Merge( brush_t *brush1, brush_t *brush2, int onlyshape ){
	int i, shared;
	brush_t *newbrush;
	face_t *face1, *face2, *newface, *f;

	// check for bounding box overlapp
	for ( i = 0; i < 3; i++ )
	{
		if ( brush1->mins[i] > brush2->maxs[i] + ON_EPSILON
			 || brush1->maxs[i] < brush2->mins[i] - ON_EPSILON ) {
			// never merge if the brushes overlap
			return NULL;
		}
	}
	//
	shared = 0;
	// check if the new brush would be convex... flipped planes make a brush non-convex
	for ( face1 = brush1->brush_faces; face1; face1 = face1->next )
	{
		// don't check the faces of brush 1 and 2 touching each other
		for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
		{
			if ( Plane_Equal( &face1->plane, &face2->plane, true ) ) {
				shared++;
				// there may only be ONE shared side
				if ( shared > 1 ) {
					return NULL;
				}
				break;
			}
		}
		// if this face plane is shared
		if ( face2 ) {
			continue;
		}
		//
		for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
		{
			// don't check the faces of brush 1 and 2 touching each other
			for ( f = brush1->brush_faces; f; f = f->next )
			{
				if ( Plane_Equal( &face2->plane, &f->plane, true ) ) {
					break;
				}
			}
			if ( f ) {
				continue;
			}
			//
			if ( Plane_Equal( &face1->plane, &face2->plane, false ) ) {
				//if the texture/shader references should be the same but are not
				if ( !onlyshape && stricmp( face1->texdef.GetName(), face2->texdef.GetName() ) != 0 ) {
					return NULL;
				}
				continue;
			}
			//
			if ( Winding_PlanesConcave( face1->face_winding, face2->face_winding,
										face1->plane.normal, face2->plane.normal,
										face1->plane.dist, face2->plane.dist ) ) {
				return NULL;
			} //end if
		} //end for
	} //end for
	  //
	newbrush = Brush_Alloc();
	//
	for ( face1 = brush1->brush_faces; face1; face1 = face1->next )
	{
		// don't add the faces of brush 1 and 2 touching each other
		for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
		{
			if ( Plane_Equal( &face1->plane, &face2->plane, true ) ) {
				break;
			}
		}
		if ( face2 ) {
			continue;
		}
		// don't add faces with the same plane twice
		for ( f = newbrush->brush_faces; f; f = f->next )
		{
			if ( Plane_Equal( &face1->plane, &f->plane, false ) ) {
				break;
			}
			if ( Plane_Equal( &face1->plane, &f->plane, true ) ) {
				break;
			}
		}
		if ( f ) {
			continue;
		}
		//
		newface = Face_Alloc();
		newface->texdef = face1->texdef;
		VectorCopy( face1->planepts[0], newface->planepts[0] );
		VectorCopy( face1->planepts[1], newface->planepts[1] );
		VectorCopy( face1->planepts[2], newface->planepts[2] );
		newface->plane = face1->plane;
		newface->next = newbrush->brush_faces;
		newbrush->brush_faces = newface;
	}
	//
	for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
	{
		// don't add the faces of brush 1 and 2 touching each other
		for ( face1 = brush1->brush_faces; face1; face1 = face1->next )
		{
			if ( Plane_Equal( &face2->plane, &face1->plane, true ) ) {
				break;
			}
		}
		if ( face1 ) {
			continue;
		}
		// don't add faces with the same plane twice
		for ( f = newbrush->brush_faces; f; f = f->next )
		{
			if ( Plane_Equal( &face2->plane, &f->plane, false ) ) {
				break;
			}
			if ( Plane_Equal( &face2->plane, &f->plane, true ) ) {
				break;
			}
		}
		if ( f ) {
			continue;
		}
		//
		newface = Face_Alloc();
		newface->texdef = face2->texdef;
		VectorCopy( face2->planepts[0], newface->planepts[0] );
		VectorCopy( face2->planepts[1], newface->planepts[1] );
		VectorCopy( face2->planepts[2], newface->planepts[2] );
		newface->plane = face2->plane;
		newface->next = newbrush->brush_faces;
		newbrush->brush_faces = newface;
	}
	// link the new brush to an entity
	Entity_LinkBrush( brush1->owner, newbrush );
	// build windings for the faces
	Brush_BuildWindings( newbrush, false );

	return newbrush;
}

/*
   =============
   Brush_MergeListPairs

   Returns a list with merged brushes.
   Tries to merge brushes pair wise.
   The input list is destroyed.
   Input and output should be a single linked list using .next
   =============
 */
brush_t *Brush_MergeListPairs( brush_t *brushlist, int onlyshape ){
	int nummerges, merged;
	brush_t *b1, *b2, *tail, *newbrush, *newbrushlist;
	brush_t *lastb2;

	if ( !brushlist ) {
		return NULL;
	}

	nummerges = 0;
	do
	{
		for ( tail = brushlist; tail; tail = tail->next )
		{
			if ( !tail->next ) {
				break;
			}
		}
		merged = 0;
		newbrushlist = NULL;
		for ( b1 = brushlist; b1; b1 = brushlist )
		{
			lastb2 = b1;
			for ( b2 = b1->next; b2; b2 = b2->next )
			{
				newbrush = Brush_Merge( b1, b2, onlyshape );
				if ( newbrush ) {
					tail->next = newbrush;
					lastb2->next = b2->next;
					brushlist = brushlist->next;
					b1->next = b1->prev = NULL;
					b2->next = b2->prev = NULL;
					Brush_Free( b1 );
					Brush_Free( b2 );
					for ( tail = brushlist; tail; tail = tail->next )
					{
						if ( !tail->next ) {
							break;
						}
					} //end for
					merged++;
					nummerges++;
					break;
				}
				lastb2 = b2;
			}
			//if b1 can't be merged with any of the other brushes
			if ( !b2 ) {
				brushlist = brushlist->next;
				//keep b1
				b1->next = newbrushlist;
				newbrushlist = b1;
			}
		}
		brushlist = newbrushlist;
	} while ( merged );
	return newbrushlist;
}

/*
   =============
   Brush_MergeList

   Tries to merge all brushes in the list into one new brush.
   The input brush list stays intact.
   Returns NULL if no merged brush can be created.
   To create a new brush the brushes in the list may not overlap and
   the outer faces of the brushes together should make a new convex brush.

   if onlyshape is true then the merge is allowed based on the shape only
   otherwise the texture/shader references of faces in the same plane have to
   be the same as well.
   =============
 */
brush_t *Brush_MergeList( brush_t *brushlist, int onlyshape ){
	brush_t *brush1, *brush2, *brush3, *newbrush;
	face_t *face1, *face2, *face3, *newface, *f;

	if ( !brushlist ) {
		return NULL;
	}
	for ( brush1 = brushlist; brush1; brush1 = brush1->next )
	{
		// check if the new brush would be convex... flipped planes make a brush concave
		for ( face1 = brush1->brush_faces; face1; face1 = face1->next )
		{
			// don't check face1 if it touches another brush
			for ( brush2 = brushlist; brush2; brush2 = brush2->next )
			{
				if ( brush2 == brush1 ) {
					continue;
				}
				for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
				{
					if ( Plane_Equal( &face1->plane, &face2->plane, true ) ) {
						break;
					}
				}
				if ( face2 ) {
					break;
				}
			}
			// if face1 touches another brush
			if ( brush2 ) {
				continue;
			}
			//
			for ( brush2 = brush1->next; brush2; brush2 = brush2->next )
			{
				// don't check the faces of brush 2 touching another brush
				for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
				{
					for ( brush3 = brushlist; brush3; brush3 = brush3->next )
					{
						if ( brush3 == brush2 ) {
							continue;
						}
						for ( face3 = brush3->brush_faces; face3; face3 = face3->next )
						{
							if ( Plane_Equal( &face2->plane, &face3->plane, true ) ) {
								break;
							}
						}
						if ( face3 ) {
							break;
						}
					}
					// if face2 touches another brush
					if ( brush3 ) {
						continue;
					}
					//
					if ( Plane_Equal( &face1->plane, &face2->plane, false ) ) {
						//if the texture/shader references should be the same but are not
						if ( !onlyshape && stricmp( face1->texdef.GetName(), face2->texdef.GetName() ) != 0 ) {
							return NULL;
						}
						continue;
					}
					//
					if ( Winding_PlanesConcave( face1->face_winding, face2->face_winding,
												face1->plane.normal, face2->plane.normal,
												face1->plane.dist, face2->plane.dist ) ) {
						return NULL;
					}
				}
			}
		}
	}
	//
	newbrush = Brush_Alloc();
	//
	for ( brush1 = brushlist; brush1; brush1 = brush1->next )
	{
		for ( face1 = brush1->brush_faces; face1; face1 = face1->next )
		{
			// don't add face1 to the new brush if it touches another brush
			for ( brush2 = brushlist; brush2; brush2 = brush2->next )
			{
				if ( brush2 == brush1 ) {
					continue;
				}
				for ( face2 = brush2->brush_faces; face2; face2 = face2->next )
				{
					if ( Plane_Equal( &face1->plane, &face2->plane, true ) ) {
						break;
					}
				}
				if ( face2 ) {
					break;
				}
			}
			if ( brush2 ) {
				continue;
			}
			// don't add faces with the same plane twice
			for ( f = newbrush->brush_faces; f; f = f->next )
			{
				if ( Plane_Equal( &face1->plane, &f->plane, false ) ) {
					break;
				}
				if ( Plane_Equal( &face1->plane, &f->plane, true ) ) {
					break;
				}
			}
			if ( f ) {
				continue;
			}
			//
			newface = Face_Alloc();
			newface->texdef = face1->texdef;
			VectorCopy( face1->planepts[0], newface->planepts[0] );
			VectorCopy( face1->planepts[1], newface->planepts[1] );
			VectorCopy( face1->planepts[2], newface->planepts[2] );
			newface->plane = face1->plane;
			newface->next = newbrush->brush_faces;
			newbrush->brush_faces = newface;
		}
	}
	// link the new brush to an entity
	Entity_LinkBrush( brushlist->owner, newbrush );
	// build windings for the faces
	Brush_BuildWindings( newbrush, false );

	return newbrush;
}

/*
   =============
   Brush_Subtract

   Returns a list of brushes that remain after B is subtracted from A.
   May by empty if A is contained inside B.
   The originals are undisturbed.
   =============
 */
brush_t *Brush_Subtract( brush_t *a, brush_t *b ){
	// a - b = out (list)
	brush_t *front, *back;
	brush_t *in, *out, *next;
	face_t *f;

	in = a;
	out = NULL;
	for ( f = b->brush_faces; f && in; f = f->next )
	{
		Brush_SplitBrushByFace( in, f, &front, &back );
		if ( in != a ) {
			Brush_Free( in );
		}
		if ( front ) { // add to list
			front->next = out;
			out = front;
		}
		in = back;
	}
	//NOTE: in != a just in case brush b has no faces
	if ( in && in != a ) {
		Brush_Free( in );
	}
	else
	{   //didn't really intersect
		for ( b = out; b; b = next )
		{
			next = b->next;
			b->next = b->prev = NULL;
			Brush_Free( b );
		}
		return a;
	}
	return out;
}

/*
   =============
   CSG_Subtract
   =============
 */
void CSG_Subtract( void ){
	brush_t     *b, *s, *fragments, *nextfragment, *frag, *next, *snext;
	brush_t fragmentlist;
	int i, numfragments, numbrushes;

	Sys_Printf( "Subtracting...\n" );

	if ( selected_brushes.next == &selected_brushes ) {
		Sys_Printf( "No brushes selected.\n" );
		return;
	}

	fragmentlist.next = &fragmentlist;
	fragmentlist.prev = &fragmentlist;

	numfragments = 0;
	numbrushes = 0;
	for ( b = selected_brushes.next ; b != &selected_brushes ; b = next )
	{
		next = b->next;

		if ( b->owner->eclass->fixedsize ) {
			continue;   // can't use texture from a fixed entity, so don't subtract

		}
		// chop all fragments further up
		for ( s = fragmentlist.next; s != &fragmentlist; s = snext )
		{
			snext = s->next;

			for ( i = 0 ; i < 3 ; i++ )
				if ( b->mins[i] >= s->maxs[i] - ON_EPSILON
					 || b->maxs[i] <= s->mins[i] + ON_EPSILON ) {
					break;
				}
			if ( i != 3 ) {
				continue;   // definately don't touch
			}
			fragments = Brush_Subtract( s, b );
			// if the brushes did not really intersect
			if ( fragments == s ) {
				continue;
			}
			// try to merge fragments
			fragments = Brush_MergeListPairs( fragments, true );
			// add the fragments to the list
			for ( frag = fragments; frag; frag = nextfragment )
			{
				nextfragment = frag->next;
				frag->next = NULL;
				frag->owner = s->owner;
				Brush_AddToList( frag, &fragmentlist );
			}
			// free the original brush
			Brush_Free( s );
		}

		// chop any active brushes up
		for ( s = active_brushes.next; s != &active_brushes; s = snext )
		{
			snext = s->next;

			if ( s->owner->eclass->fixedsize || s->patchBrush || s->bFiltered ) {
				continue;
			}

			if ( s->brush_faces->pShader->getFlags() & QER_NOCARVE ) {
				continue;
			}

			for ( i = 0 ; i < 3 ; i++ )
				if ( b->mins[i] >= s->maxs[i] - ON_EPSILON
					 || b->maxs[i] <= s->mins[i] + ON_EPSILON ) {
					break;
				}
			if ( i != 3 ) {
				continue;   // definately don't touch

			}
			fragments = Brush_Subtract( s, b );
			// if the brushes did not really intersect
			if ( fragments == s ) {
				continue;
			}
			//
			Undo_AddBrush( s );
			// one extra brush chopped up
			numbrushes++;
			// try to merge fragments
			fragments = Brush_MergeListPairs( fragments, true );
			// add the fragments to the list
			for ( frag = fragments; frag; frag = nextfragment )
			{
				nextfragment = frag->next;
				frag->next = NULL;
				frag->owner = s->owner;
				Brush_AddToList( frag, &fragmentlist );
			}
			// free the original brush
			Brush_Free( s );
		}
	}

	// move all fragments to the active brush list
	for ( frag = fragmentlist.next; frag != &fragmentlist; frag = nextfragment )
	{
		nextfragment = frag->next;
		numfragments++;
		Brush_RemoveFromList( frag );
		Brush_AddToList( frag, &active_brushes );
		Undo_EndBrush( frag );
	}

	/*if (numfragments == 0)
	   {
	    Sys_Printf("Selected brush%s did not intersect with any other brushes.\n",
	                (selected_brushes.next->next == &selected_brushes) ? "":"es");
	    return;
	   }*/
	Sys_Printf( "done. (created %d fragment%s out of %d brush%s)\n", numfragments, ( numfragments == 1 ) ? "" : "s",
				numbrushes, ( numbrushes == 1 ) ? "" : "es" );
	Sys_UpdateWindows( W_ALL );
}

/*
   =============
   CSG_Merge
   =============
 */
void CSG_Merge( void ){
	brush_t *b, *next, *newlist, *newbrush;
	struct entity_s *owner;

	Sys_Printf( "Merging...\n" );

	if ( selected_brushes.next == &selected_brushes ) {
		Sys_Printf( "No brushes selected.\n" );
		return;
	}

	if ( selected_brushes.next->next == &selected_brushes ) {
		Sys_Printf( "At least two brushes have to be selected.\n" );
		return;
	}

	owner = selected_brushes.next->owner;

	for ( b = selected_brushes.next; b != &selected_brushes; b = next )
	{
		next = b->next;

		if ( b->owner->eclass->fixedsize ) {
			// can't use texture from a fixed entity, so don't subtract
			Sys_Printf( "Cannot add fixed size entities.\n" );
			return;
		}

		if ( b->patchBrush ) {
			Sys_Printf( "Cannot add patches.\n" );
			return;
		}

		// TTimo: cleanup
		// disable the qer_nocarve for CSG-MERGE operations
#if 0
		if ( b->brush_faces->d_texture->bFromShader && ( b->brush_faces->d_texture->nShaderFlags & QER_NOCARVE ) ) {
			Sys_Printf( "Cannot add brushes using shaders that don't allows CSG operations.\n" );
			return;
		}
#endif

		if ( b->owner != owner ) {
			Sys_Printf( "Cannot add brushes from different entities.\n" );
			return;
		}

	}

	newlist = NULL;
	for ( b = selected_brushes.next; b != &selected_brushes; b = next )
	{
		next = b->next;

		Brush_RemoveFromList( b );
		b->next = newlist;
		b->prev = NULL;
		newlist = b;
	}

	newbrush = Brush_MergeList( newlist, true );
	// if the new brush would not be convex
	if ( !newbrush ) {
		// add the brushes back into the selection
		for ( b = newlist; b; b = next )
		{
			next = b->next;
			b->next = NULL;
			b->prev = NULL;
			Brush_AddToList( b, &selected_brushes );
		}
		Sys_Printf( "Cannot add a set of brushes with a concave hull.\n" );
		return;
	}
	// free the original brushes
	for ( b = newlist; b; b = next )
	{
		next = b->next;
		b->next = NULL;
		b->prev = NULL;
		Brush_Free( b );
	}

	newbrush->bFiltered = FilterBrush( newbrush ); // spog - set filters for the new brush

	Brush_AddToList( newbrush, &selected_brushes );

	Sys_Printf( "done.\n" );
	Sys_UpdateWindows( W_ALL );
}