csg.cpp

来自「quake3工具源码。包括生成bsp文件」· C++ 代码 · 共 661 行 · 第 1/2 页

					}
					//
					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->hiddenBrush)
				continue;

			//face_t *pFace = s->brush_faces;
			if (s->brush_faces->d_texture->bFromShader && (s->brush_faces->d_texture->nShaderFlags & 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;
		}

		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;
		}

		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);
	}
	Brush_AddToList(newbrush, &selected_brushes);

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