gim_box_set.h

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#ifndef GIM_BOX_SET_H_INCLUDED
#define GIM_BOX_SET_H_INCLUDED

/*
-----------------------------------------------------------------------------
This source file is part of GIMPACT Library.

For the latest info, see http://gimpact.sourceforge.net/

Copyright (c) 2006 Francisco Leon Najera. C.C. 80087371.
email: projectileman@yahoo.com

 This library is free software; you can redistribute it and/or
 modify it under the terms of EITHER:
   (1) The GNU Lesser General Public License as published by the Free
       Software Foundation; either version 2.1 of the License, or (at
       your option) any later version. The text of the GNU Lesser
       General Public License is included with this library in the
       file GIMPACT-LICENSE-LGPL.TXT.
   (2) The BSD-style license that is included with this library in
       the file GIMPACT-LICENSE-BSD.TXT.
   (3) The zlib/libpng license that is included with this library in
       the file GIMPACT-LICENSE-ZLIB.TXT.

 This library 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 files
 GIMPACT-LICENSE-LGPL.TXT, GIMPACT-LICENSE-ZLIB.TXT and GIMPACT-LICENSE-BSD.TXT for more details.

-----------------------------------------------------------------------------
*/

#include "gim_array.h"
#include "gim_radixsort.h"
#include "gim_box_collision.h"
#include "gim_tri_collision.h"

struct GIM_PAIR
{
        GUINT m_index1;
        GUINT m_index2;
        GIM_PAIR()
        {
        }

        GIM_PAIR(const GIM_PAIR& p)
        {
                m_index1 = p.m_index1;
                m_index2 = p.m_index2;
        }

        GIM_PAIR(GUINT index1, GUINT index2)
        {
                m_index1 = index1;
                m_index2 = index2;
        }
};

class gim_pair_set : public gim_array<GIM_PAIR>
{
public:
        gim_pair_set() : gim_array<GIM_PAIR>(32)
        {
        }
        inline void push_pair(GUINT index1, GUINT index2)
        {
                push_back(GIM_PAIR(index1, index2));
        }

        inline void push_pair_inv(GUINT index1, GUINT index2)
        {
                push_back(GIM_PAIR(index2, index1));
        }
};


class GIM_PRIMITIVE_MANAGER_PROTOTYPE
{
public:
        virtual ~GIM_PRIMITIVE_MANAGER_PROTOTYPE() {}
        virtual bool is_trimesh() = 0;
        virtual GUINT get_primitive_count() = 0;
        virtual void get_primitive_box(GUINT prim_index, GIM_AABB& primbox) = 0;
        virtual void get_primitive_triangle(GUINT prim_index, GIM_TRIANGLE& triangle) = 0;
};

struct GIM_AABB_DATA
{
        GIM_AABB m_bound;
        GUINT m_data;
};

struct GIM_BOX_TREE_NODE
{
        GIM_AABB m_bound;
        GUINT m_left;         
        GUINT m_right;        
        GUINT m_escapeIndex;  
        GUINT m_data;         

        GIM_BOX_TREE_NODE()
        {
                m_left = 0;
                m_right = 0;
                m_escapeIndex = 0;
                m_data = 0;
        }

        SIMD_FORCE_INLINE bool is_leaf_node() const
        {
                return (!m_left && !m_right);
        }
};

class GIM_BOX_TREE
{
protected:
        GUINT m_num_nodes;
        gim_array<GIM_BOX_TREE_NODE> m_node_array;

protected:
        GUINT _sort_and_calc_splitting_index(
                gim_array<GIM_AABB_DATA>& primitive_boxes,
                GUINT startIndex, GUINT endIndex, GUINT splitAxis);

        GUINT _calc_splitting_axis(gim_array<GIM_AABB_DATA>& primitive_boxes, GUINT startIndex, GUINT endIndex);

        void _build_sub_tree(gim_array<GIM_AABB_DATA>& primitive_boxes, GUINT startIndex, GUINT endIndex);

public:
        GIM_BOX_TREE()
        {
                m_num_nodes = 0;
        }

        void build_tree(gim_array<GIM_AABB_DATA>& primitive_boxes);

        SIMD_FORCE_INLINE void clearNodes()
        {
                m_node_array.clear();
                m_num_nodes = 0;
        }

        SIMD_FORCE_INLINE GUINT getNodeCount() const
        {
                return m_num_nodes;
        }

        SIMD_FORCE_INLINE bool isLeafNode(GUINT nodeindex) const
        {
                return m_node_array[nodeindex].is_leaf_node();
        }

        SIMD_FORCE_INLINE GUINT getNodeData(GUINT nodeindex) const
        {
                return m_node_array[nodeindex].m_data;
        }

        SIMD_FORCE_INLINE void getNodeBound(GUINT nodeindex, GIM_AABB& bound) const
        {
                bound = m_node_array[nodeindex].m_bound;
        }

        SIMD_FORCE_INLINE void setNodeBound(GUINT nodeindex, const GIM_AABB& bound)
        {
                m_node_array[nodeindex].m_bound = bound;
        }

        SIMD_FORCE_INLINE GUINT getLeftNodeIndex(GUINT nodeindex) const
        {
                return m_node_array[nodeindex].m_left;
        }

        SIMD_FORCE_INLINE GUINT getRightNodeIndex(GUINT nodeindex) const
        {
                return m_node_array[nodeindex].m_right;
        }

        SIMD_FORCE_INLINE GUINT getScapeNodeIndex(GUINT nodeindex) const
        {
                return m_node_array[nodeindex].m_escapeIndex;
        }

};


template <typename _GIM_PRIMITIVE_MANAGER_PROTOTYPE, typename _GIM_BOX_TREE_PROTOTYPE>
class GIM_BOX_TREE_TEMPLATE_SET
{
protected:
        _GIM_PRIMITIVE_MANAGER_PROTOTYPE m_primitive_manager;
        _GIM_BOX_TREE_PROTOTYPE m_box_tree;

protected:
        //stackless refit
        SIMD_FORCE_INLINE void refit()
        {
                GUINT nodecount = getNodeCount();
                while (nodecount--)
                {
                        if (isLeafNode(nodecount))
                        {
                                GIM_AABB leafbox;
                                m_primitive_manager.get_primitive_box(getNodeData(nodecount), leafbox);
                                setNodeBound(nodecount, leafbox);
                        }
                        else
                        {
                                //get left bound
                                GUINT childindex = getLeftNodeIndex(nodecount);
                                GIM_AABB bound;
                                getNodeBound(childindex, bound);
                                //get right bound
                                childindex = getRightNodeIndex(nodecount);
                                GIM_AABB bound2;
                                getNodeBound(childindex, bound2);
                                bound.merge(bound2);

                                setNodeBound(nodecount, bound);
                        }
                }
        }

public:
        GIM_BOX_TREE_TEMPLATE_SET()
        {
        }

        SIMD_FORCE_INLINE GIM_AABB getGlobalBox() const
        {
                GIM_AABB totalbox;
                getNodeBound(0, totalbox);
                return totalbox;
        }

        SIMD_FORCE_INLINE void setPrimitiveManager(const _GIM_PRIMITIVE_MANAGER_PROTOTYPE& primitive_manager)
        {
                m_primitive_manager = primitive_manager;
        }

        const _GIM_PRIMITIVE_MANAGER_PROTOTYPE& getPrimitiveManager() const
        {
                return m_primitive_manager;
        }

        _GIM_PRIMITIVE_MANAGER_PROTOTYPE& getPrimitiveManager()
        {
                return m_primitive_manager;
        }


        SIMD_FORCE_INLINE void update()
        {
                refit();
        }

        SIMD_FORCE_INLINE void buildSet()
        {
                //obtain primitive boxes
                gim_array<GIM_AABB_DATA> primitive_boxes;
                primitive_boxes.resize(m_primitive_manager.get_primitive_count(), false);

                for (GUINT i = 0; i < primitive_boxes.size(); i++)
                {
                        m_primitive_manager.get_primitive_box(i, primitive_boxes[i].m_bound);
                        primitive_boxes[i].m_data = i;
                }

                m_box_tree.build_tree(primitive_boxes);
        }

        SIMD_FORCE_INLINE bool boxQuery(const GIM_AABB& box, gim_array<GUINT>& collided_results) const
        {
                GUINT curIndex = 0;
                GUINT numNodes = getNodeCount();

                while (curIndex < numNodes)
                {
                        GIM_AABB bound;
                        getNodeBound(curIndex, bound);

                        //catch bugs in tree data

                        bool aabbOverlap = bound.has_collision(box);
                        bool isleafnode = isLeafNode(curIndex);

                        if (isleafnode && aabbOverlap)
                        {
                                collided_results.push_back(getNodeData(curIndex));
                        }

                        if (aabbOverlap || isleafnode)
                        {
                                //next subnode
                                curIndex++;
                        }
                        else
                        {
                                //skip node
                                curIndex += getScapeNodeIndex(curIndex);
                        }
                }
                if (collided_results.size() > 0) return true;
                return false;
        }

        SIMD_FORCE_INLINE bool boxQueryTrans(const GIM_AABB& box,
                                                                                 const btTransform& transform, gim_array<GUINT>& collided_results) const
        {
                GIM_AABB transbox = box;
                transbox.appy_transform(transform);
                return boxQuery(transbox, collided_results);
        }

        SIMD_FORCE_INLINE bool rayQuery(
                const btVector3& ray_dir, const btVector3& ray_origin,
                gim_array<GUINT>& collided_results) const
        {
                GUINT curIndex = 0;
                GUINT numNodes = getNodeCount();

                while (curIndex < numNodes)
                {
                        GIM_AABB bound;
                        getNodeBound(curIndex, bound);

                        //catch bugs in tree data

                        bool aabbOverlap = bound.collide_ray(ray_origin, ray_dir);
                        bool isleafnode = isLeafNode(curIndex);

                        if (isleafnode && aabbOverlap)
                        {
                                collided_results.push_back(getNodeData(curIndex));
                        }

                        if (aabbOverlap || isleafnode)
                        {
                                //next subnode
                                curIndex++;
                        }
                        else
                        {
                                //skip node
                                curIndex += getScapeNodeIndex(curIndex);
                        }
                }
                if (collided_results.size() > 0) return true;
                return false;
        }

        SIMD_FORCE_INLINE bool hasHierarchy() const
        {
                return true;
        }

        SIMD_FORCE_INLINE bool isTrimesh() const
        {
                return m_primitive_manager.is_trimesh();
        }

        SIMD_FORCE_INLINE GUINT getNodeCount() const
        {
                return m_box_tree.getNodeCount();
        }

        SIMD_FORCE_INLINE bool isLeafNode(GUINT nodeindex) const
        {
                return m_box_tree.isLeafNode(nodeindex);
        }

        SIMD_FORCE_INLINE GUINT getNodeData(GUINT nodeindex) const
        {
                return m_box_tree.getNodeData(nodeindex);
        }

        SIMD_FORCE_INLINE void getNodeBound(GUINT nodeindex, GIM_AABB& bound) const
        {
                m_box_tree.getNodeBound(nodeindex, bound);
        }

        SIMD_FORCE_INLINE void setNodeBound(GUINT nodeindex, const GIM_AABB& bound)
        {
                m_box_tree.setNodeBound(nodeindex, bound);
        }

        SIMD_FORCE_INLINE GUINT getLeftNodeIndex(GUINT nodeindex) const
        {
                return m_box_tree.getLeftNodeIndex(nodeindex);
        }

        SIMD_FORCE_INLINE GUINT getRightNodeIndex(GUINT nodeindex) const
        {
                return m_box_tree.getRightNodeIndex(nodeindex);
        }

        SIMD_FORCE_INLINE GUINT getScapeNodeIndex(GUINT nodeindex) const
        {
                return m_box_tree.getScapeNodeIndex(nodeindex);
        }

        SIMD_FORCE_INLINE void getNodeTriangle(GUINT nodeindex, GIM_TRIANGLE& triangle) const
        {
                m_primitive_manager.get_primitive_triangle(getNodeData(nodeindex), triangle);
        }
};


template <typename _GIM_PRIMITIVE_MANAGER_PROTOTYPE>
class GIM_BOX_TREE_SET : public GIM_BOX_TREE_TEMPLATE_SET<_GIM_PRIMITIVE_MANAGER_PROTOTYPE, GIM_BOX_TREE>
{
public:
};

template <typename BOX_SET_CLASS0, typename BOX_SET_CLASS1>
class GIM_TREE_TREE_COLLIDER
{
public:
        gim_pair_set* m_collision_pairs;
        BOX_SET_CLASS0* m_boxset0;
        BOX_SET_CLASS1* m_boxset1;
        GUINT current_node0;
        GUINT current_node1;
        bool node0_is_leaf;
        bool node1_is_leaf;
        bool t0_is_trimesh;
        bool t1_is_trimesh;
        bool node0_has_triangle;
        bool node1_has_triangle;
        GIM_AABB m_box0;
        GIM_AABB m_box1;
        GIM_BOX_BOX_TRANSFORM_CACHE trans_cache_1to0;
        btTransform trans_cache_0to1;
        GIM_TRIANGLE m_tri0;
        btVector4 m_tri0_plane;
        GIM_TRIANGLE m_tri1;
        btVector4 m_tri1_plane;

public:
        GIM_TREE_TREE_COLLIDER()
        {
                current_node0 = G_UINT_INFINITY;
                current_node1 = G_UINT_INFINITY;
        }

protected:
        SIMD_FORCE_INLINE void retrieve_node0_triangle(GUINT node0)
        {
                if (node0_has_triangle) return;
                m_boxset0->getNodeTriangle(node0, m_tri0);
                //transform triangle
                m_tri0.m_vertices[0] = trans_cache_0to1(m_tri0.m_vertices[0]);
                m_tri0.m_vertices[1] = trans_cache_0to1(m_tri0.m_vertices[1]);
                m_tri0.m_vertices[2] = trans_cache_0to1(m_tri0.m_vertices[2]);
                m_tri0.get_plane(m_tri0_plane);

                node0_has_triangle = true;
        }

        SIMD_FORCE_INLINE void retrieve_node1_triangle(GUINT node1)
        {
                if (node1_has_triangle) return;
                m_boxset1->getNodeTriangle(node1, m_tri1);
                //transform triangle
                m_tri1.m_vertices[0] = trans_cache_1to0.transform(m_tri1.m_vertices[0]);
                m_tri1.m_vertices[1] = trans_cache_1to0.transform(m_tri1.m_vertices[1]);
                m_tri1.m_vertices[2] = trans_cache_1to0.transform(m_tri1.m_vertices[2]);
                m_tri1.get_plane(m_tri1_plane);

                node1_has_triangle = true;
        }

        SIMD_FORCE_INLINE void retrieve_node0_info(GUINT node0)
        {
                if (node0 == current_node0) return;
                m_boxset0->getNodeBound(node0, m_box0);
                node0_is_leaf = m_boxset0->isLeafNode(node0);
                node0_has_triangle = false;
                current_node0 = node0;
        }

        SIMD_FORCE_INLINE void retrieve_node1_info(GUINT node1)
        {
                if (node1 == current_node1) return;
                m_boxset1->getNodeBound(node1, m_box1);
                node1_is_leaf = m_boxset1->isLeafNode(node1);
                node1_has_triangle = false;
                current_node1 = node1;
        }

        SIMD_FORCE_INLINE bool node_collision(GUINT node0, GUINT node1)
        {
                retrieve_node0_info(node0);
                retrieve_node1_info(node1);
                bool result = m_box0.overlapping_trans_cache(m_box1, trans_cache_1to0, true);
                if (!result) return false;

                if (t0_is_trimesh && node0_is_leaf)
                {
                        //perform primitive vs box collision
                        retrieve_node0_triangle(node0);
                        //do triangle vs box collision
                        m_box1.increment_margin(m_tri0.m_margin);

                        result = m_box1.collide_triangle_exact(
                                m_tri0.m_vertices[0], m_tri0.m_vertices[1], m_tri0.m_vertices[2], m_tri0_plane);

                        m_box1.increment_margin(-m_tri0.m_margin);

                        if (!result) return false;
                        return true;
                }
                else if (t1_is_trimesh && node1_is_leaf)
                {
                        //perform primitive vs box collision
                        retrieve_node1_triangle(node1);
                        //do triangle vs box collision
                        m_box0.increment_margin(m_tri1.m_margin);

                        result = m_box0.collide_triangle_exact(
                                m_tri1.m_vertices[0], m_tri1.m_vertices[1], m_tri1.m_vertices[2], m_tri1_plane);

                        m_box0.increment_margin(-m_tri1.m_margin);

                        if (!result) return false;
                        return true;
                }
                return true;
        }

        //stackless collision routine
        void find_collision_pairs()
        {
                gim_pair_set stack_collisions;
                stack_collisions.reserve(32);

                //add the first pair
                stack_collisions.push_pair(0, 0);

                while (stack_collisions.size())
                {
                        //retrieve the last pair and pop
                        GUINT node0 = stack_collisions.back().m_index1;
                        GUINT node1 = stack_collisions.back().m_index2;
                        stack_collisions.pop_back();
                        if (node_collision(node0, node1))  // a collision is found
                        {
                                if (node0_is_leaf)
                                {
                                        if (node1_is_leaf)
                                        {
                                                m_collision_pairs->push_pair(m_boxset0->getNodeData(node0), m_boxset1->getNodeData(node1));
                                        }
                                        else
                                        {
                                                //collide left
                                                stack_collisions.push_pair(node0, m_boxset1->getLeftNodeIndex(node1));

                                                //collide right
                                                stack_collisions.push_pair(node0, m_boxset1->getRightNodeIndex(node1));
                                        }
                                }
                                else
                                {
                                        if (node1_is_leaf)
                                        {
                                                //collide left
                                                stack_collisions.push_pair(m_boxset0->getLeftNodeIndex(node0), node1);
                                                //collide right
                                                stack_collisions.push_pair(m_boxset0->getRightNodeIndex(node0), node1);
                                        }
                                        else
                                        {
                                                GUINT left0 = m_boxset0->getLeftNodeIndex(node0);
                                                GUINT right0 = m_boxset0->getRightNodeIndex(node0);
                                                GUINT left1 = m_boxset1->getLeftNodeIndex(node1);
                                                GUINT right1 = m_boxset1->getRightNodeIndex(node1);
                                                //collide left
                                                stack_collisions.push_pair(left0, left1);
                                                //collide right
                                                stack_collisions.push_pair(left0, right1);
                                                //collide left
                                                stack_collisions.push_pair(right0, left1);
                                                //collide right
                                                stack_collisions.push_pair(right0, right1);

                                        }  // else if node1 is not a leaf
                                }      // else if node0 is not a leaf

                        }  // if(node_collision(node0,node1))
                }      //while(stack_collisions.size())
        }

public:
        void find_collision(BOX_SET_CLASS0* boxset1, const btTransform& trans1,
                                                BOX_SET_CLASS1* boxset2, const btTransform& trans2,
                                                gim_pair_set& collision_pairs, bool complete_primitive_tests = true)
        {
                m_collision_pairs = &collision_pairs;
                m_boxset0 = boxset1;
                m_boxset1 = boxset2;

                trans_cache_1to0.calc_from_homogenic(trans1, trans2);

                trans_cache_0to1 = trans2.inverse();
                trans_cache_0to1 *= trans1;

                if (complete_primitive_tests)
                {
                        t0_is_trimesh = boxset1->getPrimitiveManager().is_trimesh();
                        t1_is_trimesh = boxset2->getPrimitiveManager().is_trimesh();
                }
                else
                {
                        t0_is_trimesh = false;
                        t1_is_trimesh = false;
                }

                find_collision_pairs();
        }
};

#endif  // GIM_BOXPRUNING_H_INCLUDED