source: cpp/frams/canvas/nn_smart_layout.cpp @ 1217

// This file is a part of Framsticks SDK.  http://www.framsticks.com/
// Copyright (C) 1999-2021  Maciej Komosinski and Szymon Ulatowski.
// See LICENSE.txt for details.

#include "nn_layout.h"
#include <vector>
#include <algorithm>
#ifdef __BORLANDC__
 #include <alloc.h> //borland needs for alloc/free
#endif
#if (defined MACOS) | (defined EMSCRIPTEN)
 #include <stdlib.h>
#endif

//#define DB(x) x
#define DB(x)

#if DB(1)+0
#include <assert.h>
#endif

class block;

/** Information about a single element (neuron). There are N einfo objects in an array called "einfo" */
struct einfo
{
        /** Element's owner */
        class block *block;

        /** Integer coordinates (neurons are simply placed in a grid, (x,y) is a grid cell) */
        int x, y;
};

/** Array[0..N-1] - one einfo for each neuron */
static struct einfo* einfo;

/** Array[0..N-1] - initially each neuron resides in its own block. The algorithm merges blocks until one single block is created */
static block **blocks;

/** N = number of neurons */
static int N;

/** Provides neuron connections information and receives the layout result */
static NNLayoutState *nn;

static char *JEDEN = (char*)"1";

/** Block is a group of neurons.
        After "blocking" some neurons, their relative location will not change. */
class block
{
public:

        /** Block's id is its index in the "blocks" array */
        int id;

        /** Block members (neurons), or actually neuron indexes (0..N-1 ints)  */
        std::vector<int> elementy;

        /** Block's bounding box (a rectangle containing all elemens)
                w=maxx-minx+1; h=maxy-miny+1;
                */
        int w, h;
        int minx, miny, maxx, maxy;

        /** 2d array, w*h cells, indicating if a given (x,y) location is taken.
                This speeds up checking if neurons from two blocks overlap.
                */
        char *map;

        /** Creating an initial block consisting of a single neuron */
        block(int nr) : id(nr), w(1), h(1), minx(0), miny(0), maxx(0), maxy(0)
        {
                DB(printf("new block(%d)\n", nr));
                dodajelement(nr, 0, 0);
                blocks[id] = this;
                map = JEDEN;
        }

        ~block()
        {
                DB(printf("~ block(%d)\n", id));
                blocks[id] = 0;
                zwolnijmape();
        }

        void zwolnijmape(void)
        {
                if (map)
                {
                        if (map != JEDEN) free(map);
                        map = 0;
                }
        }

        void potrzebnamapa(void)
        {
                if (map) return;
                odtworzmape();
        }

        void odtworzmape(void)
        {
                zwolnijmape();
                w = maxx - minx + 1;
                h = maxy - miny + 1;
                map = (char*)calloc(1, w*h);
                DB(printf("mapa bloku #%d\n", id));
                for (size_t i = 0; i < elementy.size(); i++)
                {
                        int e = elementy[i];
                        map[w*(einfo[e].y - miny) + (einfo[e].x - minx)] = 1;
                }
                DB(for (int i = 0; i < h; i++){ for (int e = 0; e < w; e++)printf("%c", map[w*i + e] ? '*' : '.'); printf("\n"); })
        }

        /** Add a neuron to a block at location(x,y) */
        void dodajelement(int nr, int x, int y)
        {
                elementy.push_back(nr);
                einfo[nr].x = x;
                einfo[nr].y = y;
                einfo[nr].block = this;
        }
};

static int moznadolaczyc(block *b, block *b2, int dx, int dy)
{
        /* Check if block b2 can be merged with b with b2 shifted by (dx,dy) so no overlap occurs.
           All coordinates are relative to b->minx/miny
           */
        int x1, y1, x2, y2; // union rectangle
        x1 = std::max(0, b2->minx - b->minx + dx);
        x2 = std::min(b->maxx - b->minx, -b->minx + dx + b2->maxx);
        if (x1 > x2) return 1;
        y1 = std::max(0, b2->miny - b->miny + dy);
        y2 = std::min(b->maxy - b->miny, -b->miny + dy + b2->maxy);
        if (y1 > y2) return 1;
        int x, y;
        dx += b2->minx - b->minx; //dx,dy relative to minx,miny
        dy += b2->miny - b->miny;
        b->potrzebnamapa();
        b2->potrzebnamapa();
        for (y = y1; y <= y2; y++)
        {
                for (x = x1; x <= x2; x++)
                        if (b->map[b->w*y + x] && b2->map[b2->w*(y - dy) + (x - dx)]) return 0;
        }
        return 1;
}

/** Merge b2 with b shifting b2 by (dx,dy) - adds all b2's neurons to b and deletes b2 */
static int dolaczblock(block *b, block *b2, int dx, int dy)
{ // return 1 if successful
        if (!moznadolaczyc(b, b2, dx, dy)) return 0; // merging causes no collision
        DB(printf("#%d(%d,%d,%d,%d) + #%d(%d,%d,%d,%d)<%d,%d>", b->id, b->minx, b->miny, b->maxx, b->maxy, b2->id, b2->minx, b2->miny, b2->maxx, b2->maxy, dx, dy));

        b->zwolnijmape();
        for (size_t i = 0; i < b2->elementy.size(); i++)
        {
                int e = b2->elementy[i];
                b->dodajelement(e, einfo[e].x + dx, einfo[e].y + dy);
        }
        b->minx = std::min(b->minx, dx + b2->minx);
        b->miny = std::min(b->miny, dy + b2->miny);
        b->maxx = std::max(b->maxx, dx + b2->maxx);
        b->maxy = std::max(b->maxy, dy + b2->maxy);

        DB(
        printf(" -> (%d,%d,%d,%d)\n", b->minx, b->miny, b->maxx, b->maxy);

        printf(" ...#%d...(%d)...", b->id, b->elementy.size());
        for (size_t i = 0; i < b->elementy.size(); i++)
        {
                int e = b->elementy[i];
                assert(einfo[e].x >= b->minx);
                        assert(einfo[e].x <= b->maxx);
                        assert(einfo[e].y >= b->miny);
                        assert(einfo[e].y <= b->maxy);
                        printf("(%d)%d,%d ", e, einfo[e].x, einfo[e].y);
        }

        printf("\n")
        );

        delete b2;
        return 1;
}

/** e2 neuron will be connected to e neuron's input:
        - e and e2 belong to different blocks: shift/merge the blocks so e2 is to the left of e
        - same block: nothing can be done
        */
static void polaczjakowejscie(int e, int e2)
{
        block *b, *b2;
        b = einfo[e].block;
        if (!einfo[e2].block) new block(e2);
        b2 = einfo[e2].block;
        if (b == b2)
        {
                DB(printf("--- b==b2 -> cancel\n"));
                return;
        }
        int dx, dy;
        dx = einfo[e].x - einfo[e2].x;
        dy = einfo[e].y - einfo[e2].y;
        DB(printf("  elem.%d (%d,%d@%d) + elem.%d (%d,%d@%d)...\n", e, einfo[e].x, einfo[e].y, b->id, e2, einfo[e2].x, einfo[e2].y, b2->id));
        if (dolaczblock(b, b2, dx - 1, dy)) return;
        int proba; // retry - increasing the y offset (keeps x offset at -1)
        for (proba = 1;; proba++)
        {
                if (dolaczblock(b, b2, dx - 1, dy - proba)) return;
                if (dolaczblock(b, b2, dx - 1, dy + proba)) return;
        }
}

/** Retrieve the information about neuron e inputs and place the input neurons accordingly
        unless they are already processed
        */
static void ustawelement(int e)
{
        if (einfo[e].block)
        {
                DB(printf("block#%d exists\n", e));
                return;
        }
        new block(e);
        int we;
        int n = nn->GetInputs(e);
        for (we = 0; we < n; we++)
        {
                int e2 = nn->GetLink(e, we);
                if (e2 < 0) continue;
                if (e == e2) continue;
                ustawelement(e2);
                polaczjakowejscie(e, e2);
        }
}

/**
   The algorithm:
   1. Phase one
    - for each neuron, place its input neurons to the left
      (at relative location (-1,dy), where dy is any number, ideally 0)
    - the neuron's location in a block is never changed after the initial assignment
    - which means that any further connections within a given block are ignored (neurons are already fixed in place)
    - foreign block connections cause block merges, shifting the blocks so the (-1,dy) condition is met
      (which also affects all neurons in the other block, since their relative positions are fixed)
    - the final result is a set of blocks corresponding to the "islands" in the neural network
   2. Phase two
    - "islands" are merged into one final block. Any relative offsets can be used, as their neurons
      are not connected anyway. Here a simple method is used: placing the islands in a vertical stack.
 */
void smartlayout(NNLayoutState *nnlayout)
{
        DB(printf("\n >>>>>>>>> smartlayout <<<<<<<<<<<\n"));
        nn = nnlayout;
        N = nn->GetElements();
        einfo = (struct einfo*)calloc(N, sizeof(struct einfo));
        blocks = (class block**)calloc(N, sizeof(class block*));

        int el;
        for (el = 0; el < N; el++) ustawelement(el);

        DB(printf(" - - merging blocks - -\n"));

        block *first;
        for (el = 0; el < N; el++) if (blocks[el]) { first = blocks[el]; el++; break; }
        while (el<N)
        {
                if ((first->maxx - first->minx)>(first->maxy - first->miny))
                {
                        int y = first->maxy + 2;
                        int x = first->minx;
                        int ex = first->maxx;
                        while (el<N)
                        {
                                if (blocks[el])
                                {
                                        int dx = blocks[el]->maxx - blocks[el]->minx + 2;
                                        dolaczblock(first, blocks[el], x - blocks[el]->minx, y - blocks[el]->miny);
                                        x += dx;
                                        if (x>ex) break;
                                }
                                el++;
                        }
                }
                else
                {
                        int x = first->maxx + 2;
                        int y = first->miny;
                        int ey = first->maxy;
                        while (el<N)
                        {
                                if (blocks[el])
                                {
                                        int dy = blocks[el]->maxy - blocks[el]->miny + 2;
                                        dolaczblock(first, blocks[el], x - blocks[el]->minx, y - blocks[el]->miny);
                                        y += dy;
                                        if (y>ey) break;
                                }
                                el++;
                        }
                }
        }
        /*
        for (;el<N;el++)
        if (blocks[el])
        dolaczblock(first,blocks[el],first->minx-blocks[el]->minx,first->maxy-blocks[el]->miny+1);
        */
        if (first) // at this stage we have a single block containing all neurons
        {
                DB(printf(" - - setting coordinates - -\n"));
                DB(first->odtworzmape());
                for (size_t i = 0; i < first->elementy.size(); i++)
                {
                        el = first->elementy[i];
                        nn->SetXYWH(el, einfo[el].x * 70, -einfo[el].y * 70, 50, 50);
                }
                delete first;
        }

        free(blocks);
        free(einfo);
        DB(printf("--------------------------------\n\n"));
}