+/*
+ * Copyright Droids, Microb Technology (2010)
+ *
+ * This program 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.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Revision : $Id: strat.c,v 1.6 2009-11-08 17:24:33 zer0 Exp $
+ *
+ * Olivier MATZ <zer0@droids-corp.org>
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <math.h>
+
+#include <aversive.h>
+#include <aversive/pgmspace.h>
+
+#include <vect_base.h>
+
+/* XXX TODO
+static
+const
+change x,y -> i,j to avoid confusion with coords
+could be optimized in mem space: it is not needed to store the x,y coord,
+ we can process it from idx. however it will be less optimized for speed
+
+*/
+
+#define OFFSET_CORN_X 150
+#define OFFSET_CORN_Y 222
+#define STEP_CORN_X 225
+#define STEP_CORN_Y 250
+
+#define CORN_NB 18
+
+#define WAYPOINTS_NBX 13
+#define WAYPOINTS_NBY 8
+
+/* enum is better */
+#define TYPE_WAYPOINT 0
+#define TYPE_DANGEROUS 1
+#define TYPE_WHITE_CORN 2
+#define TYPE_BLACK_CORN 3
+#define TYPE_OBSTACLE 4
+#define TYPE_UNKNOWN 5
+
+/* XXX enum possible ? else just rename */
+#define START 0
+#define UP 1
+#define UP_RIGHT 2
+#define DOWN_RIGHT 3
+#define DOWN 4
+#define DOWN_LEFT 5
+#define UP_LEFT 6
+#define END 7
+
+struct point {
+ int32_t x;
+ int32_t y;
+};
+
+struct djpoint {
+ struct point pos;
+ uint16_t weight;
+ struct djpoint *parent;
+
+ uint8_t type:3;
+ uint8_t parent_pos:3;
+ uint8_t updated:1;
+ uint8_t todo:1;
+};
+
+uint8_t corn_table[CORN_NB];
+
+const uint8_t corn_coord_i[CORN_NB] = {
+ 0, 0, 0, 2, 2, 2, 4, 4, 6,
+ 6, 8, 8, 10, 10, 10, 12, 12, 12,
+};
+
+const uint8_t corn_coord_j[CORN_NB] = {
+ 2, 4, 6, 3, 5, 7, 4, 6, 5,
+ 7, 4, 6, 3, 5, 7, 2, 4, 6,
+};
+
+static struct djpoint djpoints[WAYPOINTS_NBX][WAYPOINTS_NBY];
+
+/* table to find the symetric idx */
+uint8_t corn_sym[] = {
+ 15, 16, 17, 12, 13, 14, 10, 11, 8, 9, 6, 7, 3, 4, 5, 0, 1, 2
+};
+
+uint8_t corn_side_confs[9][2] = {
+ { 1, 4 },
+ { 0, 4 },
+ { 2, 4 },
+ { 2, 3 },
+ { 0, 3 },
+ { 1, 3 },
+ { 1, 6 },
+ { 0, 6 },
+ { 2, 6 },
+};
+uint8_t corn_center_confs[4][2] = {
+ { 5, 8 },
+ { 7, 8 },
+ { 5, 9 },
+ { 7, 8 },
+};
+
+
+/* return index from neigh pointer */
+#define PT2IDX(neigh) ( ((void *)(neigh)-(void *)(&djpoints)) / sizeof(*neigh) )
+
+void dump(void)
+{
+ int8_t i, j;
+ struct djpoint *pt;
+
+ printf_P(PSTR(" "));
+ for (i=0; i<WAYPOINTS_NBX; i++) {
+ printf_P(PSTR(" %2d "), i);
+ }
+ printf_P(PSTR("\r\n"));
+
+ for (j=WAYPOINTS_NBY*2-1; j>=0; j--) {
+ printf_P(PSTR("%3d "), j/2);
+
+ if ((j&1) == 0)
+ printf_P(PSTR(" "));
+
+ for (i=0; i<WAYPOINTS_NBX; i++) {
+ pt = &djpoints[i][j/2];
+
+ if (((i+j) & 1) == 0)
+ continue;
+
+ if (pt->type == TYPE_OBSTACLE)
+ printf_P(PSTR(" X "));
+ else if (pt->type == TYPE_DANGEROUS)
+ printf_P(PSTR(" D "));
+ else if (pt->type == TYPE_WHITE_CORN)
+ printf_P(PSTR(" W "));
+ else if (pt->type == TYPE_BLACK_CORN)
+ printf_P(PSTR(" B "));
+ else if (pt->type == TYPE_WAYPOINT)
+ printf_P(PSTR(" %5d "), pt->weight);
+ else
+ printf_P(PSTR(" ? "));
+ }
+ printf_P(PSTR("\r\n"));
+ }
+}
+
+static inline uint8_t opposite_position(uint8_t pos)
+{
+ pos += 3;
+ if (pos > UP_LEFT)
+ pos -= 6;
+ return pos;
+}
+
+/* return coord of the entry in the table from the pointer */
+static void djpoint2ij(struct djpoint *pt, int8_t *x, int8_t *y)
+{
+ int8_t idx = PT2IDX(pt);
+ *x = idx / WAYPOINTS_NBY;
+ *y = idx % WAYPOINTS_NBY;
+}
+
+/* get the neighbour of the point at specified position */
+static struct djpoint *get_neigh(struct djpoint *pt,
+ uint8_t position)
+{
+ int8_t i,j;
+ struct djpoint *neigh;
+
+ djpoint2ij(pt, &i, &j);
+
+ switch (position) {
+ case UP:
+ j++;
+ break;
+ case UP_RIGHT:
+ if (!(i & 1)) j++;
+ i++;
+ break;
+ case DOWN_RIGHT:
+ if (i & 1) j--;
+ i++;
+ break;
+ case DOWN:
+ j--;
+ break;
+ case DOWN_LEFT:
+ if (i & 1) j--;
+ i--;
+ break;
+ case UP_LEFT:
+ if (!(i & 1)) j++;
+ i--;
+ break;
+ default:
+ return NULL;
+ }
+ if (i < 0 || j < 0 || i >= WAYPOINTS_NBX || j >= WAYPOINTS_NBY)
+ return NULL;
+
+ neigh = &djpoints[i][j];
+
+ if (neigh->type != TYPE_WAYPOINT)
+ return NULL;
+
+ return neigh;
+}
+
+static struct djpoint *get_next_neigh(struct djpoint *pt, uint8_t *position)
+{
+ struct djpoint *neigh = NULL;
+ uint8_t pos = *position + 1;
+
+ for (pos = *position + 1; pos < END; pos++) {
+ neigh = get_neigh(pt, pos);
+ if (neigh != NULL)
+ break;
+ }
+
+ *position = pos;
+ return neigh;
+}
+
+/* browse all points */
+#define POINT_FOREACH(cur) \
+ for (cur = &djpoints[0][0]; \
+ cur < &djpoints[WAYPOINTS_NBX][WAYPOINTS_NBY]; \
+ cur ++)
+
+/* XXX comment */
+#define NEIGH_FOREACH(neigh, pos, point) \
+ for (pos = START, neigh = get_next_neigh(point, &pos); \
+ neigh; \
+ neigh = get_next_neigh(point, &pos))
+
+int dijkstra_init(void)
+{
+ return 0;
+}
+
+static uint16_t dist(struct djpoint *p1, struct djpoint *p2)
+{
+ double vx, vy;
+ vx = p2->pos.x - p1->pos.x;
+ vy = p2->pos.y - p1->pos.y;
+ return sqrt(vx * vx + vy * vy);
+}
+
+void dijkstra_process_neighs(struct djpoint *pt)
+{
+ struct djpoint *neigh;
+ uint8_t pos, parent_pos;
+ uint16_t weight;
+ int8_t i,j;
+
+ djpoint2ij(pt, &i, &j);
+ printf_P(PSTR("at %d %d:\r\n"), i, j);
+
+ NEIGH_FOREACH(neigh, pos, pt) {
+ weight = pt->weight + dist(pt, neigh);
+ parent_pos = opposite_position(pos);
+
+ /* bonus if we keep the same direction */
+ if (parent_pos == pt->parent_pos ||
+ pt->parent_pos == END)
+ weight = weight - 1;
+
+ printf_P(PSTR(" pos=%d: ppos=%d opos=%d nw=%d w=%d\r\n"), pos,
+ pt->parent_pos, parent_pos,
+ neigh->weight, weight);
+ if (neigh->weight == 0 || weight < neigh->weight) {
+ djpoint2ij(neigh, &i, &j);
+ //printf_P(PSTR(" %d,%d updated\r\n"), i, j);
+ neigh->weight = weight;
+ neigh->parent_pos = parent_pos;
+ neigh->updated = 1;
+ }
+ }
+}
+
+int dijkstra(struct djpoint *start)
+{
+ struct djpoint *cur;
+ uint8_t todolist = 1;
+
+ start->todo = 1;
+
+ while (todolist) {
+ printf_P(PSTR("\r\n"));
+ dump();
+ /* process all neighbours of todo list */
+ POINT_FOREACH(cur) {
+ if (!cur->todo)
+ continue;
+ dijkstra_process_neighs(cur);
+ cur->todo = 0;
+ }
+
+ /* convert updated list in todo list */
+ todolist = 0;
+ POINT_FOREACH(cur) {
+ if (!cur->updated)
+ continue;
+ todolist = 1;
+ cur->todo = 1;
+ cur->updated = 0;
+ }
+ }
+ return 0; /* XXX */
+}
+
+int8_t ijcoord_to_corn_idx(uint8_t i, uint8_t j)
+{
+ uint8_t n;
+ for (n = 0; n < CORN_NB; n ++) {
+ if (i == corn_coord_i[n] &&
+ j == corn_coord_j[n])
+ return n;
+ }
+ return -1;
+}
+
+int8_t corn_idx_to_coordij(uint8_t idx, uint8_t *i, uint8_t *j)
+{
+ if (idx >= CORN_NB)
+ return -1;
+ *i = corn_coord_i[idx];
+ *j = corn_coord_j[idx];
+ return 0;
+}
+
+/* return the index of the closest corn at these coordinates. If the
+ * corn is really too far (~20cm), return -1. The x and y pointer are
+ * updated with the real position of the corn */
+int8_t xycoord_to_corn_idx(int16_t *x, int16_t *y)
+{
+ uint8_t idx = -1, n, i, j;
+ int16_t d, x_corn, y_corn;
+ int16_t x_corn_min = 0, y_corn_min = 0;
+ int16_t d_min = 0;
+
+ for (n = 0; n < CORN_NB; n ++) {
+ corn_idx_to_coordij(n, &i, &j);
+ x_corn = (OFFSET_CORN_X + i*STEP_CORN_X);
+ y_corn = (OFFSET_CORN_Y + j*STEP_CORN_Y);
+ d = xy_norm(x_corn, y_corn, *x, *y);
+ if (d < 200 && (d_min == 0 || d < d_min)) {
+ d_min = d;
+ idx = n;
+ x_corn_min = x_corn;
+ y_corn_min = y_corn;
+ }
+ }
+ if (d_min == 0)
+ return -1;
+
+ *x = x_corn_min;
+ *y = y_corn_min;
+
+ return idx;
+}
+
+int8_t corn_get_sym(int8_t i)
+{
+ if (i >= CORN_NB)
+ return -1;
+ return corn_sym[i];
+}
+
+void init_corn_table(int8_t conf_side, int8_t conf_center)
+{
+ int8_t sym, i;
+
+ /* before match */
+ if (conf_side == -1) {
+ for (i=0; i<CORN_NB; i++)
+ corn_table[i] = TYPE_UNKNOWN;
+ return;
+ }
+
+ /* for test */
+ printf_P(PSTR("confs = %d, %d\r\n"), conf_side, conf_center);
+ for (i=0; i<CORN_NB; i++) {
+ if (i == corn_side_confs[conf_side][0] ||
+ i == corn_side_confs[conf_side][1]) {
+ corn_table[i] = TYPE_BLACK_CORN;
+ continue;
+ }
+ sym = corn_get_sym(i);
+ if (sym == corn_side_confs[conf_side][0] ||
+ sym == corn_side_confs[conf_side][1]) {
+ corn_table[i] = TYPE_BLACK_CORN;
+ continue;
+ }
+ if (i == corn_center_confs[conf_center][0] ||
+ i == corn_center_confs[conf_center][1]) {
+ corn_table[i] = TYPE_BLACK_CORN;
+ continue;
+ }
+ sym = corn_get_sym(i);
+ if (sym == corn_center_confs[conf_center][0] ||
+ sym == corn_center_confs[conf_center][1]) {
+ corn_table[i] = TYPE_BLACK_CORN;
+ continue;
+ }
+ corn_table[i] = TYPE_WHITE_CORN;
+ }
+}
+
+/* init waypoints position */
+void init_waypoints(void)
+{
+ int8_t i, j;
+ int32_t x, y;
+ struct djpoint *pt;
+
+ x = OFFSET_CORN_X;
+ for (i=0; i<WAYPOINTS_NBX; i++) {
+
+ if (i & 1)
+ y = OFFSET_CORN_Y - STEP_CORN_Y/2;
+ else
+ y = OFFSET_CORN_Y;
+
+ for (j=0; j<WAYPOINTS_NBY; j++) {
+ pt = &djpoints[i][j];
+
+ pt->pos.x = x;
+ pt->pos.y = y;
+
+ pt->type = TYPE_WAYPOINT;
+ pt->parent_pos = END;
+ pt->updated = 0;
+ pt->todo = 0;
+
+ y += STEP_CORN_Y;
+ }
+
+ x += STEP_CORN_X;
+ }
+}
+
+/* update the type and weight of waypoints, before starting
+ * dijkstra */
+void update_waypoints(void)
+{
+ int8_t i, j, c;
+ struct djpoint *pt;
+
+ for (i=0; i<WAYPOINTS_NBX; i++) {
+
+ for (j=0; j<WAYPOINTS_NBY; j++) {
+ pt = &djpoints[i][j];
+
+ pt->weight = 0;
+
+ /* corn */
+ c = ijcoord_to_corn_idx(i, j);
+ if (c >= 0) {
+ pt->type = corn_table[c];
+ continue;
+ }
+ /* too close of border */
+ if ((i & 1) == 1 && j == (WAYPOINTS_NBY-1)) {
+ pt->type = TYPE_OBSTACLE;
+ continue;
+ }
+ /* hill */
+ if (i >= 2 && i < (WAYPOINTS_NBX-2) && j < 2) {
+ pt->type = TYPE_OBSTACLE;
+ continue;
+ }
+ /* dangerous points */
+ if (i == 0 || i == (WAYPOINTS_NBX-1)) {
+ pt->type = TYPE_DANGEROUS;
+ continue;
+ }
+ if ( (i&1) == 0 && j == (WAYPOINTS_NBY-1)) {
+ pt->type = TYPE_DANGEROUS;
+ continue;
+ }
+ pt->type = TYPE_WAYPOINT;
+ }
+ }
+}
+
+int get_path(struct djpoint *start, struct djpoint *end)
+{
+ struct djpoint *cur;
+ uint8_t prev_direction = 0;
+
+ for (cur=start;
+ cur != NULL && cur->parent_pos != END && cur != end;
+ cur = get_neigh(cur, cur->parent_pos)) {
+ if (prev_direction != cur->parent_pos) {
+ printf_P(PSTR("%d %d (%d)\r\n"),
+ cur->pos.x, cur->pos.y,
+ cur->parent_pos);
+ }
+ prev_direction = cur->parent_pos;
+ }
+ printf_P(PSTR("%d %d\r\n"), end->pos.x, end->pos.y);
+
+ return 0; /* XXX */
+}
+
+#if 0
+int main(void)
+{
+ struct djpoint *start;
+ struct djpoint *end;
+
+ start = &djpoints[1][1];
+ end = &djpoints[12][1];
+
+ init_corn_table(0, 0);
+ init_waypoints();
+ update_waypoints();
+
+ dijkstra(end);
+ dump();
+
+ get_path(start, end);
+
+ return 0;
+}
+#endif