root / trunk / code / projects / traffic_navigation / validTurns.c @ 1884
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/*
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* Deterministic turning implemented using table lookup. Using a
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* table, the function looks up a value from the table using the
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* barcode value, and then the robot decides to go straight,
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* left, right, or u-turn depending on the valid turn types
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* for the intersection it is at.
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*
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*/
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#include <dragonfly_lib.h> |
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#include "validTurns.h" |
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/******************************Random Num Gen Version of validTurns
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int randomNumGen(int max){
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int x = range_read_distance(IR2);
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if (x>0) return range_read_distance(IR2)%max;
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else return randomNumGen(max);
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}
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int getCrossType(int barcode)
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{
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int x = randomNumGen(4);
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if (x == DOUBLE) {
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int y = randomNumGen(2);
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if (y == 0) x = DOUBLE_C;
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else x = DOUBLE_T;
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}
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return x;
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}
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int getCrossPos(int barcode, int max)
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{
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return randomNumGen(max);
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}
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int getTurnType(int barcode)
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{
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return randomNumGen(4);
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}
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*/
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int getCrossType(int barcode){ |
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int crosstype = (barcode>>2)&7; |
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return crosstype;
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} |
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int getCrossPos(int barcode, int max){ |
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//@TODO: implement some max checking
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return (barcode)&3; |
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} |
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int validateTurn(int barcode, int turn_type) |
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{
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int cross_type;
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int cross_pos;
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cross_type = getCrossType(barcode); |
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switch (cross_type)
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{
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case INTERSECTION_DOUBLE_C:
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{
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cross_pos = getCrossPos(barcode, 4);
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if (0<=cross_pos && cross_pos<=3) |
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return turn_type;
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break;
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} |
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case DOUBLE: //Implements DOUBLE as DOUBLE_T |
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//@TODO: we really shouldn't use DOUBLE, it's part of another system. but it equals 0, so error checking.
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case INTERSECTION_DOUBLE_T:
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{
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cross_pos = getCrossPos(barcode, 3);
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switch (cross_pos)
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{
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case TLEFT:
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{
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if (turn_type == ILEFT) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case TRIGHT:
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{
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if (turn_type == IRIGHT) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case TMIDDLE:
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{
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if (turn_type == ISTRAIGHT) turn_type = IUTURN;
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return turn_type;
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break;
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} |
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default:
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return -1; |
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} |
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break;
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} |
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case INTERSECTION_SINGLE:
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{
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cross_pos = getCrossPos(barcode, 2);
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switch (cross_pos)
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{
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case SACROSS:
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{
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if (turn_type == IRIGHT || turn_type == IUTURN) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case SUP:
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{
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if (turn_type == ILEFT || turn_type == IUTURN) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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default:
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return -1; |
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} |
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break;
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} |
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case INTERSECTION_ON_RAMP:
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{
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cross_pos = getCrossPos(barcode, 3);
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switch (cross_pos)
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{
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case R_LEFT:
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{
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if (turn_type == ILEFT || turn_type == IUTURN) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case R_RIGHT:
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{
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if (turn_type == IRIGHT || turn_type == IUTURN) turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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default:
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return -1; |
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} |
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break;
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} |
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case INTERSECTION_OFF_RAMP:
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{
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cross_pos = getCrossPos(barcode, 3);
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switch (cross_pos)
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{
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case R_LEFT:
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{
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int turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case R_RIGHT:
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{
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int turn_type = ISTRAIGHT;
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return turn_type;
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break;
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} |
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case R_RAMP:
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{
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if (turn_type == ISTRAIGHT || turn_type == IUTURN) turn_type = ILEFT;
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return turn_type;
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break;
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} |
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default:
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return -1; |
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} |
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break;
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} |
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default:
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return -1; |
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} |
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} |