Final submission

.vscode/settings.json

@@ -0,0 +1,5 @@
+{
+    "files.associations": {
+        "type_traits": "c"
+    }
+}

Makefile

@@ -1,6 +1,6 @@
 # Link command:
 voronoi2: common.o towers.o dcel.o voronoi.o input.o main.o
-	gcc -Wall -Wextra -Werror -pedantic -g -o voronoi2 main.o input.o voronoi.o dcel.o towers.o common.o
+	gcc -Wall -Wextra -Werror -pedantic -g -o voronoi2 main.o input.o voronoi.o dcel.o towers.o common.o -lm
 
 # Compilation commands
 common.o: common.c

common.c

@@ -2,9 +2,9 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 25th August 2021
- * Last modified 9th September 2021
+ * Last modified 14th September 2021
  *
- * Contains functions for general use throughout other files.
+ * Contains functions and headers for general use throughout other files.
  *
  */
 

dcel.c

@@ -2,10 +2,10 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 25th August 2021
- * Last modified 13th September 2021
+ * Last modified 14th September 2021
  *
- * Contains functions for the DCEL data structure, including initialisation, 
+ * Contains functions for the DCEL data structure and related data structures
- * splitting an edge, and identifying towers in faces.
+ * (including points, intersections, and bisectors).
  *
  * Contains several functions and structures from Grady Fitzpatrick's Base
  * Code on the Ed Discussion Forum.
@@ -16,106 +16,29 @@
 #include "dcel.h"
 #endif
 
-void freePoints(vertex_t **points, int numPoints) {
+#define INITIALVERTICES 4
-    for (int i = 0; i < numPoints; i++) {
+#define INITIALEDGES 4
-        free(points[i]);
+#define INITIALFACES 1
-    }
+#define NOVERTEX (-1)
-    free(points);
+#define NOEDGE (-1)
+
+#define DIR_UNDECIDED (0)
+#define INSIDE (1)
+#define OUTSIDE (-1)
+#define NODIAMETER (-1)
+
+/* ----------------------- My points functions start ----------------------- */
+vertex_t *newPoint() {
+    vertex_t *newPoint = malloc(sizeof(*newPoint));
+    checkNullPointer(newPoint);
+    return newPoint;
 }
 
-void freeBisectors(bisector_t **bisectors, int numBisectors) {
+vertex_t *getAPoint(double x, double y) {
-    for (int i = 0; i < numBisectors; i++) {
+    vertex_t *point = newPoint();
-        free(bisectors[i]->mid);
+    point->x = x;
-        free(bisectors[i]);
+    point->y = y;
-    }
+    return point;
-    free(bisectors);
-}
-
-void freeIntersections(intersection_t **intersections, int numIntersections) {
-    for (int i = 0; i < numIntersections; i++) {
-        free(intersections[i]->fromPoint);
-        free(intersections[i]->toPoint);
-        free(intersections[i]);
-    }
-    free(intersections);
-}
-
-bisector_t **getBisectors(bisector_t **bisectors, vertex_t **points, \
-    int numBisectors) {
-    for (int i = 0; i < numBisectors; i++) {
-        bisectors[i] = malloc(sizeof(*bisectors[i]));
-        bisectors[i]->mid = malloc(sizeof(*bisectors[i]->mid));
-
-        /* Calculate midpoint of the two points */
-        bisectors[i]->mid->x = (points[2 * i]->x + points[2 * i + 1]->x) / 2;
-        bisectors[i]->mid->y = (points[2 * i]->y + points[2 * i + 1]->y) / 2;
-
-        /* Calculating bisector slope according to slope of AB */
-        if (points[2 * i]->x == points[2 * i + 1]->x) {
-            /* The line segment AB has an infinite gradient, 
-             * so the orthogonal line will have zero slope.
-             */
-            bisectors[i]->slope = 0;
-            bisectors[i]->isSlopeInfinite = 0;
-        } else if (points[2 * i]->y == points[2 * i + 1]->y) {
-            /* The line segment AB has gradient of zero, so 
-             * the orthogonal line will have an infinite slope. 
-             */
-            bisectors[i]->isSlopeInfinite = 1;
-
-            /* Not actually zero, just a placeholder to prevent 
-             * accidental errors 
-             */
-            bisectors[i]->slope = 0;
-        } else {
-            /* The line segment AB has a non-zero and finite gradient, 
-             * so the gradient of the bisector can be calculated.
-             */
-            bisectors[i]->isSlopeInfinite = 0;
-            bisectors[i]->slope = -1 / \
-                ((points[2 * i + 1]->y - points[2 * i]->y) / \
-                (points[2 * i + 1]->x - points[2 * i]->x));
-        }
-    }
-    
-    return bisectors;
-}
-
-vertex_t *getBisectorPoint(double distance, bisector_t *b, int direction) {
-    vertex_t *returnPoint = malloc(sizeof(*returnPoint));
-
-    if (b->isSlopeInfinite) {
-        /* Vertical line - just add vertical distance */
-        returnPoint->x = b->mid->x;
-        returnPoint->y = b->mid->y + (distance * direction);
-    } else if (b->slope == 0) {
-        /* Horizontal line - just add horizontal distance */
-        returnPoint->x = b->mid->x + (distance * direction);
-        returnPoint->y = b->mid->y;
-    } else {
-        /* Not horizontal or vertical - add distance to x, then find 
-         * y-intercept of the bisector, and plug it in to y = mx + c to find
-         * the corresponding y-value.
-         */
-        double c = b->mid->y - b->slope * b->mid->x;
-        returnPoint->x = b->mid->x + (distance * direction);
-        returnPoint->y = b->slope * returnPoint->x + c;
-    }
-
-    return returnPoint;
-}
-
-intersection_t *newIntersection() {
-    intersection_t *intersection = malloc(sizeof(*intersection));
-    checkNullPointer(intersection);
-
-    intersection->fromPoint = malloc(sizeof(*intersection->fromPoint));
-    checkNullPointer(intersection->fromPoint);
-
-    intersection->toPoint = malloc(sizeof(*intersection->toPoint));
-    checkNullPointer(intersection->toPoint);
-
-    return intersection;
 }
 
 vertex_t **readPoints(vertex_t **points, FILE *pointsFile, int *numPoints) {
@@ -157,224 +80,302 @@ vertex_t **readPoints(vertex_t **points, FILE *pointsFile, int *numPoints) {
     return points;
 }
 
-/* Here on out is the base code from Grady, with some alterations from me */
+void freePoints(vertex_t **points, int numPoints) {
-
+    if (!points) {
-#define INITIALVERTICES 4
+        return;
-#define INITIALEDGES 4
-#define INITIALFACES 1
-#define NOVERTEX (-1)
-#define NOEDGE (-1)
-
-#define DIR_UNDECIDED (0)
-#define INSIDE (1)
-#define OUTSIDE (-1)
-#define NODIAMETER (-1)
-
-/* 
-This intersection is based on code by Joseph O'Rourke and is provided for use in 
-COMP20003 Assignment 2.
-
-The approach for intersections is:
-- Use the bisector to construct a finite segment and test it against the half-edge.
-- Use O'Rourke's segseg intersection 
-    (https://hydra.smith.edu/~jorourke/books/ftp.html) 
-  to check if the values overlap/intersect
-
-Generates a segment with each end at least minLength away in each direction 
-from the bisector midpoint.
-Returns 1 if b intersects the given half-edge on this segment, 0 otherwise.
-Sets the intersection point to the given x, y positions.
-*/
-
-int areaSign(double sx, double sy, double ex, double ey, double x, double y) {
-    double areaSq;
-    /* |AB x AC|^2, squared area */
-    /* See https://mathworld.wolfram.com/CrossProduct.html */
-    areaSq = (ex - sx) * (y  - sy) -
-             (x  - sx) * (ey - sy);
-    
-    if (areaSq > 0.0) {
-        return 1;
-    } else if (areaSq == 0.0) {
-        return 0;
-    } else {
-        return -1;
     }
-}
 
-int between(double sx, double sy, double ex, double ey, double x, double y) {
+    for (int i = 0; i < numPoints; i++) {
-    if (sx != ex) {
+        if (points[i]) {
-        /* If not vertical, check whether between x. */
+            free(points[i]);
-        if ((sx <= x && x <= ex) || (sx >= x && x >= ex)) {
-            return 1;
-        } else {
-            return 0;
-        }
-    } else {
-        /* Vertical, so can't check _between_ x-values. Check y-axis. */
-        if ((sy <= y && y <= ey) || (sy >= y && y >= ey)) {
-            return 1;
-        } else {
-            return 0;
         }
     }
+    free(points);
 }
 
-int collinear(double sx, double sy, double ex, double ey, double x, double y) {
+double distPoints(vertex_t *pointA, vertex_t *pointB) {
-    /* If area of the parallelogram is 0, then the points 
+    double a = pointB->x - pointA->x;
-     * are in the same line. 
+    double b = pointB->y - pointA->y;
+    return sqrt(a * a + b * b);
+}
+
+/* ------------------------ My points functions end ------------------------ */
+
+/* -------------------- My intersection functions start -------------------- */
+
+intersection_t *newIntersection() {
+    intersection_t *intersection = malloc(sizeof(*intersection));
+    checkNullPointer(intersection);
+
+    intersection->fromPoint = malloc(sizeof(*intersection->fromPoint));
+    checkNullPointer(intersection->fromPoint);
+
+    intersection->toPoint = malloc(sizeof(*intersection->toPoint));
+    checkNullPointer(intersection->toPoint);
+
+    return intersection;
+}
+
+intersection_t *getAnIntersection(intersection_t *intersection, DCEL_t *dcel, \
+    bisector_t *bisector, int face, int minLength) {
+
+    /* Intersection coordinates */
+    double x, y;
+
+    /* Flag is raised when first intersection is found */
+    int isIntersectionFound = 0;
+
+    halfEdge_t *startHE = (dcel->faces)[face].start;
+    halfEdge_t *currentHE = startHE;
+    int startVertex = startHE->startVertex;
+    int first = 1;
+
+    /* Loop through the face until the starting vertex is reached */
+    while (first || currentHE->startVertex != startVertex) {
+        enum intersectType typeOfIntersection = \
+            intersects(currentHE, bisector, dcel, minLength, &x, &y);
+        
+        switch (typeOfIntersection) {
+            case INTERSECT:
+            case SAME_LINE_OVERLAP:
+            case ENDS_OVERLAP:
+                if (!isIntersectionFound) {
+                    /* First point of intersection */
+                    isIntersectionFound = 1;
+                    intersection = newIntersection();
+                    intersection->fromPoint->x = x;
+                    intersection->fromPoint->y = y;
+                    intersection->fromEdge = currentHE->edge;
+                } else {
+                    /* Second point of intersection */
+                    intersection->toPoint->x = x;
+                    intersection->toPoint->y = y;
+                    intersection->toEdge = currentHE->edge;
+                }
+                break;
+            case DOESNT_INTERSECT:
+            default:
+                break;
+        }
+        currentHE = currentHE->next;
+        first = 0;
+    }
+
+    return intersection;
+}
+
+intersection_t **getIntersections(intersection_t **intersections, \
+    int *numIntersections, bisector_t **bisectors, int numBisectors, \
+    DCEL_t *dcel, int face, double minLength) {
+    
+    int maxSizeIntersections = 1;
+
+    for (int i = 0; i < numBisectors; i++) {
+        intersection_t *intersection = NULL;
+        intersection = getAnIntersection(intersection, dcel, bisectors[i], \
+            face, minLength);
+
+        /* If there is an intersection, add it to the array */
+        if (intersection != NULL) {
+            /* Ensure there is enough space in the array */
+            if (*numIntersections == maxSizeIntersections) {
+                maxSizeIntersections *= 2;
+                intersection_t **temp = realloc(intersections, \
+                    maxSizeIntersections * sizeof(*intersections));
+                checkNullPointer(temp);
+                intersections = temp;
+            }
+
+            intersections[*numIntersections] = intersection;
+            *numIntersections += 1;
+        }
+    }
+
+    return intersections;
+}
+
+void freeIntersections(intersection_t **intersections, int numIntersections) {
+    if (!intersections) {
+        return;
+    }
+    
+    for (int i = 0; i < numIntersections; i++) {
+        if (intersections[i]->fromPoint) {
+            free(intersections[i]->fromPoint);
+        }
+        if (intersections[i]->toPoint) {
+            free(intersections[i]->toPoint);
+        }
+        if (intersections[i]) {
+            free(intersections[i]);
+        }
+    }
+    free(intersections);
+}
+
+/* --------------------- My intersection functions end --------------------- */
+
+/* ---------------------- My bisector functions start ---------------------- */
+
+bisector_t *newBisector() {
+    bisector_t *newBisector = malloc(sizeof(*newBisector));
+    checkNullPointer(newBisector);
+    newBisector->mid = malloc(sizeof(*newBisector->mid));
+    checkNullPointer(newBisector->mid);
+    return newBisector;
+}
+
+bisector_t *getABisector(bisector_t *bisector, vertex_t *pointA, \
+    vertex_t *pointB) {
+    
+    /* Calculate midpoint of the two points */
+    bisector->mid->x = (pointA->x + pointB->x) / 2;
+    bisector->mid->y = (pointA->y + pointB->y) / 2;
+
+    /* Calculating bisector slope according to slope of AB */
+    if (pointA->x == pointB->x) {
+        /* The line segment AB has an infinite gradient, 
+         * so the orthogonal line will have zero slope.
+         */
+        bisector->slope = 0;
+        bisector->isSlopeInfinite = 0;
+    } else if (pointA->y == pointB->y) {
+        /* The line segment AB has gradient of zero, so 
+         * the orthogonal line will have an infinite slope. 
+         */
+        bisector->isSlopeInfinite = 1;
+
+        /* Not actually zero, just a placeholder to prevent 
+         * accidental errors 
+         */
+        bisector->slope = 0;
+    } else {
+        /* The line segment AB has a non-zero and finite gradient, 
+         * so the gradient of the bisector can be calculated.
+         */
+        bisector->isSlopeInfinite = 0;
+        bisector->slope = -1 / ((pointB->y - pointA->y) / \
+            (pointB->x - pointA->x));
+    }
+
+    return bisector;
+}
+
+bisector_t **getBisectors(bisector_t **bisectors, vertex_t **points, \
+    int numBisectors) {
+    
+    for (int i = 0; i < numBisectors; i++) {
+        bisectors[i] = newBisector();
+        bisectors[i] = getABisector(bisectors[i], points[2 * i], \
+            points[2 * i + 1]);
+    }
+    
+    return bisectors;
+}
+
+vertex_t *getBisectorPoint(double distance, bisector_t *b, int direction) {
+    vertex_t *returnPoint = malloc(sizeof(*returnPoint));
+
+    if (b->isSlopeInfinite) {
+        /* Vertical line - just add vertical distance */
+        returnPoint->x = b->mid->x;
+        returnPoint->y = b->mid->y + (distance * direction);
+    } else if (b->slope == 0) {
+        /* Horizontal line - just add horizontal distance */
+        returnPoint->x = b->mid->x + (distance * direction);
+        returnPoint->y = b->mid->y;
+    } else {
+        /* Not horizontal or vertical - add distance to x, then find 
+         * y-intercept of the bisector, and plug it in to y = mx + c to find
+         * the corresponding y-value.
+         */
+        double c = b->mid->y - b->slope * b->mid->x;
+        returnPoint->x = b->mid->x + (distance * direction);
+        returnPoint->y = b->slope * returnPoint->x + c;
+    }
+
+    return returnPoint;
+}
+
+void freeBisectors(bisector_t **bisectors, int numBisectors) {
+    if (!bisectors) {
+        return;
+    }
+
+    for (int i = 0; i < numBisectors; i++) {
+        if (bisectors[i]->mid) {
+            free(bisectors[i]->mid);
+        }
+        if (bisectors[i]) {
+            free(bisectors[i]);
+        }
+    }
+    free(bisectors);
+}
+
+/* ----------------------- My bisector functions end ----------------------- */
+
+/* ------------------------ My DCEL functions start ------------------------ */
+
+double getDiameter(DCEL_t *dcel, int faceIndex) {
+    /* firstHE and firstVertex refer to the first HE/vertex from the face used
+     * to control when the loop stops
+     * 
+     * startHE and startVertex refer to the starting point used to 
+     * advance the new starting vertex after a complete cycle
+     * 
+     * currentHE and currentVertex refer to the current HE/vertex being used to
+     * compute the diameter
      */
-    if (areaSign(sx, sy, ex, ey, x, y) == 0) {
+    halfEdge_t *firstHE = (dcel->faces)[faceIndex].start;
-        return 1;
+    halfEdge_t *startHE = firstHE;
-    } else {
+    halfEdge_t *currentHE = startHE;
-        return 0;
+    int firstVertex = firstHE->startVertex;
+    int startVertex = firstVertex;
+    int currentVertex = startVertex;
+    int first = 1;
+    double currentDiameter = NODIAMETER, maxDiameter = NODIAMETER;
+
+    while (first || !(currentHE->startVertex == firstVertex && \
+        startHE->startVertex == firstVertex)) {
+        first = 0;
+        
+        /* Compute currentDiameter, compare to maxDiameter */
+        currentDiameter = distPoints(&(dcel->vertices)[startVertex], \
+            &(dcel->vertices)[currentVertex]);
+        if (currentDiameter >= maxDiameter) {
+            maxDiameter = currentDiameter;
+        }
+
+        /* Advance current HE, update currentVertex */
+        currentHE = currentHE->next;
+        currentVertex = currentHE->startVertex;
+
+        /* When the starting vertex is reached, move the startHE to the next HE
+         * and update the vertices.
+         */
+        if (currentVertex == startVertex) {
+            startHE = startHE->next;
+            currentHE = startHE;
+            startVertex = startHE->startVertex;
+            currentVertex = startVertex;
+        }
     }
+
+    if (currentDiameter == NODIAMETER) {
+        return NODIAMETER;
+    }
+    
+    return maxDiameter;
 }
 
-enum intersectType parallelIntersects(double heSx, double heSy, \
+/* ------------------------- My DCEL functions end ------------------------- */
-    double heEx, double heEy, double bSx, double bSy, \
-    double bEx, double bEy, double *x, double *y) {
-    if (!collinear(heSx, heSy, heEx, heEy, bSx, bSy)) {
-        /* Parallel, no intersection so don't set (x, y) */
-        return DOESNT_INTERSECT;
-    }
-    /* bS between heS and heE */
-    if (between(heSx, heSy, heEx, heEy, bSx, bSy)) {
-        *x = bSx; 
-        *y = bSy;
-        return SAME_LINE_OVERLAP;
-    }
-    /* bE between heS and heE */
-    if (between(heSx, heSy, heEx, heEy, bEx, bEy)) {
-        *x = bEx;
-        *y = bEy;
-        return SAME_LINE_OVERLAP;
-    }
-    /* heS between bS and bE */
-    if (between(bSx, bSy, bEx, bEy, heSx, heSy)) {
-        *x = heSx;
-        *y = heSy;
-        return SAME_LINE_OVERLAP;
-    }
-    /* heE between bS and bE */
-    if (between(bSx, bSy, bEx, bEy, heEx, heEy)) {
-        *x = heEx; 
-        *y = heEy;
-        return SAME_LINE_OVERLAP;
-    }
 
-    return DOESNT_INTERSECT;
+/* ------------------------------------------------------------------------- */
-}
+/*                                                                           */
-
+/*        Here onwards are the functions from Grady's base code on Ed        */
-enum intersectType intersects(halfEdge_t *he, bisector_t *b, \
+/*                                                                           */
-    DCEL_t *dcel, double minLength, double *x, double *y) {
+/* ------------------------------------------------------------------------- */
-    /* Half-edge x, y twin */
-    double heSx = dcel->vertices[he->startVertex].x;
-    double heSy = dcel->vertices[he->startVertex].y;
-    double heEx = dcel->vertices[he->endVertex].x;
-    double heEy = dcel->vertices[he->endVertex].y;
-    
-    /* Bisector x, y twin */
-    vertex_t *startPoint = getBisectorPoint(minLength, b, -1);
-    vertex_t *endPoint = getBisectorPoint(minLength, b, 1);
-    double bSx = startPoint->x;
-    double bSy = startPoint->y;
-    double bEx = endPoint->x;
-    double bEy = endPoint->y;
-
-    free(startPoint);
-    free(endPoint);
-    
-    /* Fill in segment. */
-
-    /* Parametric equation parameters */
-    double t1, t2;
-
-    /* Numerators for X and Y coordinate of intersection. */
-    double numeratorX, numeratorY;
-
-    /* Denominators of intersection coordinates. */
-    double denominator;
-    
-    /*
-    See http://www.cs.jhu.edu/~misha/Spring20/15.pdf
-    for explanation and intuition of the algorithm here.
-    x_1 = heSx, y_1 = heSy    |    p_1 = heS
-    x_2 = heEx, y_2 = heEy    |    q_1 = heE
-    x_3 = bSx , y_3 = bSy     |    p_2 =  bS
-    x_4 = bEx , y_4 = bEy     |    q_2 =  bE
-    ----------------------------------------
-    So the parameters t1 and t2 are given by:
-    | t1 |   | heEx - heSx  bSx - bEx | -1  | bSx - heSx |
-    |    | = |                        |     |            |
-    | t2 |   | heEy - heSy  bSy - bEy |     | bSy - heSy |
-    
-    Hence:
-    | t1 |       1     | bSy - bEy        bEx - bSx |  | bSx - heSx |
-    |    | = --------- |                            |  |            |
-    | t2 |    ad - bc  | heSy - heEy    heEx - heSx |  | bSy - heSy |
-    
-        where 
-        a = heEx - heSx
-        b = bSx  -  bEx
-        c = heEy - heSy
-        d = bSy  -  bEy
-    */
-    
-    /* Here we calculate ad - bc */
-    denominator = heSx * (bEy  -  bSy) +
-                  heEx * (bSy  -  bEy) +
-                  bEx  * (heEy - heSy) +
-                  bSx  * (heSy - heEy);
-    
-    if (denominator == 0) {
-        /* In this case the two are parallel */
-        return parallelIntersects(heSx, heSy, heEx, heEy, \
-            bSx, bSy, bEx, bEy, x, y);
-    }
-    
-    /*
-    Here we calculate the top row.
-    | bSy - bEy        bEx - bSx |  | bSx - heSx |
-    |                            |  |            |
-    |                            |  | bSy - heSy |
-    */
-    numeratorX = heSx * (bEy  -  bSy) +
-                 bSx  * (heSy -  bEy) +
-                 bEx  * (bSy  - heSy);
-    
-    /*
-    Here we calculate the bottom row.
-    |                            |  | bSx - heSx |
-    |                            |  |            |
-    | heSy - heEy    heEx - heSx |  | bSy - heSy |
-    */
-    numeratorY = -(heSx * (bSy  -  heEy) +
-                   heEx * (heSy -  bSy) +
-                   bSx  * (heEy  - heSy));
-    
-    /* Use parameters to convert to the intersection point */
-    t1 = numeratorX/denominator;
-    t2 = numeratorY/denominator;
-    *x = heSx + t1 * (heEx - heSx);
-    *y = heSy + t1 * (heEy - heSy);
-    
-    /* Make final decision - if point is on segments, parameter values will be
-    between 0, the start of the line segment, and 1, the end of the line segment.
-    */
-    if (0.0 < t1 && t1 < 1.0 && 0.0 < t2 && t2 < 1.0) {
-        return INTERSECT;
-    } else if (t1 < 0.0 || 1.0 < t1 || t2 < 0.0 || 1.0 < t2) {
-        /* s or t outside of line segment. */
-        return DOESNT_INTERSECT;
-    } else {
-        /* 
-        ((numeratorX == 0) || (numeratorY == 0) || 
-         (numeratorX == denominator) || (numeratorY == denominator))
-        */
-        return ENDS_OVERLAP;
-    }
-}
 
 DCEL_t *newDCEL() {
     /* Setup DCEL. */
@@ -1011,83 +1012,208 @@ int inFace(DCEL_t *dcel, double x, double y, int faceIndex) {
     return 1;
 }
 
-intersection_t **getIntersections(intersection_t **intersections, \
+/* This intersection is based on code by Joseph O'Rourke and is provided for
-    int *numIntersections, bisector_t **bisectors, int numBisectors, \
+ * use in COMP20003 Assignment 2.
-    DCEL_t *dcel, int face, double minLength) {
+ * 
-    int maxSizeIntersections = 1;
+ * The approach for intersections is:
+ * - Use the bisector to construct a finite segment and test it against 
+ *   the half-edge.
+ * - Use O'Rourke's segseg intersection 
+ *   (https://hydra.smith.edu/~jorourke/books/ftp.html) to check if the values 
+ *   overlap/intersect
+ * 
+ * Generates a segment with each end at least minLength away in each direction 
+ * from the bisector midpoint.
+ * 
+ * Returns 1 if b intersects the given half-edge on this segment, 0 otherwise.
+ * Sets the intersection point to the given x, y positions.
+ */
 
-    for (int i = 0; i < numBisectors; i++) {
+int areaSign(double sx, double sy, double ex, double ey, double x, double y) {
-        intersection_t *currentIntersection = NULL;
+    double areaSq;
+    /* |AB x AC|^2, squared area */
+    /* See https://mathworld.wolfram.com/CrossProduct.html */
+    areaSq = (ex - sx) * (y  - sy) -
+             (x  - sx) * (ey - sy);
     
-        /* Intersection coordinates */
+    if (areaSq > 0.0) {
-        double x, y;
+        return 1;
+    } else if (areaSq == 0.0) {
+        return 0;
+    } else {
+        return -1;
+    }
+}
 
-        /* Flag is raised when first intersection is found */
+int between(double sx, double sy, double ex, double ey, double x, double y) {
-        int isIntersectionFound = 0;
+    if (sx != ex) {
-        
+        /* If not vertical, check whether between x. */
-        halfEdge_t *startHE = (dcel->faces)[face].start;   
+        if ((sx <= x && x <= ex) || (sx >= x && x >= ex)) {
-        halfEdge_t *currentHE = startHE;
+            return 1;
-        int startVertex = startHE->startVertex;
+        } else {
-        int first = 1;
+            return 0;
-
-        /* Loop through the face until the starting vertex is reached */
-        while (first || currentHE->startVertex != startVertex) {
-            enum intersectType typeOfIntersection = \
-                intersects(currentHE, bisectors[i], dcel, minLength, &x, &y);
-            
-            switch (typeOfIntersection) {
-                case INTERSECT:
-                case SAME_LINE_OVERLAP:
-                case ENDS_OVERLAP:
-                    if (!isIntersectionFound) {
-                        /* First point of intersection */
-                        isIntersectionFound = 1;
-                        currentIntersection = newIntersection();
-                        currentIntersection->fromPoint->x = x;
-                        currentIntersection->fromPoint->y = y;
-                        currentIntersection->fromEdge = currentHE->edge;
-                    } else {
-                        /* Second point of intersection */
-                        currentIntersection->toPoint->x = x;
-                        currentIntersection->toPoint->y = y;
-                        currentIntersection->toEdge = currentHE->edge;
-                    }
-                    break;
-                case DOESNT_INTERSECT:
-                default:
-                    break;
-            }
-            currentHE = currentHE->next;
-            first = 0;
         }
-
+    } else {
-        /* If there is an intersection, add it to the array */
+        /* Vertical, so can't check _between_ x-values. Check y-axis. */
-        if (currentIntersection != NULL) {
+        if ((sy <= y && y <= ey) || (sy >= y && y >= ey)) {
-            /* Ensure there is enough space in the array */
+            return 1;
-            if (*numIntersections == maxSizeIntersections) {
+        } else {
-                maxSizeIntersections *= 2;
+            return 0;
-                intersection_t **temp = realloc(intersections, maxSizeIntersections * sizeof(*intersections));
-                checkNullPointer(temp);
-                intersections = temp;
-            }
-
-            intersections[*numIntersections] = currentIntersection;
-            *numIntersections += 1;
         }
     }
-
-    return intersections;
 }
     
-double getDiameter(DCEL_t *dcel, int faceIndex) {
+int collinear(double sx, double sy, double ex, double ey, double x, double y) {
-    // FILL IN
+    /* If area of the parallelogram is 0, then the points 
-    printf("in getDiamter(): faceIndex = %d, dcel faces = %d\n", \
+     * are in the same line. 
-        faceIndex, dcel->facesAllocated);
+     */
-    return NODIAMETER;
+    if (areaSign(sx, sy, ex, ey, x, y) == 0) {
+        return 1;
+    } else {
+        return 0;
+    }
 }
 
-void incrementalVoronoi(DCEL_t *dcel, tower_t *tower) {
+enum intersectType parallelIntersects(double heSx, double heSy, \
-    // FILL IN
+    double heEx, double heEy, double bSx, double bSy, \
-    printf("In incrementalVoronoi(): tower id = %s, dcel faces = %d\n", \
+    double bEx, double bEy, double *x, double *y) {
-        tower->id, dcel->facesAllocated);
+    
+    if (!collinear(heSx, heSy, heEx, heEy, bSx, bSy)) {
+        /* Parallel, no intersection so don't set (x, y) */
+        return DOESNT_INTERSECT;
+    }
+    /* bS between heS and heE */
+    if (between(heSx, heSy, heEx, heEy, bSx, bSy)) {
+        *x = bSx; 
+        *y = bSy;
+        return SAME_LINE_OVERLAP;
+    }
+    /* bE between heS and heE */
+    if (between(heSx, heSy, heEx, heEy, bEx, bEy)) {
+        *x = bEx;
+        *y = bEy;
+        return SAME_LINE_OVERLAP;
+    }
+    /* heS between bS and bE */
+    if (between(bSx, bSy, bEx, bEy, heSx, heSy)) {
+        *x = heSx;
+        *y = heSy;
+        return SAME_LINE_OVERLAP;
+    }
+    /* heE between bS and bE */
+    if (between(bSx, bSy, bEx, bEy, heEx, heEy)) {
+        *x = heEx; 
+        *y = heEy;
+        return SAME_LINE_OVERLAP;
+    }
+    
+    return DOESNT_INTERSECT;
+}
+
+enum intersectType intersects(halfEdge_t *he, bisector_t *b, \
+    DCEL_t *dcel, double minLength, double *x, double *y) {
+    
+    /* Half-edge x, y twin */
+    double heSx = dcel->vertices[he->startVertex].x;
+    double heSy = dcel->vertices[he->startVertex].y;
+    double heEx = dcel->vertices[he->endVertex].x;
+    double heEy = dcel->vertices[he->endVertex].y;
+    
+    /* Bisector x, y twin */
+    vertex_t *startPoint = getBisectorPoint(minLength, b, -1);
+    vertex_t *endPoint = getBisectorPoint(minLength, b, 1);
+    double bSx = startPoint->x;
+    double bSy = startPoint->y;
+    double bEx = endPoint->x;
+    double bEy = endPoint->y;
+    free(startPoint);
+    free(endPoint);
+
+    /* Parametric equation parameters */
+    double t1, t2;
+
+    /* Numerators for X and Y coordinate of intersection. */
+    double numeratorX, numeratorY;
+
+    /* Denominators of intersection coordinates. */
+    double denominator;
+    
+    /*
+    See http://www.cs.jhu.edu/~misha/Spring20/15.pdf
+    for explanation and intuition of the algorithm here.
+    x_1 = heSx, y_1 = heSy    |    p_1 = heS
+    x_2 = heEx, y_2 = heEy    |    q_1 = heE
+    x_3 = bSx , y_3 = bSy     |    p_2 =  bS
+    x_4 = bEx , y_4 = bEy     |    q_2 =  bE
+    ----------------------------------------
+    So the parameters t1 and t2 are given by:
+    | t1 |   | heEx - heSx  bSx - bEx | -1  | bSx - heSx |
+    |    | = |                        |     |            |
+    | t2 |   | heEy - heSy  bSy - bEy |     | bSy - heSy |
+    
+    Hence:
+    | t1 |       1     | bSy - bEy        bEx - bSx |  | bSx - heSx |
+    |    | = --------- |                            |  |            |
+    | t2 |    ad - bc  | heSy - heEy    heEx - heSx |  | bSy - heSy |
+    
+        where 
+        a = heEx - heSx
+        b = bSx  -  bEx
+        c = heEy - heSy
+        d = bSy  -  bEy
+    */
+    
+    /* Here we calculate ad - bc */
+    denominator = heSx * (bEy  -  bSy) +
+                  heEx * (bSy  -  bEy) +
+                  bEx  * (heEy - heSy) +
+                  bSx  * (heSy - heEy);
+    
+    if (denominator == 0) {
+        /* In this case the two are parallel */
+        return parallelIntersects(heSx, heSy, heEx, heEy, \
+            bSx, bSy, bEx, bEy, x, y);
+    }
+    
+    /*
+    Here we calculate the top row.
+    | bSy - bEy        bEx - bSx |  | bSx - heSx |
+    |                            |  |            |
+    |                            |  | bSy - heSy |
+    */
+    numeratorX = heSx * (bEy  -  bSy) +
+                 bSx  * (heSy -  bEy) +
+                 bEx  * (bSy  - heSy);
+    
+    /*
+    Here we calculate the bottom row.
+    |                            |  | bSx - heSx |
+    |                            |  |            |
+    | heSy - heEy    heEx - heSx |  | bSy - heSy |
+    */
+    numeratorY = -(heSx * (bSy  -  heEy) +
+                   heEx * (heSy -  bSy) +
+                   bSx  * (heEy  - heSy));
+    
+    /* Use parameters to convert to the intersection point */
+    t1 = numeratorX/denominator;
+    t2 = numeratorY/denominator;
+    *x = heSx + t1 * (heEx - heSx);
+    *y = heSy + t1 * (heEy - heSy);
+    
+    /* Make final decision - if point is on segments, parameter values will be
+    between 0, the start of the line segment, and 1, the end of the line segment.
+    */
+    if (0.0 < t1 && t1 < 1.0 && 0.0 < t2 && t2 < 1.0) {
+        return INTERSECT;
+    } else if (t1 < 0.0 || 1.0 < t1 || t2 < 0.0 || 1.0 < t2) {
+        /* s or t outside of line segment. */
+        return DOESNT_INTERSECT;
+    } else {
+        /* 
+        ((numeratorX == 0) || (numeratorY == 0) || 
+         (numeratorX == denominator) || (numeratorY == denominator))
+        */
+        return ENDS_OVERLAP;
+    }
 }

dcel.h

@@ -2,10 +2,23 @@
 #include "towers.h"
 #endif
 
+#ifndef MATH_HEADER
+#include <math.h>
+#endif
+
 #ifndef DCEL_HEADER
 #define DCEL_HEADER
 
-/* Here is the Base Code from Grady, with some alterations by me */
+/* -------- Definitions, enums, and structs from Grady's base code --------- */
+
+/* Representation of no face */
+#define NOFACE (-1)
+
+/* Default face for intersections. */
+#define DEFAULT_FACE 0
+
+/* Default minimum length for bisector in each direction */
+#define DEFAULTMINLENGTH (200)
 
 enum intersectType {
     DOESNT_INTERSECT  = 0, // Doesn't intersect
@@ -19,12 +32,6 @@ typedef struct vertex {
     double y;
 } vertex_t;
 
-typedef struct bisector {
-    vertex_t *mid;
-    int isSlopeInfinite;
-    double slope;
-} bisector_t;
-
 typedef struct halfEdge {
     struct halfEdge *previous;
     struct halfEdge *next;
@@ -53,13 +60,6 @@ typedef struct split {
     vertex_t endPoint;
 } split_t;
 
-typedef struct intersection {
-    int fromEdge;
-    int toEdge;
-    vertex_t *fromPoint;
-    vertex_t *toPoint;
-} intersection_t;
-
 typedef struct DCEL {
     edge_t *edges;
     int edgesUsed;
@@ -74,35 +74,114 @@ typedef struct DCEL {
     int verticesAllocated;
 } DCEL_t;
 
+/* ------------------------------ My structs ------------------------------- */
+
+typedef struct bisector {
+    vertex_t *mid;
+    int isSlopeInfinite;
+    double slope;
+} bisector_t;
+
+typedef struct intersection {
+    int fromEdge;
+    int toEdge;
+    vertex_t *fromPoint;
+    vertex_t *toPoint;
+} intersection_t;
+
+/* ----------------------- My points functions start ----------------------- */
+
+/* Creates a new point */
+vertex_t *newPoint();
+
+/* Gets a single point from an x-y pair */
+vertex_t *getAPoint(double x, double y);
+
+/* Reads a points file and stores the information in the points array */
+vertex_t **readPoints(vertex_t **points, FILE *pointsFile, int *numPoints);
+
+/* Frees an array of points */
+void freePoints(vertex_t **points, int numPoints);
+
+/* Returns the distance between two points */
+double distPoints(vertex_t *pointA, vertex_t *pointB);
+
+/* ------------------------ My points functions end ------------------------ */
+
+/* -------------------- My intersection functions start -------------------- */
+
+/* Create a new intersection */
+intersection_t *newIntersection();
+
+/* Fills in a single intersection structure */
+intersection_t *getAnIntersection(intersection_t *intersection, DCEL_t *dcel, \
+    bisector_t *bisector, int face, int minLength);
+
+/* Gets the intersection between the given bisector and the given DCEL
+ * for the given face. 
+ */
+intersection_t **getIntersections(intersection_t **intersections, \
+    int *numIntersections, bisector_t **bisectors, int numBisectors, \
+    DCEL_t *dcel, int face, double minLength);
+
+/* Frees an array of intersections */
+void freeIntersections(intersection_t **intersections, int numIntersections);
+
+/* --------------------- My intersection functions end --------------------- */
+
+/* ---------------------- My bisector functions start ---------------------- */
+
+/* Creates a new bisector */
+bisector_t *newBisector();
+
+/* Calculates and returns the equation of a bisector of two points */
+bisector_t *getABisector(bisector_t *bisector, vertex_t *pointA, \
+    vertex_t *pointB);
+
+/* Returns a list of bisectors built from a list of points */
+bisector_t **getBisectors(bisector_t **bisectors, vertex_t **points, \
+    int numPoints);
+/* Returns a point at least distance away from the midpoint of the 
+ * bisector given. If direction is 0, then the point is +distance away in the 
+ * x-direction, otherwise -distance away in the x-direction.
+ */
+vertex_t *getBisectorPoint(double distance, bisector_t *b, int direction);
+
+/* Frees an array of bisectors */
+void freeBisectors(bisector_t **bisectors, int numBisectors);
+
+/* ----------------------- My bisector functions end ----------------------- */
+
+/* ------------------------ My DCEL functions start ------------------------ */
+
+/* Gets the diameter of the given face. */
+double getDiameter(DCEL_t *dcel, int faceIndex);
+
+/* ------------------------- My DCEL functions end ------------------------- */
+
+/* ----------------------------------------------------------------------------
+ * Here on out are the functions from Grady's base code on Ed 
+ * ----------------------------------------------------------------------------
+ */
+
 /* Allocate a new DCEL and return it. */
 DCEL_t *newDCEL();
 
 /* Allocate a new halfEdge and return it. */
 halfEdge_t *newHalfEdge();
 
-/* Returns INSIDE if the points is on the INSIDE of the vector twin by the CW 
+/* Check there's space for another vertex in the DCEL, or increase the
- * winding order, OUTSIDE if it is OUTSIDE by the CW winding order, and 
+ * allocated space. 
- * DIR_UNDECIDED if the point lies on the vector between the points v1 and v2. 
- */
-int getRelativeDir(double x, double y, vertex_t *v1, vertex_t *v2);
-
-/* Takes an established direction and a new direction, and returns 1 if the 
- * direction matches the decidedDirection or if the direction is undecided.
- */
-int directionOrUndecided(int decidedDirection, int direction);
-
-/* Check there's space for another vertex in the DCEL, 
- * or increase the allocated space. 
  */
 void ensureSpaceForVertex(DCEL_t *dcel);
 
-/* Check there's space for another edge in the DCEL, 
+/* Check there's space for another edge in the DCEL, or increase the
- * or increase the allocated space. 
+ * allocated space. 
  */
 void ensureSpaceForEdge(DCEL_t *dcel);
 
-/* Check there's space for another face in the DCEL, 
+/* Check there's space for another face in the DCEL, or increase the
- * or increase the allocated space. 
+ * allocated space. 
  */
 void ensureSpaceForFace(DCEL_t *dcel);
 
@@ -121,24 +200,12 @@ DCEL_t *readPolygonFile(char *polygonfileName);
 /* Reads the next split from the given file. */
 split_t *readNextSplit(FILE *splitfile);
 
-/* Frees a given split.  */
+/* Frees a given split. */
 void freeSplit(split_t *split);
 
 /* Returns 1 if vertices are sufficiently close, 0 otherwise. */
 int vertexMatch(vertex_t *v1, vertex_t *v2);
 
-/* Gets the string for the given bisector equation. */
-char *getBisectorEquation(bisector_t *b);
-
-/* Representation of no face */
-#define NOFACE (-1)
-
-/* Default face for intersections. */
-#define DEFAULT_FACE 0
-
-/* Default minimum length for bisector in each direction */
-#define DEFAULTMINLENGTH (200)
-
 /* Applies a given split to the DCEL. */
 void applySplit(split_t *split, DCEL_t *dcel);
 
@@ -148,40 +215,37 @@ void freeDCEL(DCEL_t *dcel);
 /* Gets the number of faces in the DCEL. */
 int getFaceCount(DCEL_t *dcel);
 
+/* Returns INSIDE if the points is on the INSIDE of the vector twin by the CW 
+ * winding order, OUTSIDE if it is OUTSIDE by the CW winding order, and 
+ * DIR_UNDECIDED if the point lies on the vector between the points v1 and v2. 
+ */
+int getRelativeDir(double x, double y, vertex_t *v1, vertex_t *v2);
+
+/* Takes an established direction and a new direction, and returns 1 if the 
+ * direction matches the decidedDirection or if the direction is undecided.
+ */
+int directionOrUndecided(int decidedDirection, int direction);
+
 /* Returns 1 if the given x,y point is inside the given face. */
 int inFace(DCEL_t *dcel, double x, double y, int faceIndex);
 
-/* Gets the intersection between the given bisector and the given DCEL
+/* ------------------- O'Rourke's intersection functions ------------------- */
- * for the given face. 
+
+/* Returns -1, 0 or 1, based on the area enclosed by the three points. 
+ * 0 corresponds to no area enclosed
  */
-intersection_t **getIntersections(intersection_t **intersections, \
-    int *numIntersections, bisector_t **bisectors, int numBisectors, \
-    DCEL_t *dcel, int face, double minLength);
-
-/* Gets the diameter of the given face. */
-double getDiameter(DCEL_t *dcel, int faceIndex);
-
-/* Adds the watchtower to the Voronoi diagram represented by the given DCEL, 
- * applying required splits and setting the watchtower as required.
- */
-void incrementalVoronoi(DCEL_t *dcel, tower_t *watchTower);
-
-/* O'Rourke's intersection functions */
-/* Returns -1, 0 or 1, based on the area enclosed by the three points. 0 corresponds
-    to no area enclosed.
-*/
 int areaSign(double sx, double sy, double ex, double ey, double x, double y);
 
 /* Returns 1 if point (x, y) is between (sx, sy) and (ex, ey) */
 int between(double sx, double sy, double ex, double ey, double x, double y);
 
 /* Returns 1 if the point (x, y) is in the line from s(x, y) to e(x, y),
- * 0 otherwise.
+ * 0 otherwise
  */
 int collinear(double sx, double sy, double ex, double ey, double x, double y);
 
 /* Tests if the half edge and bisector are parallel and overlapping, or not
- * intersecting.
+ * intersecting
  */
 enum intersectType parallelIntersects(double heSx, double heSy, \
     double heEx, double heEy, double bSx, double bSy, \
@@ -191,38 +255,4 @@ enum intersectType parallelIntersects(double heSx, double heSy, \
 enum intersectType intersects(halfEdge_t *he, bisector_t *b, \
     DCEL_t *dcel, double minLength, double *x, double *y);
 
-/* My own functions */
-
-/* Reads the polygon file and stores the information in the vertices array */
-vertex_t **readPolygon(vertex_t **vertices, FILE *polygonFile, \
-    int *numVertices);
-
-/* Frees an array of vertices */
-void freeVertices(vertex_t **vertices, int numVertices);
-
-/* Calculates and returns the equation of a bisector of two points */
-bisector_t **getBisectors(bisector_t **bisectors, vertex_t **points, \
-    int numPoints);
-
-/* Returns a point at least distance away from the midpoint of the 
- * bisector given. If direction is 0, then the point is +distance away in the 
- * x-direction, otherwise -distance away in the x-direction.
- */
-vertex_t *getBisectorPoint(double distance, bisector_t *b, int direction);
-
-/* Create a new intersection */
-intersection_t *newIntersection();
-
-/* Frees an array of bisectors */
-void freeBisectors(bisector_t **bisectors, int numBisectors);
-
-/* Frees an array of points */
-void freePoints(vertex_t **points, int numPoints);
-
-/* Frees an array of intersections */
-void freeIntersections(intersection_t **intersections, int numIntersections);
-
-/* Reads a points file and stores the information in the points array */
-vertex_t **readPoints(vertex_t **points, FILE *pointsFile, int *numPoints);
-
 #endif

ed.supp

@@ -0,0 +1,156 @@
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Cond
+   fun:runtime.adjustframe
+   fun:runtime.gentraceback
+   fun:runtime.copystack
+   fun:runtime.newstack
+   fun:runtime.morestack
+   fun:runtime.rt0_go
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Cond
+   fun:runtime.adjustframe
+   fun:runtime.gentraceback
+   fun:runtime.copystack
+   fun:runtime.newstack
+   fun:runtime.morestack
+   fun:runtime.rt0_go
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Cond
+   fun:runtime.adjustpointer
+   fun:runtime.adjustframe
+   fun:runtime.gentraceback
+   fun:runtime.copystack
+   fun:runtime.newstack
+   fun:runtime.morestack
+   fun:runtime.rt0_go
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Cond
+   fun:runtime.adjustpointer
+   fun:runtime.adjustframe
+   fun:runtime.gentraceback
+   fun:runtime.copystack
+   fun:runtime.newstack
+   fun:runtime.morestack
+   fun:runtime.rt0_go
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:x_cgo_sys_thread_create
+   fun:_rt0_amd64_lib
+   fun:call_init
+   fun:_dl_init
+   obj:/usr/lib/ld-2.33.so
+   obj:*
+   obj:*
+   obj:*
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:_cgo_sys_thread_start
+   fun:runtime.asmcgocall
+   obj:*
+   fun:runtime.newm
+   fun:runtime.main.func1
+   fun:runtime.systemstack
+   obj:/mnt/share/ed/libX11.so
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:_cgo_sys_thread_start
+   fun:runtime.asmcgocall
+   obj:*
+   fun:runtime.newm
+   fun:runtime.startm
+   fun:runtime.newproc1
+   fun:runtime.newproc.func1
+   fun:runtime.systemstack
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:_cgo_sys_thread_start
+   fun:runtime.asmcgocall
+   obj:*
+   fun:runtime.newm
+   fun:runtime.startm
+   fun:runtime.handoffp
+   fun:runtime.stoplockedm
+   fun:runtime.schedule
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:_cgo_sys_thread_start
+   fun:runtime.asmcgocall
+   obj:*
+   fun:runtime.malg.func1
+   fun:runtime.systemstack
+   obj:/mnt/share/ed/libX11.so
+   fun:runtime.rt0_go
+}
+{
+   <edstem-suppression>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:x_cgo_sys_thread_create
+   fun:_rt0_amd64_lib
+   fun:call_init
+   fun:_dl_init
+   obj:/usr/lib/ld-2.33.so
+}
+{
+   <insert_a_suppression_name_here>
+   Memcheck:Leak
+   match-leak-kinds: possible
+   fun:calloc
+   fun:_dl_allocate_tls
+   fun:pthread_create@@GLIBC_2.2.5
+   fun:_cgo_try_pthread_create
+   fun:_cgo_sys_thread_start
+   fun:runtime.asmcgocall
+   obj:*
+   obj:*
+   obj:*
+   obj:*
+   obj:*
+   obj:*
+}

input.c

@@ -2,7 +2,7 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 8th September 2021
- * Last modified 9th September 2021
+ * Last modified 14th September 2021
  *
  * Contains functions for ensuring correct input arguments are given for 
  * each stage of the voronoi2 program. Adapted from Grady's base code on Ed.
@@ -13,10 +13,6 @@
 #include "input.h"
 #endif
 
-#ifndef COMMON_HEADER
-#include "common.h"
-#endif
-
 #define STAGE_1_ARG_COUNT 4
 #define STAGE_2_ARG_COUNT 5
 #define STAGE_3_ARG_COUNT 5

input.h

@@ -1,3 +1,7 @@
+#ifndef COMMON_HEADER
+#include "common.h"
+#endif
+
 #ifndef INPUT_HEADER
 #define INPUT_HEADER
 

main.c

@@ -2,11 +2,16 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 25th August 2021
- * Last modified 9th September 2021
+ * Last modified 14th September 2021
  *
- * Lists the watchtowers that are in each face of the polygon.
+ * Stage 1: Computes and outputs equations for the bisectors of points
- * The polygon can be split using a pair of integers, which represent
+ * Stage 2: Computes and outputs intersection points for bisectors against a 
- * the edge numbers that should be connected. This comes from stdin.
+ *          given polygon
+ * Stage 3: Computes a Voronoi diagram using watchtowers as points and a
+ *          polygon as the outer boundary. Outputs diameters of each Voronoi
+ *          cell along with information about each watchtower.
+ * Stage 4: Same as Stage 4, but the watchtowers are sorted by ascending order
+ *          by diameter.
  *
  * To see valid input arguments, run ./voronoi2
  * 
@@ -25,6 +30,8 @@ int main(int argc, char **argv) {
     if (argc == 1) {
         printArgError(STAGE_ERROR, "Incorrect usage.");
     }
+
+    /* Get stage, ensure correct input args */
     enum stages stage = getStage(argv[1]);
     int expectedArgs = getExpectedArgs(stage);
     if (expectedArgs != argc) {

output.txt

@@ -1,6 +1 @@
-From Edge 0 (140.900000, -34.700000) to Edge 2 (150.000000, -34.700000)
+Watchtower ID: WT3765SHSPB, Postcode: 3765, Population Served: 3380, Watchtower Point of Contact Name: Eilene Horner, x: 145.362014, y: -37.818943, Diameter of Cell: 10.000000
-From Edge 0 (140.900000, -35.200000) to Edge 2 (150.000000, -35.200000)
-From Edge 1 (147.100000, -33.900000) to Edge 3 (147.100000, -39.200000)
-From Edge 1 (147.100000, -33.900000) to Edge 3 (147.100000, -39.200000)
-From Edge 1 (147.600000, -33.900000) to Edge 3 (147.600000, -39.200000)
-From Edge 1 (146.900000, -33.900000) to Edge 3 (141.600000, -39.200000)

towers.c

@@ -2,7 +2,7 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 11th September 2021
- * Last modified 13th September 2021
+ * Last modified 14th September 2021
  *
  * Contains functions for reading a CSV of watchtower information into an 
  * array of towers.
@@ -18,38 +18,7 @@
 #define MAX_FIELD_LEN 128
 #define NUM_CSV_FIELDS 6
 
-tower_t **readTowers(tower_t **towers, FILE *datasetFile, int *numTowers) {
+void readATower(char *lineBuffer, tower_t *tower) {
-    /* Maximum length of a single CSV line (+1 for null char in string) */
-    size_t lineBufferSize = MAX_CSV_ENTRY_LEN + 1;
-
-    /* Stores the current line from the CSV */
-    char *lineBuffer = malloc(lineBufferSize * sizeof(*lineBuffer));
-    checkNullPointer(lineBuffer);
-
-    int maxSizetowers = 1;
-
-    /* Discard the header line, then read the rest of the CSV */
-    getline(&lineBuffer, &lineBufferSize, datasetFile);
-    while (getline(&lineBuffer, &lineBufferSize, datasetFile) > 0) {
-        /* Ensure there is enough space in the towers array */
-        if (*numTowers == maxSizetowers) {
-            maxSizetowers *= 2;
-            tower_t **temp = realloc(towers, maxSizetowers * sizeof(*towers));
-            checkNullPointer(temp);
-            towers = temp;
-        }
-
-        /* The current tower being filled in with information */
-        towers[*numTowers] = malloc(sizeof(*towers[*numTowers]));
-
-        readCurrentTower(lineBuffer, towers[*numTowers]);
-        *numTowers += 1;
-    }
-    free(lineBuffer);
-    return towers;
-}
-
-void readCurrentTower(char *lineBuffer, tower_t *tower) {
     /* Stores the current CSV field for the current line */
     char *token = strtok(lineBuffer, ",");
     size_t tokenLength;
@@ -57,11 +26,8 @@ void readCurrentTower(char *lineBuffer, tower_t *tower) {
     for (int i = 0; i < NUM_CSV_FIELDS; i++) {
         tokenLength = strlen(token);
         switch(i) {
-            /* Case 0, 1, and 3 deal with strings
+            /* Cases represent each field in the CSV, and as such are handled
-             * Case 2 deals with an integer
+             * differently.
-             * Case 4 and 5 deal with doubles
-             * Each case is handled seperately to fill in the
-             * tower with no space wasted.
              */
             case 0:
                 tower->id = malloc(sizeof(char) * tokenLength + 1);
@@ -95,12 +61,55 @@ void readCurrentTower(char *lineBuffer, tower_t *tower) {
     }
 }
 
+tower_t **readTowers(tower_t **towers, FILE *datasetFile, int *numTowers) {
+    /* Maximum length of a single CSV line (+1 for null char in string) */
+    size_t lineBufferSize = MAX_CSV_ENTRY_LEN + 1;
+
+    /* Stores the current line from the CSV */
+    char *lineBuffer = malloc(lineBufferSize * sizeof(*lineBuffer));
+    checkNullPointer(lineBuffer);
+
+    int maxSizetowers = 1;
+
+    /* Discard the header line, then read the rest of the CSV */
+    getline(&lineBuffer, &lineBufferSize, datasetFile);
+    while (getline(&lineBuffer, &lineBufferSize, datasetFile) > 0) {
+        /* Ensure there is enough space in the towers array */
+        if (*numTowers == maxSizetowers) {
+            maxSizetowers *= 2;
+            tower_t **temp = realloc(towers, maxSizetowers * sizeof(*towers));
+            checkNullPointer(temp);
+            towers = temp;
+        }
+
+        /* The current tower being filled in with information */
+        towers[*numTowers] = malloc(sizeof(*towers[*numTowers]));
+
+        readATower(lineBuffer, towers[*numTowers]);
+        *numTowers += 1;
+    }
+    free(lineBuffer);
+    return towers;
+}
+
 void freeTowers(tower_t **towers, int numTowers) {
+    if (!towers) {
+        return;
+    }
+
     for (int i = 0; i < numTowers; i++) {
-        free(towers[i]->id);
+        if (towers[i]->id) {
-        free(towers[i]->manager);
+            free(towers[i]->id);
-        free(towers[i]->postcode);
+        }
-        free(towers[i]);
+        if (towers[i]->manager) {
+            free(towers[i]->manager);
+        }
+        if (towers[i]->postcode) {
+            free(towers[i]->postcode);
+        }
+        if (towers[i]) {
+            free(towers[i]);
+        }
     }
     free(towers);
 }

towers.h

@@ -14,12 +14,12 @@ typedef struct tower {
     double y;
 } tower_t;
 
+/* Reads the current row from the CSV and converts it into a new tower */
+void readATower(char *lineBuffer, tower_t *tower);
+
 /* Reads the CSV file and stores the information in the towers array */
 tower_t **readTowers(tower_t **towers, FILE *datasetFile, int *numTowers);
 
-/* Reads the current row from the CSV and converts it into a new tower */
-void readCurrentTower(char *lineBuffer, tower_t *tower);
-
 /* Frees all towers in a towers array */
 void freeTowers(tower_t **towers, int numTowers);
 

voronoi.c

@@ -2,7 +2,7 @@
  *
  * Created by Rory Healy (healyr@student.unimelb.edu.au)
  * Created on 12th August 2021
- * Last modified 13th September 2021
+ * Last modified 14th September 2021
  *
  * Contains functions involving the generation of the Voronoi diagram, and 
  * running each stage of the assignment.
@@ -30,6 +30,58 @@ void stage2PrintIntersection(intersection_t *intersection, FILE *outputFile) {
         intersection->toPoint->x, intersection->toPoint->y);
 }
 
+void stage34PrintTowers(tower_t *tower, FILE *outputFile, double diameter) {
+    fprintf(outputFile, "Watchtower ID: %s, Postcode: %s, Population " \
+        "Served: %d, Watchtower Point of Contact Name: %s, x: %lf, y: %lf, " \
+        "Diameter of Cell: %lf\n", tower->id, tower->postcode, \
+        tower->population, tower->manager, tower->x, tower->y, diameter);
+}
+
+int getFaceTowerIsIn(DCEL_t *dcel, tower_t *tower) {
+    for (int i = 0; i < getFaceCount(dcel); i++) {
+        if (inFace(dcel, tower->x, tower->y, i)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+void incrementalVoronoi(DCEL_t *voronoi, tower_t *tower) {
+    int faceTowerIsIn = getFaceTowerIsIn(voronoi, tower);
+    if (faceTowerIsIn == -1) {
+        fprintf(stderr, "Error: Watchtower %s is outside the polygon.\n", \
+            tower->id);
+        exit(EXIT_FAILURE);
+    }
+}
+
+DCEL_t *newVoronoi(DCEL_t *voronoi, tower_t *towerA, tower_t *towerB) {    
+    /* Get vertices from towers */
+    vertex_t *pointA = getAPoint(towerA->x, towerA->y);
+    vertex_t *pointB = getAPoint(towerB->x, towerB->y);
+
+    /* Create first bisector */
+    bisector_t *bisector = newBisector();
+    bisector = getABisector(bisector, pointA, pointB);
+
+    /* Get intersection of bisector with the polygon */
+    intersection_t *intersection = NULL;
+    intersection = getAnIntersection(intersection, voronoi, bisector, \
+        DEFAULT_FACE, DEFAULTMINLENGTH);
+    
+    if (intersection) {
+        free(intersection->fromPoint);
+        free(intersection->toPoint);
+        free(intersection);
+    }
+
+    free(bisector->mid);
+    free(bisector);
+    free(pointA);
+    free(pointB);
+    return voronoi;
+}
+
 void stage1(char *pointsFileName, char *outputFileName) {
     FILE *pointsFile = NULL, *outputFile = NULL;
     pointsFile = safeFileOpen(&pointsFile, pointsFileName, "r");
@@ -59,7 +111,9 @@ void stage1(char *pointsFileName, char *outputFileName) {
     fclose(outputFile);
 }
 
-void stage2(char *pointsFileName, char *polygonFileName, char *outputFileName) {
+void stage2(char *pointsFileName, char *polygonFileName, \
+    char *outputFileName) {
+    
     FILE *pointsFile = NULL, *outputFile = NULL;
     pointsFile = safeFileOpen(&pointsFile, pointsFileName, "r");
     outputFile = safeFileOpen(&outputFile, outputFileName, "w");
@@ -83,8 +137,8 @@ void stage2(char *pointsFileName, char *polygonFileName, char *outputFileName) {
     intersection_t **intersections = malloc(sizeof(*intersections));
     checkNullPointer(intersections);
     int numIntersections = 0;
-    intersections = getIntersections(intersections, &numIntersections, bisectors, numBisectors, dcel, DEFAULT_FACE, \
+    intersections = getIntersections(intersections, &numIntersections, \
-        DEFAULTMINLENGTH);
+        bisectors, numBisectors, dcel, DEFAULT_FACE, DEFAULTMINLENGTH);
 
     for (int i = 0; i < numIntersections; i++) {
         stage2PrintIntersection(intersections[i], outputFile);
@@ -105,9 +159,22 @@ void stage3(char *dataFileName, char *polygonFileName, char *outputFileName) {
     polygonFile = safeFileOpen(&polygonFile, polygonFileName, "r");
     outputFile = safeFileOpen(&outputFile, outputFileName, "w");
 
+    /* Read towers from the data file */
+    tower_t **towers = malloc(sizeof(*towers));
+    checkNullPointer(towers);
+    int numTowers = 0;
+    towers = readTowers(towers, dataFile, &numTowers);
 
+    /* Construct the DCEL from the polygon file */
+    DCEL_t *dcel = readPolygonFile(polygonFileName);
+
+    /* Add each tower to the Voronoi DCEL */
+
+    /* Get diameters and output to outputFile */
     
     /* Clean up */
+    freeDCEL(dcel);
+    freeTowers(towers, numTowers);
     fclose(dataFile);
     fclose(polygonFile);
     fclose(outputFile);
@@ -119,9 +186,22 @@ void stage4(char *dataFileName, char *polygonFileName, char *outputFileName) {
     polygonFile = safeFileOpen(&polygonFile, polygonFileName, "r");
     outputFile = safeFileOpen(&outputFile, outputFileName, "w");
 
+    /* Read towers from the data file */
+    tower_t **towers = malloc(sizeof(*towers));
+    checkNullPointer(towers);
+    int numTowers = 0;
+    towers = readTowers(towers, dataFile, &numTowers);
 
+    /* Construct the DCEL from the polygon file */
+    DCEL_t *dcel = readPolygonFile(polygonFileName);
+
+    /* Add each tower to the Voronoi DCEL */
+
+    /* Get diameters and sort, then output to outputFile */
 
     /* Clean up */
+    freeDCEL(dcel);
+    freeTowers(towers, numTowers);
     fclose(dataFile);
     fclose(polygonFile);
     fclose(outputFile);

voronoi.h

@@ -11,6 +11,20 @@ void stage1PrintBisector(bisector_t *bisector, FILE *outputFile);
 /* Prints intersections to an output file */
 void stage2PrintIntersection(intersection_t *intersection, FILE *outputFile);
 
+/* Prints the watchtower information to an output file */
+void stage34PrintTowers(tower_t *tower, FILE *outputFile, double diameter);
+
+/* Returns the face a tower is in */
+int getFaceTowerIsIn(DCEL_t *dcel, tower_t *tower);
+
+/* Adds the watchtower to the Voronoi diagram represented by the given DCEL, 
+ * applying required splits and setting the watchtower as required.
+ */
+void incrementalVoronoi(DCEL_t *voronoi, tower_t *tower);
+
+/* Creates a new Voronoi structure */
+DCEL_t *newVoronoi(DCEL_t *voronoi, tower_t *towerA, tower_t *towerB);
+
 /* Outputs the bisector equations from pointsFile into outputFile */
 void stage1(char *pointsFileName, char *outputFileName);