HERE IS THE QUESTION: https://www.chegg.com/homework-help/questions-and-answers/nothing-artificial-intelligence-structs-pointers-linked-list-dynamic-memory-allocation-c-p-q70791343

========================= display.c ========================= #include #include #include #include

#include "obstacles.h" #include "display.h"

#define VERTEX_RADIUS 5

const int OBSTACLE_COLOR = 0x7799FF; const int BORDER_COLOR = 0x000000; const int EDGE_COLOR = 0x000000; const int SELECTED_COLOR = 0xDD0000; const int VERTEX_COLOR = 0xDD0000;

//Display-related variables Display *display; Window win; GC gc;

// Initialize and open the simulator window with size ENV_WIDTH x ENV_HEIGHT. void initializeWindow() { // Open connection to X server display = XOpenDisplay(NULL);

// Create a simple window, set the title and get the graphics context then // make is visible and get ready to draw win = XCreateSimpleWindow(display, RootWindow(display, 0), 0, 0, ENV_WIDTH, ENV_HEIGHT, 0, 0x000000, 0xFFFFFF); XStoreName(display, win, "Path Maker"); gc = XCreateGC(display, win, 0, NULL); XMapWindow(display, win); XFlush(display); usleep(20000); // sleep for 20 milliseconds. }

// Close the display window void closeWindow() { XFreeGC(display, gc); XUnmapWindow(display, win); XDestroyWindow(display, win); XCloseDisplay(display); }

// Redraw all the obstacles and the edges and the vertices void displayEnvironment(Environment *env) { Vertex *v = NULL; Neighbour *n = NULL; // Erase the background XSetForeground(display, gc, 0xFFFFFF); XFillRectangle(display, win, gc, 0, 0, ENV_WIDTH, ENV_HEIGHT);

// Draw all the obstacles for (int i=0; inumObstacles; i++) { XSetForeground(display, gc, OBSTACLE_COLOR); XFillRectangle(display, win, gc, env->obstacles[i].x,ENV_HEIGHT-env->obstacles[i].y, env->obstacles[i].w, env->obstacles[i].h); XSetForeground(display, gc, BORDER_COLOR); XDrawRectangle(display, win, gc, env->obstacles[i].x,ENV_HEIGHT-env->obstacles[i].y, env->obstacles[i].w, env->obstacles[i].h); }

// Draw all the edges XSetForeground(display, gc, EDGE_COLOR); v = env->firstVertex; while (v != NULL) { n = v->firstNeighbour; while (n != NULL) { XDrawLine(display, win, gc, v->x, ENV_HEIGHT-(v->y), n->vertex->x, ENV_HEIGHT-(n->vertex->y)); n = n->next; } v = v->nextVertex; } // Draw all the vertices v = env->firstVertex; while(v != NULL) { XSetForeground(display, gc, VERTEX_COLOR); XFillArc(display, win, gc, v->x-VERTEX_RADIUS, ENV_HEIGHT-(v->y+VERTEX_RADIUS), 2*VERTEX_RADIUS, 2*VERTEX_RADIUS, 0, 360*64); XSetForeground(display, gc, BORDER_COLOR); XDrawArc(display, win, gc, v->x-VERTEX_RADIUS, ENV_HEIGHT-(v->y+VERTEX_RADIUS), 2*VERTEX_RADIUS, 2*VERTEX_RADIUS, 0, 360*64); v = v->nextVertex; }

XFlush(display); usleep(2000); } ========================= display.h ========================= #define ENV_WIDTH 740 #define ENV_HEIGHT 540

// These are the external functions being used by the test program extern void initializeWindow() ; extern void closeWindow(); extern void displayEnvironment(Environment *);