2 // fileio.cpp: Architektonas file save/load support
4 // Part of the Architektonas Project
5 // (C) 2013 Underground Software
6 // See the README and GPLv3 files for licensing and warranty information
8 // JLH = James Hammons <jlhamm@acm.org>
11 // --- ---------- ------------------------------------------------------------
12 // JLH 02/20/2013 Created this file
25 How to handle connected objects
26 -------------------------------
28 Every Object has a vector<Object *> which enumerates all Objects connected to
29 the one we're looking at. So it looks like we'll have to take a two pass
30 approach to loading and saving.
32 Basically, in the saving case, first we write out all objects, keeping a
33 pointer-to-index-number record. Second, we loop through all the objects we
34 wrote out, writing connection lists. Format (indices are 1-based):
42 In the reading case, we do pretty much the same: we construct pointer-to-index-
43 number list, then read the connection list. The PTIN connects the index to the
44 Object pointers we've created. Then we simply call the Object's Connect()
45 function to connect the objects.
47 Small problem though: How does a Dimension know which points on a Line it's
48 connected to? This approach tells the Dimension it's connected to the Line and
49 the Line that it's connected to the Dimension, but not which points.
51 How to handle them then? Do we list the point with the Object pointed at? A
52 Line can contain an infinite number of points to connect with besides its
55 So with each connection Object in the vector, there would also have to be a
56 corresponding point to go with it, that would be gotten from the other Object's
57 Connect() function. Or, instead of a point, a parameter value?
59 Doing that, with the Line and a parameter "t", if t == 0 we have endpoint 1.
60 if t == 1, then we have endpoint 2. With a Circle, the parameter is a number
61 between 0 and 1 (scaled to 0 to 2π). With an Arc, the parameter goes from 0 to
62 1, 0 being enpoint 1 and 1 being endpoint 2.
64 How does this work for moving objects that are connected? Again, with the Line
65 and Dimension. The Line's connections looks like this:
70 Dimension looks like this:
72 Object *: line1, t = 0
73 Object *: line1, t = 1
75 For Dimensions, it can query the connected object (if any) using something like
76 GetPointForParameter(). That way it can figure out where its endpoints are. If
77 there is no connected point, then it uses its internal point.
80 Dimensions are special cases of lines: They have exactly *two* points and none
81 in between. Therefore, the Dimension object only needs to have two points. But
82 those points can be connected to multiple objects. The can also be connected to
83 no points/Objects too.
85 How to describe them and their connections (or lack thereof)?
87 Would have to be a 2nd pass, after all objects have been written out in order.
88 Then you could do something like:
91 8 (the Dimension #): 1 (the Object # for point 1) 1 (the Object # for point 2)
96 Connection attributes: E.g., between a Line a Circle, it can be tangent,
97 perpendicular, or an arbitrary angle. How to encode that information? It's not
98 intrinsic to either the Line or the Circle, but is a function of the
99 relationship between them by virtue of their connection.
102 OTHER CONSIDERATIONS:
103 ---------------------
105 - Need to figure out how to store the Layer list (should layer list be optional?)
106 - Need to figure out how to store the Block list and blocks
111 enum ObjectTypeFile { OTFContainer, OTFContainerEnd, OTFLine, OTFCircle, OTFArc,
112 OTFDimension, OTFPolygon, OTFText, OTFImage, OTFBlock, OTFEndOfFile };
115 /*static*/ bool FileIO::SaveAtnsFile(FILE * file, Container * object)
117 /* Approach: loop through the container, doing a depth-first traversal. Any extra
118 containers found are looped through until there aren't any more down, then
119 ordinary objects are described. This can be handled by a virtual Object function
120 that reports the object by itself if it's a non-Container, otherwise it
121 enumerates all objects within itself. */
123 fprintf(file, "ARCHITEKTONAS DRAWING V1.0\n");
125 object->Enumerate(file);
126 fprintf(file, "END\n");
134 /*static*/ bool FileIO::LoadAtnsFile(FILE * file, Container * drawing)
139 fscanf(file, "ARCHITEKTONAS DRAWING V%f", &version);
141 //printf("Load: version = %f\n", version);
144 /* Approach: read each object in the file, one by one. If the object is a Container,
145 add objects to it until an "endContainer" marker is found. This will require a
146 stack to maintain the current Container. */
149 std::vector<Container *> containerStack;
150 Container * currentTopContainer = drawing;//new Container(Vector(0, 0));
152 // ObjectType objectType;
157 if (FileIO::GetObjectFromFile(file, currentTopContainer, &object, &objectType) == false)
160 // object->type down below can be replaced with objType.
161 // Above could be: bool FileIO::GetObjectFromFile(FILE *, Object *, ObjectType *);
162 // where the return value tells if it's a valid object, Object * returns the
163 // reconstructed object and ObjectType * returns the object type.
165 if (objectType == OTFEndOfFile)
167 //printf("Load: container size = %li\n", drawing->objects.size());
170 else if (objectType == OTFContainer)
172 containerStack.push_back(currentTopContainer);
173 currentTopContainer = new Container(Vector(0, 0), currentTopContainer);
175 else if (objectType == OTFContainerEnd)
177 Container * containerToAdd = currentTopContainer;
178 currentTopContainer = containerStack.back();
179 containerStack.pop_back();
180 currentTopContainer->Add(containerToAdd);
184 currentTopContainer->Add(object);
185 //printf("Load: Adding object. Container size = %li (%li)\n", drawing->objects.size(), currentTopContainer->objects.size());
196 /*static*/ bool FileIO::GetObjectFromFile(FILE * file, Object * parent, Object ** object, int * objectType)
201 int num = fscanf(file, "%s", buffer);
202 bool recognized = false;
204 //printf("FileIO: fscanf returned %i, buffer = \"%s\"\n", num, buffer);
206 // The following fugliness is for troubleshooting. Can remove later.
207 if ((strcmp(buffer, "END") != 0) && (strcmp(buffer, "ENDCONTAINER") != 0))
210 num = fscanf(file, " %i ", &foundLayer);
211 //printf("FileIO: fscanf returned %i, foundLayer = %i\n", num, foundLayer);
216 else if (errno == EBADF)
218 else if (errno == EILSEQ)
220 else if (errno == EINTR)
222 else if (errno == EINVAL)
224 else if (errno == ENOMEM)
226 else if (errno == ERANGE)
229 printf("errno = %i\n", errno);
233 if (strcmp(buffer, "LINE") == 0)
235 //printf(" Found LINE.\n");
238 fscanf(file, "(%lf,%lf) (%lf,%lf)", &v1.x, &v1.y, &v2.x, &v2.y);
239 //printf(" Number of params recognized: %i\n", n);
240 *object = new Line(v1, v2, parent);
241 *objectType = OTFLine;
243 else if (strcmp(buffer, "CIRCLE") == 0)
248 fscanf(file, "(%lf,%lf) %lf", &v.x, &v.y, &r);
249 *object = new Circle(v, r, parent);
250 *objectType = OTFCircle;
252 else if (strcmp(buffer, "ARC") == 0)
257 fscanf(file, "(%lf,%lf) %lf, %lf, %lf", &v.x, &v.y, &r, &a1, &a2);
258 *object = new Arc(v, r, a1, a2, parent);
259 *objectType = OTFArc;
261 else if (strcmp(buffer, "DIMENSION") == 0)
266 fscanf(file, "(%lf,%lf) (%lf,%lf) %i", &v1.x, &v1.y, &v2.x, &v2.y, &type);
267 *object = new Dimension(v1, v2, type, parent);
268 *objectType = OTFDimension;
270 else if (strcmp(buffer, "CONTAINER") == 0)
273 *objectType = OTFContainer;
275 else if (strcmp(buffer, "ENDCONTAINER") == 0)
278 *objectType = OTFContainerEnd;
280 else if (strcmp(buffer, "END") == 0)
283 *objectType = OTFEndOfFile;
287 (*object)->layer = foundLayer;