In the following example, the ShowPick module colors the entire object in white, except for the Field, element, or vertex containing the pick point(s). The color of the latter is specified by the user.
The module description file for ShowPick is:
MODULE ShowPick CATEGORY User DESCRIPTION sets a triangle in a picked Field to a particular color INPUT input; object; (none); object with picked points INPUT pickobject; field; (none); picking structure INPUT color; string; "red"; color to set INPUT colorwhich; integer; 0; color the element (0), vertex (1) or entire field (2) INPUT poke; integer; (all); poke selection INPUT pick; integer; (all); pick selection INPUT depth; integer; (bottom); selection depth OUTPUT output; object; object with picked structures marked using color
As the .mdf file shows, the ShowPick module takes seven inputs and generates one output. To create a version of Data Explorer that includes this module, copy the following files to the directory where you want to work:
/usr/local/dx/samples/program_guide/Makefile_supported workstation model /usr/local/dx/samples/program_guide/showpick.c /usr/local/dx/samples/program_guide/showpick.mdfNow rename the makefile to Makefile and enter: make showpick. This command creates an executable that contains the ShowPick module.
To invoke this version (from the directory to which the files were copied), enter:
dx -mdf ./showpick.mdf -exec ./dxexecThis command starts Data Explorer (the showpick.mdf file tells the graphical user interface about ShowPick and its inputs and outputs). With this version of Data Explorer you can now run any visual program that uses the ShowPick module. One such program is showpick.net in the /usr/local/dx/samples/program_guide directory.
01 #include <dx/dx.h>
02 #include "pick.h"
03
04 static Error DoPick(Object, Object, RGBColor, int, int, int, int);
05 static Error SetColor(Object, RGBColor);
06
07 Error m_ShowPick(Object *in, Object *out)
08 {
09 Object o = NULL, pickfield;
10 char *colorstring;
11 int colorwhich, poke, pick, depth;
12 RGBColor color;
Copy the structure of in[0], the object in which picking took place.
13 if (!in[0]) {
14 DXSetError(ERROR_BAD_PARAMETER, "missing input");
15 goto error;
16 }
17 o = (Object)DXCopy(in[0], COPY_STRUCTURE);
18 if (!o)
19 goto error;
First, set all the colors to white, to initialize. (The SetColor routine is defined below.)
20 if (!SetColor(o, DXRGB(1.0, 1.0, 1.0))) 21 goto error;
in[1] is the pick Field. If the pick Field is NULL or an empty Field, just return the copy of the object.
22 if (!in[1] || DXEmptyField(in[1])) {
23 out[0] = o;
24 return OK;
25 }
26 pickfield = in[1];
Get the color that will be used for picked Objects, which is in[2].
27 if (in[2]) {
28 if (!DXExtractString((Object)in[2], &colorstring)) {
29 DXSetError(ERROR_BAD_PARAMETER,"color must be a string");
30 goto error;
31 }
Convert the color name to an RGB vector.
32
33 if (!DXColorNameToRGB(colorstring, &color))
34 goto error;
35 }
36 else {
If in[2] is not specified, then the default color is red.
37 color = DXRGB(1.0, 0.0, 0.0); 38 }
Determine if we are to color just the picked element, just the vertex closest to the picked point, or the entire Field. The default is to color just the picked element.
39 if (!in[3]) {
40 colorwhich = 0;
41 }
42 else {
43 if (!DXExtractInteger(in[3], &colorwhich)) {
44 DXSetError(ERROR_BAD_PARAMETER,"colorwhich flag must be 0, 1, or 2");
45 goto error;
46 }
47 if ((colorwhich < 0)&&(colorwhich > 2)) {
48 DXSetError(ERROR_BAD_PARAMETER,"colorwhich flag must be 0, 1, or 2");
49 goto error;
50 }
51 }
Determine if we are to select a particular poke, or all of them. The default is to select all of them.
52
53 if (!in[4]) {
54 poke = -1;
55 }
56 else {
57 if (!DXExtractInteger(in[4], &poke)) {
58 DXSetError(ERROR_BAD_PARAMETER,"poke must be a nonnegative integer");
59 goto error;
60 }
61 if (poke < 0) {
62 DXSetError(ERROR_BAD_PARAMETER,"poke must be a nonnegative integer");
63 goto error;
64 }
65 }
Determine if we are to select a particular pick, or all of them. The default is to select all of them.
66 if (!in[5]) {
67 pick = -1;
68 }
69 else {
70 if (!DXExtractInteger(in[5], &pick)) {
71 DXSetError(ERROR_BAD_PARAMETER,"pick must be a nonnegative integer");
72 goto error;
73 }
74 if (pick < 0) {
75 DXSetError(ERROR_BAD_PARAMETER,"pick must be a nonnegative integer");
76 goto error;
77 }
78 }
Determine if we are to select a depth. The default is to select the deepest level.
79 if (!in[6]) {
80 depth = -1;
81 }
82 else {
83 if (!DXExtractInteger(in[6], &depth)) {
84 DXSetError(ERROR_BAD_PARAMETER,"depth must be a nonnegative integer");
85 goto error;
86 }
87 if (depth < 0) {
88 DXSetError(ERROR_BAD_PARAMETER,"depth must be a nonnegative integer");
89 goto error;
90 }
91 }
Traverse the picked object, using the pick structure, passing the given parameters.
92 if (!DoPick(o, pickfield, color, colorwhich, poke, pick, depth)) 93 goto error;
Delete the opacities component.
94 if (DXExists(o, "opacities")) 95 DXRemove(o,"opacities");
Successful return.
96 out[0] = o; 97 return OK;
Return on error.
98 error: 99 DXDelete(o); 100 return ERROR; 101 }
The DoPick() routine traverses the picked object.
102 static
103 Error
104 DoPick(Object o, Object pickfield, RGBColor color, int colorwhich,
105 int pokes, int picks, int depth)
106 {
107 int pokecount, pickcount, poke, pick, i, pathlength;
108 int vertexid, elementid, *path, numitems, index;
109 Object current;
110 Matrix matrix;
111 Array a, newcolors=NULL, oldcolors;
112 char *depatt;
113 RGBColor *newcolors_ptr, oldcolor;
114 int pokemin, pokemax;
115 int pickmin, pickmax;
116 int thisdepth;
pickfield is expected to be a Field.
117 if (!(DXGetObjectClass(pickfield)==CLASS_FIELD)) {
118 DXSetError(ERROR_INVALID_DATA,"pickfield must be a field");
119 goto error;
120 }
Find out the number of pokes.
121 DXQueryPokeCount(pickfield, &pokecount);
The user has chosen to mark all pokes.
122 if (pokes < 0) {
123 pokemin = 0, pokemax = pokecount-1;
124 }
The user has specified a poke larger than the number present.
125 else if (pokes > pokecount-1) {
126 DXSetError(ERROR_BAD_PARAMETER,
127 "only %d pokes are present", pokecount);
128 return ERROR;
129 }
Consider only the specified poke.
130 else 131 pokemin = pokemax = pokes;
For each poke...
132 for (poke=pokemin; poke<=pokemax; poke++) {
Find out how many picks there are in this poke.
133 if (!DXQueryPickCount(pickfield, poke, &pickcount)) 134 goto error;
Issue warning if this particular poke does not contain as many picks as the user has specified.
135 if (picks > pickcount-1) {
136 DXWarning("poke %d contains only %d picks", poke, pickcount);
137 }
138
139 else {
140 if (picks < 0) {
141 pickmin = 0, pickmax = pickcount-1;
142 }
143 else {
144 pickmin = pickmax = picks;
145 }
For each pick...
146
147 for (pick=pickmin; pick<=pickmax; pick++) {
For the given pickfield, the current poke number, and the current pick number, get the traversal path path, the length of the traversal path pathlength, and the IDs of the picked element and the picked vertex.
148 DXQueryPickPath(pickfield, poke, pick, &pathlength, &path, 149 &elementid, &vertexid);
Initialize current to the picked object, and matrix to the identity matrix.
150 current = o; 151 matrix = Identity; 152 if (depth != -1 && pathlength > depth) 153 thisdepth = depth; 154 else 155 thisdepth = pathlength;
Iterate through the pick path.
156 for (i=0; i<thisdepth; i++) {
157 current = DXTraversePickPath(current, path[i], &matrix);
158 if (!current)
159 goto error;
160 }
current is now the Field level of the picked Object, and we have the element and vertex IDs of the picked object.
161 if (colorwhich == 2 || DXGetObjectClass(current) != CLASS_FIELD) {
We are simply to color the entire Field.
162 if (!SetColor(current, color))
163 goto error;
164 }
165 else {
Otherwise, we want to set the indicated element or vertex to the given color. We start by making a new colors component (not compact), but only if the input colors component is still compact. If it is already expanded, then modify it.
First, determine the dependency of the colors.
166 if (colorwhich == 0) {
167 if (a = DXGetComponentValue(current, "connections")) {
168 index = elementid;
169 depatt = "connections";
170 }
171 else if (a = DXGetComponentValue(current, "faces")) {
172 index = elementid;
173 depatt = "faces";
174 }
175 else {
176 a = DXGetComponentValue(current, "positions");
177 index = vertexid;
178 depatt = "positions";
179 }
180 }
181 else {
182 a = DXGetComponentValue(current, "positions");
183 index = vertexid;
184 depatt = "positions";
185 }
Determine the number of items.
186 if (!DXGetArrayInfo(a, &numitems,NULL,NULL,NULL,NULL)) 187 goto error;
If the traversal index is greater than the number of items, something is wrong.
188 if (index >= numitems) {
189 DXSetError(ERROR_INVALID_DATA,
190 "pick structure does not correspond to picked object");
191 goto error;
192 }
Get the original colors component.
193 oldcolors = DXGetComponentValue((Field)current, "colors");
If it is a constant Array, we need to expand it so that we can set just one element or vertex to the given color.
194 if (DXQueryConstantArray(oldcolors, NULL, &oldcolor)) {
Create a new colors Array and allocate space to it.
195 newcolors = DXNewArray(TYPE_FLOAT,CATEGORY_REAL, 1, 3); 196 if (!DXAddArrayData(newcolors, 0, numitems, NULL)) 197 goto error;
Start by setting all colors to the original constant color.
198 newcolors_ptr = (RGBColor *)DXGetArrayData(newcolors);
199 for (i=0; i<numitems; i++) {
200 newcolors_ptr[i] = oldcolor;
201 }
Replace the colors in the Field with the new colors component.
202 if (!DXSetComponentValue((Field)current, "colors",
203 (Object)newcolors))
204 goto error;
205 newcolors=NULL;
206
207 DXSetComponentAttribute((Field)current, "colors", "dep",
208 (Object)DXNewString(depatt));
209 }
210
211
212 else {
The colors are already expanded, presumably from an earlier pick in this Field.
213 newcolors_ptr = (RGBColor *)DXGetArrayData(oldcolors); 214 }
Set the correct triangle or position to the given color.
215 newcolors_ptr[index] = color; 216 } 217 } 218 } 219 } 220 221 return OK; 222 223 error: 224 DXDelete((Object)newcolors); 225 return ERROR; 226 }
This routine sets all colors in object o to the given color.
227 static Error SetColor(Object o, RGBColor color)
228 {
229 Object subo;
230 Array a, newcolors=NULL;
231 int numitems, i;
232
233
234 switch (DXGetObjectClass(o)) {
235
236
237 case (CLASS_GROUP):
238
If o is a Group, call SetColor recursively on its children.
239 for (i=0; subo = DXGetEnumeratedMember((Group)o, i, NULL); i++)) 240 SetColor(subo, color); 241 break; 242 243 244 case (CLASS_XFORM):
If o is an Xform, call SetColor on its child.
245 DXGetXformInfo((Xform)o, &subo, NULL); 246 SetColor(subo, color); 247 break; 248 249 250 case (CLASS_CLIPPED):
If o is a Clipped object, call SetColor on its child.
251 DXGetClippedInfo((Clipped)o, &subo, NULL); 252 SetColor(subo, color); 253 break; 254 255 256 case (CLASS_FIELD):
If o is a Field, set the colors to the given color.
257 if (DXEmptyField((Field)o)) 258 return OK;
The number of colors and the dependency of the colors will depend on whether connections are present. If not, it is checked for the presence of faces. Otherwise, the colors will be dependent on positions.
259 if (a = DXGetComponentValue((Field)o, "connections")) {
260 DXGetArrayInfo(a, &numitems, NULL, NULL, NULL, NULL);
261 newcolors = (Array)DXNewConstantArray(numitems, &color,
262 TYPE_FLOAT,
263 CATEGORY_REAL, 1, 3);
264 DXSetComponentValue((Field)o, "colors", (Object)newcolors);
265 newcolors = NULL;
266 DXSetComponentAttribute((Field)o,"colors", "dep",
267 (Object)DXNewString("connections"));
268 }
269 else if (a = DXGetComponentValue((Field)o, "faces")) {
270 DXGetArrayInfo(a, &numitems, NULL, NULL, NULL, NULL);
271 newcolors = (Array)DXNewConstantArray(numitems, &color,
272 TYPE_FLOAT,
273 CATEGORY_REAL, 1, 3);
274 DXSetComponentValue((Field)o, "colors", (Object)newcolors);
275 newcolors = NULL;
276 DXSetComponentAttribute((Field)o,"colors", "dep",
277 (Object)DXNewString("faces"));
278 }
279 else {
280 a = DXGetComponentValue((Field)o, "positions");
281 DXGetArrayInfo(a, &numitems, NULL, NULL, NULL, NULL);
282 newcolors = (Array)DXNewConstantArray(numitems, &color,
283 TYPE_FLOAT,
284 CATEGORY_REAL, 1, 3);
285 DXSetComponentValue((Field)o, "colors", (Object)newcolors);
286 newcolors = NULL;
287 DXSetComponentAttribute((Field)o,"colors", "dep",
288 (Object)DXNewString("positions"));
289 }
290
291 break;
292 }
293
Successful return or return on error.
294 295 return OK; 296 error: 297 DXDelete((Object)newcolors); 298 return ERROR; 299 }