Tool spikey
Tool_spikey is a basic example plugin. This wiki page is intended as a walkthrough of the code in order to help you better understand the SDK.
This plugin adds the spikey tool to the suite of tools modo has. The tool takes surfaces and makes them more "spikey", as illustrated in screenshots below
Code Walkthrough
Class Declarations
We want this class to display structured data in the log. In this case it's used to show feedback on the current spikey factor, and as such will be called whenever the spikey tool is activate. To that end, we inherit from CLxImpl_LogInfoBlock as we are going to want our data to be in the form of a log info block. The first method here indicates the name of the command, which in this case is test.spikey. The next three walk the list of fields, setting the count as 1(there can only be one tool), the name of the data as 'factor', and the data type as percent. These are all put into arrays that we can later access.
class CSpikeyLogBlock :
public CLxImpl_LogInfoBlock
{
public:
LxResult
lb_Name (
const char **name) LXx_OVERRIDE
{
name[0] = "test.spikey";
return LXe_OK;
}
LxResult
lb_FieldCount (
unsigned int *count) LXx_OVERRIDE
{
count[0] = 1;
return LXe_OK;
}
LxResult
lb_FieldName (
unsigned int index,
const char **name) LXx_OVERRIDE
{
name[0] = "factor";
return LXe_OK;
}
LxResult
lb_FieldType (
unsigned int index,
const char **type) LXx_OVERRIDE
{
type[0] = LXsTYPE_PERCENT;
return LXe_OK;
}
};
The Spikey tool. In order to have our class create a tool, we inherit from CLxImpl_Tool and CLxImpl_ToolModel. The attributes interface is inherited from the utility class; we inherit from it in order to be able to display the attributes of our tool. First off, the tmod_Initialize function is called whenever the tool is activated/deactivated. Next, the tmod_Flags function sets flags that indicate certain attributes about the tool. Because we have chosen to use hauling for this tool, we have a tmod_Haul method that indicates which attribute we want to haul. Next, we start implementing our basic tool methods. The tool_Reset function resets all of our tool's attributes to their original values. tool_VectorType returns the tool vector type, describing the vector packets required for processing. tool_Order specifies the order in the pipe by returning an Ordinal string. tool_Task describes the type of task performed by the tool. tool_Evaluate takes all these methods and uses them to actually perform the tool's action(s).
class CSpikeyTool :
public CLxImpl_Tool,
public CLxImpl_ToolModel,
public CLxDynamicAttributes
{
public:
CSpikeyTool ();
void tool_Reset () LXx_OVERRIDE;
LXtObjectID tool_VectorType () LXx_OVERRIDE;
const char * tool_Order () LXx_OVERRIDE;
LXtID4 tool_Task () LXx_OVERRIDE;
void tool_Evaluate (ILxUnknownID vts) LXx_OVERRIDE;
unsigned tmod_Flags () LXx_OVERRIDE;
void tmod_Initialize (ILxUnknownID vts, ILxUnknownID adjust, unsigned flags) LXx_OVERRIDE;
const char * tmod_Haul (unsigned index) LXx_OVERRIDE;
CLxUser_LogService s_log;
CLxUser_LayerService s_layer;
CLxUser_VectorType v_type;
unsigned offset_falloff, offset_view;
unsigned mode_select;
};
This class is a map visitor that collects the maps in vectors based on type. In order to create a map visitor, we are going to need to inherit from CLxImpl_AbstractVisitor, which allows us to build our custom visitor.
class CSpikeMapListVisitor : public CLxImpl_AbstractVisitor
{
...
};
This class does evaluation. It does so with a polygon visitor which holds the current state of the action.
class CSpikePolygonVisitor : public CLxImpl_AbstractVisitor
{
public:
LxResult Evaluate ();
bool Normalize (LXtVector);
void VertexPos (unsigned index, LXtFVector pos);
bool VertexCross (unsigned i0, unsigned i1, unsigned i2, LXtVector dir);
bool GoodNormal (LXtVector dir);
bool GetSpike (LXtVector pos);
LXtMeshMapID map_id;
LXtID4 map_type;
unsigned vrt_count;
double pol_weight;
CSpikeMapListVisitor e_maps;
CLxUser_Mesh e_mesh;
CLxUser_Polygon e_poly, e_dest;
CLxUser_Point e_vert;
CLxUser_FalloffPacket e_falloff;
double e_factor;
bool edit_any;
};
Initialize
This initialize method exports two servers. The first is dependent on the CSpikeyTool class and includes the interface for all the classes that CSpikeyTool inherited from. The same is done for the second server, with the exception that the class in question here is CSpikeyLogBlock. We want the server dependent on the CSpikeyLogBlock class to be activated at the same time as the one that activates the Spikey tool because it writes information about the Spikey tool to the log so we give them the same name.
void
initialize ()
{
CLxGenericPolymorph *srv;
srv = new CLxPolymorph<CSpikeyTool>;
srv->AddInterface (new CLxIfc_Tool <CSpikeyTool>);
srv->AddInterface (new CLxIfc_ToolModel <CSpikeyTool>);
srv->AddInterface (new CLxIfc_Attributes<CSpikeyTool>);
thisModule.AddServer ("test.spikey", srv);
srv = new CLxPolymorph<CSpikeyLogBlock>;
srv->AddInterface (new CLxIfc_LogInfoBlock<CSpikeyLogBlock>);
thisModule.AddServer ("test.spikey", srv);
}
Implementations
The CSpikeyTool constructor adds one tool attribute. This causes the plugin to query us for a value for this attribute whenever it is constructed, which happens on activation. To us, this appears as the Spike Strength value. It also allocates a vector type (which doesn't seem to need anything in it!), the falloff packet offset and the select mode mask.
CSpikeyTool::CSpikeyTool ()
{
CLxUser_PacketService sPkt;
CLxUser_MeshService sMesh;
dyna_Add (ATTRs_FACTOR, LXsTYPE_PERCENT);
sPkt.NewVectorType (LXsCATEGORY_TOOL, v_type);
sPkt.AddPacket (v_type, LXsP_TOOL_FALLOFF, LXfVT_GET);
sPkt.AddPacket (v_type, LXsP_TOOL_VIEW_EVENT, LXfVT_GET);
offset_falloff = sPkt.GetOffset (LXsCATEGORY_TOOL, LXsP_TOOL_FALLOFF);
offset_view = sPkt.GetOffset (LXsCATEGORY_TOOL, LXsP_TOOL_VIEW_EVENT);
mode_select = sMesh.SetMode ("select");
}
Reset sets the attributes back to defaults, in this case 0.
void
CSpikeyTool::tool_Reset ()
{
attr_SetFlt (0, 0.0);
}
Boilerplate methods that identify this as an action (state altering) tool.
LXtObjectID
CSpikeyTool::tool_VectorType ()
{
return v_type.m_loc; // peek method; does not add-ref
}
const char *
CSpikeyTool::tool_Order ()
{
return LXs_ORD_ACTR;
}
LXtID4
CSpikeyTool::tool_Task ()
{
return LXi_TASK_ACTR;
}
We employ the simplest possible tool model -- default hauling. We indicate that we want to haul one attribute, we name the attribute, and we implement Initialize() which is what to do when the tool activates or re-activates. In this case set the factor back to zero.
unsigned
CSpikeyTool::tmod_Flags ()
{
return LXfTMOD_I0_ATTRHAUL;
}
void
CSpikeyTool::tmod_Initialize (
ILxUnknownID vts,
ILxUnknownID adjust,
unsigned int flags)
{
CLxUser_AdjustTool at (adjust);
at.SetFlt (0, 0.0);
}
const char *
CSpikeyTool::tmod_Haul (
unsigned index)
{
if (index == 0)
return ATTRs_FACTOR;
else
return 0;
}
Get a vertex position. This gets the position of the given vertex of the polygon relative to the current map. This allows us to evaluate the shape of polygons in morphs.
void
CSpikePolygonVisitor::VertexPos (
unsigned index,
LXtFVector pos)
{
e_vert.SelectPolygonVertex (e_poly.ID (), index);
if (map_type == LXi_VMAP_OBJECTPOS)
e_vert.Pos (pos);
else if (map_type == LXi_VMAP_SPOT) {
if (e_vert.MapValue (map_id, pos) != LXe_OK)
e_vert.Pos (pos);
} else {
LXtFVector delta;
e_vert.Pos (pos);
e_vert.MapEvaluate (map_id, delta);
LXx_VADD (pos, delta);
}
}
Normalize a vector, if possible.
bool
CSpikePolygonVisitor::Normalize (
LXtVector v)
{
double len;
len = LXx_VLEN (v);
if (len) {
LXx_VSCL (v, 1.0 / len);
return true;
} else {
LXx_VCLR (v);
return false;
}
}
Get the normalized cross-product of edge vectors defined by the three points of the polygon.
bool
CSpikePolygonVisitor::VertexCross (
unsigned i0,
unsigned i1,
unsigned i2,
LXtVector dir)
{
LXtFVector p0, p1, p2;
LXtFVector e0, e1;
VertexPos (i0, p0);
VertexPos (i1, p1);
VertexPos (i2, p2);
LXx_VSUB3 (e0, p1, p0);
LXx_VSUB3 (e1, p2, p1);
LXx_VCROSS (dir, e0, e1);
return Normalize (dir);
}
Compute a good normal (one that's symmetry safe, which the basic polygon normal is not). This takes the cross product of the 0'th point, then adds in the rest flipping as needed. Final result is renormalized.
bool
CSpikePolygonVisitor::GoodNormal (
LXtVector dir)
{
LXtVector base, norm;
unsigned i;
if (!VertexCross (vrt_count - 1, 0, 1, base))
return false;
LXx_VCPY (dir, base);
for (i = 1; i < vrt_count; i++)
if (VertexCross (i - 1, i, (i + 1) % vrt_count, norm))
if (LXx_VDOT (base, norm) < 0.0)
LXx_VSUB (dir, norm);
else
LXx_VADD (dir, norm);
return Normalize (dir);
}
Compute the position of the spike for the current polygon in the current morph map. We compute the average position and the perimeter and normal of the polygon, and compute a position along the normal with an offset given by average edge length modulated by weight. Returns false if it cannot be computed.
bool
CSpikePolygonVisitor::GetSpike (
LXtVector pos)
{
LXtVector dir;
LXtFVector p0, p1;
double perimeter;
unsigned i;
LXx_VCLR (pos);
perimeter = 0.0;
VertexPos (vrt_count - 1, p0);
for (i = 0; i < vrt_count; i++) {
VertexPos (i, p1);
LXx_VSUB3 (dir, p0, p1);
perimeter += LXx_VLEN (dir);
LXx_VADD (pos, p1);
LXx_VCPY (p0, p1);
}
if (perimeter <= 0.0)
return false;
if (!GoodNormal (dir))
return false;
LXx_VSCL (pos, 1.0 / vrt_count);
LXx_VADDS (pos, dir, pol_weight * e_factor * perimeter / vrt_count);
return true;
}
Evaluation replaces the polygon with a fan of triangles. The central point is given a spike position in all morphs, and other maps are interpolated.
LxResult
CSpikePolygonVisitor::Evaluate ()
{
LXtPointID vrt, vl[3];
LXtPolygonID pol;
LXtFVector fvec;
LXtVector tip, tip1;
unsigned i;
std::vector<LXtMeshMapID>::iterator
mit;
e_poly.VertexCount (&vrt_count);
if (vrt_count < 3)
return LXe_OK;
/*
* Compute average weight of all vertices, rejecting zero-weight polys.
*/
pol_weight = 0.0;
for (i = 0; i < vrt_count; i++) {
e_poly.VertexByIndex (i, &vrt);
e_vert.Pos (fvec);
pol_weight += e_falloff.Evaluate (fvec, vrt);
}
if (pol_weight <= 0.0)
return LXe_OK;
pol_weight /= vrt_count;
/*
* Create vertex using the basic spike position, if any.
*/
map_id = e_maps.opos;
map_type = LXi_VMAP_OBJECTPOS;
if (!GetSpike (tip))
return LXe_OK;
e_vert.New (tip, &vl[2]);
/*
* Compute morph positions for the spike tip. MORF maps are deltas from
* the base position and can be unset if close to zero.
*/
map_type = LXi_VMAP_MORPH;
for (mit = e_maps.morph.begin(); mit < e_maps.morph.end(); mit++) {
map_id = *mit;
if (GetSpike (tip1)) {
LXx_VSUB3 (fvec, tip1, tip);
if (LXx_VLEN (fvec) > 1.0e-5) {
e_vert.Select (vl[2]);
e_vert.SetMapValue (map_id, fvec);
}
}
}
/*
* Compute morph positions for the spike tip. SPOT maps are absolute
* positions and can be unset if the same as the base position.
*/
map_type = LXi_VMAP_SPOT;
for (mit = e_maps.spot.begin(); mit < e_maps.spot.end(); mit++) {
map_id = *mit;
if (GetSpike (tip1)) {
LXx_VSUB3 (fvec, tip1, tip);
if (LXx_VLEN (fvec) > 1.0e-5) {
LXx_VCPY (fvec, tip1);
e_vert.Select (vl[2]);
e_vert.SetMapValue (map_id, fvec);
}
}
}
/*
* All other maps are set as averages of the vectors from the vertices.
* This uses the allocated buffers because arbitrary vertex map types
* can have any dimension.
*/
for (mit = e_maps.other.begin(); mit < e_maps.other.end(); mit++) {
unsigned k, dim;
e_maps.map.Select (*mit);
e_maps.map.Dimension (&dim);
for (k = 0; k < dim; k++)
e_maps.acc[k] = 0.0;
for (i = 0; i < vrt_count; i++) {
e_poly.VertexByIndex (i, &vrt);
if (e_poly.MapEvaluate (*mit, vrt, e_maps.buf) != LXe_OK)
break;
for (k = 0; k < dim; k++)
e_maps.acc[k] += e_maps.buf[k];
}
if (i < vrt_count)
continue;
for (k = 0; k < dim; k++)
e_maps.acc[k] /= vrt_count;
e_vert.Select (vl[2]);
e_vert.SetMapValue (*mit, e_maps.acc);
}
/*
* Finally replace the original polygon with a fan of triangles. We also
* have to copy discontinuous vertex maps (like UV maps) from the original
* polygon to the replacements.
*/
e_poly.VertexByIndex (0, &vl[0]);
for (i = 0; i < vrt_count; i++) {
e_poly.VertexByIndex ((i + 1) % vrt_count, &vl[1]);
e_poly.NewProto (0, vl, 3, 0, &pol);
for (mit = e_maps.other.begin(); mit < e_maps.other.end(); mit++) {
unsigned k;
e_maps.map.Select (*mit);
if (e_maps.map.IsContinuous () == LXe_TRUE)
continue;
e_dest.Select (pol);
for (k = 0; k < 2; k++)
if (e_poly.MapEvaluate (*mit, vl[k], e_maps.buf) == LXe_OK)
e_dest.SetMapValue (vl[k], *mit, e_maps.buf);
}
vl[0] = vl[1];
}
e_poly.Remove ();
edit_any = true;
return LXe_OK;
}
Tool evaluation uses layer scan interface to walk through all the active meshes and visit all the selected polygons.
void
CSpikeyTool::tool_Evaluate (
ILxUnknownID vts)
{
CLxUser_VectorStack vec (vts);
LXpToolViewEvent *view;
view = (LXpToolViewEvent *) vec.Read (offset_view);
if (!view || view->type != LXi_VIEWTYPE_3D)
return;
/*
* Display current spikey factor using our log block.
*/
CLxUser_LogEntry entry;
s_log.NewBlockEntry (LXe_INFO, "test.spikey", entry);
entry.SetValue (0, 0, dyna_Value (0));
/*
* Read the falloff and start the scan in edit-poly mode.
*/
CLxUser_LayerScan scan;
CSpikePolygonVisitor vis;
dyna_Value (0) . GetFlt (&vis.e_factor);
vec.ReadObject (offset_falloff, vis.e_falloff);
s_layer.BeginScan (LXf_LAYERSCAN_EDIT_POLYS, scan);
#if 0
// NOTE: this is for marking new polygons for selection, if any are already
//
tool->mark = SelNumElements (ID_POLY) ? MARK_NEWSEL : MODE_NIL;
#endif
/*
* Enumerate all selected polygons in all mesh layers. If a mesh is
* edited we set the "geometry" change flag indicating that points
* and polygons have both changed.
*/
unsigned i, n;
n = scan.NumLayers ();
for (i = 0; i < n; i++) {
scan.EditMeshByIndex (i, vis.e_mesh);
vis.e_vert.fromMeshObj (vis.e_mesh);
vis.e_poly.fromMeshObj (vis.e_mesh);
vis.e_dest.fromMeshObj (vis.e_mesh);
vis.e_maps.fromMeshObj (vis.e_mesh);
vis.e_maps.Collect ();
vis.edit_any = false;
vis.e_poly.Enum (&vis, mode_select);
if (vis.edit_any)
scan.SetMeshChange (i, LXf_MESHEDIT_GEOMETRY);
}
scan.Apply ();
}
