PYMOL-1538 Picking support for ObjectCGO

No nice API available yet. Pick event can be captured like this:

>>> cmd.button("single_left", "none", "clik")
>>> cmd.set_key("F1", lambda: print(_cmd.get_click_string(cmd._COb)))

(press "F1" after a pick)

- Add pick colors to CGO demo (for testing/demo)

data/demo/cgo03.py

@@ -30,6 +30,7 @@ for a in range(0,63):
       for y in range(0,30):
          z[x][y]=(math.cos((aa)+x/2.0)+math.sin((aa)+(y/2.0)))
 
+   obj += [PICK_COLOR, 0, cPickableGadget]
    obj.extend( [ COLOR, 0.3, 0.3, 1.0 ] )
    
    for x in range(0,30):
@@ -46,14 +47,17 @@ for a in range(0,63):
 
    # add into this a couple circulating spheres
 
+   obj += [PICK_COLOR, 1, cPickableGadget]
    obj.extend( [ COLOR, 1.0, 0.2, 0.2 ] )
    obj.extend( [ SPHERE, 5*math.cos(ab)+15.0, 5*math.sin(ab)+15.0, 6.0, 1.0 ] )
 
+   obj += [PICK_COLOR, 2, cPickableGadget]
    obj.extend( [ COLOR, 1.0, 1.0, 0.2 ] )
    obj.extend( [ SPHERE, 5*math.cos(aa)+15.0, 5*math.sin(aa)+15.0, 3.0, 2.0 ] )
 
    # now add a colorful cylinder
 
+   obj += [PICK_COLOR, 3, cPickableGadget]
    obj.extend( [ CYLINDER,
                  5.0,  15+math.sin(aa)*10, -5.0,      # XYZ 1
                  25.0, 15+math.sin(aa)*10, -5.0,      # XYZ 2

layer1/CGO.cpp

@@ -339,6 +339,12 @@ static PyObject *CGOArrayAsPyList(const CGO * I)
       ++pc;
       --sz;
       break;
+    case CGO_PICK_COLOR:
+      assert(sz == 2);
+      flat.push_back(*reinterpret_cast<const int*>(pc++)); // atom index
+      flat.push_back(*reinterpret_cast<const int*>(pc++)); // bond index
+      sz -= 2;
+      break;
     case CGO_DRAW_ARRAYS:
       {
         auto sp = reinterpret_cast<const cgo::draw::arrays*>(pc);
@@ -415,6 +421,12 @@ static int CGOArrayFromPyListInPlace(PyObject * list, CGO * I)
       CGO_write_int(fdata, GET_INT(i++));
       sz--;
       break;
+    case CGO_PICK_COLOR:
+      ok_assert(1, i + 1 < l);
+      CGO_write_int(fdata, GET_INT(i++)); // atom index
+      CGO_write_int(fdata, GET_INT(i++)); // bond index
+      sz -= 2;
+      break;
     case CGO_DRAW_ARRAYS:
       {
         // has abstract superclass, need to be constructed!
@@ -627,6 +639,11 @@ int CGOFromFloatArray(CGO * I, const float *src, int len)
         iarg = (int) *(tf);
         CGO_write_int(tf, iarg);
         break;
+      case CGO_PICK_COLOR:
+        tf = save_pc + 1;
+        CGO_write_int(tf, int(save_pc[1])); // atom index
+        CGO_write_int(tf, int(save_pc[2])); // bond index
+        break;
       }
       save_pc = pc;
       I->c += sz + 1;

layer2/ObjectCGO.cpp

@@ -261,9 +261,13 @@ static void ObjectCGORenderState(PyMOLGlobals* G, RenderPass pass, CRay* ray,
         CGOFree(cgo_copy);
       }
     }
-  } else if(G->HaveGUI && G->ValidContext && pass != RenderPass::Antialias) {
-    if(info->pick) { // no picking yet
-    } else {
+  } else if (G->HaveGUI && G->ValidContext) {
+    if (info->pick) {
+      PickContext context;
+      context.object = I;
+      context.state = sobj - I->State;
+      CGORenderGLPicking(sobj->renderCGO, info, &context, I->Setting, nullptr);
+    } else if (pass != RenderPass::Antialias) {
       bool pass_is_opaque = pass == RenderPass::Opaque;
       if(sobj && ((sobj->hasTransparency ^ pass_is_opaque) || (sobj->hasOpaque == pass_is_opaque))){
 	{
@@ -373,6 +377,7 @@ static void ObjectCGOGenerateCGO(PyMOLGlobals * G, ObjectCGO * I, ObjectCGOState
       }
 
       CGO* convertcgo = CGONew(G);
+      CGOPickColor(convertcgo, 0, cPickableGadget);
       CGOColorv(convertcgo, colorWithA);
       CGOAlpha(convertcgo, colorWithA[3]);
       CGOAppend(convertcgo, inputCGO);
@@ -431,14 +436,18 @@ static void ObjectCGOGenerateCGO(PyMOLGlobals * G, ObjectCGO * I, ObjectCGOState
 	preOpt.reset(CGOCombineBeginEnd(preOpt.get(), 0));
       }
 
-      preOpt.reset(CGOOptimizeToVBOIndexedWithColorEmbedTransparentInfo(
-          preOpt.get(), 0, colorWithA, false));
+      if (hasTransparency) {
+        preOpt.reset(CGOOptimizeToVBOIndexedWithColorEmbedTransparentInfo(
+            preOpt.get(), 0, colorWithA, false));
 
-      if (someLinesWithoutNormals){
-        // if some lines without normals, turn lighting off on lines
-        CGO* convertcgo = preOpt.release();
-        preOpt.reset(CGOTurnLightingOnLinesOff(convertcgo, use_shader));
-        CGOFreeWithoutVBOs(convertcgo);
+        if (someLinesWithoutNormals){
+          // if some lines without normals, turn lighting off on lines
+          CGO* convertcgo = preOpt.release();
+          preOpt.reset(CGOTurnLightingOnLinesOff(convertcgo, use_shader));
+          CGOFreeWithoutVBOs(convertcgo);
+        }
+      } else {
+        preOpt.reset(CGOOptimizeToVBONotIndexed(preOpt.get(), 0));
       }
 
       if (allCylinders){
@@ -493,7 +502,7 @@ void ObjectCGO::render(RenderInfo * info)
   if(!I->State)
     return;
 
-  if(pass != RenderPass::Antialias || info->ray) {
+  if(pass != RenderPass::Antialias || info->ray || info->pick) {
     if((I->visRep & cRepCGOBit)) {
       for(StateIterator iter(G, I->Setting, state, I->NState); iter.next();) {
         sobj = I->State + iter.state;

modules/pymol/cgo.py

@@ -64,8 +64,18 @@ ALPHA              = 25.0
 QUADRIC            = 26.0 # NOTE: Only works with ellipsoids and disks
 CONE               = 27.0
 
+PICK_COLOR         = 31.0 # 0x1F [PICK_COLOR, index, bond/cPickable_t]
+
 LIGHTING           = float(0x0B50)
 
+# enum cPickable_t:
+cPickableAtom = -1.0
+cPickableLabel = -2.0
+cPickableGadget = -3.0
+cPickableNoPick = -4.0
+cPickableThrough = -5.0
+
+
 def molauto(name="mols", sele="(all)", marg="-nice", _self=cmd):
     _self.save("molauto.pdb",sele)
     print("molauto %s -nocentre molauto.pdb | molscript -r > molauto.r3d"%marg)