0026969: Visualization - support custom vertex attributes in GLSL program

Graphic3d_TypeOfData - added Graphic3d_TOD_FLOAT for passing single-float vertex attributes.
Graphic3d_TOA_CUSTOM - changed value to increase the range for custom vertex attributes locations (to fit into hardware limits).
Graphic3d_ShaderProgram::SetVertexAttributes() - introduced API for defining custom vertex attributes.

For compatibility with automated wrappers:
- Graphic3d_Buffer::Init() - added prototype taking NCollection_Array1<Graphic3d_Attribute> instead of C array
- Graphic3d_IndexBuffer::InitInt32() - added typed initialization method.
- Graphic3d_ShaderProgram::PushVariableVec3() and others - added typed methods to push uniform varibales.

src/Graphic3d/FILES

@@ -100,6 +100,8 @@ Graphic3d_RenderingParams.hxx
 Graphic3d_SequenceOfGroup.hxx
 Graphic3d_SequenceOfHClipPlane.hxx
 Graphic3d_SequenceOfStructure.hxx
+Graphic3d_ShaderAttribute.cxx
+Graphic3d_ShaderAttribute.hxx
 Graphic3d_ShaderObject.cxx
 Graphic3d_ShaderObject.hxx
 Graphic3d_ShaderProgram.cxx

src/Graphic3d/Graphic3d_Buffer.hxx

@@ -15,6 +15,7 @@
 #define _Graphic3d_Buffer_HeaderFile
 
 #include <Graphic3d_Vec.hxx>
+#include <NCollection_Array1.hxx>
 #include <NCollection_Buffer.hxx>
 
 //! Type of attribute in Vertex Buffer
@@ -24,7 +25,7 @@ enum Graphic3d_TypeOfAttribute
   Graphic3d_TOA_NORM,         //!< normal
   Graphic3d_TOA_UV,           //!< texture coordinates
   Graphic3d_TOA_COLOR,        //!< per-vertex color
-  Graphic3d_TOA_CUSTOM = 10,  //!< custom attributes
+  Graphic3d_TOA_CUSTOM,       //!< custom attributes
 };
 
 //! Type of the element in Vertex or Index Buffer
@@ -36,6 +37,7 @@ enum Graphic3d_TypeOfData
   Graphic3d_TOD_VEC3,    //!< 3-components float vector
   Graphic3d_TOD_VEC4,    //!< 4-components float vector
   Graphic3d_TOD_VEC4UB,  //!< 4-components unsigned byte vector
+  Graphic3d_TOD_FLOAT,   //!< float value
 };
 
 //! Vertex attribute definition.
@@ -57,12 +59,15 @@ struct Graphic3d_Attribute
       case Graphic3d_TOD_VEC3:   return sizeof(Graphic3d_Vec3);
       case Graphic3d_TOD_VEC4:   return sizeof(Graphic3d_Vec4);
       case Graphic3d_TOD_VEC4UB: return sizeof(Graphic3d_Vec4ub);
+      case Graphic3d_TOD_FLOAT:  return sizeof(float);
     }
     return 0;
   }
 
 };
 
+typedef NCollection_Array1<Graphic3d_Attribute> Graphic3d_Array1OfAttribute;
+
 //! Buffer of vertex attributes.
 class Graphic3d_Buffer : public NCollection_Buffer
 {
@@ -195,6 +200,13 @@ public:
     return true;
   }
 
+  //! Allocates new empty array
+  bool Init (const Standard_Integer             theNbElems,
+             const Graphic3d_Array1OfAttribute& theAttribs)
+  {
+    return Init (theNbElems, &theAttribs.First(), theAttribs.Size());
+  }
+
 public:
 
   Standard_Integer Stride;       //!< the distance to the attributes of the next vertex

src/Graphic3d/Graphic3d_IndexBuffer.hxx

@@ -48,6 +48,12 @@ public:
     return true;
   }
 
+  //! Allocates new empty index array
+  bool InitInt32 (const Standard_Integer theNbElems)
+  {
+    return Init<int> (theNbElems);
+  }
+
   //! Access index at specified position
   Standard_Integer Index (const Standard_Integer theIndex) const
   {

src/Graphic3d/Graphic3d_ShaderAttribute.cxx

@@ -0,0 +1,39 @@
+// Created on: 2016-02-19
+// Created by: Kirill Gavrilov
+// Copyright (c) 2016 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#include <Graphic3d_ShaderAttribute.hxx>
+
+IMPLEMENT_STANDARD_RTTIEXT(Graphic3d_ShaderAttribute,Standard_Transient)
+
+// =======================================================================
+// function : Graphic3d_ShaderAttribute
+// purpose  :
+// =======================================================================
+Graphic3d_ShaderAttribute::Graphic3d_ShaderAttribute (const TCollection_AsciiString& theName,
+                                                      const int theLocation)
+: myName (theName),
+  myLocation (theLocation)
+{
+  //
+}
+
+// =======================================================================
+// function : ~Graphic3d_ShaderAttribute
+// purpose  :
+// =======================================================================
+Graphic3d_ShaderAttribute::~Graphic3d_ShaderAttribute()
+{
+  //
+}

src/Graphic3d/Graphic3d_ShaderAttribute.hxx

@@ -0,0 +1,59 @@
+// Created on: 2016-02-19
+// Created by: Kirill Gavrilov
+// Copyright (c) 2016 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _Graphic3d_ShaderAttribute_HeaderFile
+#define _Graphic3d_ShaderAttribute_HeaderFile
+
+#include <Standard_Transient.hxx>
+#include <TCollection_AsciiString.hxx>
+
+//! Describes custom vertex shader attribute.
+class Graphic3d_ShaderAttribute : public Standard_Transient
+{
+public:
+
+  //! Creates new attribute.
+  Standard_EXPORT Graphic3d_ShaderAttribute (const TCollection_AsciiString& theName,
+                                             const int theLocation);
+
+  //! Destructor.
+  Standard_EXPORT virtual ~Graphic3d_ShaderAttribute();
+
+  //! Returns name of shader variable.
+  const TCollection_AsciiString& Name() const
+  {
+    return myName;
+  }
+
+  //! Returns attribute location to be bound on GLSL program linkage stage.
+  int Location() const
+  {
+    return myLocation;
+  }
+
+protected:
+
+  TCollection_AsciiString myName;     //!< attribute name
+  int                     myLocation; //!< attribute location
+
+public:
+
+  DEFINE_STANDARD_RTTIEXT(Graphic3d_ShaderAttribute,Standard_Transient)
+
+};
+
+DEFINE_STANDARD_HANDLE (Graphic3d_ShaderAttribute, Standard_Transient)
+
+#endif // _Graphic3d_ShaderAttribute_HeaderFile

src/Graphic3d/Graphic3d_ShaderProgram.cxx

@@ -217,3 +217,12 @@ void Graphic3d_ShaderProgram::ClearVariables()
 {
   myVariables.Clear();
 }
+
+// =======================================================================
+// function : SetAttributes
+// purpose  :
+// =======================================================================
+void Graphic3d_ShaderProgram::SetVertexAttributes (const Graphic3d_ShaderAttributeList& theAttributes)
+{
+  myAttributes = theAttributes;
+}

src/Graphic3d/Graphic3d_ShaderProgram.hxx

@@ -16,6 +16,7 @@
 #ifndef _Graphic3d_ShaderProgram_HeaderFile
 #define _Graphic3d_ShaderProgram_HeaderFile
 
+#include <Graphic3d_ShaderAttribute.hxx>
 #include <Graphic3d_ShaderObject.hxx>
 #include <Graphic3d_ShaderVariable.hxx>
 #include <Graphic3d_TextureParams.hxx>
@@ -27,6 +28,9 @@ typedef NCollection_Sequence<Handle(Graphic3d_ShaderObject)> Graphic3d_ShaderObj
 //! List of custom uniform shader variables.
 typedef NCollection_Sequence<Handle(Graphic3d_ShaderVariable)> Graphic3d_ShaderVariableList;
 
+//! List of custom vertex shader attrubures
+typedef NCollection_Sequence<Handle(Graphic3d_ShaderAttribute)> Graphic3d_ShaderAttributeList;
+
 //! This class is responsible for managing shader programs.
 class Graphic3d_ShaderProgram : public Standard_Transient
 {
@@ -82,10 +86,20 @@ public:
   //! Returns list of attached shader objects.
   const Graphic3d_ShaderObjectList& ShaderObjects() const { return myShaderObjects; }
 
-  //! Returns list of custom uniform variables.
+  //! The list of currently pushed but not applied custom uniform variables.
+  //! This list is automatically cleared after applying to GLSL program.
   const Graphic3d_ShaderVariableList& Variables() const { return myVariables; }
 
+  //! Return the list of custom vertex attributes.
+  const Graphic3d_ShaderAttributeList& VertexAttributes() const { return myAttributes; }
+
+  //! Assign the list of custom vertex attributes.
+  //! Should be done before GLSL program initialization.
+  Standard_EXPORT void SetVertexAttributes (const Graphic3d_ShaderAttributeList& theAttributes);
+
   //! Pushes custom uniform variable to the program.
+  //! The list of pushed variables is automatically cleared after applying to GLSL program.
+  //! Thus after program recreation even unchanged uniforms should be pushed anew.
   template<class T>
   Standard_Boolean PushVariable (const TCollection_AsciiString& theName,
                                  const T&                       theValue);
@@ -93,6 +107,30 @@ public:
   //! Removes all custom uniform variables from the program.
   Standard_EXPORT void ClearVariables();
 
+  //! Pushes float uniform.
+  Standard_Boolean PushVariableFloat (const TCollection_AsciiString& theName, const float theValue)            { return PushVariable (theName, theValue); }
+
+  //! Pushes vec2 uniform.
+  Standard_Boolean PushVariableVec2  (const TCollection_AsciiString& theName, const Graphic3d_Vec2& theValue)  { return PushVariable (theName, theValue); }
+
+  //! Pushes vec3 uniform.
+  Standard_Boolean PushVariableVec3  (const TCollection_AsciiString& theName, const Graphic3d_Vec3& theValue)  { return PushVariable (theName, theValue); }
+
+  //! Pushes vec4 uniform.
+  Standard_Boolean PushVariableVec4  (const TCollection_AsciiString& theName, const Graphic3d_Vec4& theValue)  { return PushVariable (theName, theValue); }
+
+  //! Pushes int uniform.
+  Standard_Boolean PushVariableInt   (const TCollection_AsciiString& theName, const int theValue)              { return PushVariable (theName, theValue); }
+
+  //! Pushes vec2i uniform.
+  Standard_Boolean PushVariableVec2i (const TCollection_AsciiString& theName, const Graphic3d_Vec2i& theValue) { return PushVariable (theName, theValue); }
+
+  //! Pushes vec3i uniform.
+  Standard_Boolean PushVariableVec3i (const TCollection_AsciiString& theName, const Graphic3d_Vec3i& theValue) { return PushVariable (theName, theValue); }
+
+  //! Pushes vec4i uniform.
+  Standard_Boolean PushVariableVec4i (const TCollection_AsciiString& theName, const Graphic3d_Vec4i& theValue) { return PushVariable (theName, theValue); }
+
 public:
 
   //! The path to GLSL programs determined from CSF_ShadersDirectory or CASROOT environment variables.
@@ -105,10 +143,11 @@ public:
 
 private:
 
-  TCollection_AsciiString      myID;            //!< The unique identifier of program object.
-  Graphic3d_ShaderObjectList   myShaderObjects; //!< the list of attached shader objects.
-  Graphic3d_ShaderVariableList myVariables;     //!< the list of custom uniform variables.
-  TCollection_AsciiString      myHeader;        //!< GLSL header with version code and used extensions
+  TCollection_AsciiString       myID;            //!< the unique identifier of program object
+  Graphic3d_ShaderObjectList    myShaderObjects; //!< the list of attached shader objects
+  Graphic3d_ShaderVariableList  myVariables;     //!< the list of custom uniform variables
+  Graphic3d_ShaderAttributeList myAttributes;    //!< the list of custom vertex attributes
+  TCollection_AsciiString       myHeader;        //!< GLSL header with version code and used extensions
 
 };
 

src/OpenGl/OpenGl_PrimitiveArray.cxx

@@ -53,6 +53,9 @@ namespace
       case Graphic3d_TOD_VEC4UB:
         theNbComp = 4;
         return GL_UNSIGNED_BYTE;
+      case Graphic3d_TOD_FLOAT:
+        theNbComp = 1;
+        return GL_FLOAT;
     }
     theNbComp = 0;
     return GL_NONE;

src/OpenGl/OpenGl_ShaderProgram.cxx

@@ -297,6 +297,16 @@ Standard_Boolean OpenGl_ShaderProgram::Initialize (const Handle(OpenGl_Context)&
   SetAttributeName (theCtx, Graphic3d_TOA_UV,    "occTexCoord");
   SetAttributeName (theCtx, Graphic3d_TOA_COLOR, "occVertColor");
 
+  // bind custom Vertex Attributes
+  if (!myProxy.IsNull())
+  {
+    for (Graphic3d_ShaderAttributeList::Iterator anAttribIter (myProxy->VertexAttributes());
+         anAttribIter.More(); anAttribIter.Next())
+    {
+      SetAttributeName (theCtx, anAttribIter.Value()->Location(), anAttribIter.Value()->Name().ToCString());
+    }
+  }
+
   if (!Link (theCtx))
   {
     TCollection_AsciiString aLog;