add helper functions for shader based picking

ACG/GL/GLPrimitives.cc

@@ -229,6 +229,25 @@ void GLPrimitive::draw_primitive()
 
 //------------------------------------------------------------------------
 
+void GLPrimitive::draw_primitive(GLSL::Program* _program)
+{
+  if (checkVBO())
+  {
+    glBindBuffer(GL_ARRAY_BUFFER, vbo_);
+    vertexDecl_.activateShaderPipeline(_program);
+
+    if (numTris_)
+      glDrawArrays(GL_TRIANGLES, 0, numTris_ * 3);
+    else
+      glDrawArrays(GL_LINES, 0, numLines_ * 2);
+
+    vertexDecl_.deactivateShaderPipeline(_program);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+  }
+}
+
+//------------------------------------------------------------------------
+
 void GLPrimitive::addToRenderer_primitive( class IRenderer* _renderer, RenderObject* _ro )
 {
   if (checkVBO())

ACG/GL/GLPrimitives.hh

@@ -80,9 +80,17 @@ public:
   GLPrimitive();
   virtual ~GLPrimitive();
 
-  // bind vbo + gl draw call
+  // bind vbo + gl draw call (fixed function mode)
+  // use this function in compatibility profile
   void draw_primitive();
 
+  // activate vertex declaration + gl draw call  (shader mode)
+  // _program may be nullptr, in that case the attribute locations are as follows.
+  //  0 : float3 position
+  //  1 : float3 normal
+  //  2 : float2 texcoord
+  void draw_primitive(GLSL::Program* _program);
+
   // add to deferred draw call to renderer
   void addToRenderer_primitive(class IRenderer* _renderer, struct RenderObject* _ro);
 

ACG/GL/GLState.cc

@@ -59,6 +59,7 @@
 #include <ACG/GL/acg_glew.hh>
 #include "GLState.hh"
 
+#include <OpenMesh/Core/Utils/vector_cast.hh>
 #include <cstring>
 
 
@@ -1070,6 +1071,19 @@ Vec4uc GLState::pick_get_name_color (size_t _idx)
 
 //-----------------------------------------------------------------------------
 
+Vec4f GLState::pick_get_name_color_norm (unsigned int _idx)
+{
+  Vec4f rv(0.0f, 0.0f, 0.0f, 0.0f);
+  if (colorPicking_)
+  {
+    Vec4uc color_abs = colorStack_.getIndexColor(_idx);
+    rv = OpenMesh::vector_cast<Vec4f, Vec4uc>(color_abs) / 255.0f;
+  }
+  return rv;
+}
+
+//-----------------------------------------------------------------------------
+
 void GLState::pick_push_name (size_t _idx)
 {
   colorStack_.pushIndex (_idx);

ACG/GL/GLState.hh

@@ -1114,6 +1114,9 @@ public:
   /// for each primitive
   Vec4uc pick_get_name_color (size_t _idx);
 
+  /// same as pick_get_name_color, but the resulting color channels are normalized in [0.0, 1.0] range
+  Vec4f pick_get_name_color_norm (unsigned int _idx);
+
   /// creates a new name the stack (like glPushName())
   void pick_push_name (size_t _idx);