address review comments

Author: tusharpm

include/fg/pie.h

@@ -53,13 +53,13 @@ FGAPI fg_err fg_retain_pie(fg_pie *pOut, fg_pie pIn);
 FGAPI fg_err fg_release_pie(fg_pie pPie);
 
 /**
-   Set the color of bar in the bar graph(pie)
+   Set the color of all sectors in the pie chart
 
    This is global alpha value for the pie rendering that takes
-   effect if individual bar alphas are not set by calling the following
-   member functions
-       - Pie::alphas()
-       - Pie::alphasSize()
+   effect if individual sector alphas are not set in the buffer
+   obtained by the following functions
+      - fg_get_pie_alpha_buffer
+      - fg_get_pie_alpha_buffer_size
 
    \param[in] pPie is the pie handle
    \param[in] pRed is Red component in range [0, 1]
@@ -193,17 +193,17 @@ class Pie {
         FGAPI ~Pie();
 
         /**
-           Set the color of bar in the bar graph(pie)
+           Set the color of all sectors in the pie chart
 
-           \param[in] pColor takes values of type forge::Color to define bar color
+           \param[in] pColor takes values of type forge::Color to define sector color
         **/
         FGAPI void setColor(const Color pColor);
 
         /**
-           Set the color of bar in the bar graph(pie)
+           Set the color of all sectors in the pie chart
 
            This is global alpha value for the pie rendering that takes
-           effect if individual bar alphas are not set by calling the following
+           effect if individual sector alphas are not set by calling the following
            member functions
                - Pie::alphas()
                - Pie::alphasSize()

src/backend/opengl/pie_impl.hpp

@@ -14,7 +14,6 @@
 
 #include <glm/glm.hpp>
 
-#include <memory>
 #include <map>
 
 namespace forge