Image: make several methods const (#310)

The Data, RGBData, and AvgColor methods do not modify any object data but are not marked as const, which prevents other const methods from calling them. This change API, so it must be done on the main branch. Signed-off-by: Steve Peters <[email protected]>
gazebosim · Feb 10, 2022 · 4256a57 · 4256a57
1 parent 47e6a3a
commit 4256a57
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Showing 3 changed files with 14 additions and 8 deletions.
diff --git a/Migration.md b/Migration.md
@@ -5,6 +5,12 @@ Deprecated code produces compile-time warnings. These warning serve as
 notification to users that their code should be upgraded. The next major
 release will remove the deprecated code.
 
+## Ignition Common 4.X to 5.X
+
+### Modifications
+
+1. `Image::AvgColor`, `Image::Data` and `Image::RGBData` methods are now `const`.
+
 ## Ignition Common 3.X to 4.X
 
 ### Modifications

diff --git a/graphics/include/ignition/common/Image.hh b/graphics/include/ignition/common/Image.hh
@@ -125,13 +125,13 @@ namespace ignition
       /// \brief Get the image as a data array
       /// \param[out] _data Pointer to a NULL array of char.
       /// \param[out] _count The resulting data array size
-      public: void Data(unsigned char **_data, unsigned int &_count);
+      public: void Data(unsigned char **_data, unsigned int &_count) const;
 
       /// \brief Get only the RGB data from the image. This will drop the
       /// alpha channel if one is present.
       /// \param[out] _data Pointer to a NULL array of char.
       /// \param[out] _count The resulting data array size
-      public: void RGBData(unsigned char **_data, unsigned int &_count);
+      public: void RGBData(unsigned char **_data, unsigned int &_count) const;
 
       /// \brief Get the width
       /// \return The image width
@@ -166,7 +166,7 @@ namespace ignition
 
       /// \brief Get the average color
       /// \return The average color
-      public: math::Color AvgColor();
+      public: math::Color AvgColor() const;
 
       /// \brief Get the max color
       /// \return The max color

diff --git a/graphics/src/Image.cc b/graphics/src/Image.cc
@@ -61,7 +61,7 @@ namespace ignition
       /// \param[in] _height Height of the image
       /// \return bitmap data with red and blue pixels swapped
       public: FIBITMAP* SwapRedBlue(const unsigned int &_width,
-                                    const unsigned int &_height);
+                                    const unsigned int &_height) const;
     };
   }
 }
@@ -249,7 +249,7 @@ int Image::Pitch() const
 }
 
 //////////////////////////////////////////////////
-void Image::RGBData(unsigned char **_data, unsigned int &_count)
+void Image::RGBData(unsigned char **_data, unsigned int &_count) const
 {
   FIBITMAP *tmp = this->dataPtr->bitmap;
   FIBITMAP *tmp2 = nullptr;
@@ -266,7 +266,7 @@ void Image::RGBData(unsigned char **_data, unsigned int &_count)
 }
 
 //////////////////////////////////////////////////
-void Image::Data(unsigned char **_data, unsigned int &_count)
+void Image::Data(unsigned char **_data, unsigned int &_count) const
 {
   if (this->dataPtr->ShouldSwapRedBlue())
   {
@@ -398,7 +398,7 @@ math::Color Image::Pixel(unsigned int _x, unsigned int _y) const
 }
 
 //////////////////////////////////////////////////
-math::Color Image::AvgColor()
+math::Color Image::AvgColor() const
 {
   unsigned int x, y;
   double rsum, gsum, bsum;
@@ -582,7 +582,7 @@ bool Image::Implementation::CanSwapRedBlue() const
 
 //////////////////////////////////////////////////
 FIBITMAP* Image::Implementation::SwapRedBlue(const unsigned int &_width,
-                                    const unsigned int &_height)
+                                    const unsigned int &_height) const
 {
   FIBITMAP *copy = FreeImage_Copy(this->bitmap, 0, 0, _width, _height);