WideAngleCamera: specify cube map texture format

The WideAngleCamera has a texture for a cube map that
uses the same pixel format as the camera image. If there
are intermediate shaders applied to the camera, the choice
of this image format may cause pixel values to be truncated.
To provide flexibility to the user, the pixel format for
the cube map texture can be specified with a custom SDFormat
element in `//camera/lens/gazebo:env_texture_format`
using the same values as `//camera/image/format`.

Signed-off-by: Steve Peters <scpeters@openrobotics.org>

gazebo/rendering/WideAngleCamera.cc

@@ -457,6 +457,10 @@ void WideAngleCamera::Load()
 {
   Camera::Load();
 
+  // Cube map texture format defaults to matching image pixel format
+  this->dataPtr->envCubeMapTextureFormat =
+    static_cast<Ogre::PixelFormat>(this->imageFormat);
+
   this->CreateEnvCameras();
 
   if (this->sdf->HasElement("lens"))
@@ -467,6 +471,13 @@ void WideAngleCamera::Load()
 
     if (sdfLens->HasElement("env_texture_size"))
       this->dataPtr->envTextureSize = sdfLens->Get<int>("env_texture_size");
+
+    const std::string envTextureFormat = "gazebo:env_texture_format";
+    if (sdfLens->HasElement(envTextureFormat))
+    {
+      this->dataPtr->envCubeMapTextureFormat = static_cast<Ogre::PixelFormat>(
+        this->OgrePixelFormat(sdfLens->Get<std::string>(envTextureFormat)));
+    }
   }
   else
     this->dataPtr->lens->Load();
@@ -660,7 +671,7 @@ void WideAngleCamera::CreateEnvRenderTexture(const std::string &_textureName)
           this->dataPtr->envTextureSize,
           this->dataPtr->envTextureSize,
           0,
-          static_cast<Ogre::PixelFormat>(this->imageFormat),
+          this->dataPtr->envCubeMapTextureFormat,
           Ogre::TU_RENDERTARGET,
           0,
           false,

gazebo/rendering/WideAngleCameraPrivate.hh

@@ -20,6 +20,7 @@
 #include <mutex>
 
 #include "gazebo/msgs/msgs.hh"
+#include "gazebo/rendering/ogre_gazebo.h"
 #include "gazebo/util/system.hh"
 
 
@@ -59,6 +60,9 @@ namespace gazebo
       /// \brief Viewports for the render targets
       public: Ogre::Viewport *envViewports[6];
 
+      /// \brief Pixel format for cube map texture
+      public: Ogre::PixelFormat envCubeMapTextureFormat;
+
       /// \brief A single cube map texture
       public: Ogre::Texture *envCubeMapTexture;