[Render/Texture2D] Recovering the image can now work with OpenGL ES

- The workaround is to set the texture as a read framebuffer output, then recover this
  - It was done in tests until now and has been moved to the actual function

include/RaZ/Render/Texture.hpp

@@ -158,14 +158,12 @@ class Texture2D final : public Texture {
   /// Fills the texture with a single color.
   /// \param color Color to fill the texture with.
   void fill(const Color& color);
-#if !defined(USE_OPENGL_ES)
   /// Retrieves the texture's data from the GPU.
   /// \warning The pixel storage pack & unpack alignments should be set to 1 in order to recover actual pixels.
   /// \see Renderer::setPixelStorage()
   /// \warning Retrieving an image from the GPU is slow; use this function with caution.
   /// \return Recovered image.
   Image recoverImage() const;
-#endif
 
 private:
   void load() const override;

src/RaZ/Render/Texture.cpp

@@ -1,5 +1,8 @@
 #include "RaZ/Data/Color.hpp"
 #include "RaZ/Data/Image.hpp"
+#if defined(USE_OPENGL_ES)
+#include "RaZ/Render/Framebuffer.hpp"
+#endif
 #include "RaZ/Render/Renderer.hpp"
 #include "RaZ/Render/Texture.hpp"
 #include "RaZ/Utils/Logger.hpp"
@@ -321,21 +324,30 @@ void Texture2D::fill(const Color& color) {
   unbind();
 }
 
-#if !defined(USE_OPENGL_ES) // Renderer::recoverTextureData() is unavailable with OpenGL ES
 Image Texture2D::recoverImage() const {
   Image img(m_width, m_height, static_cast<ImageColorspace>(m_colorspace), (m_dataType == TextureDataType::BYTE ? ImageDataType::BYTE : ImageDataType::FLOAT));
 
+  const PixelDataType pixelDataType = (m_dataType == TextureDataType::BYTE ? PixelDataType::UBYTE : PixelDataType::FLOAT);
+
+#if !defined(USE_OPENGL_ES)
   bind();
-  Renderer::recoverTextureData(TextureType::TEXTURE_2D,
-                               0,
-                               recoverFormat(m_colorspace),
-                               (m_dataType == TextureDataType::BYTE ? PixelDataType::UBYTE : PixelDataType::FLOAT),
-                               img.getDataPtr());
+  Renderer::recoverTextureData(TextureType::TEXTURE_2D, 0, recoverFormat(m_colorspace), pixelDataType, img.getDataPtr());
   unbind();
+#else
+  // Recovering an image directly from a texture (glGetTexImage()) is not possible with OpenGL ES; a framebuffer must be used to read the texture from instead
+  // See: https://stackoverflow.com/a/53993894/3292304
+
+  const Framebuffer dummyFramebuffer;
+  Renderer::bindFramebuffer(dummyFramebuffer.getIndex(), FramebufferType::READ_FRAMEBUFFER);
+
+  Renderer::setFramebufferTexture2D(FramebufferAttachment::COLOR0, m_index, 0, TextureType::TEXTURE_2D, FramebufferType::READ_FRAMEBUFFER);
+  Renderer::recoverFrame(m_width, m_height, recoverFormat(m_colorspace), pixelDataType, img.getDataPtr());
+
+  Renderer::unbindFramebuffer(FramebufferType::READ_FRAMEBUFFER);
+#endif
 
   return img;
 }
-#endif
 
 void Texture2D::load() const {
   if (m_colorspace == TextureColorspace::INVALID)

tests/src/RaZ/Render/RenderProcess.cpp

@@ -25,24 +25,7 @@ Raz::Image renderFrame(Raz::World& world, const Raz::Texture2DPtr& output, const
   //  fail under Linux (as the second rendered frame of each test might be empty)
   world.update({});
 
-#if !defined(USE_OPENGL_ES)
   Raz::Image renderedImg = output->recoverImage();
-#else
-  // Recovering an image directly from a texture (glReadPixels()) is not possible with OpenGL ES; a framebuffer must be used to read the texture from instead
-  // See: https://stackoverflow.com/a/53993894/3292304
-  const Raz::Framebuffer intermFramebuffer;
-  Raz::Renderer::bindFramebuffer(intermFramebuffer.getIndex(), Raz::FramebufferType::READ_FRAMEBUFFER);
-  Raz::Renderer::setFramebufferTexture2D(Raz::FramebufferAttachment::COLOR0,
-                                         output->getIndex(),
-                                         0,
-                                         Raz::TextureType::TEXTURE_2D,
-                                         Raz::FramebufferType::READ_FRAMEBUFFER);
-
-  Raz::Image renderedImg(output->getWidth(), output->getHeight(), Raz::ImageColorspace::RGB, Raz::ImageDataType::BYTE);
-  Raz::Renderer::recoverFrame(output->getWidth(), output->getHeight(), Raz::TextureFormat::RGB, Raz::PixelDataType::UBYTE, renderedImg.getDataPtr());
-
-  Raz::Renderer::unbindFramebuffer(Raz::FramebufferType::READ_FRAMEBUFFER);
-#endif
 
   if (!renderedImgPath.isEmpty())
     Raz::ImageFormat::save(renderedImgPath, renderedImg, true);