10 files changed, 46 insertions, 0 deletions
diff --git a/src/graphicsmanager.cpp b/src/graphicsmanager.cpp
index 938c0ccf1..4661563e2 100644
--- a/src/graphicsmanager.cpp
+++ b/src/graphicsmanager.cpp
@@ -1054,6 +1054,16 @@ void GraphicsManager::initOpenGLFunctions()
         {
             logger->log1("GL_ARB_vertex_attrib_binding not supported");
         }
+        if (checkGLVersion(4, 3)
+            || supportExtension("GL_ARB_invalidate_subdata"))
+        {
+            logger->log1("found GL_ARB_invalidate_subdata");
+            assignFunction(glInvalidateTexImage, "glInvalidateTexImage");
+        }
+        else
+        {
+            logger->log1("GL_ARB_invalidate_subdata not supported");
+        }
         if (checkGLVersion(4, 4) || supportExtension("GL_ARB_multi_bind"))
         {
             logger->log1("found GL_ARB_multi_bind");
diff --git a/src/render/mgl.cpp b/src/render/mgl.cpp
index 63730fbad..9818b7f04 100644
--- a/src/render/mgl.cpp
+++ b/src/render/mgl.cpp
@@ -95,6 +95,7 @@ defName(glBindVertexBuffers);
 defName(glIsBuffer);
 defName(glVertexAttribIFormat);
 defName(glVertexAttribIPointer);
+defName(glInvalidateTexImage);
 
 #ifdef WIN32
 defName(wglGetExtensionsString);
diff --git a/src/render/mgl.h b/src/render/mgl.h
index 53c6b714b..dbd9a4b38 100644
--- a/src/render/mgl.h
+++ b/src/render/mgl.h
@@ -98,6 +98,7 @@ defNameE(glBindVertexBuffers);
 defNameE(glIsBuffer);
 defNameE(glVertexAttribIFormat);
 defNameE(glVertexAttribIPointer);
+defNameE(glInvalidateTexImage);
 
 #ifdef WIN32
 defNameE(wglGetExtensionsString);
diff --git a/src/render/mgltypes.h b/src/render/mgltypes.h
index 9deefd41f..14b3b5760 100644
--- a/src/render/mgltypes.h
+++ b/src/render/mgltypes.h
@@ -144,6 +144,7 @@ typedef void (APIENTRY *glVertexAttribIFormat_t) (GLuint attribindex,
     GLint size, GLenum type, GLuint relativeoffset);
 typedef void (APIENTRY *glVertexAttribIPointer_t) (GLuint index, GLint size,
     GLenum type, GLsizei stride, const GLvoid * pointer);
+typedef void (APIENTRY *glInvalidateTexImage_t) (GLuint texture, GLint level);
 
 // callback
 typedef void (APIENTRY *GLDEBUGPROC_t) (GLenum source, GLenum type, GLuint id,
diff --git a/src/resources/image.cpp b/src/resources/image.cpp
index d9d2a8a01..d6f5cd27c 100644
--- a/src/resources/image.cpp
+++ b/src/resources/image.cpp
@@ -467,3 +467,12 @@ void Image::SDLTerminateAlphaCache()
     SDLCleanCache();
     mUseAlphaCache = false;
 }
+
+#ifdef USE_OPENGL
+void Image::decRef()
+{
+    if (getRefCount() <= 1)
+        OpenGLImageHelper::invalidate(mGLImage);
+    Resource::decRef();
+}
+#endif
diff --git a/src/resources/image.h b/src/resources/image.h
index 2c67281b7..868b5690e 100644
--- a/src/resources/image.h
+++ b/src/resources/image.h
@@ -167,6 +167,8 @@ class Image notfinal : public Resource
         GLuint getGLImage() const A_WARN_UNUSED
         { return mGLImage; }
 
+        void decRef() override;
+
         GLuint mGLImage;
         int mTexWidth;
         int mTexHeight;
diff --git a/src/resources/openglimagehelper.cpp b/src/resources/openglimagehelper.cpp
index 2ce4bd405..2eadf35ff 100644
--- a/src/resources/openglimagehelper.cpp
+++ b/src/resources/openglimagehelper.cpp
@@ -348,4 +348,13 @@ void OpenGLImageHelper::postInit()
     glGenTextures(texturesSize, &mTextures[mFreeTextureIndex]);
 }
 
+void OpenGLImageHelper::invalidate(const GLuint textureId)
+{
+    if (mglInvalidateTexImage)
+    {
+        logger->log("invalidate: %u", textureId);
+        mglInvalidateTexImage(textureId, 0);
+    }
+}
+
 #endif
diff --git a/src/resources/openglimagehelper.h b/src/resources/openglimagehelper.h
index d87052592..2a91689d9 100644
--- a/src/resources/openglimagehelper.h
+++ b/src/resources/openglimagehelper.h
@@ -116,6 +116,8 @@ class OpenGLImageHelper final : public ImageHelper
         static void setUseTextureSampler(const bool b)
         { mUseTextureSampler = b; }
 
+        static void invalidate(const GLuint textureId);
+
         SDL_Surface *create32BitSurface(int width,
                                         int height) const override final;
 
diff --git a/src/resources/subimage.cpp b/src/resources/subimage.cpp
index 717858ae0..ef9827810 100644
--- a/src/resources/subimage.cpp
+++ b/src/resources/subimage.cpp
@@ -211,3 +211,10 @@ Image *SubImage::getSubImage(const int x, const int y,
     else
         return nullptr;
 }
+
+#ifdef USE_OPENGL
+void SubImage::decRef()
+{
+    Resource::decRef();
+}
+#endif
diff --git a/src/resources/subimage.h b/src/resources/subimage.h
index 27a76d277..2fe562c30 100644
--- a/src/resources/subimage.h
+++ b/src/resources/subimage.h
@@ -79,6 +79,10 @@ class SubImage final : public Image
                            const int width,
                            const int height) override final A_WARN_UNUSED;
 
+#ifdef USE_OPENGL
+        void decRef() override final;
+#endif
+
         SDL_Rect mInternalBounds;
 
     private: