Merge branch 'readbuffer_save' into 'master'

Fix black save game screenshots under certain settings (#6543)

Closes #6543

See merge request OpenMW/openmw!1546

1 files changed, 6 insertions, 3 deletions

diff --git a/apps/openmw/mwrender/screenshotmanager.cpp b/apps/openmw/mwrender/screenshotmanager.cpp
index 1973ca4025..5c3d925c9b 100644
--- a/apps/openmw/mwrender/screenshotmanager.cpp
+++ b/apps/openmw/mwrender/screenshotmanager.cpp
@@ -91,15 +91,18 @@ namespace MWRender
             int width = screenW - leftPadding*2;
             int height = screenH - topPadding*2;
 
-            // Ensure we are reading from the resolved framebuffer and not the multisampled render buffer when in use.
-            // glReadPixel() cannot read from multisampled targets.
+            // Ensure we are reading from the resolved framebuffer and not the multisampled render buffer. Also ensure that the readbuffer is set correctly with rendeirng to FBO.
+            // glReadPixel() cannot read from multisampled targets
             PostProcessor* postProcessor = dynamic_cast<PostProcessor*>(renderInfo.getCurrentCamera()->getUserData());
 
-            if (postProcessor && postProcessor->getFbo() && postProcessor->getMsaaFbo())
+            if (postProcessor && postProcessor->getFbo())
             {
                 osg::GLExtensions* ext = osg::GLExtensions::Get(renderInfo.getContextID(), false);
                 if (ext)
+                {
                     ext->glBindFramebuffer(GL_FRAMEBUFFER_EXT, postProcessor->getFbo()->getHandle(renderInfo.getContextID()));
+                    renderInfo.getState()->glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
+                }
             }
 
             mImage->readPixels(leftPadding, topPadding, width, height, GL_RGB, GL_UNSIGNED_BYTE);