From a8123ff65ec552034611f3ceb38e1bcbe94d7452 Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Thu, 15 Feb 2024 10:54:20 +0200
Subject: [PATCH 1/2] plugins/screencast: Fix window screencasts being
 vertically mirrored with memfd

WindowScreenCastSource::render(GLFramebuffer) renders windows with the y
axis flipped, but the offscreen has no FlipY flag set.

BUG: 478223
---
 src/plugins/screencast/windowscreencastsource.cpp | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/plugins/screencast/windowscreencastsource.cpp b/src/plugins/screencast/windowscreencastsource.cpp
index a9dc8a4af75..f3acbeb9ba9 100644
--- a/src/plugins/screencast/windowscreencastsource.cpp
+++ b/src/plugins/screencast/windowscreencastsource.cpp
@@ -52,24 +52,21 @@ void WindowScreenCastSource::render(spa_data *spa, spa_video_format format)
     if (!offscreenTexture) {
         return;
     }
-    GLFramebuffer offscreenTarget(offscreenTexture.get());
+    offscreenTexture->setContentTransform(OutputTransform::FlipY);
 
+    GLFramebuffer offscreenTarget(offscreenTexture.get());
     render(&offscreenTarget);
     grabTexture(offscreenTexture.get(), spa, format);
 }
 
 void WindowScreenCastSource::render(GLFramebuffer *target)
 {
-    const QRectF geometry = m_window->clientGeometry();
-    QMatrix4x4 projectionMatrix;
-    projectionMatrix.scale(1, -1);
-    projectionMatrix.ortho(geometry);
+    RenderTarget renderTarget(target);
+    RenderViewport viewport(m_window->clientGeometry(), 1, renderTarget);
 
     WindowPaintData data;
-    data.setProjectionMatrix(projectionMatrix);
+    data.setProjectionMatrix(viewport.projectionMatrix());
 
-    RenderTarget renderTarget(target);
-    RenderViewport viewport(geometry, 1, renderTarget);
     GLFramebuffer::pushFramebuffer(target);
     glClearColor(0.0, 0.0, 0.0, 0.0);
     glClear(GL_COLOR_BUFFER_BIT);
-- 
GitLab


From 9a006a820e3e9e0a9726f98cea1491973d91d4fc Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Thu, 15 Feb 2024 10:55:23 +0200
Subject: [PATCH 2/2] plugins/screencast: Make region screen cast nicer to
 memfd

Set the FlipY flag so when the memfd code grabs the texture contents, it
doesn't need to flip the texture on the cpu side.
---
 src/plugins/screencast/regionscreencastsource.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/plugins/screencast/regionscreencastsource.cpp b/src/plugins/screencast/regionscreencastsource.cpp
index 567c5a652bf..c81295942d3 100644
--- a/src/plugins/screencast/regionscreencastsource.cpp
+++ b/src/plugins/screencast/regionscreencastsource.cpp
@@ -59,6 +59,7 @@ void RegionScreenCastSource::updateOutput(Output *output)
 
         ShaderBinder shaderBinder(ShaderTrait::MapTexture | ShaderTrait::TransformColorspace);
         QMatrix4x4 projectionMatrix;
+        projectionMatrix.scale(1, -1);
         projectionMatrix.ortho(m_region);
         projectionMatrix.translate(outputGeometry.left(), outputGeometry.top());
 
@@ -82,6 +83,7 @@ void RegionScreenCastSource::ensureTexture()
         if (!m_renderedTexture) {
             return;
         }
+        m_renderedTexture->setContentTransform(OutputTransform::FlipY);
         m_renderedTexture->setFilter(GL_LINEAR);
         m_renderedTexture->setWrapMode(GL_CLAMP_TO_EDGE);
 
-- 
GitLab