From 69859aec283875870f81325dcf651c60d2eccbad Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Sun, 13 Nov 2022 15:19:49 +0200
Subject: [PATCH] kwineffects: Bring back OffscreenEffect::setShader()

OffscreenEffect can be still used to apply a shader effect to a window.
---
 src/libkwineffects/kwinoffscreeneffect.cpp | 7 +++++++
 src/libkwineffects/kwinoffscreeneffect.h   | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/src/libkwineffects/kwinoffscreeneffect.cpp b/src/libkwineffects/kwinoffscreeneffect.cpp
index 5caf3f3d32..82c1977ccc 100644
--- a/src/libkwineffects/kwinoffscreeneffect.cpp
+++ b/src/libkwineffects/kwinoffscreeneffect.cpp
@@ -72,6 +72,13 @@ void OffscreenEffect::unredirect(EffectWindow *window)
     }
 }
 
+void OffscreenEffect::setShader(EffectWindow *window, GLShader *shader)
+{
+    if (const auto it = d->windows.find(window); it != d->windows.end()) {
+        it->second->setShader(shader);
+    }
+}
+
 void OffscreenEffect::apply(EffectWindow *window, int mask, WindowPaintData &data, WindowQuadList &quads)
 {
 }
diff --git a/src/libkwineffects/kwinoffscreeneffect.h b/src/libkwineffects/kwinoffscreeneffect.h
index fba5b787d5..fee4b5a2ee 100644
--- a/src/libkwineffects/kwinoffscreeneffect.h
+++ b/src/libkwineffects/kwinoffscreeneffect.h
@@ -13,6 +13,7 @@ namespace KWin
 
 class OffscreenEffectPrivate;
 class CrossFadeEffectPrivate;
+class ShaderEffectPrivate;
 
 /**
  * The OffscreenEffect class is the base class for effects that paint deformed windows.
@@ -56,6 +57,11 @@ protected:
      */
     virtual void apply(EffectWindow *window, int mask, WindowPaintData &data, WindowQuadList &quads);
 
+    /**
+     * Allows to specify a @p shader to draw the redirected texture for @p window.
+     * Can only be called once the window is redirected.
+     **/
+    void setShader(EffectWindow *window, GLShader *shader);
 
 private Q_SLOTS:
     void handleWindowDamaged(EffectWindow *window);