add colorspace metadata to surfaces and items, and use it in the OpenGL renderer

src/scene/item.cpp

@@ -442,6 +442,16 @@ void Item::markSortedChildItemsDirty()
     m_sortedChildItems.reset();
 }
 
+const ColorDescription &Item::colorDescription() const
+{
+    return m_colorDescription;
+}
+
+void Item::setColorDescription(const ColorDescription &description)
+{
+    m_colorDescription = description;
+}
+
 } // namespace KWin
 
 #include "moc_item.cpp"

src/scene/item.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include "libkwineffects/colorspace.h"
 #include "libkwineffects/kwineffects.h"
 #include "libkwineffects/kwinglobals.h"
 
@@ -111,6 +112,7 @@ public:
 
     WindowQuadList quads() const;
     virtual void preprocess();
+    const ColorDescription &colorDescription() const;
 
 Q_SIGNALS:
     void childAdded(Item *item);
@@ -132,6 +134,7 @@ Q_SIGNALS:
 protected:
     virtual WindowQuadList buildQuads() const;
     void discardQuads();
+    void setColorDescription(const ColorDescription &description);
 
 private:
     void addChild(Item *item);
@@ -159,6 +162,7 @@ private:
     QMap<SceneDelegate *, QRegion> m_repaints;
     mutable std::optional<WindowQuadList> m_quads;
     mutable std::optional<QList<Item *>> m_sortedChildItems;
+    ColorDescription m_colorDescription = ColorDescription::sRGB;
 };
 
 } // namespace KWin

src/scene/itemrenderer_opengl.cpp

@@ -175,6 +175,7 @@ void ItemRendererOpenGL::createRenderNode(Item *item, RenderContext *context)
                 .hasAlpha = true,
                 .coordinateType = UnnormalizedCoordinates,
                 .scale = scale,
+                .colorDescription = item->colorDescription(),
             });
         }
     } else if (auto decorationItem = qobject_cast<DecorationItem *>(item)) {
@@ -188,6 +189,7 @@ void ItemRendererOpenGL::createRenderNode(Item *item, RenderContext *context)
                 .hasAlpha = true,
                 .coordinateType = UnnormalizedCoordinates,
                 .scale = scale,
+                .colorDescription = item->colorDescription(),
             });
         }
     } else if (auto surfaceItem = qobject_cast<SurfaceItem *>(item)) {
@@ -202,6 +204,7 @@ void ItemRendererOpenGL::createRenderNode(Item *item, RenderContext *context)
                     .hasAlpha = pixmap->hasAlphaChannel(),
                     .coordinateType = NormalizedCoordinates,
                     .scale = scale,
+                    .colorDescription = item->colorDescription(),
                 });
             }
         }
@@ -215,6 +218,7 @@ void ItemRendererOpenGL::createRenderNode(Item *item, RenderContext *context)
                 .hasAlpha = imageItem->image().hasAlphaChannel(),
                 .coordinateType = NormalizedCoordinates,
                 .scale = scale,
+                .colorDescription = item->colorDescription(),
             });
         }
     }
@@ -281,10 +285,7 @@ void ItemRendererOpenGL::renderItem(const RenderTarget &renderTarget, const Rend
         return;
     }
 
-    ShaderTraits shaderTraits = ShaderTrait::MapTexture;
-    if (renderTarget.colorDescription() != ColorDescription::sRGB) {
-        shaderTraits |= ShaderTrait::TransformColorspace;
-    }
+    ShaderTraits shaderTraits = ShaderTrait::MapTexture | ShaderTrait::TransformColorspace;
 
     if (data.brightness() != 1.0) {
         shaderTraits |= ShaderTrait::Modulate;
@@ -330,9 +331,6 @@ void ItemRendererOpenGL::renderItem(const RenderTarget &renderTarget, const Rend
         shader->setUniform(GLShader::Saturation, data.saturation());
         shader->setUniform(GLShader::Vec3Uniform::PrimaryBrightness, QVector3D(toXYZ(1, 0), toXYZ(1, 1), toXYZ(1, 2)));
     }
-    if (shaderTraits & ShaderTrait::TransformColorspace) {
-        shader->setColorspaceUniformsFromSRGB(renderTarget.colorDescription());
-    }
 
     if (renderContext.hardwareClipping) {
         glEnable(GL_SCISSOR_TEST);
@@ -363,6 +361,7 @@ void ItemRendererOpenGL::renderItem(const RenderTarget &renderTarget, const Rend
                                modulate(renderNode.opacity, data.brightness()));
             opacity = renderNode.opacity;
         }
+        shader->setColorspaceUniforms(renderNode.colorDescription, renderTarget.colorDescription());
 
         renderNode.texture->bind();
 

src/scene/itemrenderer_opengl.h

@@ -27,6 +27,7 @@ public:
         bool hasAlpha = false;
         TextureCoordinateType coordinateType = UnnormalizedCoordinates;
         qreal scale = 1.0;
+        ColorDescription colorDescription;
     };
 
     struct RenderContext

src/scene/surfaceitem_wayland.cpp

@@ -40,6 +40,8 @@ SurfaceItemWayland::SurfaceItemWayland(SurfaceInterface *surface, Scene *scene,
             this, &SurfaceItemWayland::addDamage);
     connect(surface, &SurfaceInterface::childSubSurfaceRemoved,
             this, &SurfaceItemWayland::handleChildSubSurfaceRemoved);
+    connect(surface, &SurfaceInterface::colorDescriptionChanged,
+            this, &SurfaceItemWayland::handleColorDescriptionChanged);
 
     SubSurfaceInterface *subsurface = surface->subSurface();
     if (subsurface) {
@@ -162,7 +164,12 @@ std::unique_ptr<SurfacePixmap> SurfaceItemWayland::createPixmap()
 
 ContentType SurfaceItemWayland::contentType() const
 {
-    return m_surface->contentType();
+    return m_surface ? m_surface->contentType() : ContentType::None;
+}
+
+void SurfaceItemWayland::handleColorDescriptionChanged()
+{
+    setColorDescription(m_surface->colorDescription());
 }
 
 SurfacePixmapWayland::SurfacePixmapWayland(SurfaceItemWayland *item, QObject *parent)

src/scene/surfaceitem_wayland.h

@@ -46,6 +46,7 @@ private Q_SLOTS:
     void handleChildSubSurfacesChanged();
     void handleSubSurfacePositionChanged();
     void handleSubSurfaceMappedChanged();
+    void handleColorDescriptionChanged();
 
 protected:
     std::unique_ptr<SurfacePixmap> createPixmap() override;

src/wayland/surface.cpp

@@ -639,6 +639,10 @@ void SurfaceState::mergeInto(SurfaceState *target)
         target->presentationHint = presentationHint;
         target->tearingIsSet = true;
     }
+    if (colorDescriptionIsSet) {
+        target->colorDescription = colorDescription;
+        target->colorDescriptionIsSet = true;
+    }
 
     *this = SurfaceState{};
     serial = target->serial;
@@ -657,6 +661,7 @@ void SurfaceInterfacePrivate::applyState(SurfaceState *next)
     const bool slideChanged = next->slideIsSet;
     const bool subsurfaceOrderChanged = next->subsurfaceOrderChanged;
     const bool visibilityChanged = bufferChanged && bool(current->buffer) != bool(next->buffer);
+    const bool colorDescriptionChanged = next->colorDescriptionIsSet;
 
     const QSizeF oldSurfaceSize = surfaceSize;
     const QSize oldBufferSize = bufferSize;
@@ -749,6 +754,9 @@ void SurfaceInterfacePrivate::applyState(SurfaceState *next)
     if (subsurfaceOrderChanged) {
         Q_EMIT q->childSubSurfacesChanged();
     }
+    if (colorDescriptionChanged) {
+        Q_EMIT q->colorDescriptionChanged();
+    }
 
     if (bufferChanged) {
         if (current->buffer && (!current->damage.isEmpty() || !current->bufferDamage.isEmpty())) {
@@ -1138,6 +1146,11 @@ PresentationHint SurfaceInterface::presentationHint() const
     return d->current->presentationHint;
 }
 
+const ColorDescription &SurfaceInterface::colorDescription() const
+{
+    return d->current->colorDescription;
+}
+
 void SurfaceInterface::setPreferredBufferScale(qreal scale)
 {
     if (scale == d->preferredBufferScale) {

src/wayland/surface.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include "core/output.h"
+#include "libkwineffects/colorspace.h"
 
 #include <QMatrix4x4>
 #include <QObject>
@@ -371,6 +372,8 @@ public:
     Transaction *lastTransaction() const;
     void setLastTransaction(Transaction *transaction);
 
+    const ColorDescription &colorDescription() const;
+
 Q_SIGNALS:
     /**
      * This signal is emitted when the underlying wl_surface resource is about to be freed.
@@ -456,6 +459,8 @@ Q_SIGNALS:
      */
     void inhibitsIdleChanged();
 
+    void colorDescriptionChanged();
+
     /**
      * Emitted when the Surface has been committed.
      *

src/wayland/surface_p.h

@@ -52,6 +52,7 @@ struct SurfaceState
     bool bufferTransformIsSet = false;
     bool contentTypeIsSet = false;
     bool tearingIsSet = false;
+    bool colorDescriptionIsSet = false;
     qint32 bufferScale = 1;
     OutputTransform bufferTransform = OutputTransform::Normal;
     wl_list frameCallbacks;
@@ -63,6 +64,7 @@ struct SurfaceState
     QPointer<SlideInterface> slide;
     ContentType contentType = ContentType::None;
     PresentationHint presentationHint = PresentationHint::VSync;
+    ColorDescription colorDescription = ColorDescription::sRGB;
 
     struct
     {