File indexing completed on 2025-03-23 11:13:59

 /*
     SPDX-FileCopyrightText: 2021 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "kwinoffscreeneffect.h"
 #include "kwingltexture.h"
 #include "kwinglutils.h"
 
 namespace KWin
 {
 
 struct OffscreenData
 {
 public:
     virtual ~OffscreenData();
     void setDirty();
     void setShader(GLShader *newShader);
     void setVertexSnappingMode(RenderGeometry::VertexSnappingMode mode);
 
     void paint(EffectWindow *window, const QRegion &region,
                const WindowPaintData &data, const WindowQuadList &quads);
 
     void maybeRender(EffectWindow *window);
 
 private:
     std::unique_ptr<GLTexture> m_texture;
     std::unique_ptr<GLFramebuffer> m_fbo;
     bool m_isDirty = true;
     GLShader *m_shader = nullptr;
     RenderGeometry::VertexSnappingMode m_vertexSnappingMode = RenderGeometry::VertexSnappingMode::Round;
 };
 
 class OffscreenEffectPrivate
 {
 public:
     std::map<EffectWindow *, std::unique_ptr<OffscreenData>> windows;
     QMetaObject::Connection windowDamagedConnection;
     QMetaObject::Connection windowDeletedConnection;
     RenderGeometry::VertexSnappingMode vertexSnappingMode = RenderGeometry::VertexSnappingMode::Round;
 };
 
 OffscreenEffect::OffscreenEffect(QObject *parent)
     : Effect(parent)
     , d(std::make_unique<OffscreenEffectPrivate>())
 {
 }
 
 OffscreenEffect::~OffscreenEffect() = default;
 
 bool OffscreenEffect::supported()
 {
     return effects->isOpenGLCompositing();
 }
 
 void OffscreenEffect::redirect(EffectWindow *window)
 {
     std::unique_ptr<OffscreenData> &offscreenData = d->windows[window];
     if (offscreenData) {
         return;
     }
     offscreenData = std::make_unique<OffscreenData>();
     offscreenData->setVertexSnappingMode(d->vertexSnappingMode);
 
     if (d->windows.size() == 1) {
         setupConnections();
     }
 }
 
 void OffscreenEffect::unredirect(EffectWindow *window)
 {
     d->windows.erase(window);
     if (d->windows.empty()) {
         destroyConnections();
     }
 }
 
 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)
 {
 }
 
 void OffscreenData::maybeRender(EffectWindow *window)
 {
     QRectF logicalGeometry = window->expandedGeometry();
     QRectF deviceGeometry = scaledRect(logicalGeometry, effects->renderTargetScale());
 
     QSize textureSize = deviceGeometry.toAlignedRect().size();
 
     if (!m_texture || m_texture->size() != textureSize) {
         m_texture.reset(new GLTexture(GL_RGBA8, textureSize));
         m_texture->setFilter(GL_LINEAR);
         m_texture->setWrapMode(GL_CLAMP_TO_EDGE);
         m_fbo.reset(new GLFramebuffer(m_texture.get()));
         m_isDirty = true;
     }
 
     if (m_isDirty) {
         GLFramebuffer::pushFramebuffer(m_fbo.get());
         glClearColor(0.0, 0.0, 0.0, 0.0);
         glClear(GL_COLOR_BUFFER_BIT);
 
         QMatrix4x4 projectionMatrix;
         projectionMatrix.ortho(QRectF(0, 0, deviceGeometry.width(), deviceGeometry.height()));
 
         WindowPaintData data;
         data.setXTranslation(-logicalGeometry.x());
         data.setYTranslation(-logicalGeometry.y());
         data.setOpacity(1.0);
         data.setProjectionMatrix(projectionMatrix);
 
         const int mask = Effect::PAINT_WINDOW_TRANSFORMED | Effect::PAINT_WINDOW_TRANSLUCENT;
         effects->drawWindow(window, mask, infiniteRegion(), data);
 
         GLFramebuffer::popFramebuffer();
         m_isDirty = false;
     }
 }
 
 OffscreenData::~OffscreenData()
 {
 }
 
 void OffscreenData::setDirty()
 {
     m_isDirty = true;
 }
 
 void OffscreenData::setShader(GLShader *newShader)
 {
     m_shader = newShader;
 }
 
 void OffscreenData::setVertexSnappingMode(RenderGeometry::VertexSnappingMode mode)
 {
     m_vertexSnappingMode = mode;
 }
 
 void OffscreenData::paint(EffectWindow *window, const QRegion &region,
                           const WindowPaintData &data, const WindowQuadList &quads)
 {
     GLShader *shader = m_shader ? m_shader : ShaderManager::instance()->shader(ShaderTrait::MapTexture | ShaderTrait::Modulate | ShaderTrait::AdjustSaturation);
     ShaderBinder binder(shader);
 
     const qreal scale = effects->renderTargetScale();
 
     GLVertexBuffer *vbo = GLVertexBuffer::streamingBuffer();
     vbo->reset();
     vbo->setAttribLayout(GLVertexBuffer::GLVertex2DLayout, 2, sizeof(GLVertex2D));
 
     RenderGeometry geometry;
     geometry.setVertexSnappingMode(m_vertexSnappingMode);
     for (auto &quad : quads) {
         geometry.appendWindowQuad(quad, scale);
     }
     geometry.postProcessTextureCoordinates(m_texture->matrix(NormalizedCoordinates));
 
     GLVertex2D *map = static_cast<GLVertex2D *>(vbo->map(geometry.count() * sizeof(GLVertex2D)));
     geometry.copy(std::span(map, geometry.count()));
     vbo->unmap();
 
     vbo->bindArrays();
 
     const qreal rgb = data.brightness() * data.opacity();
     const qreal a = data.opacity();
 
     QMatrix4x4 mvp = data.projectionMatrix();
     mvp.translate(window->x() * scale, window->y() * scale);
 
     shader->setUniform(GLShader::ModelViewProjectionMatrix, mvp * data.toMatrix(effects->renderTargetScale()));
     shader->setUniform(GLShader::ModulationConstant, QVector4D(rgb, rgb, rgb, a));
     shader->setUniform(GLShader::Saturation, data.saturation());
     shader->setUniform(GLShader::TextureWidth, m_texture->width());
     shader->setUniform(GLShader::TextureHeight, m_texture->height());
 
     const bool clipping = region != infiniteRegion();
     const QRegion clipRegion = clipping ? effects->mapToRenderTarget(region) : infiniteRegion();
 
     if (clipping) {
         glEnable(GL_SCISSOR_TEST);
     }
 
     glEnable(GL_BLEND);
     glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
     m_texture->bind();
     vbo->draw(clipRegion, GL_TRIANGLES, 0, geometry.count(), clipping);
     m_texture->unbind();
 
     glDisable(GL_BLEND);
     if (clipping) {
         glDisable(GL_SCISSOR_TEST);
     }
     vbo->unbindArrays();
 }
 
 void OffscreenEffect::drawWindow(EffectWindow *window, int mask, const QRegion &region, WindowPaintData &data)
 {
     const auto it = d->windows.find(window);
     if (it == d->windows.end()) {
         effects->drawWindow(window, mask, region, data);
         return;
     }
     OffscreenData *offscreenData = it->second.get();
 
     const QRectF expandedGeometry = window->expandedGeometry();
     const QRectF frameGeometry = window->frameGeometry();
 
     QRectF visibleRect = expandedGeometry;
     visibleRect.moveTopLeft(expandedGeometry.topLeft() - frameGeometry.topLeft());
     WindowQuad quad;
     quad[0] = WindowVertex(visibleRect.topLeft(), QPointF(0, 0));
     quad[1] = WindowVertex(visibleRect.topRight(), QPointF(1, 0));
     quad[2] = WindowVertex(visibleRect.bottomRight(), QPointF(1, 1));
     quad[3] = WindowVertex(visibleRect.bottomLeft(), QPointF(0, 1));
 
     WindowQuadList quads;
     quads.append(quad);
     apply(window, mask, data, quads);
 
     offscreenData->maybeRender(window);
     offscreenData->paint(window, region, data, quads);
 }
 
 void OffscreenEffect::handleWindowDamaged(EffectWindow *window)
 {
     if (const auto it = d->windows.find(window); it != d->windows.end()) {
         it->second->setDirty();
     }
 }
 
 void OffscreenEffect::handleWindowDeleted(EffectWindow *window)
 {
     effects->makeOpenGLContextCurrent();
     unredirect(window);
 }
 
 void OffscreenEffect::setupConnections()
 {
     d->windowDamagedConnection =
         connect(effects, &EffectsHandler::windowDamaged, this, &OffscreenEffect::handleWindowDamaged);
 
     d->windowDeletedConnection =
         connect(effects, &EffectsHandler::windowDeleted, this, &OffscreenEffect::handleWindowDeleted);
 }
 
 void OffscreenEffect::destroyConnections()
 {
     disconnect(d->windowDamagedConnection);
     disconnect(d->windowDeletedConnection);
 
     d->windowDamagedConnection = {};
     d->windowDeletedConnection = {};
 }
 
 void OffscreenEffect::setVertexSnappingMode(RenderGeometry::VertexSnappingMode mode)
 {
     d->vertexSnappingMode = mode;
     for (auto &window : std::as_const(d->windows)) {
         window.second->setVertexSnappingMode(mode);
     }
 }
 
 class CrossFadeWindowData : public OffscreenData
 {
 public:
     QRectF frameGeometryAtCapture;
 };
 
 class CrossFadeEffectPrivate
 {
 public:
     std::map<EffectWindow *, std::unique_ptr<CrossFadeWindowData>> windows;
     qreal progress;
 };
 
 CrossFadeEffect::CrossFadeEffect(QObject *parent)
     : Effect(parent)
     , d(std::make_unique<CrossFadeEffectPrivate>())
 {
 }
 
 CrossFadeEffect::~CrossFadeEffect() = default;
 
 void CrossFadeEffect::drawWindow(EffectWindow *window, int mask, const QRegion &region, WindowPaintData &data)
 {
     const auto it = d->windows.find(window);
 
     // paint the new window (if applicable) underneath
     if (data.crossFadeProgress() > 0 || it == d->windows.end()) {
         Effect::drawWindow(window, mask, region, data);
     }
 
     if (it == d->windows.end()) {
         return;
     }
     CrossFadeWindowData *offscreenData = it->second.get();
 
     // paint old snapshot on top
     WindowPaintData previousWindowData = data;
     previousWindowData.setOpacity((1.0 - data.crossFadeProgress()) * data.opacity());
 
     const QRectF expandedGeometry = window->expandedGeometry();
     const QRectF frameGeometry = window->frameGeometry();
 
     // This is for the case of *non* live effect, when the window buffer we saved has a different size
     // compared to the size the window has now. The "old" window will be rendered scaled to the current
     // window geometry, but everything will be scaled, also the shadow if there is any, making the window
     // frame not line up anymore with window->frameGeometry()
     // to fix that, we consider how much the shadow will have scaled, and use that as margins to the
     // current frame geometry. this causes the scaled window to visually line up perfectly with frameGeometry,
     // having the scaled shadow all outside of it.
     const qreal widthRatio = offscreenData->frameGeometryAtCapture.width() / frameGeometry.width();
     const qreal heightRatio = offscreenData->frameGeometryAtCapture.height() / frameGeometry.height();
 
     const QMarginsF margins(
         (expandedGeometry.x() - frameGeometry.x()) / widthRatio,
         (expandedGeometry.y() - frameGeometry.y()) / heightRatio,
         (frameGeometry.right() - expandedGeometry.right()) / widthRatio,
         (frameGeometry.bottom() - expandedGeometry.bottom()) / heightRatio);
 
     QRectF visibleRect = QRectF(QPointF(0, 0), frameGeometry.size()) - margins;
 
     WindowQuad quad;
     quad[0] = WindowVertex(visibleRect.topLeft(), QPointF(0, 0));
     quad[1] = WindowVertex(visibleRect.topRight(), QPointF(1, 0));
     quad[2] = WindowVertex(visibleRect.bottomRight(), QPointF(1, 1));
     quad[3] = WindowVertex(visibleRect.bottomLeft(), QPointF(0, 1));
 
     WindowQuadList quads;
     quads.append(quad);
     offscreenData->paint(window, region, previousWindowData, quads);
 }
 
 void CrossFadeEffect::redirect(EffectWindow *window)
 {
     if (d->windows.empty()) {
         connect(effects, &EffectsHandler::windowDeleted, this, &CrossFadeEffect::handleWindowDeleted);
     }
 
     std::unique_ptr<CrossFadeWindowData> &offscreenData = d->windows[window];
     if (offscreenData) {
         return;
     }
     offscreenData = std::make_unique<CrossFadeWindowData>();
 
     // Avoid including blur and contrast effects. During a normal painting cycle they
     // won't be included, but since we call effects->drawWindow() outside usual compositing
     // cycle, we have to prevent backdrop effects kicking in.
     const QVariant blurRole = window->data(WindowForceBlurRole);
     window->setData(WindowForceBlurRole, QVariant());
     const QVariant contrastRole = window->data(WindowForceBackgroundContrastRole);
     window->setData(WindowForceBackgroundContrastRole, QVariant());
 
     effects->makeOpenGLContextCurrent();
     offscreenData->maybeRender(window);
     offscreenData->frameGeometryAtCapture = window->frameGeometry();
 
     window->setData(WindowForceBlurRole, blurRole);
     window->setData(WindowForceBackgroundContrastRole, contrastRole);
 }
 
 void CrossFadeEffect::unredirect(EffectWindow *window)
 {
     d->windows.erase(window);
     if (d->windows.empty()) {
         disconnect(effects, &EffectsHandler::windowDeleted, this, &CrossFadeEffect::handleWindowDeleted);
     }
 }
 
 void CrossFadeEffect::handleWindowDeleted(EffectWindow *window)
 {
     unredirect(window);
 }
 
 void CrossFadeEffect::setShader(EffectWindow *window, GLShader *shader)
 {
     if (const auto it = d->windows.find(window); it != d->windows.end()) {
         it->second->setShader(shader);
     }
 }
 
 } // namespace KWin