1 files changed, 110 insertions, 0 deletions
diff --git a/src/gui/painting/qbackingstoredefaultcompositor_p.h b/src/gui/painting/qbackingstoredefaultcompositor_p.h
new file mode 100644
index 0000000000..c5a8ffd328
--- /dev/null
+++ b/src/gui/painting/qbackingstoredefaultcompositor_p.h
@@ -0,0 +1,110 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QBACKINGSTOREDEFAULTCOMPOSITOR_P_H
+#define QBACKINGSTOREDEFAULTCOMPOSITOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <qpa/qplatformbackingstore.h>
+#include <rhi/qrhi.h>
+
+QT_BEGIN_NAMESPACE
+
+class QBackingStoreDefaultCompositor
+{
+public:
+    ~QBackingStoreDefaultCompositor();
+
+    void reset();
+
+    QRhiTexture *toTexture(const QPlatformBackingStore *backingStore,
+                           QRhi *rhi,
+                           QRhiResourceUpdateBatch *resourceUpdates,
+                           const QRegion &dirtyRegion,
+                           QPlatformBackingStore::TextureFlags *flags) const;
+
+    QPlatformBackingStore::FlushResult flush(QPlatformBackingStore *backingStore,
+                                             QRhi *rhi,
+                                             QRhiSwapChain *swapchain,
+                                             QWindow *window,
+                                             qreal sourceDevicePixelRatio,
+                                             const QRegion &region,
+                                             const QPoint &offset,
+                                             QPlatformTextureList *textures,
+                                             bool translucentBackground);
+
+private:
+    enum UpdateUniformOption {
+        NeedsRedBlueSwap = 1 << 0,
+        NeedsAlphaRotate = 1 << 1
+    };
+    Q_DECLARE_FLAGS(UpdateUniformOptions, UpdateUniformOption)
+    enum UpdateQuadDataOption {
+        NeedsLinearFiltering = 1 << 0
+    };
+    Q_DECLARE_FLAGS(UpdateQuadDataOptions, UpdateQuadDataOption)
+
+    void ensureResources(QRhiResourceUpdateBatch *resourceUpdates, QRhiRenderPassDescriptor *rpDesc);
+    QRhiTexture *toTexture(const QImage &image,
+                           QRhi *rhi,
+                           QRhiResourceUpdateBatch *resourceUpdates,
+                           const QRegion &dirtyRegion,
+                           QPlatformBackingStore::TextureFlags *flags) const;
+
+    mutable QRhi *m_rhi = nullptr;
+    mutable std::unique_ptr<QRhiTexture> m_texture;
+
+    std::unique_ptr<QRhiBuffer> m_vbuf;
+    std::unique_ptr<QRhiSampler> m_samplerNearest;
+    std::unique_ptr<QRhiSampler> m_samplerLinear;
+    std::unique_ptr<QRhiGraphicsPipeline> m_psNoBlend;
+    std::unique_ptr<QRhiGraphicsPipeline> m_psBlend;
+    std::unique_ptr<QRhiGraphicsPipeline> m_psPremulBlend;
+
+    struct PerQuadData {
+        QRhiBuffer *ubuf = nullptr;
+        // All srbs are layout-compatible.
+        QRhiShaderResourceBindings *srb = nullptr;
+        QRhiShaderResourceBindings *srbExtra = nullptr; // may be null (used for stereo)
+        QRhiTexture *lastUsedTexture = nullptr;
+        QRhiTexture *lastUsedTextureExtra = nullptr;    // may be null (used for stereo)
+        QRhiSampler::Filter lastUsedFilter = QRhiSampler::None;
+        bool isValid() const { return ubuf && srb; }
+        void reset() {
+            delete ubuf;
+            ubuf = nullptr;
+            delete srb;
+            srb = nullptr;
+            if (srbExtra) {
+                delete srbExtra;
+                srbExtra = nullptr;
+            }
+            lastUsedTexture = nullptr;
+            lastUsedTextureExtra = nullptr;
+            lastUsedFilter = QRhiSampler::None;
+        }
+    };
+    PerQuadData m_widgetQuadData;
+    QVarLengthArray<PerQuadData, 8> m_textureQuadData;
+
+    PerQuadData createPerQuadData(QRhiTexture *texture, QRhiTexture *textureExtra = nullptr);
+    void updatePerQuadData(PerQuadData *d, QRhiTexture *texture, QRhiTexture *textureExtra = nullptr,
+                           UpdateQuadDataOptions options = {});
+    void updateUniforms(PerQuadData *d, QRhiResourceUpdateBatch *resourceUpdates,
+                        const QMatrix4x4 &target, const QMatrix3x3 &source,
+                        UpdateUniformOptions options = {});
+};
+
+QT_END_NAMESPACE
+
+#endif // QBACKINGSTOREDEFAULTCOMPOSITOR_P_H