Add the graphics api independent scenegraph port

Opt in via environment variables:
QSG_RHI=1 -> enable using QRhi instead of GL
QSG_RHI_BACKEND -> set to vulkan, metal, d3d11, gl to override the default
(the default is d3d11 on Windows, metal on Mac, gl elsewhere)

Or force a given rhi backend via the existing
QQuickWindow::setSceneGraphBackend().

Otherwise the default behavior is the same as before, the rhi code path
is never active by default.

-no-opengl builds are supported in the sense that they work and default
to the software backend. However, the rhi code path cannot currently be
used in such builds, even though QRhi from qtbase is fully functional
with Vulkan, D3D, or Metal even when qtbase was configured with
-no-opengl. This cannot be utilized by Quick atm due to OpenGL usage
being all over the place in the sources corresponding to the default
backend, and those host the rhi code path as well. This will be cleaned up
hopefully in Qt 6, with the removal all direct OpenGL usage.

Other env.vars.:
QSG_RHI_DEBUG_LAYER=1 -> enable D3D debug or Vulkan validation layer
(assuming the system is set up for this)
QSG_RHI_SHADEREFFECT_DEBUG=1 -> print stuff from ShaderEffect
QSG_SAMPLES=1,2,4,... -> MSAA sample count (but QSurfaceFormat works too)
QT_D3D_ADAPTER_INDEX=0,1,... -> D3D adapter index
QT_VK_PHYSICAL_DEVICE_INDEX=0,1,... -> Vulkan physical device index
QSG_RHI_UINT32_INDEX=1 -> always use uint index data (both
merged/unmerged, convert when needed - with some rhi backends this is
implicit)
QSG_RENDER_LOOP -> to override the render loop as usual. The default
with RHI is threaded for Metal, threaded for Vulkan on Windows, basic
for Vulkan on Linux and Android (to be checked later), while the existing
rules apply for OpenGL.

Not supported when running with QRhi:
  - particles
  - compressed atlases (though this is transparent to the apps)
  - QSGRenderNode
  - QQuickRenderControl
  - QQuickFramebufferObject
  - certain QQuickWindow functionality that depends directly on OpenGL
  - anisotropic filtering for textures
  - native text may lack some gamma correction
  - QSGEngine applicability unclear
  - some QML profiler logs may be incorrect or irrelevant

Change-Id: I7822e99ad79e342e4166275da6e9e66498d76521
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

4 files changed, 201 insertions, 11 deletions

diff --git a/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture.cpp b/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture.cpp
index 796bc870de..d3dc4978f2 100644
--- a/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture.cpp
+++ b/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture.cpp
@@ -65,7 +65,7 @@ namespace QSGCompressedAtlasTexture
 {
 
 Atlas::Atlas(const QSize &size, uint format)
-    : QSGAtlasTexture::AtlasBase(size)
+    : QSGOpenGLAtlasTexture::AtlasBase(size)
     , m_format(format)
 {
 }
@@ -117,7 +117,7 @@ void Atlas::uploadPendingTexture(int i)
 }
 
 Texture::Texture(Atlas *atlas, const QRect &textureRect, const QByteArray &data, int dataLength, int dataOffset, const QSize &size)
-    : QSGAtlasTexture::TextureBase(atlas, textureRect)
+    : QSGOpenGLAtlasTexture::TextureBase(atlas, textureRect)
     , m_nonatlas_texture(nullptr)
     , m_data(data)
     , m_size(size)
diff --git a/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture_p.h b/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture_p.h
index 59e935b623..78051778f5 100644
--- a/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture_p.h
+++ b/src/quick/scenegraph/compressedtexture/qsgcompressedatlastexture_p.h
@@ -57,7 +57,7 @@
 
 #include <QtQuick/QSGTexture>
 #include <QtQuick/private/qsgareaallocator_p.h>
-#include <QtQuick/private/qsgatlastexture_p.h>
+#include <QtQuick/private/qsgopenglatlastexture_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -67,7 +67,7 @@ namespace QSGCompressedAtlasTexture {
 
 class Texture;
 
-class Atlas : public QSGAtlasTexture::AtlasBase
+class Atlas : public QSGOpenGLAtlasTexture::AtlasBase
 {
 public:
     Atlas(const QSize &size, uint format);
@@ -84,7 +84,7 @@ private:
     uint m_format;
 };
 
-class Texture : public QSGAtlasTexture::TextureBase
+class Texture : public QSGOpenGLAtlasTexture::TextureBase
 {
     Q_OBJECT
 public:
diff --git a/src/quick/scenegraph/compressedtexture/qsgcompressedtexture.cpp b/src/quick/scenegraph/compressedtexture/qsgcompressedtexture.cpp
index d3310bc11c..1a8bddaa6e 100644
--- a/src/quick/scenegraph/compressedtexture/qsgcompressedtexture.cpp
+++ b/src/quick/scenegraph/compressedtexture/qsgcompressedtexture.cpp
@@ -44,13 +44,15 @@
 #include <QOpenGLFunctions>
 #include <QDebug>
 #include <QtQuick/private/qquickwindow_p.h>
+#include <QtGui/private/qrhi_p.h>
 
 QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(QSG_LOG_TEXTUREIO, "qt.scenegraph.textureio");
 
 QSGCompressedTexture::QSGCompressedTexture(const QTextureFileData &texData)
-    : m_textureData(texData)
+    : QSGTexture(*(new QSGCompressedTexturePrivate)),
+      m_textureData(texData)
 {
     m_size = m_textureData.size();
     m_hasAlpha = !formatIsOpaque(m_textureData.glInternalFormat());
@@ -68,6 +70,8 @@ QSGCompressedTexture::~QSGCompressedTexture()
         funcs->glDeleteTextures(1, &m_textureId);
     }
 #endif
+
+    delete m_texture;
 }
 
 int QSGCompressedTexture::textureId() const
@@ -85,6 +89,20 @@ int QSGCompressedTexture::textureId() const
     return m_textureId;
 }
 
+int QSGCompressedTexturePrivate::comparisonKey() const
+{
+    Q_Q(const QSGCompressedTexture);
+    // not textureId() as that would create an id when not yet done - that's not wanted here
+    if (q->m_textureId)
+        return q->m_textureId;
+
+    if (q->m_texture)
+        return int(qintptr(q->m_texture));
+
+    // two textures (and so materials) with not-yet-created texture underneath are never equal
+    return int(qintptr(q));
+}
+
 QSize QSGCompressedTexture::textureSize() const
 {
     return m_size;
@@ -145,6 +163,165 @@ void QSGCompressedTexture::bind()
 #endif // QT_CONFIG(opengl)
 }
 
+static QPair<QRhiTexture::Format, bool> toRhiCompressedFormat(uint glinternalformat)
+{
+    switch (glinternalformat) {
+    case QOpenGLTexture::RGB_DXT1:
+        return { QRhiTexture::BC1, false };
+    case QOpenGLTexture::SRGB_DXT1:
+        return { QRhiTexture::BC1, true };
+
+    case QOpenGLTexture::RGBA_DXT3:
+        return { QRhiTexture::BC3, false };
+    case QOpenGLTexture::SRGB_Alpha_DXT3:
+        return { QRhiTexture::BC3, true };
+
+    case QOpenGLTexture::RGBA_DXT5:
+        return { QRhiTexture::BC5, false };
+    case QOpenGLTexture::SRGB_Alpha_DXT5:
+        return { QRhiTexture::BC5, true };
+
+    case QOpenGLTexture::RGB8_ETC2:
+        return { QRhiTexture::ETC2_RGB8, false };
+    case QOpenGLTexture::SRGB8_ETC2:
+        return { QRhiTexture::ETC2_RGB8, true };
+
+    case QOpenGLTexture::RGB8_PunchThrough_Alpha1_ETC2:
+        return { QRhiTexture::ETC2_RGB8A1, false };
+    case QOpenGLTexture::SRGB8_PunchThrough_Alpha1_ETC2:
+        return { QRhiTexture::ETC2_RGB8A1, true };
+
+    case QOpenGLTexture::RGBA8_ETC2_EAC:
+        return { QRhiTexture::ETC2_RGBA8, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ETC2_EAC:
+        return { QRhiTexture::ETC2_RGBA8, true };
+
+    case QOpenGLTexture::RGBA_ASTC_4x4:
+        return { QRhiTexture::ASTC_4x4, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_4x4:
+        return { QRhiTexture::ASTC_4x4, true };
+
+    case QOpenGLTexture::RGBA_ASTC_5x4:
+        return { QRhiTexture::ASTC_5x4, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_5x4:
+        return { QRhiTexture::ASTC_5x4, true };
+
+    case QOpenGLTexture::RGBA_ASTC_5x5:
+        return { QRhiTexture::ASTC_5x5, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_5x5:
+        return { QRhiTexture::ASTC_5x5, true };
+
+    case QOpenGLTexture::RGBA_ASTC_6x5:
+        return { QRhiTexture::ASTC_6x5, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_6x5:
+        return { QRhiTexture::ASTC_6x5, true };
+
+    case QOpenGLTexture::RGBA_ASTC_6x6:
+        return { QRhiTexture::ASTC_6x6, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_6x6:
+        return { QRhiTexture::ASTC_6x6, true };
+
+    case QOpenGLTexture::RGBA_ASTC_8x5:
+        return { QRhiTexture::ASTC_8x5, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_8x5:
+        return { QRhiTexture::ASTC_8x5, true };
+
+    case QOpenGLTexture::RGBA_ASTC_8x6:
+        return { QRhiTexture::ASTC_8x6, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_8x6:
+        return { QRhiTexture::ASTC_8x6, true };
+
+    case QOpenGLTexture::RGBA_ASTC_8x8:
+        return { QRhiTexture::ASTC_8x8, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_8x8:
+        return { QRhiTexture::ASTC_8x8, true };
+
+    case QOpenGLTexture::RGBA_ASTC_10x5:
+        return { QRhiTexture::ASTC_10x5, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_10x5:
+        return { QRhiTexture::ASTC_10x5, true };
+
+    case QOpenGLTexture::RGBA_ASTC_10x6:
+        return { QRhiTexture::ASTC_10x6, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_10x6:
+        return { QRhiTexture::ASTC_10x6, true };
+
+    case QOpenGLTexture::RGBA_ASTC_10x8:
+        return { QRhiTexture::ASTC_10x8, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_10x8:
+        return { QRhiTexture::ASTC_10x8, true };
+
+    case QOpenGLTexture::RGBA_ASTC_10x10:
+        return { QRhiTexture::ASTC_10x10, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_10x10:
+        return { QRhiTexture::ASTC_10x10, true };
+
+    case QOpenGLTexture::RGBA_ASTC_12x10:
+        return { QRhiTexture::ASTC_12x10, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_12x10:
+        return { QRhiTexture::ASTC_12x10, true };
+
+    case QOpenGLTexture::RGBA_ASTC_12x12:
+        return { QRhiTexture::ASTC_12x12, false };
+    case QOpenGLTexture::SRGB8_Alpha8_ASTC_12x12:
+        return { QRhiTexture::ASTC_12x12, true };
+
+    default:
+        return { QRhiTexture::UnknownFormat, false };
+    }
+}
+
+QRhiTexture *QSGCompressedTexturePrivate::rhiTexture() const
+{
+    Q_Q(const QSGCompressedTexture);
+    return q->m_texture;
+}
+
+void QSGCompressedTexturePrivate::updateRhiTexture(QRhi *rhi, QRhiResourceUpdateBatch *resourceUpdates)
+{
+    Q_Q(QSGCompressedTexture);
+    if (q->m_uploaded)
+        return;
+
+    q->m_uploaded = true; // even if fails, no point in trying again
+
+    if (!q->m_textureData.isValid()) {
+        qCDebug(QSG_LOG_TEXTUREIO, "Invalid texture data for %s", q->m_textureData.logName().constData());
+        return;
+    }
+
+    const QPair<QRhiTexture::Format, bool> fmt = toRhiCompressedFormat(q->m_textureData.glInternalFormat());
+    if (fmt.first == QRhiTexture::UnknownFormat) {
+        qWarning("Unknown compressed format 0x%x", q->m_textureData.glInternalFormat());
+        return;
+    }
+
+    QRhiTexture::Flags texFlags = 0;
+    if (fmt.second)
+        texFlags |= QRhiTexture::sRGB;
+
+    if (!rhi->isTextureFormatSupported(fmt.first, texFlags)) {
+        qWarning("Unsupported compressed format 0x%x", q->m_textureData.glInternalFormat());
+        return;
+    }
+
+    if (!q->m_texture) {
+        q->m_texture = rhi->newTexture(fmt.first, q->m_size, 1, texFlags);
+        if (!q->m_texture->build()) {
+            qWarning("Failed to create QRhiTexture for compressed data");
+            delete q->m_texture;
+            q->m_texture = nullptr;
+            return;
+        }
+    }
+
+    // only upload mip level 0 since we never do mipmapping for compressed textures (for now?)
+    resourceUpdates->uploadTexture(q->m_texture, QRhiTextureUploadEntry(0, 0,
+        { q->m_textureData.data().constData() + q->m_textureData.dataOffset(), q->m_textureData.dataLength() }));
+
+    q->m_textureData = QTextureFileData(); // Release this memory, not needed anymore
+}
+
 QTextureFileData QSGCompressedTexture::textureData() const
 {
     return m_textureData;
diff --git a/src/quick/scenegraph/compressedtexture/qsgcompressedtexture_p.h b/src/quick/scenegraph/compressedtexture/qsgcompressedtexture_p.h
index c3b58a2389..b858d8ddee 100644
--- a/src/quick/scenegraph/compressedtexture/qsgcompressedtexture_p.h
+++ b/src/quick/scenegraph/compressedtexture/qsgcompressedtexture_p.h
@@ -52,25 +52,28 @@
 //
 
 #include <private/qtexturefiledata_p.h>
-#include <QSGTexture>
-#include <QtQuick/private/qsgcontext_p.h>
+#include <private/qsgcontext_p.h>
+#include <private/qsgtexture_p.h>
 #include <QQuickTextureFactory>
 #include <QOpenGLFunctions>
 
 QT_BEGIN_NAMESPACE
 
+class QSGCompressedTexturePrivate;
+
 class Q_QUICK_PRIVATE_EXPORT QSGCompressedTexture : public QSGTexture
 {
+    Q_DECLARE_PRIVATE(QSGCompressedTexture)
     Q_OBJECT
 public:
     QSGCompressedTexture(const QTextureFileData& texData);
     virtual ~QSGCompressedTexture();
 
-    int textureId() const override;
     QSize textureSize() const override;
     bool hasAlphaChannel() const override;
     bool hasMipmaps() const override;
 
+    int textureId() const override;
     void bind() override;
 
     QTextureFileData textureData() const;
@@ -81,14 +84,24 @@ protected:
     QTextureFileData m_textureData;
     QSize m_size;
     mutable uint m_textureId = 0;
+    QRhiTexture *m_texture = nullptr;
     bool m_hasAlpha = false;
     bool m_uploaded = false;
 };
 
-namespace QSGAtlasTexture {
+namespace QSGOpenGLAtlasTexture {
     class Manager;
 }
 
+class QSGCompressedTexturePrivate : public QSGTexturePrivate
+{
+    Q_DECLARE_PUBLIC(QSGCompressedTexture)
+public:
+    int comparisonKey() const override;
+    QRhiTexture *rhiTexture() const override;
+    void updateRhiTexture(QRhi *rhi, QRhiResourceUpdateBatch *resourceUpdates) override;
+};
+
 class Q_QUICK_PRIVATE_EXPORT QSGCompressedTextureFactory : public QQuickTextureFactory
 {
 public:
@@ -101,7 +114,7 @@ protected:
     QTextureFileData m_textureData;
 
 private:
-    friend class QSGAtlasTexture::Manager;
+    friend class QSGOpenGLAtlasTexture::Manager;
 };
 
 QT_END_NAMESPACE