Add UniformValue class

Provides a generic container for Uniform values that will allow to replace
QVariant in the backend and make processing therefore much faster.

Change-Id: I689d8505594732e786a66a76cea71b2528563df6
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

3 files changed, 374 insertions, 2 deletions

diff --git a/src/render/backend/render-backend.pri b/src/render/backend/render-backend.pri
index 256cba78e..0d7d9e57e 100644
--- a/src/render/backend/render-backend.pri
+++ b/src/render/backend/render-backend.pri
@@ -36,7 +36,8 @@ HEADERS += \
     $$PWD/stringtoint_p.h \
     $$PWD/backendnode_p.h \
     $$PWD/rendertargetoutput_p.h \
-    $$PWD/commandexecuter_p.h
+    $$PWD/commandexecuter_p.h \
+    $$PWD/uniform_p.h
 
 SOURCES += \
     $$PWD/renderthread.cpp \
@@ -66,5 +67,6 @@ SOURCES += \
     $$PWD/rendertargetoutput.cpp \
     $$PWD/attachmentpack.cpp \
     $$PWD/commandexecuter.cpp \
-    $$PWD/openglvertexarrayobject.cpp
+    $$PWD/openglvertexarrayobject.cpp \
+    $$PWD/uniform.cpp
 
diff --git a/src/render/backend/uniform.cpp b/src/render/backend/uniform.cpp
new file mode 100644
index 000000000..3bc1f78ce
--- /dev/null
+++ b/src/render/backend/uniform.cpp
@@ -0,0 +1,164 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "uniform_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+namespace Render {
+
+namespace {
+
+const int qNodeIdTypeId = qMetaTypeId<Qt3DCore::QNodeId>();
+
+}
+
+UniformValue UniformValue::fromVariant(const QVariant &variant)
+{
+    // Texture/Buffer case
+    if (variant.userType() == qNodeIdTypeId)
+        return UniformValue(variant.value<Qt3DCore::QNodeId>());
+
+    UniformValue v;
+    switch (variant.userType()) {
+    case QMetaType::Bool:
+        v.m_data.ivec[0] = variant.toBool();
+        break;
+    case QMetaType::Int:
+    case QMetaType::UInt:
+    case QMetaType::Long:
+    case QMetaType::LongLong:
+    case QMetaType::Short:
+    case QMetaType::ULong:
+    case QMetaType::ULongLong:
+    case QMetaType::UShort:
+    case QMetaType::Char:
+    case QMetaType::UChar:
+        v.m_data.ivec[0] = variant.toInt();
+        break;
+    case QMetaType::Float:
+    case QMetaType::Double: // Convert double to floats
+        v.m_data.fvec[0] = variant.toFloat();
+        break;
+    case QMetaType::QPoint: {
+        const QPoint p = variant.toPoint();
+        v.m_data.ivec[0] = p.x();
+        v.m_data.ivec[1] = p.y();
+        break;
+    }
+    case QMetaType::QSize: {
+        const QSize s = variant.toSize();
+        v.m_data.ivec[0] = s.width();
+        v.m_data.ivec[1] = s.height();
+        break;
+    }
+    case QMetaType::QRect: {
+        const QRect r = variant.toRect();
+        v.m_data.ivec[0] = r.x();
+        v.m_data.ivec[1] = r.y();
+        v.m_data.ivec[2] = r.width();
+        v.m_data.ivec[3] = r.height();
+        break;
+    }
+    case QMetaType::QSizeF: {
+        const QSizeF s = variant.toSize();
+        v.m_data.fvec[0] = s.width();
+        v.m_data.fvec[1] = s.height();
+        break;
+    }
+    case QMetaType::QPointF: {
+        const QPointF p = variant.toPointF();
+        v.m_data.fvec[0] = p.x();
+        v.m_data.fvec[1] = p.y();
+        break;
+    }
+    case QMetaType::QRectF: {
+        const QRectF r = variant.toRect();
+        v.m_data.fvec[0] = r.x();
+        v.m_data.fvec[1] = r.y();
+        v.m_data.fvec[2] = r.width();
+        v.m_data.fvec[3] = r.height();
+        break;
+    }
+    case QMetaType::QVector2D: {
+        const QVector2D vec2 = variant.value<QVector2D>();
+        v.m_data.fvec[0] = vec2.x();
+        v.m_data.fvec[1] = vec2.y();
+        break;
+    }
+    case QMetaType::QVector3D: {
+        const QVector3D vec3 = variant.value<QVector3D>();
+        v.m_data.fvec[0] = vec3.x();
+        v.m_data.fvec[1] = vec3.y();
+        v.m_data.fvec[2] = vec3.z();
+        break;
+    }
+    case QMetaType::QVector4D: {
+        const QVector4D vec4 = variant.value<QVector4D>();
+        v.m_data.fvec[0] = vec4.x();
+        v.m_data.fvec[1] = vec4.y();
+        v.m_data.fvec[2] = vec4.z();
+        v.m_data.fvec[3] = vec4.w();
+        break;
+    }
+    case QMetaType::QColor: {
+        const QColor col = variant.value<QColor>();
+        v.m_data.fvec[0] = col.redF();
+        v.m_data.fvec[1] = col.greenF();
+        v.m_data.fvec[2] = col.blueF();
+        v.m_data.fvec[3] = col.alphaF();
+        break;
+    }
+    case QMetaType::QMatrix4x4: {
+        const QMatrix4x4 mat44 = variant.value<QMatrix4x4>();
+        // Use constData because we want column-major layout
+        memcpy(v.data<float>(), mat44.constData(), sizeof(16 * sizeof(float)));
+        break;
+    }
+    default:
+        Q_UNREACHABLE();
+    }
+    return v;
+}
+
+} // namespace Render
+} // namespace Qt3DRender
+
+QT_END_NAMESPACE
diff --git a/src/render/backend/uniform_p.h b/src/render/backend/uniform_p.h
new file mode 100644
index 000000000..175f863bd
--- /dev/null
+++ b/src/render/backend/uniform_p.h
@@ -0,0 +1,206 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QT3DRENDER_RENDER_UNIFORM_P_H
+#define QT3DRENDER_RENDER_UNIFORM_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <qt3drender_global.h>
+#include <Qt3DCore/qnodeid.h>
+
+#include <QMatrix4x4>
+#include <QVector2D>
+#include <QVector3D>
+#include <QColor>
+
+#include <QDebug>
+#include <string.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+namespace Render {
+
+enum UniformType {
+    Float = 0,
+    Vec2,
+    Vec3,
+    Vec4,
+    Double,
+    DVec2,
+    DVec3,
+    DVec4,
+    Int,
+    IVec2,
+    IVec3,
+    IVec4,
+    UInt,
+    UIVec2,
+    UIVec3,
+    UIVec4,
+    Bool,
+    BVec2,
+    BVec3,
+    BVec4,
+    Mat2,
+    Mat3,
+    Mat4,
+    Mat2x3,
+    Mat3x2,
+    Mat2x4,
+    Mat4x2,
+    Mat3x4,
+    Mat4x3,
+    Sampler,
+    Unknown
+};
+
+class Q_AUTOTEST_EXPORT UniformValue
+{
+public:
+    enum ValueType {
+        ScalarValue,
+        NodeId,
+        TextureValue,
+        BufferValue
+    };
+
+    struct Texture {
+        int textureId = 0; // Set first so that glUniform1iv will work
+        Qt3DCore::QNodeId nodeId;
+    };
+
+    // UniformValue implicitely converts doubles to floats to ensure
+    // correct rendering behavior for the cases where Qt3D parameters created from
+    // a double or QVariant(double) are used to fill uniform values that in reality
+    // should be floats. This occur especially with QML where qreal might be double
+    // and not float. Otherwise, at when filling the uniforms, calling constData<float>
+    // on something that contains a double will result in wrong values
+
+    UniformValue() {}
+    UniformValue(int i) { m_data.ivec[0] = i; }
+    UniformValue(uint i) { m_data.ivec[0] = i; }
+    UniformValue(float f) { m_data.fvec[0] = f; }
+    UniformValue(double d) { m_data.fvec[0] = d; } // Double to float conversion
+    UniformValue(bool b) { m_data.ivec[0] = b; }
+    UniformValue(const QVector2D &vec2) { memcpy(&m_data, &vec2, sizeof(QVector2D)); }
+    UniformValue(const QVector3D &vec3) { memcpy(&m_data, &vec3, sizeof(QVector3D)); }
+    UniformValue(const QVector4D &vec4) { memcpy(&m_data, &vec4, sizeof(QVector4D)); }
+
+    UniformValue(const QMatrix3x3 &mat33)
+    {
+        // Use constData because we want column-major layout
+        memcpy(&m_data, mat33.constData(), 9 * sizeof(float));
+    }
+
+    UniformValue(const QMatrix4x4 &mat44)
+    {
+        // Use constData because we want column-major layout
+        memcpy(&m_data, mat44.constData(), 16 * sizeof(float));
+    }
+
+    // For nodes which will later be replaced by a Texture or Buffer
+    UniformValue(Qt3DCore::QNodeId id)
+    {
+        m_valueType = NodeId;
+        memcpy(&m_data, &id, sizeof(Qt3DCore::QNodeId));
+    }
+
+    // For textures
+    UniformValue(UniformValue::Texture t)
+    {
+        m_valueType = TextureValue;
+        memcpy(&m_data, &t, sizeof(Texture));
+    }
+
+    ValueType valueType() const { return m_valueType; }
+
+    static UniformValue fromVariant(const QVariant &variant);
+
+    template<typename T>
+    const T *constData() const
+    {
+        return reinterpret_cast<const T *>(&m_data);
+    }
+
+    template<typename T>
+    T *data()
+    {
+        return reinterpret_cast<T *>(&m_data);
+    }
+
+    bool operator==(const UniformValue &other) const
+    {
+        return memcmp(&m_data, &other.m_data, sizeof(u_Uniform)) == 0;
+    }
+
+    bool operator!=(const UniformValue &other) const
+    {
+        return !(*this == other);
+    }
+private:
+    union u_Uniform {
+        int ivec[4]; // store uint/ints/bools
+        float fvec[16]; // for matrix4 (note: we could have a special case for matrices)
+
+        u_Uniform()
+        {
+            memset(this, 0, sizeof(u_Uniform));
+        }
+    } m_data;
+
+    ValueType m_valueType = ScalarValue;
+};
+
+} // namespace Render
+} // namespace Qt3DRender
+
+QT_END_NAMESPACE
+
+#endif // QT3DRENDER_RENDER_UNIFORM_P_H