Added QPointSize RenderState

Point Sizes may be specified 2 ways: either statically via
glPointSize() (OpenGL 2.0+) or by enabling GL_PROGRAM_POINT_SIZE.

Task-number: QTBUG-49997
Change-Id: I98887484cf31df01b98801e1f324487ee7bf7492
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

8 files changed, 255 insertions, 3 deletions

diff --git a/src/render/renderstates/genericstate_p.h b/src/render/renderstates/genericstate_p.h
index 2f494b561..0b5c20433 100644
--- a/src/render/renderstates/genericstate_p.h
+++ b/src/render/renderstates/genericstate_p.h
@@ -77,7 +77,8 @@ enum StateMask
     PolygonOffsetStateMask  = 1 << 11,
     ColorStateMask          = 1 << 12,
     ClipPlaneMask           = 1 << 13,
-    StencilOpMask           = 1 << 14
+    StencilOpMask           = 1 << 14,
+    PointSizeMask           = 1 << 15
 };
 
 typedef quint64 StateMaskSet;
diff --git a/src/render/renderstates/qpointsize.cpp b/src/render/renderstates/qpointsize.cpp
new file mode 100644
index 000000000..69bb8c8e6
--- /dev/null
+++ b/src/render/renderstates/qpointsize.cpp
@@ -0,0 +1,124 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "qpointsize.h"
+#include "qrenderstate_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+class QPointSizePrivate : public QRenderStatePrivate
+{
+public:
+    QPointSizePrivate(QPointSize::Specification spec, float value)
+        : QRenderStatePrivate(QRenderState::PointSize)
+        , m_specification(spec)
+        , m_value(value)
+    {}
+
+    QPointSize::Specification m_specification;
+    float m_value;
+
+    Q_DECLARE_PUBLIC(QPointSize)
+};
+
+/*!
+    \class Qt3DRender::QPointSize
+    \inmodule Qt3DRender
+    \brief Specifies the size of rasterized points. May either be set statically
+    or by shader programs.
+
+    When using StaticValue, the value is set using glPointSize(), if available.
+    When using Programmable, gl_PointSize must be set within shader programs,
+    the value provided to this RenderState is ignored in that case.
+ */
+
+QPointSize::QPointSize(Qt3DCore::QNode *parent)
+    : QRenderState(*new QPointSizePrivate(Specification::Programmable, 0.f), parent)
+{
+}
+
+QPointSize::~QPointSize()
+{
+    QNode::cleanup();
+}
+
+QPointSize::Specification QPointSize::specification() const
+{
+    Q_D(const QPointSize);
+    return d->m_specification;
+}
+
+float QPointSize::value() const
+{
+    Q_D(const QPointSize);
+    return d->m_value;
+}
+
+bool QPointSize::isProgrammable() const
+{
+    return (specification() == QPointSize::Specification::Programmable);
+}
+
+void QPointSize::setSpecification(Specification spec)
+{
+    Q_D(QPointSize);
+    d->m_specification = spec;
+    emit specificationChanged(spec);
+}
+
+void QPointSize::setValue(float size)
+{
+    Q_D(QPointSize);
+    d->m_value = size;
+    emit valueChanged(size);
+}
+
+void QPointSize::copy(const Qt3DCore::QNode *ref)
+{
+    const QPointSize *refState = static_cast<const QPointSize *>(ref);
+
+    QRenderState::copy(ref);
+
+    Q_D(QPointSize);
+    d->m_value = refState->d_func()->m_value;
+    d->m_specification = refState->d_func()->m_specification;
+}
+
+} // namespace Qt3DRender
+
+QT_END_NAMESPACE
+
diff --git a/src/render/renderstates/qpointsize.h b/src/render/renderstates/qpointsize.h
new file mode 100644
index 000000000..716e61d54
--- /dev/null
+++ b/src/render/renderstates/qpointsize.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QT3DRENDER_QPOINTSIZE_H
+#define QT3DRENDER_QPOINTSIZE_H
+
+#include <Qt3DRender/qrenderstate.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3DRender {
+
+class QPointSizePrivate;
+
+class QT3DRENDERSHARED_EXPORT QPointSize : public QRenderState
+{
+    Q_OBJECT
+    Q_PROPERTY(Specification specification READ specification WRITE setSpecification NOTIFY specificationChanged)
+    Q_PROPERTY(float value READ value WRITE setValue NOTIFY valueChanged)
+
+public:
+    enum Specification {
+        StaticValue = 0,
+        Programmable = 1
+    };
+    Q_ENUM(Specification)
+
+    explicit QPointSize(Qt3DCore::QNode *parent = 0);
+    ~QPointSize();
+
+    Specification specification() const;
+    float value() const;
+    bool isProgrammable() const;
+
+public Q_SLOTS:
+    void setSpecification(Specification spec);
+    void setValue(float value);
+
+Q_SIGNALS:
+    void specificationChanged(Specification spec);
+    void valueChanged(float value);
+
+protected:
+    void copy(const Qt3DCore::QNode *ref) Q_DECL_FINAL;
+
+private:
+    Q_DECLARE_PRIVATE(QPointSize)
+    QT3D_CLONEABLE(QPointSize)
+};
+
+} // namespace Qt3DRender
+
+QT_END_NAMESPACE
+
+#endif // QT3DRENDER_QPOINTSIZE_H
diff --git a/src/render/renderstates/qrenderstate.h b/src/render/renderstates/qrenderstate.h
index dfe69c021..c40a11318 100644
--- a/src/render/renderstates/qrenderstate.h
+++ b/src/render/renderstates/qrenderstate.h
@@ -64,6 +64,7 @@ public:
         DepthTest,
         Dithering,
         FrontFace,
+        PointSize,
         PolygonOffset,
         ScissorTest,
         StencilTest,
diff --git a/src/render/renderstates/renderstates.cpp b/src/render/renderstates/renderstates.cpp
index 6016e590d..204803dc6 100644
--- a/src/render/renderstates/renderstates.cpp
+++ b/src/render/renderstates/renderstates.cpp
@@ -233,6 +233,21 @@ AlphaCoverage *AlphaCoverage::getOrCreate()
     return getOrCreateImpl(AlphaCoverage());
 }
 
+void PointSize::apply(GraphicsContext *gc) const
+{
+    gc->pointSize(m_1, m_2);
+}
+
+PointSize *PointSize::getOrCreate(bool programmable, GLfloat value)
+{
+    return getOrCreateImpl(PointSize(programmable, value));
+}
+
+PointSize::PointSize(bool programmable, GLfloat value)
+    : GenericState2<PointSize, bool, GLfloat>(programmable, value)
+{
+}
+
 void PolygonOffset::apply(GraphicsContext *gc) const
 {
     gc->openGLContext()->functions()->glEnable(GL_POLYGON_OFFSET_FILL);
diff --git a/src/render/renderstates/renderstates.pri b/src/render/renderstates/renderstates.pri
index dc5684230..554a0e666 100644
--- a/src/render/renderstates/renderstates.pri
+++ b/src/render/renderstates/renderstates.pri
@@ -23,7 +23,8 @@ HEADERS += \
     $$PWD/qstenciltest.h \
     $$PWD/qstenciltestseparate.h \
     $$PWD/renderstates_p.h \
-    $$PWD/renderstateset_p.h
+    $$PWD/renderstateset_p.h \
+    $$PWD/qpointsize.h
 
 
 SOURCES += \
@@ -47,4 +48,5 @@ SOURCES += \
     $$PWD/qstenciltest.cpp \
     $$PWD/qstenciltestseparate.cpp \
     $$PWD/renderstates.cpp \
-    $$PWD/renderstateset.cpp
+    $$PWD/renderstateset.cpp \
+    $$PWD/qpointsize.cpp
diff --git a/src/render/renderstates/renderstates_p.h b/src/render/renderstates/renderstates_p.h
index 055f0cb11..e2fada4ea 100644
--- a/src/render/renderstates/renderstates_p.h
+++ b/src/render/renderstates/renderstates_p.h
@@ -219,6 +219,19 @@ private:
     AlphaCoverage();
 };
 
+class Q_AUTOTEST_EXPORT PointSize : public GenericState2<PointSize, bool, GLfloat>
+{
+public:
+    void apply(GraphicsContext *gc) const Q_DECL_OVERRIDE;
+    StateMaskSet mask() const Q_DECL_OVERRIDE
+    { return PointSizeMask; }
+
+    static PointSize *getOrCreate(bool programmable, GLfloat value);
+
+private:
+    PointSize(bool programmable, GLfloat value);
+};
+
 class Q_AUTOTEST_EXPORT PolygonOffset : public GenericState2<PolygonOffset, GLfloat, GLfloat>
 {
 public:
diff --git a/src/render/renderstates/renderstateset.cpp b/src/render/renderstates/renderstateset.cpp
index faf40302d..1d2520177 100644
--- a/src/render/renderstates/renderstateset.cpp
+++ b/src/render/renderstates/renderstateset.cpp
@@ -55,6 +55,7 @@
 #include <Qt3DRender/qdepthtest.h>
 #include <Qt3DRender/qdithering.h>
 #include <Qt3DRender/qfrontface.h>
+#include <Qt3DRender/qpointsize.h>
 #include <Qt3DRender/qpolygonoffset.h>
 #include <Qt3DRender/qscissortest.h>
 #include <Qt3DRender/qstenciltest.h>
@@ -210,6 +211,10 @@ void RenderStateSet::resetMasked(StateMaskSet maskOfStatesToReset, GraphicsConte
         gc->disableAlphaCoverage();
     }
 
+    if (maskOfStatesToReset & PointSizeMask) {
+        gc->pointSize(false, 1.0f);    // reset to default
+    }
+
     if (maskOfStatesToReset & PolygonOffsetStateMask) {
         funcs->glDisable(GL_POLYGON_OFFSET_FILL);
     }
@@ -295,6 +300,10 @@ RenderState *RenderState::getOrCreateBackendState(QRenderState *renderState)
     case QRenderState::AlphaCoverage: {
         return AlphaCoverage::getOrCreate();
     }
+    case QRenderState::PointSize: {
+        QPointSize *pointSize = static_cast<QPointSize *>(renderState);
+        return PointSize::getOrCreate(pointSize->isProgrammable(), pointSize->value());
+    }
     case QRenderState::PolygonOffset: {
         QPolygonOffset *polygonOffset = static_cast<QPolygonOffset *>(renderState);
         return PolygonOffset::getOrCreate(polygonOffset->factor(),