Add PlaneMesh and use it in rollerball example as the floor

Change-Id: I566c94feb377ccb0d71a379094ff1eb7faefccef
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 271 insertions, 0 deletions

diff --git a/src/render/frontend/qplanemesh.cpp b/src/render/frontend/qplanemesh.cpp
new file mode 100644
index 000000000..cccc39c1f
--- /dev/null
+++ b/src/render/frontend/qplanemesh.cpp
@@ -0,0 +1,271 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qplanemesh.h"
+#include "qplanemesh_p.h"
+
+#include <Qt3DRenderer/renderlogging.h>
+#include <Qt3DRenderer/qattribute.h>
+#include <Qt3DRenderer/qbuffer.h>
+#include <Qt3DRenderer/meshdata.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace Qt3D {
+
+class PlaneMeshFunctor;
+
+QPlaneMeshPrivate::QPlaneMeshPrivate(QPlaneMesh *qq)
+    : QAbstractShapeMeshPrivate(qq)
+    , m_width(1.0f)
+    , m_height(1.0f)
+    , m_meshResolution(2, 2)
+{
+}
+
+QPlaneMesh::QPlaneMesh(QNode *parent)
+    : QAbstractShapeMesh(*new QPlaneMeshPrivate(this), parent)
+{
+}
+
+QPlaneMesh::QPlaneMesh(QPlaneMeshPrivate &dd, QNode *parent)
+    : QAbstractShapeMesh(dd, parent)
+{
+}
+
+void QPlaneMesh::setWidth(float width)
+{
+    Q_D(QPlaneMesh);
+    if (width != d->m_width) {
+        d->m_width = width;
+        emit widthChanged();
+        setDirty(true);
+    }
+}
+
+float QPlaneMesh::width() const
+{
+    Q_D(const QPlaneMesh);
+    return d->m_width;
+}
+
+void QPlaneMesh::setHeight(float height)
+{
+    Q_D(QPlaneMesh);
+    if (height != d->m_height) {
+        d->m_height = height;
+        emit heightChanged();
+        setDirty(true);
+    }
+}
+
+float QPlaneMesh::height() const
+{
+    Q_D(const QPlaneMesh);
+    return d->m_height;
+}
+
+void QPlaneMesh::setMeshResolution(const QSize &resolution)
+{
+    Q_D(QPlaneMesh);
+    if (resolution != d->m_meshResolution) {
+        d->m_meshResolution = resolution;
+        emit meshResolutionChanged();
+        setDirty(true);
+    }
+}
+
+QSize QPlaneMesh::meshResolution() const
+{
+    Q_D(const QPlaneMesh);
+    return d->m_meshResolution;
+}
+
+MeshDataPtr createPlaneMesh(float w, float h, const QSize &resolution);
+
+class PlaneMeshFunctor : public QAbstractMeshFunctor
+{
+public:
+    PlaneMeshFunctor(const QPlaneMesh &plane)
+        : m_width(plane.width())
+        , m_height(plane.height())
+        , m_meshResolution(plane.meshResolution())
+    {
+    }
+
+    QAbstractMeshDataPtr operator ()() Q_DECL_OVERRIDE
+    {
+        return createPlaneMesh(m_width, m_height, m_meshResolution);
+    }
+
+private:
+    float m_width;
+    float m_height;
+    QSize m_meshResolution;
+};
+
+MeshDataPtr createPlaneMesh(float w, float h, const QSize &resolution)
+{
+    Q_ASSERT(w > 0.0f);
+    Q_ASSERT(h > 0.0f);
+    Q_ASSERT(resolution.width() >= 2);
+    Q_ASSERT(resolution.height() >= 2);
+
+    const int nVerts = resolution.width() * resolution.height();
+
+    // Populate a buffer with the interleaved per-vertex data with
+    // vec3 pos, vec2 texCoord, vec3 normal, vec4 tangent
+    const quint32 elementSize = 3 + 2 + 3 + 4;
+    const quint32 stride = elementSize * sizeof(float);
+    QByteArray bufferBytes;
+    bufferBytes.resize(stride * nVerts);
+    float* fptr = reinterpret_cast<float*>(bufferBytes.data());
+
+    const float x0 = -w / 2.0f;
+    const float z0 = -h / 2.0f;
+    const float dx = w / (resolution.width() - 1);
+    const float dz = h / (resolution.height() - 1);
+    const float du = 1.0 / (resolution.width() - 1);
+    const float dv = 1.0 / (resolution.height() - 1);
+
+    // Iterate over z
+    for (int j = 0; j < resolution.height(); ++j) {
+        const float z = z0 + static_cast<float>(j) * dz;
+        const float v = static_cast<float>(j) * dv;
+
+        // Iterate over x
+        for (int i = 0; i < resolution.width(); ++i) {
+            const float x = x0 + static_cast<float>(i) * dx;
+            const float u = static_cast<float>(i) * du;
+
+            // position
+            *fptr++ = x;
+            *fptr++ = 0.0;
+            *fptr++ = z;
+
+            // texture coordinates
+            *fptr++ = u;
+            *fptr++ = v;
+
+            // normal
+            *fptr++ = 0.0f;
+            *fptr++ = 1.0f;
+            *fptr++ = 0.0f;
+
+            // tangent
+            *fptr++ = 1.0f;
+            *fptr++ = 0.0f;
+            *fptr++ = 0.0f;
+            *fptr++ = 1.0f;
+        }
+    }
+
+    // Wrap the raw bytes in a buffer
+    BufferPtr buf(new Buffer(QOpenGLBuffer::VertexBuffer));
+    buf->setUsage(QOpenGLBuffer::StaticDraw);
+    buf->setData(bufferBytes);
+
+    // Create the mesh data, specify the vertex format and data
+    MeshDataPtr mesh(new MeshData(GL_TRIANGLES));
+    quint32 offset = 0;
+    mesh->addAttribute(QAbstractMeshData::defaultPositionAttributeName(),
+                       AttributePtr(new Attribute(buf, GL_FLOAT_VEC3, nVerts, offset, stride)));
+    offset += 3 * sizeof(float);
+
+    mesh->addAttribute(QAbstractMeshData::defaultTextureCoordinateAttributeName(),
+                       AttributePtr(new Attribute(buf, GL_FLOAT_VEC2, nVerts, offset, stride)));
+    offset += 2 * sizeof(float);
+
+    mesh->addAttribute(QAbstractMeshData::defaultNormalAttributeName(),
+                       AttributePtr(new Attribute(buf, GL_FLOAT_VEC3, nVerts, offset, stride)));
+    offset += 3 * sizeof(float);
+
+    mesh->addAttribute(QAbstractMeshData::defaultTangentAttributeName(),
+                       AttributePtr(new Attribute(buf, GL_FLOAT_VEC4, nVerts, offset, stride)));
+
+    // Create the index data. 2 triangles per rectangular face
+    const int faces = 2 * (resolution.width() - 1) * (resolution.height() - 1);
+    const int indices = 3 * faces;
+    Q_ASSERT(indices < std::numeric_limits<quint16>::max());
+    QByteArray indexBytes;
+    indexBytes.resize(indices * sizeof(quint16));
+    quint16* indexPtr = reinterpret_cast<quint16*>(indexBytes.data());
+
+    // Iterate over z
+    for (int j = 0; j < resolution.height() - 1; ++j) {
+        const int rowStartIndex = j * resolution.width();
+        const int nextRowStartIndex = (j + 1) * resolution.width();
+
+        // Iterate over x
+        for (int i = 0; i < resolution.width() - 1; ++i) {
+            // Split quad into two triangles
+            *indexPtr++ = rowStartIndex + i;
+            *indexPtr++ = nextRowStartIndex + i;
+            *indexPtr++ = rowStartIndex + i + 1;
+
+            *indexPtr++ = nextRowStartIndex + i;
+            *indexPtr++ = nextRowStartIndex + i + 1;
+            *indexPtr++ = rowStartIndex + i + 1;
+        }
+    }
+
+    // Wrap the index bytes in a buffer
+    BufferPtr indexBuffer(new Buffer(QOpenGLBuffer::IndexBuffer));
+    indexBuffer->setUsage(QOpenGLBuffer::StaticDraw);
+    indexBuffer->setData(indexBytes);
+
+    // Specify index data on the mesh
+    mesh->setIndexAttribute(AttributePtr(new Attribute(indexBuffer, GL_UNSIGNED_SHORT, indices, 0, 0)));
+
+    mesh->computeBoundsFromAttribute(QAbstractMeshData::defaultPositionAttributeName());
+    qCDebug(Render::Frontend) << "computed axis-aligned bounding box is:" << mesh->boundingBox();
+
+    return mesh;
+}
+
+QAbstractMeshFunctorPtr QPlaneMesh::meshFunctor() const
+{
+    return QAbstractMeshFunctorPtr(new PlaneMeshFunctor(*this));
+}
+
+} // namespace Qt3D
+
+QT_END_NAMESPACE