1 files changed, 123 insertions, 0 deletions
diff --git a/examples/qml/openglunderqml/squircle.cpp b/examples/qml/openglunderqml/squircle.cpp
new file mode 100644
index 0000000000..b56f0baaf6
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+++ b/examples/qml/openglunderqml/squircle.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the demonstration applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** 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, Nokia gives you certain additional
+** rights. These rights are described in the Nokia 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.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "squircle.h"
+
+#include <QtQuick/qsgengine.h>
+#include <QtQuick/qquickcanvas.h>
+#include <QOpenGLShaderProgram>
+
+Squircle::Squircle()
+    : m_program(0)
+{
+    setFlag(ItemHasContents);
+}
+
+void Squircle::itemChange(ItemChange change, const ItemChangeData &)
+{
+    // The ItemSceneChange event is sent when we are first attached to a canvas.
+    if (change == ItemSceneChange) {
+        QQuickCanvas *c = canvas();
+
+        // Connect our the beforeRendering signal to our paint function.
+        // Since this call is executed on the rendering thread it must be
+        // a Qt::DirectConnection
+        connect(c, SIGNAL(beforeRendering()), this, SLOT(paint()), Qt::DirectConnection);
+
+        // If we allow QML to do the clearing, they would clear what we paint
+        // and nothing would show.
+        c->setClearBeforeRendering(false);
+    }
+}
+
+
+void Squircle::paint()
+{
+    if (!m_program) {
+        m_program = new QOpenGLShaderProgram();
+        m_program->addShaderFromSourceCode(QOpenGLShader::Vertex,
+                                           "attribute highp vec4 vertices;"
+                                           "varying highp vec2 coords;"
+                                           "void main() {"
+                                           "    gl_Position = vertices;"
+                                           "    coords = vertices.xy;"
+                                           "}");
+        m_program->addShaderFromSourceCode(QOpenGLShader::Fragment,
+                                           "uniform lowp float t;"
+                                           "varying highp vec2 coords;"
+                                           "void main() {"
+                                           "    lowp float i = 1. - (pow(coords.x, 4.) + pow(coords.y, 4.));"
+                                           "    i = smoothstep(t - 0.3, t + 0.3, i);"
+                                           "    gl_FragColor = vec4(coords / 2. + .5, i, i);"
+                                           "}");
+
+        m_program->bindAttributeLocation("vertices", 0);
+        m_program->link();
+    }
+
+    m_program->bind();
+
+    m_program->enableAttributeArray(0);
+
+    float values[] = {
+        -1, -1,
+        1, -1,
+        -1, 1,
+        1, 1
+    };
+    m_program->setAttributeArray(0, GL_FLOAT, values, 2);
+    m_program->setUniformValue("t", (float) m_t);
+
+    glDisable(GL_DEPTH_TEST);
+
+    glClearColor(0, 0, 0, 1);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+    m_program->disableAttributeArray(0);
+    m_program->release();
+}
+
+