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/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCanvas3D 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 "canvastextureprovider_p.h"
#include "texture3d_p.h"
#include <QtQuick/QQuickItem>
QT_BEGIN_NAMESPACE
QT_CANVAS3D_BEGIN_NAMESPACE
/*!
\qmltype Canvas3DTextureProvider
\since QtCanvas3D 1.1
\inqmlmodule QtCanvas3D
\brief Provides means to get QQuickItem as Canvas3DTexture.
\deprecated
\b{Deprecated in Qt 5.12.}
An uncreatable QML type that provides an extension API that can be used to get QQuickItem as
Canvas3DTexture. Only QQuickItems that implement QQuickItem::textureProvider() method can be
used as a texture source, which in most cases means the \c{layer.enabled} property of the
item must be set to \c {true}.
Typical usage would be something like this:
\code
// In QML code, declare a layered item you wish to show as texture
Rectangle {
id: textureSource
layer.enabled: true
// ...
}
.
.
// In JavaScript code, declare the variables for the extension and the texture
var textureProvider;
var myTexture;
.
.
// Get the extension after the context has been created in onInitializeGL().
textureProvider = gl.getExtension("QTCANVAS3D_texture_provider");
.
.
// Get the Canvas3DTexture object representing our source item
if (textureProvider)
myTexture = textureProvider.createTextureFromSource(textureSource);
.
.
// If you just need to access the texture in onPaingGL(), the above is usually enough.
// However, in cases where you utilize synchronous OpenGL commands or dynamically enable
// the source item layer after canvas initialization, it is not guaranteed that the texture
// is valid immediately after calling createTextureFromSource().
// To ensure you don't use the texture before it is ready, connect the textureReady() signal
// to a handler function that will use the texture.
textureProvider.textureReady.connect(function(sourceItem) {
if (sourceItem === textureSource) {
gl.bindTexture(gl.TEXTURE_2D, myTexture);
// ...
}
});
\endcode
\sa Context3D
*/
CanvasTextureProvider::CanvasTextureProvider(CanvasContext *canvasContext,
QObject *parent) :
QObject(parent),
m_canvasContext(canvasContext)
{
}
CanvasTextureProvider::~CanvasTextureProvider()
{
}
/*!
* \qmlmethod QJSValue Canvas3DTextureProvider::createTextureFromSource(Item *source)
*
* \b{Deprecated in Qt 5.12.}
* Creates and returns a Canvas3DTexture object for the supplied \a source item.
*
* The \a source item must be of a type that implements a texture provider, which in most
* cases means the \c{layer.enabled} property of the item must be set to \c {true}.
* ShaderEffectSource items can also be used as texture sources.
* The texture provider of the \a source item owns the OpenGL texture.
* If the \a source item is deleted or the \c{layer.enabled} property is set to \c{false}
* while the texture is still in use in Canvas3D, the rendered texture contents become undefined.
*
* Trying to bind the returned Canvas3DTexture object is not guaranteed to work until
* a \l{Canvas3DTextureProvider::textureReady}{textureReady()} signal corresponding to the \a source item has been emitted.
* However, if you don't have any synchronous OpenGL calls between the first use of the texture
* and the end of your paingGL() handler, and if you can guarantee that the source item has been
* fully rendered at least once after its layer was enabled, you can immediately use the returned
* texture without waiting for the \l{Canvas3DTextureProvider::textureReady}{textureReady()} signal.
*
* Disabling the \a source item's layer will destroy the underlying texture provider, so it
* is necessary to call this method again for the \a source item if you re-enable its layer.
*
* If this function is called twice for same \a source, it doesn't create a new Canvas3DTexture
* instance, but instead returns a reference to a previously created one, as long as the previous
* instance is still alive.
*
* The generated texture is owned and managed by Qt Quick's scene graph, so attempting to
* modify its parameters is not guaranteed to work.
*
* \note Qt Quick uses texture coordinates where the origin is at top left corner, which is
* different from OpenGL default coordinate system, where the origin is at bottom left corner.
* You need to account for this when specifying the UV mapping for the texture. Alternatively,
* you can specify a suitable \l{ShaderEffectSource::textureMirroring}{textureMirroring}
* value for your layer or ShaderEffectSource item.
*/
QJSValue CanvasTextureProvider::createTextureFromSource(QQuickItem *source)
{
return m_canvasContext->createTextureFromSource(source);
}
/*!
* \qmlsignal void Canvas3DTextureProvider::textureReady(Item *source)
*
* Indicates that the texture created with createTextureFromSource() method for the \a source item
* is ready to be used.
*/
QT_CANVAS3D_END_NAMESPACE
QT_END_NAMESPACE
|
