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Diffstat (limited to 'src/chartsqml2/declarativeopenglrendernode.cpp')
| -rw-r--r-- | src/chartsqml2/declarativeopenglrendernode.cpp | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/src/chartsqml2/declarativeopenglrendernode.cpp b/src/chartsqml2/declarativeopenglrendernode.cpp new file mode 100644 index 00000000..0799e36c --- /dev/null +++ b/src/chartsqml2/declarativeopenglrendernode.cpp @@ -0,0 +1,327 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the Qt Charts module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:GPL$ +** 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 General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3 or (at your option) 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.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-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "declarativeopenglrendernode.h" + +#include <QtGui/QOpenGLContext> +#include <QtGui/QOpenGLFunctions> +#include <QtGui/QOpenGLFramebufferObjectFormat> +#include <QtGui/QOpenGLFramebufferObject> +#include <QOpenGLShaderProgram> +#include <QtGui/QOpenGLBuffer> + +//#define QDEBUG_TRACE_GL_FPS +#ifdef QDEBUG_TRACE_GL_FPS +# include <QElapsedTimer> +#endif + +QT_CHARTS_BEGIN_NAMESPACE + +// This node draws the xy series data on a transparent background using OpenGL. +// It is used as a child node of the chart node. +DeclarativeOpenGLRenderNode::DeclarativeOpenGLRenderNode(QQuickWindow *window) : + QObject(), + m_texture(0), + m_imageNode(nullptr), + m_window(window), + m_textureOptions(QQuickWindow::TextureHasAlphaChannel), + m_textureSize(1, 1), + m_recreateFbo(false), + m_fbo(0), + m_program(0), + m_shaderAttribLoc(-1), + m_colorUniformLoc(-1), + m_minUniformLoc(-1), + m_deltaUniformLoc(-1), + m_pointSizeUniformLoc(-1), + m_renderNeeded(true) +{ + initializeOpenGLFunctions(); + + connect(m_window, &QQuickWindow::beforeRendering, + this, &DeclarativeOpenGLRenderNode::render); +} + +DeclarativeOpenGLRenderNode::~DeclarativeOpenGLRenderNode() +{ + delete m_texture; + delete m_fbo; + + delete m_program; + m_program = 0; + + cleanXYSeriesResources(0); +} + +static const char *vertexSource = + "attribute highp vec2 points;\n" + "uniform highp vec2 min;\n" + "uniform highp vec2 delta;\n" + "uniform highp float pointSize;\n" + "uniform highp mat4 matrix;\n" + "void main() {\n" + " vec2 normalPoint = vec2(-1, -1) + ((points - min) / delta);\n" + " gl_Position = matrix * vec4(normalPoint, 0, 1);\n" + " gl_PointSize = pointSize;\n" + "}"; +static const char *fragmentSource = + "uniform highp vec3 color;\n" + "void main() {\n" + " gl_FragColor = vec4(color,1);\n" + "}\n"; + +// Must be called on render thread and in context +void DeclarativeOpenGLRenderNode::initGL() +{ + recreateFBO(); + + m_program = new QOpenGLShaderProgram; + m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertexSource); + m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragmentSource); + m_program->bindAttributeLocation("points", 0); + m_program->link(); + + m_program->bind(); + m_colorUniformLoc = m_program->uniformLocation("color"); + m_minUniformLoc = m_program->uniformLocation("min"); + m_deltaUniformLoc = m_program->uniformLocation("delta"); + m_pointSizeUniformLoc = m_program->uniformLocation("pointSize"); + m_matrixUniformLoc = m_program->uniformLocation("matrix"); + + // Create a vertex array object. In OpenGL ES 2.0 and OpenGL 2.x + // implementations this is optional and support may not be present + // at all. Nonetheless the below code works in all cases and makes + // sure there is a VAO when one is needed. + m_vao.create(); + QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao); + +#if !defined(QT_OPENGL_ES_2) + if (!QOpenGLContext::currentContext()->isOpenGLES()) { + // Make it possible to change point primitive size and use textures with them in + // the shaders. These are implicitly enabled in ES2. + // Qt Quick doesn't change these flags, so it should be safe to just enable them + // at initialization. + glEnable(GL_PROGRAM_POINT_SIZE); + } +#endif + + m_program->release(); +} + +void DeclarativeOpenGLRenderNode::recreateFBO() +{ + QOpenGLFramebufferObjectFormat fboFormat; + fboFormat.setAttachment(QOpenGLFramebufferObject::NoAttachment); + delete m_fbo; + m_fbo = new QOpenGLFramebufferObject(m_textureSize.width(), + m_textureSize.height(), + fboFormat); + + delete m_texture; + m_texture = m_window->createTextureFromId(m_fbo->texture(), m_textureSize, m_textureOptions); + if (!m_imageNode) { + m_imageNode = m_window->createImageNode(); + m_imageNode->setFiltering(QSGTexture::Linear); + m_imageNode->setTextureCoordinatesTransform(QSGImageNode::MirrorVertically); + m_imageNode->setFlag(OwnedByParent); + if (!m_rect.isEmpty()) + m_imageNode->setRect(m_rect); + appendChildNode(m_imageNode); + } + m_imageNode->setTexture(m_texture); + + m_recreateFbo = false; +} + +// Must be called on render thread and in context +void DeclarativeOpenGLRenderNode::setTextureSize(const QSize &size) +{ + m_textureSize = size; + m_recreateFbo = true; + m_renderNeeded = true; +} + +// Must be called on render thread while gui thread is blocked, and in context +void DeclarativeOpenGLRenderNode::setSeriesData(bool mapDirty, const GLXYDataMap &dataMap) +{ + if (mapDirty) { + // Series have changed, recreate map, but utilize old data where feasible + GLXYDataMap oldMap = m_xyDataMap; + m_xyDataMap.clear(); + + GLXYDataMapIterator i(dataMap); + while (i.hasNext()) { + i.next(); + GLXYSeriesData *data = oldMap.take(i.key()); + const GLXYSeriesData *newData = i.value(); + if (!data || newData->dirty) { + data = new GLXYSeriesData; + *data = *newData; + } + m_xyDataMap.insert(i.key(), data); + } + // Delete remaining old data + i = oldMap; + while (i.hasNext()) { + i.next(); + delete i.value(); + cleanXYSeriesResources(i.key()); + } + } else { + // Series have not changed, so just copy dirty data over + GLXYDataMapIterator i(dataMap); + while (i.hasNext()) { + i.next(); + const GLXYSeriesData *newData = i.value(); + if (i.value()->dirty) { + GLXYSeriesData *data = m_xyDataMap.value(i.key()); + if (data) + *data = *newData; + } + } + } + markDirty(DirtyMaterial); + m_renderNeeded = true; +} + +void DeclarativeOpenGLRenderNode::setRect(const QRectF &rect) +{ + m_rect = rect; + + if (m_imageNode) + m_imageNode->setRect(rect); +} + +void DeclarativeOpenGLRenderNode::renderGL() +{ + glClearColor(0, 0, 0, 0); + + QOpenGLVertexArrayObject::Binder vaoBinder(&m_vao); + m_program->bind(); + m_fbo->bind(); + + glClear(GL_COLOR_BUFFER_BIT); + glEnableVertexAttribArray(0); + + glViewport(0, 0, m_textureSize.width(), m_textureSize.height()); + + GLXYDataMapIterator i(m_xyDataMap); + while (i.hasNext()) { + i.next(); + QOpenGLBuffer *vbo = m_seriesBufferMap.value(i.key()); + GLXYSeriesData *data = i.value(); + + m_program->setUniformValue(m_colorUniformLoc, data->color); + m_program->setUniformValue(m_minUniformLoc, data->min); + m_program->setUniformValue(m_deltaUniformLoc, data->delta); + m_program->setUniformValue(m_matrixUniformLoc, data->matrix); + + if (!vbo) { + vbo = new QOpenGLBuffer; + m_seriesBufferMap.insert(i.key(), vbo); + vbo->create(); + } + vbo->bind(); + if (data->dirty) { + vbo->allocate(data->array.constData(), data->array.count() * sizeof(GLfloat)); + data->dirty = false; + } + + glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0); + if (data->type == QAbstractSeries::SeriesTypeLine) { + glLineWidth(data->width); + glDrawArrays(GL_LINE_STRIP, 0, data->array.size() / 2); + } else { // Scatter + m_program->setUniformValue(m_pointSizeUniformLoc, data->width); + glDrawArrays(GL_POINTS, 0, data->array.size() / 2); + } + vbo->release(); + } + +#ifdef QDEBUG_TRACE_GL_FPS + static QElapsedTimer stopWatch; + static int frameCount = -1; + if (frameCount == -1) { + stopWatch.start(); + frameCount = 0; + } + frameCount++; + int elapsed = stopWatch.elapsed(); + if (elapsed >= 1000) { + elapsed = stopWatch.restart(); + qreal fps = qreal(0.1 * int(10000.0 * (qreal(frameCount) / qreal(elapsed)))); + qDebug() << "FPS:" << fps; + frameCount = 0; + } +#endif + + markDirty(DirtyMaterial); + m_window->resetOpenGLState(); +} + +// Must be called on render thread as response to beforeRendering signal +void DeclarativeOpenGLRenderNode::render() +{ + if (m_renderNeeded) { + if (m_xyDataMap.size()) { + if (!m_program) + initGL(); + if (m_recreateFbo) + recreateFBO(); + renderGL(); + } else { + if (m_imageNode && m_imageNode->rect() != QRectF()) { + glClearColor(0, 0, 0, 0); + m_fbo->bind(); + glClear(GL_COLOR_BUFFER_BIT); + + // If last series was removed, zero out the node rect + setRect(QRectF()); + } + } + m_renderNeeded = false; + } +} + +void DeclarativeOpenGLRenderNode::cleanXYSeriesResources(const QXYSeries *series) +{ + if (series) { + delete m_seriesBufferMap.take(series); + delete m_xyDataMap.take(series); + } else { + foreach (QOpenGLBuffer *buffer, m_seriesBufferMap.values()) + delete buffer; + m_seriesBufferMap.clear(); + foreach (GLXYSeriesData *data, m_xyDataMap.values()) + delete data; + m_xyDataMap.clear(); + } +} + +QT_CHARTS_END_NAMESPACE |