noisynode.cpp Example File | Qt Quick 5.12.4

Qt 5.12 | Qt Quick | Scene Graph - Graph | noisynode.cpp Example File

Qt 5.12.4 Reference Documentation

# noisynode.cpp Example File

scenegraph/graph/noisynode.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** 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.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include "noisynode.h"

      #include <QtCore/QRandomGenerator>
      #include <QtQuick/QSGSimpleMaterialShader>
      #include <QtQuick/QSGTexture>
      #include <QtQuick/QQuickWindow>

      #define NOISE_SIZE 64

      struct NoisyMaterial
      {
          ~NoisyMaterial() {
              delete texture;
          }

          QColor color;
          QSGTexture *texture;
      };

      class NoisyShader : public QSGSimpleMaterialShader<NoisyMaterial>
      {
          QSG_DECLARE_SIMPLE_SHADER(NoisyShader, NoisyMaterial)

      public:
          NoisyShader() {
              setShaderSourceFile(QOpenGLShader::Vertex, ":/scenegraph/graph/shaders/noisy.vsh");
              setShaderSourceFile(QOpenGLShader::Fragment, ":/scenegraph/graph/shaders/noisy.fsh");
          }

          QList<QByteArray> attributes() const override {  return QList<QByteArray>() << "aVertex" << "aTexCoord"; }

          void updateState(const NoisyMaterial *m, const NoisyMaterial *) override {

              // Set the color
              program()->setUniformValue(id_color, m->color);

              // Bind the texture and set program to use texture unit 0 (the default)
              m->texture->bind();

              // Then set the texture size so we can adjust the texture coordinates accordingly in the
              // vertex shader..
              QSize s = m->texture->textureSize();
              program()->setUniformValue(id_textureSize, QSizeF(1.0 / s.width(), 1.0 / s.height()));
          }

          void resolveUniforms() override {
              id_texture = program()->uniformLocation("texture");
              id_textureSize = program()->uniformLocation("textureSize");
              id_color = program()->uniformLocation("color");

              // We will only use texture unit 0, so set it only once.
              program()->setUniformValue(id_texture, 0);
          }

      private:
          int id_color = -1;
          int id_texture = -1;
          int id_textureSize = -1;
      };

      NoisyNode::NoisyNode(QQuickWindow *window)
      {
          // Make some noise...
          QImage image(NOISE_SIZE, NOISE_SIZE, QImage::Format_RGB32);
          uint *data = (uint *) image.bits();
          for (int i=0; i<NOISE_SIZE * NOISE_SIZE; ++i) {
              uint g = QRandomGenerator::global()->bounded(0xff);
              data[i] = 0xff000000 | (g << 16) | (g << 8) | g;
          }

          QSGTexture *t = window->createTextureFromImage(image);
          t->setFiltering(QSGTexture::Nearest);
          t->setHorizontalWrapMode(QSGTexture::Repeat);
          t->setVerticalWrapMode(QSGTexture::Repeat);

          QSGSimpleMaterial<NoisyMaterial> *m = NoisyShader::createMaterial();
          m->state()->texture = t;
          m->state()->color = QColor::fromRgbF(0.95, 0.95, 0.97);
          m->setFlag(QSGMaterial::Blending);

          setMaterial(m);
          setFlag(OwnsMaterial, true);

          QSGGeometry *g = new QSGGeometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 4);
          QSGGeometry::updateTexturedRectGeometry(g, QRect(), QRect());
          setGeometry(g);
          setFlag(OwnsGeometry, true);
      }

      void NoisyNode::setRect(const QRectF &bounds)
      {
          QSGGeometry::updateTexturedRectGeometry(geometry(), bounds, QRectF(0, 0, 1, 1));
          markDirty(QSGNode::DirtyGeometry);
      }