update

example/qml/page/T_OpenGL.qml

@@ -0,0 +1,32 @@
+import QtQuick 2.15
+import QtQuick.Layouts 1.15
+import QtQuick.Window 2.15
+import QtQuick.Controls 2.15
+import FluentUI 1.0
+import example 1.0
+import "../component"
+
+FluContentPage{
+
+    title: qsTr("OpenGL")
+
+
+    FluFrame{
+        anchors.fill: parent
+
+        OpenGLItem{
+            width: 320
+            height: 480
+            SequentialAnimation on t {
+                NumberAnimation { to: 1; duration: 2500; easing.type: Easing.InQuad }
+                NumberAnimation { to: 0; duration: 2500; easing.type: Easing.OutQuad }
+                loops: Animation.Infinite
+                running: true
+            }
+        }
+
+    }
+
+
+
+}

example/src/component/OpenGLItem.cpp

@@ -0,0 +1,93 @@
+#include "OpenGLItem.h"
+
+#include <QOpenGLFramebufferObjectFormat>
+#include <QOpenGLShaderProgram>
+
+class FBORenderer : public QQuickFramebufferObject::Renderer, protected QOpenGLFunctions {
+public:
+    explicit FBORenderer(const OpenGLItem *item);
+
+    void render() override;
+
+    QOpenGLFramebufferObject *createFramebufferObject(const QSize &size) override;
+
+    QOpenGLShaderProgram program;
+    const OpenGLItem *item = nullptr;
+};
+
+FBORenderer::FBORenderer(const OpenGLItem *item) {
+    this->item = item;
+    initializeOpenGLFunctions();
+    program.addCacheableShaderFromSourceCode(QOpenGLShader::Vertex,
+                                             "attribute highp vec4 vertices;"
+                                             "varying highp vec2 coords;"
+                                             "void main() {"
+                                             "    gl_Position = vertices;"
+                                             "    coords = vertices.xy;"
+                                             "}");
+    program.addCacheableShaderFromSourceCode(QOpenGLShader::Fragment,
+                                             "uniform lowp float t;"
+                                             "varying highp vec2 coords;"
+                                             "void main() {"
+                                             "    lowp float i = 1. - (pow(abs(coords.x), 4.) + pow(abs(coords.y), 4.));"
+                                             "    i = smoothstep(t - 0.8, t + 0.8, i);"
+                                             "    i = floor(i * 20.) / 20.;"
+                                             "    gl_FragColor = vec4(coords * .5 + .5, i, i);"
+                                             "}");
+
+    program.bindAttributeLocation("vertices", 0);
+    program.link();
+}
+
+QOpenGLFramebufferObject *FBORenderer::createFramebufferObject(const QSize &size) {
+    QOpenGLFramebufferObjectFormat format;
+    format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
+    format.setSamples(4);
+    return new QOpenGLFramebufferObject(size, format);
+}
+
+void FBORenderer::render() {
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+    glEnable(GL_DEPTH_TEST);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    program.bind();
+    program.enableAttributeArray(0);
+    float values[] = {
+            -1, -1,
+            1, -1,
+            -1, 1,
+            1, 1
+    };
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    program.setAttributeArray(0, GL_FLOAT, values, 2);
+    program.setUniformValue("t", (float) item->t());
+    glViewport(0, 0, qRound(item->width()), qRound(item->height()));
+    glDisable(GL_DEPTH_TEST);
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    program.disableAttributeArray(0);
+    program.release();
+}
+
+
+OpenGLItem::OpenGLItem(QQuickItem *parent) : QQuickFramebufferObject(parent) {
+    setMirrorVertically(true);
+    startTimer(1);
+}
+
+void OpenGLItem::timerEvent(QTimerEvent *) {
+    update();
+}
+
+void OpenGLItem::setT(qreal t) {
+    if (t == m_t)
+        return;
+    m_t = t;
+    emit tChanged();
+}
+
+
+QQuickFramebufferObject::Renderer *OpenGLItem::createRenderer() const {
+    return new FBORenderer(this);
+}

example/src/component/OpenGLItem.h

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+#pragma once
+#pragma clang diagnostic push
+#pragma ide diagnostic ignored "NotImplementedFunctions"
+
+#include <QtQuick/QQuickItem>
+#include <QOpenGLFunctions>
+#include <QQuickFramebufferObject>
+
+class FBORenderer;
+
+class OpenGLItem : public QQuickFramebufferObject, protected QOpenGLFunctions {
+Q_OBJECT
+    Q_PROPERTY(qreal t READ t WRITE setT NOTIFY tChanged)
+public:
+    explicit OpenGLItem(QQuickItem *parent = nullptr);
+
+    [[nodiscard]] QQuickFramebufferObject::Renderer *createRenderer() const override;
+
+    void timerEvent(QTimerEvent *) override;
+
+    [[nodiscard]] qreal t() const { return m_t; }
+
+    void setT(qreal t);
+
+signals:
+
+    void tChanged();
+
+private:
+    qreal m_t{};
+};
+
+#pragma clang diagnostic pop