Fix a couple of bugs in the QOpenGLWindow example

Also make the fragment shader a bit simpler

Change-Id: Ie50940da0a4f896504c9f5962cdb6c455983302f
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

3 files changed, 18 insertions, 12 deletions

diff --git a/examples/opengl/qopenglwindow/background.frag b/examples/opengl/qopenglwindow/background.frag
index 572c941f08..eecb6d3120 100644
--- a/examples/opengl/qopenglwindow/background.frag
+++ b/examples/opengl/qopenglwindow/background.frag
@@ -1,3 +1,6 @@
+#define M_PI 3.1415926535897932384626433832795
+#define SPEED 10000.0
+
 uniform int currentTime;
 uniform highp vec2 windowSize;
 
@@ -8,18 +11,20 @@ highp float noise(highp vec2 co)
 
 highp float curvSpeed()
 {
-   return mod(float(currentTime), 1000000.0) / 500.0;
+   return (mod(float(currentTime), SPEED) / SPEED) * (2.0 * M_PI);
 }
 
-highp float curv()
+highp float curv(int curvCount)
 {
-    return 1.0 - abs((gl_FragCoord.y / (windowSize.y / 10.0) - 5.0) - sin((gl_FragCoord.x / (windowSize.x/20.0)) - curvSpeed()));
+    highp float curv_y = 0.1 *(cos((gl_FragCoord.x / windowSize.x) * (float(curvCount * 2) * M_PI) - curvSpeed())) + 0.5;
+    highp float frag_y = gl_FragCoord.y / windowSize.y;
+    return 1.0 - abs(curv_y - frag_y);
 }
 
 void main()
 {
     highp float coordNoise = noise(gl_FragCoord.xy);
-    highp float proximity = smoothstep(0.5, 1.0, (curv() + 1.0) * (coordNoise ));
+    highp float proximity = smoothstep(0.85, 1.0, (curv(6) + 1.0) * (coordNoise ));
     highp vec3 color = vec3(coordNoise) * proximity;
     gl_FragColor = vec4(color, 1.0);
 }
diff --git a/examples/opengl/qopenglwindow/background_renderer.cpp b/examples/opengl/qopenglwindow/background_renderer.cpp
index 2c830ac13c..9308e9d258 100644
--- a/examples/opengl/qopenglwindow/background_renderer.cpp
+++ b/examples/opengl/qopenglwindow/background_renderer.cpp
@@ -75,8 +75,8 @@ FragmentToy::FragmentToy(const QString &fragmentSource, QObject *parent)
         m_fragment_file_last_modified = info.lastModified();
         m_fragment_file = fragmentSource;
 #ifndef QT_NO_FILESYSTEMWATCHER
-        m_watcher.addPath(info.canonicalFilePath());
-        QObject::connect(&m_watcher, &QFileSystemWatcher::fileChanged, this, &FragmentToy::fileChanged);
+        m_watcher.addPath(info.canonicalPath());
+        QObject::connect(&m_watcher, &QFileSystemWatcher::directoryChanged, this, &FragmentToy::fileChanged);
 #endif
     }
 }
@@ -94,7 +94,7 @@ void FragmentToy::draw(const QSize &windowSize)
     if (!m_vao.isCreated())
         m_vao.create();
 
-    m_vao.bind();
+    QOpenGLVertexArrayObject::Binder binder(&m_vao);
 
     if (!m_vertex_buffer.isCreated()) {
         m_vertex_buffer.create();
@@ -115,7 +115,7 @@ void FragmentToy::draw(const QSize &windowSize)
         }
     }
 
-    if (!m_fragment_shader) {
+    if (!m_fragment_shader && m_recompile_shaders) {
         QByteArray data;
         if (m_fragment_file.size()) {
             QFile file(m_fragment_file);
@@ -160,6 +160,9 @@ void FragmentToy::draw(const QSize &windowSize)
 
     }
 
+    if (!m_program->isLinked())
+        return;
+
     m_program->bind();
 
     m_vertex_buffer.bind();
@@ -167,15 +170,13 @@ void FragmentToy::draw(const QSize &windowSize)
     m_program->enableAttributeArray("vertexCoord");
     m_vertex_buffer.release();
 
-    float radiens = (QTime::currentTime().msecsSinceStartOfDay() / 60) / (2 * M_PI);
+    uint time = QDateTime::currentDateTime().toMSecsSinceEpoch();
     m_program->setUniformValue("currentTime", (uint) QDateTime::currentDateTime().toMSecsSinceEpoch());
-    m_program->setUniformValue("radiens", radiens);
     m_program->setUniformValue("windowSize", windowSize);
 
     QOpenGLContext::currentContext()->functions()->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
     m_program->release();
-    m_vao.release();
 }
 
 void FragmentToy::fileChanged(const QString &path)
diff --git a/examples/opengl/qopenglwindow/main.cpp b/examples/opengl/qopenglwindow/main.cpp
index bf95d09ecd..996feb5e96 100644
--- a/examples/opengl/qopenglwindow/main.cpp
+++ b/examples/opengl/qopenglwindow/main.cpp
@@ -97,7 +97,7 @@ private:
 // typical in pure QWindow-based applications.
 OpenGLWindow::OpenGLWindow()
     : QOpenGLWindow(QOpenGLWindow::NoPartialUpdate)
-    , m_fragment_toy("background.frag")
+    , m_fragment_toy("./background.frag")
     , m_text_layout("The triangle and this text is rendered with QPainter")
     , m_animate(true)
 {