Working scroll

image.frag

@@ -4,10 +4,11 @@ uniform sampler2D qt_Texture0;
 varying vec2 qt_TexCoord0;
 uniform vec2 scale;
 
+
 void main(void)
 {
-    float c = texture2D(qt_Texture0, qt_TexCoord0).r;
+    vec4 color = texture2D(qt_Texture0, qt_TexCoord0);
-    c = c*scale.x + scale.y;
+    color = color*scale.x + scale.y;
-    float color = pow(c, 0.4545);
+    //float color = pow(c, 0.4545);
-    gl_FragColor = vec4(color, color, color, 1.0);
+    gl_FragColor = color;
 }

image.vert

@@ -1,11 +1,17 @@
 #version 130
 
+uniform sampler2D qt_Texture0;
 attribute vec2 qt_Vertex;
 attribute vec2 qt_MultiTexCoord0;
 varying vec2 qt_TexCoord0;
+uniform vec2 viewport;
+uniform vec2 offset;
 
 void main(void)
 {
+    vec2 texSize = vec2(textureSize(qt_Texture0, 0));
+    vec2 scale = viewport / texSize;
+    vec2 offsetRel = offset / texSize;
     gl_Position = vec4(qt_Vertex, 0.0, 1.0);
-    qt_TexCoord0 = qt_MultiTexCoord0;
+    qt_TexCoord0 = qt_MultiTexCoord0 * scale + offsetRel;
 }

imagescrollareagl.cpp

@@ -4,29 +4,33 @@
 #include <QKeyEvent>
 #include <QOpenGLDebugLogger>
 #include <QOpenGLPixelTransferOptions>
+#include <QGridLayout>
 
-ImageScrollAreaGL::ImageScrollAreaGL(QWidget *parent) : QOpenGLWidget(parent)
+ImageWidget::ImageWidget(QWidget *parent) : QOpenGLWidget(parent)
 {
     setFocusPolicy(Qt::ClickFocus);
     m_range = UINT16_MAX;
     m_low = 0;
     m_high = 1;
+    m_dx = m_dy = 0;
 }
 
-ImageScrollAreaGL::~ImageScrollAreaGL()
+ImageWidget::~ImageWidget()
 {
     makeCurrent();
 }
 
-void ImageScrollAreaGL::setImage(RawImage *image)
+void ImageWidget::setImage(RawImage *image)
 {
     if(image == nullptr)return;
 
     m_image->destroy();
     m_image->setFormat(QOpenGLTexture::R16_UNorm);
     m_image->setSize(image->width(), image->height());
-    m_image->setMinMagFilters(QOpenGLTexture::LinearMipMapLinear, QOpenGLTexture::Linear);
     m_image->allocateStorage();
+    m_image->setMinMagFilters(QOpenGLTexture::LinearMipMapLinear, QOpenGLTexture::Linear);
+    m_image->setWrapMode(QOpenGLTexture::ClampToBorder);
+    m_image->setBorderColor(0, 0, 0, 0);
     switch(image->type())
     {
     case RawImage::UINT8:
@@ -44,45 +48,57 @@ void ImageScrollAreaGL::setImage(RawImage *image)
     repaint();
 }
 
-void ImageScrollAreaGL::setImage(const QPixmap &pixmap)
+void ImageWidget::setImage(const QPixmap &pixmap)
 {
     QImage img = pixmap.toImage();
 
     m_image->destroy();
     m_image->setData(img);
+    m_image->setMinMagFilters(QOpenGLTexture::LinearMipMapLinear, QOpenGLTexture::Linear);
+    m_image->setWrapMode(QOpenGLTexture::ClampToBorder);
+    m_image->setBorderColor(0, 0, 0, 0);
     repaint();
 }
 
-void ImageScrollAreaGL::setLow(int low)
+void ImageWidget::setLow(int low)
 {
     m_low = low/m_range;
     repaint();
 }
 
-void ImageScrollAreaGL::setHigh(int high)
+void ImageWidget::setHigh(int high)
 {
     m_high = high/m_range;
     repaint();
 }
 
-void ImageScrollAreaGL::paintGL()
+void ImageWidget::setOffset(int dx, int dy)
+{
+    m_dx = dx;
+    m_dy = dy;
+    repaint();
+}
+
+void ImageWidget::paintGL()
 {
     float s = 1.0f/(m_high-m_low);
     m_program->bind();
     m_program->setUniformValue("scale", s, -m_low*s);
+    m_program->setUniformValue("viewport", (float)width(), (float)height());
+    m_program->setUniformValue("offset", m_dx, m_dy);
 
     m_image->bind(0);
     f->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 }
 
-void ImageScrollAreaGL::resizeGL(int w, int h)
+void ImageWidget::resizeGL(int w, int h)
 {
     m_width = w;
     m_height = h;
     f->glViewport(0, 0, w, h);
 }
 
-void ImageScrollAreaGL::initializeGL()
+void ImageWidget::initializeGL()
 {
     f = context()->functions();
     f->glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
@@ -141,3 +157,82 @@ void ImageScrollAreaGL::initializeGL()
     m_transferOptions = std::unique_ptr<QOpenGLPixelTransferOptions>(new QOpenGLPixelTransferOptions);
     m_transferOptions->setAlignment(1);
 }
+
+ImageScrollAreaGL::ImageScrollAreaGL(QWidget *parent)
+{
+    QGridLayout *layout = new QGridLayout(this);
+    setLayout(layout);
+
+    m_imageWidget = new ImageWidget(this);
+
+    m_verticalScrollBar = new QScrollBar(Qt::Vertical, this);
+    m_horizontalScrollBar = new QScrollBar(Qt::Horizontal, this);
+
+    layout->setSpacing(0);
+    layout->addWidget(m_imageWidget, 0, 0);
+    layout->addWidget(m_verticalScrollBar, 0, 1);
+    layout->addWidget(m_horizontalScrollBar, 1, 0);
+
+    connect(m_verticalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(scrollEvent()));
+    connect(m_horizontalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(scrollEvent()));
+}
+
+ImageScrollAreaGL::~ImageScrollAreaGL()
+{
+
+}
+
+void ImageScrollAreaGL::setImage(RawImage *image)
+{
+    m_imageWidget->setImage(image);
+    m_imgWidth = image->width();
+    m_imgHeight = image->height();
+    updateScrollbars();
+}
+
+void ImageScrollAreaGL::setImage(const QPixmap &pixmap)
+{
+    m_imageWidget->setImage(pixmap);
+    m_imgWidth = pixmap.width();
+    m_imgHeight = pixmap.height();
+    updateScrollbars();
+}
+
+ImageWidget *ImageScrollAreaGL::imageWidget()
+{
+    return m_imageWidget;
+}
+
+void ImageScrollAreaGL::updateScrollbars()
+{
+    m_verticalScrollBar->setRange(0, m_imgHeight-m_verticalScrollBar->pageStep());
+    m_horizontalScrollBar->setRange(0, m_imgWidth-m_horizontalScrollBar->pageStep());
+}
+
+void ImageScrollAreaGL::resizeEvent(QResizeEvent *event)
+{
+    QWidget::resizeEvent(event);
+    qDebug() << "resize" << m_imageWidget->size();
+    m_verticalScrollBar->setPageStep(m_imageWidget->height());
+    m_horizontalScrollBar->setPageStep(m_imageWidget->width());
+    updateScrollbars();
+}
+
+void ImageScrollAreaGL::mouseMoveEvent(QMouseEvent *event)
+{
+    QPoint delta = m_lastPos - event->pos();
+    m_horizontalScrollBar->setValue(m_horizontalScrollBar->value() + delta.x());
+    m_verticalScrollBar->setValue(m_verticalScrollBar->value() + delta.y());
+    m_lastPos = event->pos();
+}
+
+void ImageScrollAreaGL::mousePressEvent(QMouseEvent *event)
+{
+    m_lastPos = event->pos();
+}
+
+void ImageScrollAreaGL::scrollEvent()
+{
+    qDebug() << m_horizontalScrollBar->value() << m_verticalScrollBar->value();
+    m_imageWidget->setOffset(m_horizontalScrollBar->value(), m_verticalScrollBar->value());
+}

imagescrollareagl.h

@@ -9,6 +9,7 @@
 #include <QOpenGLBuffer>
 #include <QOpenGLTexture>
 #include <QOpenGLVertexArrayObject>
+#include <QScrollBar>
 #include "rawimage.h"
 
 typedef enum
@@ -20,7 +21,7 @@ typedef enum
     Asinh,
 }StretchFunc;
 
-class ImageScrollAreaGL : public QOpenGLWidget
+class ImageWidget : public QOpenGLWidget
 {
     Q_OBJECT
     QOpenGLFunctions *f;
@@ -33,18 +34,43 @@ class ImageScrollAreaGL : public QOpenGLWidget
     float m_low;
     float m_high;
     float m_range;
+    float m_dx, m_dy;
 public:
-    explicit ImageScrollAreaGL(QWidget *parent = nullptr);
+    explicit ImageWidget(QWidget *parent = nullptr);
-    ~ImageScrollAreaGL();
+    ~ImageWidget();
     void setImage(RawImage *image);
     void setImage(const QPixmap &pixmap);
 public slots:
     void setLow(int low);
     void setHigh(int high);
+    void setOffset(int dx, int dy);
 protected:
     void paintGL();
     void resizeGL(int w, int h);
     void initializeGL();
 };
 
+class ImageScrollAreaGL : public QWidget
+{
+    Q_OBJECT
+    QScrollBar *m_verticalScrollBar;
+    QScrollBar *m_horizontalScrollBar;
+    ImageWidget *m_imageWidget;
+    int m_imgWidth, m_imgHeight;
+    QPoint m_lastPos;
+public:
+    explicit ImageScrollAreaGL(QWidget *parent = nullptr);
+    ~ImageScrollAreaGL();
+    void setImage(RawImage *image);
+    void setImage(const QPixmap &pixmap);
+    ImageWidget* imageWidget();
+protected:
+    void updateScrollbars();
+    void resizeEvent(QResizeEvent *event);
+    void mouseMoveEvent(QMouseEvent *event);
+    void mousePressEvent(QMouseEvent *event);
+protected slots:
+    void scrollEvent();
+};
+
 #endif // IMAGESCROLLAREAGL_H

mainwindow.cpp

@@ -49,8 +49,8 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
     addDockWidget(Qt::BottomDockWidgetArea, captureDock);
 
     StretchPanel *stretchPanel = new  StretchPanel(this);
-    connect(stretchPanel, SIGNAL(lowChanged(int)), m_imageGL, SLOT(setLow(int)));
+    connect(stretchPanel, SIGNAL(lowChanged(int)), m_imageGL->imageWidget(), SLOT(setLow(int)));
-    connect(stretchPanel, SIGNAL(highChanged(int)), m_imageGL, SLOT(setHigh(int)));
+    connect(stretchPanel, SIGNAL(highChanged(int)), m_imageGL->imageWidget(), SLOT(setHigh(int)));
 
     QDockWidget *stretchDock = new QDockWidget(tr("Stretch"), this);
     stretchDock->setWidget(stretchPanel);