Add ability to have user defined colormaps

imagewidget.cpp

@@ -9,8 +9,10 @@
 #include <QMimeData>
 #include <QDragEnterEvent>
 #include <QPainter>
-#include "imageringlist.h"
+#include <QStandardPaths>
 #include <QFloat16>
+#include <QStyle>
+#include "imageringlist.h"
 
 int FILTERING = 1;
 bool OpenGLES = false;
@@ -774,9 +776,7 @@ void ImageWidgetGL::initializeGL()
     m_lut->allocateStorage();
     m_lut->bind(2);
 
-    QImage colormap(":/colormap.png");
-    colormap = colormap.convertToFormat(QImage::Format_RGBA8888);
-    qDebug() << colormap;
+    QImage colormap = loadColormap();
     m_colormap = std::make_unique<QOpenGLTexture>(QOpenGLTexture::Target1DArray);
     m_colormap->setSize(colormap.width());
     m_colormap->setLayers(colormap.height());
@@ -970,3 +970,23 @@ void ImageWidgetGL::updateScrollBars()
     else
         emit scrollBarsUpdate(m_dx, m_width, m_imgWidth * m_scale - m_width, m_dy, m_height, m_imgHeight * m_scale - m_height);
 }
+
+QImage ImageWidget::loadColormap()
+{
+    QImage embedded(":/colormap.png");
+    QStringList path = QStandardPaths::standardLocations(QStandardPaths::AppDataLocation);
+    if(path.size())
+    {
+        QImage user(path.first() + "/colormap.png");
+        if(!user.isNull())
+        {
+            user = user.scaledToWidth(embedded.width(), Qt::SmoothTransformation);
+            QImage tmp(embedded.width(), embedded.height() + user.height(), QImage::Format_RGBA8888);
+            QPainter painter(&tmp);
+            painter.drawImage(0, 0, embedded);
+            painter.drawImage(0, embedded.height(), user);
+            return tmp;
+        }
+    }
+    return embedded.convertToFormat(QImage::Format_RGBA8888);
+}