From 24ddf1dc61e57b1015a900ca9dd2254af71d5040 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Du=C5=A1an=20Poizl?= <nou.spiro@gmail.com>
Date: Sun, 2 Mar 2025 14:32:09 +0100
Subject: [PATCH] Add ability to have user defined colormaps

---
 imagescrollarea.h |  1 +
 imagewidget.cpp   | 28 ++++++++++++++++++++++++----
 imagewidget.h     |  4 +++-
 mainwindow.cpp    | 12 ++++++------
 4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/imagescrollarea.h b/imagescrollarea.h
index 1ff9a5a..8a6ce74 100644
--- a/imagescrollarea.h
+++ b/imagescrollarea.h
@@ -2,6 +2,7 @@
 #define IMAGESCROLLAREA_H
 
 #include "imagewidget.h"
+#include <QScrollBar>
 
 class ImageScrollArea : public QWidget
 {
diff --git a/imagewidget.cpp b/imagewidget.cpp
index c8ca9e3..3f5ca8a 100644
--- a/imagewidget.cpp
+++ b/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);
+}
diff --git a/imagewidget.h b/imagewidget.h
index 946059a..12e8fc7 100644
--- a/imagewidget.h
+++ b/imagewidget.h
@@ -10,7 +10,7 @@
 #include <QOpenGLFunctions>
 #include "database.h"
 #include "rawimage.h"
-#include "imageinfo.h"
+#include "imageinfodata.h"
 #include "stretchtoolbar.h"
 
 class ImageWidget
@@ -37,6 +37,8 @@ public:
     virtual QImage renderToImage() = 0;
     virtual void thumbnailLoaded(const Image *image) = 0;
     virtual void showThumbnail(bool enable) = 0;
+
+    static QImage loadColormap();
 };
 
 struct ImageThumb
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 06a6454..e00cda2 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -211,14 +211,14 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
     "Inferno", "Plasma", "Viridis", "Cividis", "Twilight", "Twilight shifted", "Turbo", "Deepgreen"};
     QMenu *colormapMenu = viewMenu->addMenu(tr("Colormap"));
     QActionGroup *colormapActionGroup = new QActionGroup(this);
-    int idx = 0;
-    QImage cmImg(":/colormap.png");
-    for(QString &colormap : colormaps)
+
+    QImage cmImg = ImageWidget::loadColormap();
+    for(int i=0; i<cmImg.height(); i++)
     {
-        QImage icon = cmImg.copy(0, idx, cmImg.width(), 1).scaled(32, 32);
-        QAction *action = colormapActionGroup->addAction(colormap);
+        QImage icon = cmImg.copy(0, i, cmImg.width(), 1).scaled(32, 32);
+        QAction *action = colormapActionGroup->addAction(i < colormaps.size() ? colormaps[i] : tr("User %1").arg(i - colormaps.size() + 1));
         action->setIcon(QPixmap::fromImage(icon));
-        action->setCheckable(true); action->setData(idx++);
+        action->setCheckable(true); action->setData(i);
         colormapMenu->addAction(action);
     }
     viewMenu->addMenu(colormapMenu);