Misc (#19)

* get image returns optional<Mat> instead of unique_ptr<Mat>

* introduce complexity

* rename image load function

* add example for a basic reader for binary image files

* fix windows build?

* add a status bar underneath the menu bar

* use status bar in custom_0 example app

* clang formats

* packing w/ pragma push

* add "Save As" functions to image views

* resize over reserve

* rm local override uri

* add simple thread pool

* rename to simple_thread_pool

* get rid of useless renderlib

* document version inc

* extract hardcoded values to in-header

* clang format patch

* clone registered image in custom_0

* document binary-file header

* minor fixes

* clang format

* rm unused render cmake

lib/app/rendering/RenderHelpers.cpp

@@ -0,0 +1,32 @@
+#include "RenderHelpers.hpp"
+
+#include <cstdlib>
+
+/// @brief Checks if the dimensions of two ImVec2 vectors have changed significantly.
+/// @param ref_rect The reference ImVec2 vector.
+/// @param new_rect The new ImVec2 vector to compare against.
+/// @return True if the absolute difference between the y-coordinates is greater than 5 or the x-coordinates are
+/// different; otherwise, false.
+bool pixelarium::application::dim_changed_p(const ImVec2& ref_rect, const ImVec2& new_rect)
+{
+    if (std::abs(ref_rect.y - new_rect.y) > 5 || std::abs(ref_rect.x - new_rect.x))
+    {
+        return true;
+    }
+
+    return false;
+}
+
+/// @brief Calculates dimensions to maintain aspect ratio.
+/// @param img The input image.
+/// @param curr_dim The current dimensions.
+/// @return The calculated dimensions maintaining aspect ratio.
+ImVec2 pixelarium::application::aspect_const_dimensions(const ImVec2& raw_dim, const ImVec2& curr_dim)
+{
+    const auto w_fact = (curr_dim.x / raw_dim.x);
+    const auto h_fact = (curr_dim.y / raw_dim.y);
+
+    const auto fact = w_fact < h_fact ? w_fact : h_fact;
+
+    return ImVec2(raw_dim.x * fact, raw_dim.y * fact);
+}