fix mem runaway

lib/rendering/CvMatRender.cpp

@@ -1,14 +1,15 @@
 #include "CvMatRender.hpp"
 #include <cstdint>
+#include <memory>
 
 using namespace pixelarium::imaging;
 
-pixelarium::render::CvMatRender::CvMatRender(const Image& img)
+pixelarium::render::CvMatRender::CvMatRender(const std::shared_ptr<Image>& img)
+    : _base(img), _texture(0)
 {
-    this->_img = img.GetImage();
-    this->_texture = 0;
-
-    cv::cvtColor(this->_img, this->_img, cv::COLOR_BGR2RGBA);
+    this->_img = this->_base->GetImage().clone();
+    // // storing a copy of the to-be-rendered image with a "well-behaved"
+    // cv::cvtColor(this->_img, this->_img, cv::COLOR_BGR2RGBA);
 }
 
 /*static*/ void pixelarium::render::matToTexture(const cv::Mat& image, GLuint* texture)
@@ -42,8 +43,11 @@ pixelarium::render::CvMatRender::CvMatRender(const Image& img)
     }
 }
 
-GLuint pixelarium::render::CvMatRender::Render()
+GLuint* pixelarium::render::CvMatRender::Render()
 {
-    matToTexture(this->_img, &this->_texture);
-    return this->_texture;
+    // storing a copy of the to-be-rendered image with a "well-behaved"
+    cv::cvtColor(this->_img, this->_img, cv::COLOR_BGR2RGBA);
+    if (this->_texture == 0)
+        matToTexture(this->_img, &this->_texture);
+    return &this->_texture;
 }

lib/rendering/CvMatRender.hpp

@@ -1,4 +1,8 @@
 #pragma once
+// windows. must come before GL/GL.h here.
+// clang format would change this, effectively rendering the build broken.
+// clang-format off
+#include <memory>
 #ifdef _WIN32
 #include <windows.h>
 #include <GL/GL.h>
@@ -10,20 +14,21 @@
 #include <GLFW/glfw3.h>  // Will drag system OpenGL headers
 #endif
 #include "imaging/Image.hpp"
+// clang-format on
 
 namespace pixelarium::render
 {
-    static void matToTexture(const cv::Mat& image,
-                         GLuint* texture);
+static void matToTexture(const cv::Mat& image, GLuint* texture);
 class CvMatRender
 {
    public:
-    explicit CvMatRender(const pixelarium::imaging::Image& img);
-    // void* Render();
-    GLuint Render();
+    CvMatRender() = default;
+    explicit CvMatRender(const std::shared_ptr<pixelarium::imaging::Image>& img);
+    GLuint* Render();
 
    private:
     cv::Mat _img;
+    std::shared_ptr<pixelarium::imaging::Image> _base;
     GLuint _texture;
 };