Adding basic functionality

.vscode/settings.json

+{
+    "files.associations": {
+        "iostream": "cpp",
+        "iosfwd": "cpp"
+    }
+}
\ No newline at end of file

src/editor.cpp

+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "stb/stb_image.h"
+#include "stb/stb_image_write.h"
+#include "include/editor.hpp"
+#include <iostream>
+
+Editor::Editor()
+: image_stack_filled(0)
+{
+    for (size_t i = 0; i < STACKSIZE; i++)
+       images[i].image = nullptr;
+    
+}
+
+Editor::~Editor()
+{
+    for (size_t i = 0; i < STACKSIZE; i++)
+        if (images[i].image != nullptr)
+            stbi_image_free(images[i].image);
+}
+
+int Editor::load_image(const string & filename)
+{
+    if (image_stack_filled == STACKSIZE - 1)
+        return NOIMAGESPACE;
+
+    Image & image = images[image_stack_filled];
+
+    //hardcoded BW COLOR
+    image.filename = filename;
+    image.image = stbi_load(filename.c_str(), 
+                            &image.width, &image.height, 
+                            &image.channels, STBI_grey);
+
+    cout << &(image.image) << endl;
+                                    
+
+    return OPOK;
+}
+
+int Editor::drop_image(string filename){
+    size_t index;
+
+    for (index = 0; index < STACKSIZE; index++)
+        if (images[index].filename == filename)
+            break;
+
+    if (index >= STACKSIZE || images[index].image == nullptr)
+        return EMPTYIMAGESLOT;
+
+    stbi_image_free(images[index].image);
+    images[index].image = nullptr;
+    images[index].filename.clear();
+
+    return OPOK;
+}
+
+const Image * Editor::get_image(size_t index) const
+{
+    if (index >= STACKSIZE || images[index].image == nullptr)
+        return nullptr;
+
+    return images + index;
+}
\ No newline at end of file

src/include/editor.hpp

+#pragma once
+#include <cstdlib>
+#include <string>
+
+#define STACKSIZE 16
+#define NOIMAGESPACE -1
+#define EMPTYIMAGESLOT -1
+#define OPOK 0
+
+using namespace std;
+
+struct Image {
+    string filename;
+    unsigned char * image;
+    int width;
+    int height;
+    int channels;
+};
+
+class Editor {
+public:
+    Editor();
+    ~Editor();
+    int load_image(const string & filename);
+    int drop_image(string filename);
+    const Image * get_image(size_t index) const;
+
+protected:
+    Image images[STACKSIZE];
+    size_t image_stack_filled;
+};
\ No newline at end of file

src/include/interface.hpp

+#pragma once
+#include "editor.hpp"
+
+class Interface {
+public:
+    Interface();
+    void run();
+
+
+protected:
+    void load_image(istringstream & iss);
+    void drop_image(istringstream & iss);
+    void print_help() const;
+    void print_image_stack() const;
+
+    Editor editor;
+};

src/interface.cpp

+#include <iostream>
+#include <string>
+#include <sstream>
+#include <cstring>
+#include "include/interface.hpp"
+#include "include/editor.hpp"
+
+#define PROMPT ">>>"
+
+using namespace std;
+
+Interface::Interface()
+{
+    cout << "Initializing the application..." << endl;
+}
+
+void Interface::run()
+{
+
+    cout << PROMPT << flush;
+    string line, input;
+
+    //main loop until exit
+    while (getline(cin, line))
+    {
+        if (!line.empty())
+        {
+            istringstream iss(line);
+            iss >> input;
+
+            if (input == "open")
+                load_image(iss);
+
+            if (input == "drop")
+                drop_image(iss);
+
+            if (input == "help")
+                print_help();
+
+            if (input == "images")
+                print_image_stack();
+
+            if (input == "exit")
+            {
+                iss.clear();
+                return;
+            }
+        }
+
+        if (cin.eof())
+            return;
+
+        cout << PROMPT << flush;
+    }
+}
+
+void Interface::load_image(istringstream &iss)
+{
+    string filename;
+    iss >> filename;
+
+    if (filename.empty())
+    {
+        cout << "command: open <filename>" << endl;
+        return;
+    }
+
+    cout << "loading " << filename << endl;
+
+    int status = editor.load_image(filename);
+
+    if (status == OPOK)
+        cout << "image " << filename << " loaded" << endl;
+    else
+        cout << "there was some error loading the image" << endl;
+}
+
+void Interface::drop_image(istringstream &iss)
+{
+    string filename;
+    iss >> filename;
+
+    if (filename.empty())
+    {
+        cout << "command: drop <filename>" << endl;
+        return;
+    }
+
+    cout << "dropping " << filename << endl;
+    int status = editor.drop_image(filename);
+
+    if (status == OPOK)
+        cout << "image " << filename << " dropped" << endl;
+    else
+        cout << "there was some error loading the image" << endl;
+}
+
+void Interface::print_help() const
+{
+    cout << "Overview of available commands:\n\n"
+            "    open <filename>     loads image from file onto image stack\n\n"
+            "    drop <filename>     drop first image with corresponding\n"
+            "                        filename from image stack\n\n"
+            "    exit                exit the application\n\n";
+}
+
+void Interface::print_image_stack() const{
+    for (size_t i = 0; i < STACKSIZE; i++)
+    {
+        const Image * image = editor.get_image(i);
+        cout << i;
+
+        if (image == nullptr)
+        {
+            cout << ": no entry" << endl;
+            continue; 
+        }
+
+        cout << ": " << image->filename << " : " << image->width << "x" << image->height << endl; 
+    }
+}
\ No newline at end of file

src/main.cpp

-#define STB_IMAGE_IMPLEMENTATION
-#define STB_IMAGE_WRITE_IMPLEMENTATION
-#include "stb/stb_image.h"
-#include "stb/stb_image_write.h"
-
-
+#include "include/interface.hpp"
 
 int main(int argc, char const *argv[])
 {
+    //init application interface
+    Interface interface;
+
+    //run the interface
+    interface.run();
+
 
-    int width, height, channels;
-    //stbi_set_flip_vertically_on_load(true);
+    /*int width, height, channels;
     unsigned char *image = stbi_load("cicabw.png", &width, &height, &channels, STBI_grey);
 
     
 
     stbi_write_png("output.png", width, height, 1, image, 0);
-    stbi_image_free(image);    
+    stbi_image_free(image);    */
     return 0;
 }