Added entropy view

include/views/view_entropy.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "views/view.hpp"
+
+#include <cstdio>
+
+namespace hex {
+
+    namespace prv { class Provider; }
+
+    class ViewEntropy : public View {
+    public:
+        explicit ViewEntropy(prv::Provider* &dataProvider);
+        ~ViewEntropy() override;
+
+        void createView() override;
+        void createMenu() override;
+
+    private:
+        prv::Provider* &m_dataProvider;
+        bool m_windowOpen = true;
+
+        double m_entropy = 0;
+        float m_valueCounts[256] = { 0 };
+        bool m_shouldInvalidate = true;
+    };
+
+}

source/main.cpp

@@ -5,6 +5,7 @@
 #include "views/view_pattern.hpp"
 #include "views/view_pattern_data.hpp"
 #include "views/view_hashes.hpp"
+#include "views/view_entropy.hpp"
 
 #include "providers/provider.hpp"
 
@@ -22,6 +23,7 @@ int main() {
     window.addView<hex::ViewPattern>(highlights);
     window.addView<hex::ViewPatternData>(dataProvider, highlights);
     window.addView<hex::ViewHashes>(dataProvider);
+    window.addView<hex::ViewEntropy>(dataProvider);
 
     window.loop();
 

source/views/view_entropy.cpp

@@ -0,0 +1,84 @@
+#include "views/view_entropy.hpp"
+
+#include "providers/provider.hpp"
+
+#include "utils.hpp"
+
+#include <vector>
+#include <cstring>
+#include <cmath>
+
+namespace hex {
+
+    ViewEntropy::ViewEntropy(prv::Provider* &dataProvider) : View(), m_dataProvider(dataProvider) {
+
+    }
+
+    ViewEntropy::~ViewEntropy() {
+
+    }
+
+
+    void ViewEntropy::createView() {
+        if (!this->m_windowOpen)
+            return;
+
+        if (ImGui::Begin("Entropy", &this->m_windowOpen)) {
+            ImGui::BeginChild("##scrolling", ImVec2(0, 0), false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoNav);
+
+            if (this->m_dataProvider != nullptr && this->m_dataProvider->isReadable()) {
+                if (this->m_shouldInvalidate) {
+                    std::vector<u8> buffer(512, 0x00);
+                    std::memset(this->m_valueCounts, 0x00, sizeof(this->m_valueCounts));
+
+                    for (u64 i = 0; i < this->m_dataProvider->getSize(); i += 512) {
+                        this->m_dataProvider->read(i, buffer.data(), std::min(512ULL, this->m_dataProvider->getSize() - i));
+
+                        for (u16 j = 0; j < 512; j++)
+                            this->m_valueCounts[buffer[j]]++;
+                    }
+
+                    size_t numBytes = this->m_dataProvider->getSize();
+                    this->m_entropy = 0;
+                    for (u16 i = 0; i < 256; i++) {
+                        this->m_valueCounts[i] /= numBytes;
+
+                        if (this->m_valueCounts[i] > 0)
+                            this->m_entropy -= this->m_valueCounts[i] * std::log2(this->m_valueCounts[i]);
+                    }
+
+                    this->m_entropy /= 8;
+
+                    this->m_shouldInvalidate = false;
+                }
+
+                ImGui::LabelText("Entropy", "%.8f", this->m_entropy);
+
+                if (this->m_entropy > 0.99)
+                    ImGui::TextUnformatted("This file is most likely encrypted or compressed!");
+
+                ImGui::Separator();
+                ImGui::NewLine();
+                ImGui::PlotHistogram("Byte Distribution", this->m_valueCounts, 256, 0, nullptr, FLT_MAX, FLT_MAX, ImVec2(0, 100));
+
+                ImGui::NewLine();
+                ImGui::Separator();
+                ImGui::NewLine();
+
+                if (ImGui::Button("Invalidate"))
+                    this->m_shouldInvalidate = true;
+            }
+
+            ImGui::EndChild();
+        }
+        ImGui::End();
+    }
+
+    void ViewEntropy::createMenu() {
+        if (ImGui::BeginMenu("View")) {
+            ImGui::MenuItem("Entropy View", "", &this->m_windowOpen);
+            ImGui::EndMenu();
+        }
+    }
+
+}