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Display entropy by always creating 2048 blocks for every file

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WerWolv 2020-11-14 14:41:15 +01:00
parent 41c70bce44
commit 72f9da2a67
2 changed files with 8 additions and 5 deletions
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1
include/views/view_information.hpp
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@ -23,6 +23,7 @@ namespace hex {
prv::Provider* &m_dataProvider;
bool m_windowOpen = true;
u32 m_blockSize = 0;
float m_averageEntropy = 0;
float m_highestBlockEntropy = 0;
std::vector<float> m_blockEntropy;

12
source/views/view_information.cpp
View file

@ -55,19 +55,20 @@ namespace hex {
if (this->m_shouldInvalidate) {
{
std::vector<u8> buffer(512, 0x00);
this->m_blockSize = std::ceil(this->m_dataProvider->getSize() / 2048.0F);
std::vector<u8> buffer(this->m_blockSize, 0x00);
std::memset(this->m_valueCounts.data(), 0x00, this->m_valueCounts.size() * sizeof(u32));
this->m_blockEntropy.clear();
for (u64 i = 0; i < this->m_dataProvider->getSize(); i += 512) {
for (u64 i = 0; i < this->m_dataProvider->getSize(); i += this->m_blockSize) {
std::array<float, 256> blockValueCounts = { 0 };
this->m_dataProvider->read(i, buffer.data(), std::min(size_t(512), this->m_dataProvider->getSize() - i));
this->m_dataProvider->read(i, buffer.data(), std::min(size_t(this->m_blockSize), this->m_dataProvider->getSize() - i));
for (u16 j = 0; j < 512; j++) {
for (size_t j = 0; j < this->m_blockSize; j++) {
blockValueCounts[buffer[j]]++;
this->m_valueCounts[buffer[j]]++;
}
this->m_blockEntropy.push_back(calculateEntropy(blockValueCounts, 512));
this->m_blockEntropy.push_back(calculateEntropy(blockValueCounts, this->m_blockSize));
}
this->m_averageEntropy = calculateEntropy(this->m_valueCounts, this->m_dataProvider->getSize());
@ -138,6 +139,7 @@ namespace hex {
ImGui::NewLine();
ImGui::LabelText("Block size", "2048 blocks à %lu bytes", this->m_blockSize);
ImGui::LabelText("Average entropy", "%.8f", this->m_averageEntropy);
ImGui::LabelText("Highest entropy block", "%.8f", this->m_highestBlockEntropy);