Problems with BMP - c++

Question

Wrote a simple BMP generation code but instead of outputting what I want (red that gradually goes to black (from left to right)) it returns an image with some some weird layout far from what I expect to see. Was inspecting the way header and pixels written in the memory and everything seems alright
Output
#include <iostream>
#include <fstream>
size_t width = 1000, height = 1000, CPP = 3;
//this creates an array of pixels
//supposed to be from red to black from left to right
uint8_t* createBitMapI(const size_t& width, const size_t& height)
{
uint8_t _color[3] = { 255, 0, 0 };
uint8_t* bitMap = new uint8_t[width * height * 3];
//creating one row
for (float i = 0; i < width; i++)
{
*(bitMap + (int)(i * 3)) = (uint8_t)_color[0] * (1 - i / width);
*(bitMap + 1 + (int)(i * 3)) = 0;//(uint8_t)_color[1] * (1 - i / width);
*(bitMap + 2 + (int)(i * 3)) = 0;//(uint8_t)_color[2] * (1 - i / width);
}
//copying previously created row to others
for (size_t i = 1; i < height; i++)
{
memcpy(bitMap + (width * 3) * i, bitMap, width * 3);
}
return bitMap;
}
//creates BMP file and writes contents into it
class BMP
{
public:
BMP(const size_t& width, const size_t& height,
uint8_t* arr, const char* name)
{
const char pad_[3] = { 0, 0, 0 };
char padding = (4 - width % 4) % 4;
fullSize = (width + padding) * height * 3 + 54;
image.open(name);
writeHeader();
image.write((const char*)header, 54);
for (size_t i = 0; i < height; i++)
{
image.write((const char*)arr + (i * width), width * 3);
image.write(pad_, padding);
}
image.close();
}
void writeHeader()
{
memcpy(header, "BM", 2);
*(size_t*)(header + 2) = fullSize;
*(size_t*)(header + 10) = 54;
*(size_t*)(header + 14) = 40;
*(size_t*)(header + 18) = width;
*(size_t*)(header + 22) = height;
*(uint16_t*)(header + 26) = 1;
*(uint16_t*)(header + 28) = 24;
}
private:
std::ofstream image;
uint8_t header[54];
uint8_t* pixels;
size_t fullSize;
};
int main()
{
uint8_t* arr = createBitMapI(width, height);
BMP newImage(width, height, arr, "image.bmp");
delete[] arr;
}
upd: changing image.open(name) to image.open(name, std::ios::binary) gives us output2