Files
panopainter/src/image.cpp

152 lines
4.0 KiB
C++

#include "pch.h"
#include "log.h"
#include "image.h"
#include "asset.h"
#include <stb/stb_image.h>
bool Image::load(std::string filename)
{
if (Asset::is_asset(filename))
{
Asset file;
if (!(file.open(filename.c_str()) && file.read_all()))
{
file.close();
return false;
}
stbi_set_flip_vertically_on_load(false);
uint8_t* buffer = stbi_load_from_memory(file.m_data, file.m_len, &width, &height, nullptr, 4);
file.close();
comp = 4;
m_data = std::unique_ptr<uint8_t[]>(buffer);
return true;
}
else
{
return load_file(filename);
}
}
bool Image::load_file(std::string filename)
{
stbi_set_flip_vertically_on_load(false);
uint8_t* buffer = stbi_load(filename.c_str(), &width, &height, nullptr, 4);
if (!buffer)
return false;
comp = 4;
m_data = std::unique_ptr<uint8_t[]>(buffer);
return true;
}
bool Image::save(const std::string& path)
{
return stbi_write_png(path.c_str(), width, height, comp, data(), 0);
}
void Image::flip()
{
auto flipped = std::make_unique<uint8_t[]>(width*height*4);
int line_size = width * 4;
const uint8_t* src = m_data.get();
uint8_t* dst = flipped.get() + line_size * (height - 1);
for (int y = 0; y < height; y++)
{
std::copy(src, src+line_size, dst);
src += line_size;
dst -= line_size;
}
std::swap(m_data, flipped);
}
void Image::gayscale_alpha()
{
int np = width * height;
auto ptr = reinterpret_cast<glm::u8vec4*>(m_data.get());
for (int i = 0; i < np; i++)
{
auto& c = ptr[i];
c.g = c.b = c.r = 255 - c.a;
c.a = 255;
}
}
Image Image::resize(int w, int h) const
{
Image ret;
ret.create(w, h);
auto temp = (glm::u8vec4*)ret.data();
auto pixels = (glm::u8vec4*)data();
float x_ratio = ((float)(width - 1)) / w;
float y_ratio = ((float)(height - 1)) / h;
int offset = 0;
for (int i = 0; i < h; i++) {
for (int j = 0; j < w; j++) {
int x = (int)(x_ratio * j);
int y = (int)(y_ratio * i);
float x_diff = (x_ratio * j) - x;
float y_diff = (y_ratio * i) - y;
int index = y * width + x;
// range is 0 to 255 thus bitwise AND with 0xff
glm::vec4 A = pixels[index];
glm::vec4 B = pixels[index + 1];
glm::vec4 C = pixels[index + width];
glm::vec4 D = pixels[index + width + 1];
// Y = A(1-w)(1-h) + B(w)(1-h) + C(h)(1-w) + Dwh
glm::vec4 gray = A*(1 - x_diff)*(1 - y_diff) + B * (x_diff)*(1 - y_diff) +
C * (y_diff)*(1 - x_diff) + D * (x_diff*y_diff);
temp[offset++] = glm::clamp(gray, glm::vec4(0), glm::vec4(255));
}
}
return ret;
}
Image Image::resize_power2() const
{
int w = pow(2, ceil(log(width) / log(2)));
int h = pow(2, ceil(log(height) / log(2)));
if (w == width && h == height)
{
Image i;
i.create(width, height);
std::copy(m_data.get(), m_data.get() + width * height * comp, i.m_data.get());
return i;
}
return resize(w, h);
}
Image Image::resize_squared() const
{
Image ret;
if (width == height)
{
ret.create(width, height);
std::copy(m_data.get(), m_data.get() + width * height * comp, ret.m_data.get());
}
else
{
int pad_x = 0;
int pad_y = 0;
int size = 0;
if (height > width)
{
size = height;
pad_x = (size - width) / 2;
}
else
{
size = width;
pad_y = (size - height) / 2;
}
ret.create(size, size);
auto ptr_src = reinterpret_cast<glm::u8vec4*>(m_data.get());
auto ptr_dst = reinterpret_cast<glm::u8vec4*>(ret.m_data.get());
std::fill_n(ptr_dst, size * size, glm::u8vec4(0));
for (int y = 0; y < height; y++)
std::copy_n(ptr_src + y * width, width, ptr_dst + pad_x + (y + pad_y) * ret.width);
}
return ret;
}