/
ImageOperations.cpp
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/
ImageOperations.cpp
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// Copyright 2019 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include "InputCommon/ImageOperations.h"
#include <algorithm>
#include <cmath>
#include <limits>
#include <stack>
#include <string>
#include <vector>
#include "Common/File.h"
#include "Common/FileUtil.h"
#include "Common/Image.h"
namespace InputCommon
{
namespace
{
Pixel SampleNearest(const ImagePixelData& src, double u, double v)
{
const u32 x = std::clamp(static_cast<u32>(u * src.width), 0u, src.width - 1);
const u32 y = std::clamp(static_cast<u32>(v * src.height), 0u, src.height - 1);
return src.pixels[x + y * src.width];
}
} // namespace
void CopyImageRegion(const ImagePixelData& src, ImagePixelData& dst, const Rect& src_region,
const Rect& dst_region)
{
if (src_region.GetWidth() != dst_region.GetWidth() ||
src_region.GetHeight() != dst_region.GetHeight())
{
return;
}
for (u32 x = 0; x < dst_region.GetWidth(); x++)
{
for (u32 y = 0; y < dst_region.GetHeight(); y++)
{
dst.pixels[(y + dst_region.top) * dst.width + x + dst_region.left] =
src.pixels[(y + src_region.top) * src.width + x + src_region.left];
}
}
}
std::optional<ImagePixelData> LoadImage(const std::string& path)
{
File::IOFile file;
file.Open(path, "rb");
std::vector<u8> buffer(file.GetSize());
file.ReadBytes(buffer.data(), file.GetSize());
ImagePixelData image;
std::vector<u8> data;
if (!Common::LoadPNG(buffer, &data, &image.width, &image.height))
return std::nullopt;
image.pixels.resize(image.width * image.height);
for (u32 x = 0; x < image.width; x++)
{
for (u32 y = 0; y < image.height; y++)
{
const u32 index = y * image.width + x;
const auto pixel =
Pixel{data[index * 4], data[index * 4 + 1], data[index * 4 + 2], data[index * 4 + 3]};
image.pixels[index] = pixel;
}
}
return image;
}
bool WriteImage(const std::string& path, const ImagePixelData& image)
{
std::vector<u8> buffer;
buffer.reserve(image.width * image.height * 4);
for (u32 y = 0; y < image.height; ++y)
{
for (u32 x = 0; x < image.width; ++x)
{
const auto index = x + y * image.width;
const auto pixel = image.pixels[index];
buffer.push_back(pixel.r);
buffer.push_back(pixel.g);
buffer.push_back(pixel.b);
buffer.push_back(pixel.a);
}
}
return Common::SavePNG(path, buffer.data(), Common::ImageByteFormat::RGBA, image.width,
image.height);
}
ImagePixelData Resize(ResizeMode mode, const ImagePixelData& src, u32 new_width, u32 new_height)
{
ImagePixelData result(new_width, new_height);
for (u32 x = 0; x < new_width; x++)
{
const double u = x / static_cast<double>(new_width - 1);
for (u32 y = 0; y < new_height; y++)
{
const double v = y / static_cast<double>(new_height - 1);
switch (mode)
{
case ResizeMode::Nearest:
result.pixels[y * new_width + x] = SampleNearest(src, u, v);
break;
}
}
}
return result;
}
ImagePixelData ResizeKeepAspectRatio(ResizeMode mode, const ImagePixelData& src, u32 new_width,
u32 new_height, const Pixel& background_color)
{
ImagePixelData result(new_width, new_height, background_color);
const double corrected_height = new_width * (src.height / static_cast<double>(src.width));
const double corrected_width = new_height * (src.width / static_cast<double>(src.height));
// initially no borders
u32 top = 0;
u32 left = 0;
ImagePixelData resized;
if (corrected_height <= new_height)
{
// Handle vertical padding
const int diff = new_height - std::trunc(corrected_height);
top = diff / 2;
if (diff % 2 != 0)
{
// If the difference is odd, we need to have one side be slightly larger
top += 1;
}
resized = Resize(mode, src, new_width, corrected_height);
}
else
{
// Handle horizontal padding
const int diff = new_width - std::trunc(corrected_width);
left = diff / 2;
if (diff % 2 != 0)
{
// If the difference is odd, we need to have one side be slightly larger
left += 1;
}
resized = Resize(mode, src, corrected_width, new_height);
}
CopyImageRegion(resized, result, Rect{0, 0, resized.width, resized.height},
Rect{left, top, left + resized.width, top + resized.height});
return result;
}
} // namespace InputCommon