dolphin/Source/Core/VideoCommon/ImageWrite.cpp

146 lines
3.8 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <list>
#include <string>
#include <vector>
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/MsgHandler.h"
#include "VideoCommon/ImageWrite.h"
#include "png.h"
bool SaveData(const std::string& filename, const std::string& data)
{
std::ofstream f;
OpenFStream(f, filename, std::ios::binary);
f << data;
return true;
}
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4611)
#endif
/*
TextureToPng
Inputs:
data : This is an array of RGBA with 8 bits per channel. 4 bytes for each pixel.
row_stride: Determines the amount of bytes per row of pixels.
*/
bool TextureToPng(const u8* data, int row_stride, const std::string& filename, int width,
int height, bool saveAlpha)
{
if (!data)
return false;
bool success = false;
char title[] = "Dolphin Screenshot";
char title_key[] = "Title";
png_structp png_ptr = nullptr;
png_infop info_ptr = nullptr;
std::vector<u8> buffer;
// Open file for writing (binary mode)
File::IOFile fp(filename, "wb");
if (!fp.IsOpen())
{
PanicAlertT("Screenshot failed: Could not open file \"%s\" (error %d)", filename.c_str(),
errno);
goto finalise;
}
// Initialize write structure
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (png_ptr == nullptr)
{
PanicAlert("Screenshot failed: Could not allocate write struct");
goto finalise;
}
// Initialize info structure
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == nullptr)
{
PanicAlert("Screenshot failed: Could not allocate info struct");
goto finalise;
}
// Classical libpng error handling uses longjmp to do C-style unwind.
// Modern libpng does support a user callback, but it's required to operate
// in the same way (just gives a chance to do stuff before the longjmp).
// Instead of futzing with it, we use gotos specifically so the compiler
// will still generate proper destructor calls for us (hopefully).
// We also do not use any local variables outside the region longjmp may
// have been called from if they were modified inside that region (they
// would need to be volatile).
if (setjmp(png_jmpbuf(png_ptr)))
{
PanicAlert("Screenshot failed: Error during PNG creation");
goto finalise;
}
// Begin region which may call longjmp
png_init_io(png_ptr, fp.GetHandle());
// Write header (8 bit color depth)
png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
png_text title_text;
title_text.compression = PNG_TEXT_COMPRESSION_NONE;
title_text.key = title_key;
title_text.text = title;
png_set_text(png_ptr, info_ptr, &title_text, 1);
png_write_info(png_ptr, info_ptr);
if (!saveAlpha)
buffer.resize(width * 4);
// Write image data
for (auto y = 0; y < height; ++y)
{
const u8* row_ptr = data + y * row_stride;
if (!saveAlpha)
{
for (int x = 0; x < width; x++)
{
for (int i = 0; i < 3; i++)
buffer[4 * x + i] = row_ptr[4 * x + i];
buffer[4 * x + 3] = 0xff;
}
row_ptr = buffer.data();
}
// The old API uses u8* instead of const u8*. It doesn't write
// to this pointer, but to fit the API, we have to drop the const qualifier.
png_write_row(png_ptr, const_cast<u8*>(row_ptr));
}
// End write
png_write_end(png_ptr, nullptr);
// End region which may call longjmp
success = true;
finalise:
if (info_ptr != nullptr)
png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
if (png_ptr != nullptr)
png_destroy_write_struct(&png_ptr, (png_infopp) nullptr);
return success;
}
#ifdef _MSC_VER
#pragma warning(pop)
#endif