angle/util/png_utils.cpp

117 строки
2.8 KiB
C++

//
// Copyright 2020 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// png_utils: Wrapper around libpng.
//
#include "util/png_utils.h"
#include <array>
#include <cstring>
#include <png.h>
namespace angle
{
namespace
{
class ScopedFILE
{
public:
ScopedFILE(FILE *fp) : mFP(fp) {}
~ScopedFILE() { close(); }
FILE *get() const { return mFP; }
void close()
{
if (mFP)
{
fclose(mFP);
mFP = nullptr;
}
}
private:
FILE *mFP;
};
} // namespace
bool SavePNGRGB(const char *fileName,
const char *title,
uint32_t width,
uint32_t height,
const std::vector<uint8_t> &data)
{
ScopedFILE fp(fopen(fileName, "wb"));
if (!fp.get())
{
fprintf(stderr, "Error opening '%s'.\n", fileName);
return false;
}
png_struct *writeStruct =
png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (!writeStruct)
{
fprintf(stderr, "Error on png_create_write_struct.\n");
return false;
}
png_info *infoStruct = png_create_info_struct(writeStruct);
if (!infoStruct)
{
fprintf(stderr, "Error on png_create_info_struct.\n");
return false;
}
if (setjmp(png_jmpbuf(writeStruct)))
{
fp.close();
png_free_data(writeStruct, infoStruct, PNG_FREE_ALL, -1);
png_destroy_write_struct(&writeStruct, &infoStruct);
return false;
}
png_init_io(writeStruct, fp.get());
// Write header (8 bit colour depth)
png_set_IHDR(writeStruct, infoStruct, width, height, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
// Set title
if (title != nullptr && strlen(title) > 0)
{
std::array<char, 50> mutableKey = {};
strcpy(mutableKey.data(), "Title");
std::array<char, 200> mutableText = {};
strncpy(mutableText.data(), title, 199);
png_text titleText;
titleText.compression = PNG_TEXT_COMPRESSION_NONE;
titleText.key = mutableKey.data();
titleText.text = mutableText.data();
png_set_text(writeStruct, infoStruct, &titleText, 1);
}
png_write_info(writeStruct, infoStruct);
// RGB 3-byte stride.
const uint32_t rowStride = width * 3;
for (uint32_t row = 0; row < height; ++row)
{
uint32_t rowOffset = row * rowStride;
png_write_row(writeStruct, &data[rowOffset]);
}
png_write_end(writeStruct, infoStruct);
fp.close();
png_free_data(writeStruct, infoStruct, PNG_FREE_ALL, -1);
png_destroy_write_struct(&writeStruct, &infoStruct);
return true;
}
} // namespace angle