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// Copyright 2019 The Amber Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "samples/png.h"
#include <cassert>
#include "amber/result.h"
#include "amber/value.h"
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wweak-vtables"
#include "third_party/lodepng/lodepng.h"
#pragma clang diagnostic pop
namespace png {
namespace {
unsigned char byte0(uint32_t word) {
return static_cast<unsigned char>(word);
}
unsigned char byte1(uint32_t word) {
return static_cast<unsigned char>(word >> 8);
}
unsigned char byte2(uint32_t word) {
return static_cast<unsigned char>(word >> 16);
}
unsigned char byte3(uint32_t word) {
return static_cast<unsigned char>(word >> 24);
}
} // namespace
std::pair<amber::Result, std::string> ConvertToPNG(
uint32_t width,
uint32_t height,
const std::vector<amber::Value>& values) {
assert(values.size() == width * height);
std::vector<unsigned char> data;
// Prepare data as lodepng expects it
for (amber::Value value : values) {
const uint32_t pixel = value.AsUint32();
data.push_back(byte2(pixel)); // R
data.push_back(byte1(pixel)); // G
data.push_back(byte0(pixel)); // B
data.push_back(byte3(pixel)); // A
}
std::vector<unsigned char> png;
unsigned error = lodepng::encode(png, data, width, height);
if (error) {
return std::make_pair(amber::Result("lodepng::encode() returned non-zero"),
nullptr);
}
return std::make_pair(amber::Result(), std::string(png.begin(), png.end()));
}
} // namespace png
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