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93 lines
3.5 KiB
C++
93 lines
3.5 KiB
C++
/*
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LodePNG Examples
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Copyright (c) 2005-2012 Lode Vandevenne
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source
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distribution.
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*/
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#include "lodepng.h"
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#include <iostream>
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/*
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3 ways to encode a PNG from RGBA pixel data to a file (and 2 in-memory ways).
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NOTE: this samples overwrite the file or test.png without warning!
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*/
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//g++ lodepng.cpp examples/example_encode.cpp -I./ -ansi -pedantic -Wall -Wextra -O3
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//Example 1
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//Encode from raw pixels to disk with a single function call
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//The image argument has width * height RGBA pixels or width * height * 4 bytes
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void encodeOneStep(const char* filename, std::vector<unsigned char>& image, unsigned width, unsigned height) {
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//Encode the image
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unsigned error = lodepng::encode(filename, image, width, height);
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//if there's an error, display it
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if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl;
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}
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//Example 2
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//Encode from raw pixels to an in-memory PNG file first, then write it to disk
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//The image argument has width * height RGBA pixels or width * height * 4 bytes
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void encodeTwoSteps(const char* filename, std::vector<unsigned char>& image, unsigned width, unsigned height) {
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std::vector<unsigned char> png;
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unsigned error = lodepng::encode(png, image, width, height);
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if(!error) lodepng::save_file(png, filename);
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//if there's an error, display it
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if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl;
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}
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//Example 3
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//Save a PNG file to disk using a State, normally needed for more advanced usage.
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//The image argument has width * height RGBA pixels or width * height * 4 bytes
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void encodeWithState(const char* filename, std::vector<unsigned char>& image, unsigned width, unsigned height) {
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std::vector<unsigned char> png;
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lodepng::State state; //optionally customize this one
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unsigned error = lodepng::encode(png, image, width, height, state);
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if(!error) lodepng::save_file(png, filename);
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//if there's an error, display it
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if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl;
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}
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//saves image to filename given as argument. Warning, this overwrites the file without warning!
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int main(int argc, char *argv[]) {
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//NOTE: this sample will overwrite the file or test.png without warning!
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const char* filename = argc > 1 ? argv[1] : "test.png";
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//generate some image
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unsigned width = 512, height = 512;
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std::vector<unsigned char> image;
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image.resize(width * height * 4);
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for(unsigned y = 0; y < height; y++)
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for(unsigned x = 0; x < width; x++) {
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image[4 * width * y + 4 * x + 0] = 255 * !(x & y);
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image[4 * width * y + 4 * x + 1] = x ^ y;
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image[4 * width * y + 4 * x + 2] = x | y;
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image[4 * width * y + 4 * x + 3] = 255;
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}
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encodeOneStep(filename, image, width, height);
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}
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