From ad8aab2a14a7b4dc01e33312d151b6f535f3c41e Mon Sep 17 00:00:00 2001 From: Lode Date: Sun, 24 Aug 2014 20:09:39 +0200 Subject: add example and dev files to LodePNG repository --- example_encode.cpp | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 example_encode.cpp (limited to 'example_encode.cpp') diff --git a/example_encode.cpp b/example_encode.cpp new file mode 100644 index 0000000..31dd0b8 --- /dev/null +++ b/example_encode.cpp @@ -0,0 +1,97 @@ +/* +LodePNG Examples + +Copyright (c) 2005-2012 Lode Vandevenne + +This software is provided 'as-is', without any express or implied +warranty. In no event will the authors be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + + 3. This notice may not be removed or altered from any source + distribution. +*/ + +#include "lodepng.h" +#include + +/* +3 ways to encode a PNG from RGBA pixel data to a file (and 2 in-memory ways). +NOTE: this samples overwrite the file or test.png without warning! +*/ + +//g++ lodepng.cpp example_encode.cpp -ansi -pedantic -Wall -Wextra -O3 + +//Example 1 +//Encode from raw pixels to disk with a single function call +//The image argument has width * height RGBA pixels or width * height * 4 bytes +void encodeOneStep(const char* filename, std::vector& image, unsigned width, unsigned height) +{ + //Encode the image + unsigned error = lodepng::encode(filename, image, width, height); + + //if there's an error, display it + if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl; +} + +//Example 2 +//Encode from raw pixels to an in-memory PNG file first, then write it to disk +//The image argument has width * height RGBA pixels or width * height * 4 bytes +void encodeTwoSteps(const char* filename, std::vector& image, unsigned width, unsigned height) +{ + std::vector png; + + unsigned error = lodepng::encode(png, image, width, height); + if(!error) lodepng::save_file(png, filename); + + //if there's an error, display it + if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl; +} + +//Example 3 +//Save a PNG file to disk using a State, normally needed for more advanced usage. +//The image argument has width * height RGBA pixels or width * height * 4 bytes +void encodeWithState(const char* filename, std::vector& image, unsigned width, unsigned height) +{ + std::vector png; + lodepng::State state; //optionally customize this one + + unsigned error = lodepng::encode(png, image, width, height, state); + if(!error) lodepng::save_file(png, filename); + + //if there's an error, display it + if(error) std::cout << "encoder error " << error << ": "<< lodepng_error_text(error) << std::endl; +} + +//saves image to filename given as argument. Warning, this overwrites the file without warning! +int main(int argc, char *argv[]) +{ + //NOTE: this sample will overwrite the file or test.png without warning! + const char* filename = argc > 1 ? argv[1] : "test.png"; + + //generate some image + unsigned width = 512, height = 512; + std::vector image; + image.resize(width * height * 4); + for(unsigned y = 0; y < height; y++) + for(unsigned x = 0; x < width; x++) + { + image[4 * width * y + 4 * x + 0] = 255 * !(x & y); + image[4 * width * y + 4 * x + 1] = x ^ y; + image[4 * width * y + 4 * x + 2] = x | y; + image[4 * width * y + 4 * x + 3] = 255; + } + + encodeOneStep(filename, image, width, height); +} -- cgit v1.2.3