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112 lines
3.4 KiB
C
112 lines
3.4 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 <stdio.h>
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#include <stdlib.h>
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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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/*
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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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*/
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void encodeOneStep(const char* filename, const unsigned char* image, unsigned width, unsigned height) {
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/*Encode the image*/
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unsigned error = lodepng_encode32_file(filename, image, width, height);
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/*if there's an error, display it*/
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if(error) printf("error %u: %s\n", error, lodepng_error_text(error));
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}
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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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*/
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void encodeTwoSteps(const char* filename, const unsigned char* image, unsigned width, unsigned height) {
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unsigned char* png;
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size_t pngsize;
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unsigned error = lodepng_encode32(&png, &pngsize, image, width, height);
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if(!error) lodepng_save_file(png, pngsize, filename);
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/*if there's an error, display it*/
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if(error) printf("error %u: %s\n", error, lodepng_error_text(error));
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free(png);
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}
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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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*/
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void encodeWithState(const char* filename, const unsigned char* image, unsigned width, unsigned height) {
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unsigned error;
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unsigned char* png;
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size_t pngsize;
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LodePNGState state;
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lodepng_state_init(&state);
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/*optionally customize the state*/
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error = lodepng_encode(&png, &pngsize, image, width, height, &state);
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if(!error) lodepng_save_file(png, pngsize, filename);
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/*if there's an error, display it*/
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if(error) printf("error %u: %s\n", error, lodepng_error_text(error));
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lodepng_state_cleanup(&state);
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free(png);
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}
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int main(int argc, char *argv[]) {
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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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unsigned char* image = malloc(width * height * 4);
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unsigned x, y;
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for(y = 0; y < height; y++)
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for(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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/*run an example*/
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encodeOneStep(filename, image, width, height);
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free(image);
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return 0;
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}
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