diff options
| author | Lode <lvandeve@gmail.com> | 2014-08-24 20:09:39 +0200 |
|---|---|---|
| committer | Lode <lvandeve@gmail.com> | 2014-08-24 20:09:39 +0200 |
| commit | ad8aab2a14a7b4dc01e33312d151b6f535f3c41e (patch) | |
| tree | 0af431f67446a8e102263787a26a1b90ca5e9b1b /example_encode.cpp | |
| parent | 148987254da889a317e2d249c5f7f68849267de5 (diff) | |
add example and dev files to LodePNG repository
Diffstat (limited to 'example_encode.cpp')
| -rw-r--r-- | example_encode.cpp | 97 |
1 files changed, 97 insertions, 0 deletions
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 <iostream>
+
+/*
+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<unsigned char>& 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<unsigned char>& image, unsigned width, unsigned height)
+{
+ std::vector<unsigned char> 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<unsigned char>& image, unsigned width, unsigned height)
+{
+ std::vector<unsigned char> 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<unsigned char> 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);
+}
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