minetest/src/imagefilters.h

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/*
Copyright (C) 2015 Aaron Suen <warr1024@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _IMAGE_FILTERS_H_
#define _IMAGE_FILTERS_H_
#include "irrlichttypes_extrabloated.h"
/* Fill in RGB values for transparent pixels, to correct for odd colors
* appearing at borders when blending. This is because many PNG optimizers
* like to discard RGB values of transparent pixels, but when blending then
* with non-transparent neighbors, their RGB values will shpw up nonetheless.
*
* This function modifies the original image in-place.
*
* Parameter "threshold" is the alpha level below which pixels are considered
* transparent. Should be 127 for 3d where alpha is threshold, but 0 for
* 2d where alpha is blended.
*/
void imageCleanTransparent(video::IImage *src, u32 threshold);
/* Scale a region of an image into another image, using nearest-neighbor with
* anti-aliasing; treat pixels as crisp rectangles, but blend them at boundaries
* to prevent non-integer scaling ratio artifacts. Note that this may cause
* some blending at the edges where pixels don't line up perfectly, but this
* filter is designed to produce the most accurate results for both upscaling
* and downscaling.
*/
void imageScaleNNAA(video::IImage *src, const core::rect<s32> &srcrect, video::IImage *dest);
#endif