koffice/chalk/core/kis_alpha_mask.h

107 lines
3.1 KiB

/*
* Copyright (c) 2004 Boudewijn Rempt <boud@valdyas.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU 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 KIS_ALPHA_MASK_
#define KIS_ALPHA_MASK_
#include <tqimage.h>
#include <tqvaluevector.h>
#include <ksharedptr.h>
#include "kis_global.h"
#include "kis_types.h"
/**
* KisAlphaMask is intended to create alpha values from a TQImage for use
* in brush creation. It is not a generic alpha mask that can be used with
* KisPaintDevices: use a KisSelection for that.
*/
class KisAlphaMask : public KShared {
public:
/**
Create an alpha mask based on the specified TQImage. If the image is
not a grayscale, the mask value is calculated from the effective grey
level and alpha value.
*/
KisAlphaMask(const TQImage& img);
/**
As above except quicker as the image does not need to be scanned
to see if it has any colour pixels.
*/
KisAlphaMask(const TQImage& img, bool hasColor);
/**
Create a transparent mask.
*/
KisAlphaMask(TQ_INT32 width, TQ_INT32 height);
virtual ~KisAlphaMask();
/**
@return the number of alpha values in a scanline.
*/
TQ_INT32 height() const;
/**
@return the number of lines in the mask.
*/
TQ_INT32 width() const;
/**
@return the alpha value at the specified position.
Returns TQ_UINT8 OPACITY_TRANSPARENT if the value is
outside the bounds of the mask.
XXX: this is, of course, not the best way of masking.
Better would be to let KisAlphaMask fill a chunk of memory
with the alpha values at the right position, something like
void applyMask(TQ_UINT8 *pixeldata, TQ_INT32 pixelWidth,
TQ_INT32 alphaPos). That would be fastest, or we could
provide an iterator over the mask, that would be nice, too.
*/
inline TQ_UINT8 alphaAt(TQ_INT32 x, TQ_INT32 y) const
{
if (y >= 0 && y < m_height && x >= 0 && x < m_width) {
return m_data[(y * m_width) + x];
}
else {
return OPACITY_TRANSPARENT;
}
}
void setAlphaAt(TQ_INT32 x, TQ_INT32 y, TQ_UINT8 alpha);
// Create a new mask by interpolating between mask1 and mask2 as t
// goes from 0 to 1.
static KisAlphaMaskSP interpolate(KisAlphaMaskSP mask1, KisAlphaMaskSP mask2, double t);
private:
void computeAlpha(const TQImage& img);
void copyAlpha(const TQImage& img);
TQValueVector<TQ_UINT8> m_data;
TQ_INT32 m_width;
TQ_INT32 m_height;
};
#endif // KIS_ALPHA_MASK_