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/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkMask_DEFINED
#define SkMask_DEFINED
#include "SkRect.h"
/** \class SkMask
SkMask is used to describe alpha bitmaps, either 1bit, 8bit, or
the 3-channel 3D format. These are passed to SkMaskFilter objects.
*/
struct SkMask {
enum Format {
kBW_Format, //!< 1bit per pixel mask (e.g. monochrome)
kA8_Format, //!< 8bits per pixel mask (e.g. antialiasing)
k3D_Format, //!< 3 8bit per pixl planes: alpha, mul, add
kLCD_Format //!< 3 bytes/pixel: r/g/b
};
enum {
kCountMaskFormats = kLCD_Format + 1
};
uint8_t* fImage;
SkIRect fBounds;
uint32_t fRowBytes;
Format fFormat;
/** Returns true if the mask is empty: i.e. it has an empty bounds.
*/
bool isEmpty() const { return fBounds.isEmpty(); }
/** Return the byte size of the mask, assuming only 1 plane.
Does not account for k3D_Format. For that, use computeTotalImageSize().
If there is an overflow of 32bits, then returns 0.
*/
size_t computeImageSize() const;
/** Return the byte size of the mask, taking into account
any extra planes (e.g. k3D_Format).
If there is an overflow of 32bits, then returns 0.
*/
size_t computeTotalImageSize() const;
/** Returns the address of the byte that holds the specified bit.
Asserts that the mask is kBW_Format, and that x,y are in range.
x,y are in the same coordiate space as fBounds.
*/
uint8_t* getAddr1(int x, int y) const {
SkASSERT(fFormat == kBW_Format);
SkASSERT(fBounds.contains(x, y));
SkASSERT(fImage != NULL);
return fImage + ((x - fBounds.fLeft) >> 3) + (y - fBounds.fTop) * fRowBytes;
}
/** Returns the address of the specified byte.
Asserts that the mask is kA8_Format, and that x,y are in range.
x,y are in the same coordiate space as fBounds.
*/
uint8_t* getAddr(int x, int y) const {
SkASSERT(fFormat != kBW_Format);
SkASSERT(fBounds.contains(x, y));
SkASSERT(fImage != NULL);
return fImage + x - fBounds.fLeft + (y - fBounds.fTop) * fRowBytes;
}
static uint8_t* AllocImage(size_t bytes);
static void FreeImage(void* image);
enum CreateMode {
kJustComputeBounds_CreateMode, //!< compute bounds and return
kJustRenderImage_CreateMode, //!< render into preallocate mask
kComputeBoundsAndRenderImage_CreateMode //!< compute bounds, alloc image and render into it
};
};
#endif
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