/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPixmap_DEFINED
#define SkPixmap_DEFINED
#include "SkColor.h"
#include "SkFilterQuality.h"
#include "SkImageInfo.h"
class SkData;
struct SkMask;
/** \class SkPixmap
SkPixmap provides a utility to pair SkImageInfo with pixels and row bytes.
SkPixmap is a low level class which provides convenience functions to access
raster destinations. SkCanvas can not draw SkPixmap, nor does SkPixmap provide
a direct drawing destination.
Use SkBitmap to draw pixels referenced by SkPixmap; use SkSurface to draw into
pixels referenced by SkPixmap.
SkPixmap does not try to manage the lifetime of the pixel memory. Use SkPixelRef
to manage pixel memory; SkPixelRef is safe across threads.
*/
class SK_API SkPixmap {
public:
/** Creates an empty SkPixmap without pixels, with kUnknown_SkColorType, with
kUnknown_SkAlphaType, and with a width and height of zero. Use
reset() to associate pixels, SkColorType, SkAlphaType, width, and height
after SkPixmap has been created.
@return empty SkPixmap
*/
SkPixmap()
: fPixels(nullptr), fRowBytes(0), fInfo(SkImageInfo::MakeUnknown(0, 0))
{}
/** Creates SkPixmap from info width, height, SkAlphaType, and SkColorType.
addr points to pixels, or nullptr. rowBytes should be info.width() times
info.bytesPerPixel(), or larger.
No parameter checking is performed; it is up to the caller to ensure that
addr and rowBytes agree with info.
The memory lifetime of pixels is managed by the caller. When SkPixmap goes
out of scope, addr is unaffected.
SkPixmap may be later modified by reset() to change its size, pixel type, or
storage.
@param info width, height, SkAlphaType, SkColorType of SkImageInfo
@param addr pointer to pixels allocated by caller; may be nullptr
@param rowBytes size of one row of addr; width times pixel size, or larger
@return initialized SkPixmap
*/
SkPixmap(const SkImageInfo& info, const void* addr, size_t rowBytes)
: fPixels(addr), fRowBytes(rowBytes), fInfo(info)
{}
/** Sets width, height, row bytes to zero; pixel address to nullptr; SkColorType to
kUnknown_SkColorType; and SkAlphaType to kUnknown_SkAlphaType.
The prior pixels are unaffected; it is up to the caller to release pixels
memory if desired.
*/
void reset();
/** Sets width, height, SkAlphaType, and SkColorType from info.
Sets pixel address from addr, which may be nullptr.
Sets row bytes from rowBytes, which should be info.width() times
info.bytesPerPixel(), or larger.
Does not check addr. Asserts if built with SK_DEBUG defined and if rowBytes is
too small to hold one row of pixels.
The memory lifetime pixels are managed by the caller. When SkPixmap goes
out of scope, addr is unaffected.
@param info width, height, SkAlphaType, SkColorType of SkImageInfo
@param addr pointer to pixels allocated by caller; may be nullptr
@param rowBytes size of one row of addr; width times pixel size, or larger
*/
void reset(const SkImageInfo& info, const void* addr, size_t rowBytes);
/** Changes SkColorSpace in SkImageInfo; preserves width, height, SkAlphaType, and
SkColorType in SkImage, and leaves pixel address and row bytes unchanged.
SkColorSpace reference count is incremented.
@param colorSpace SkColorSpace moved to SkImageInfo
*/
void setColorSpace(sk_sp<SkColorSpace> colorSpace);
/** To be deprecated soon.
*/
bool SK_WARN_UNUSED_RESULT reset(const SkMask& mask);
/** Sets subset width, height, pixel address to intersection of SkPixmap with area,
if intersection is not empty; and return true. Otherwise, leave subset unchanged
and return false.
Failing to read the return value generates a compile time warning.
@param subset storage for width, height, pixel address of intersection
@param area bounds to intersect with SkPixmap
@return true if intersection of SkPixmap and area is not empty
*/
bool SK_WARN_UNUSED_RESULT extractSubset(SkPixmap* subset, const SkIRect& area) const;
/** Returns width, height, SkAlphaType, SkColorType, and SkColorSpace.
@return reference to ImageInfo
*/
const SkImageInfo& info() const { return fInfo; }
/** Returns row bytes, the interval from one pixel row to the next. Row bytes
is at least as large as: width() * info().bytesPerPixel().
Returns zero if colorType() is kUnknown_SkColorType.
It is up to the SkBitmap creator to ensure that row bytes is a useful value.
@return byte length of pixel row
*/
size_t rowBytes() const { return fRowBytes; }
/** Returns pixel address, the base address corresponding to the pixel origin.
It is up to the SkPixmap creator to ensure that pixel address is a useful value.
@return pixel address
*/
const void* addr() const { return fPixels; }
/** Returns pixel count in each pixel row. Should be equal or less than:
rowBytes() / info().bytesPerPixel().
@return pixel width in SkImageInfo
*/
int width() const { return fInfo.width(); }
/** Returns pixel row count.
@return pixel height in SkImageInfo
*/
int height() const { return fInfo.height(); }
/** Returns SkColorType, one of: kUnknown_SkColorType, kAlpha_8_SkColorType,
kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType,
kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType,
kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType.
@return SkColorType in SkImageInfo
*/
SkColorType colorType() const { return fInfo.colorType(); }
/** Returns SkAlphaType, one of: kUnknown_SkAlphaType, kOpaque_SkAlphaType,
kPremul_SkAlphaType, kUnpremul_SkAlphaType.
@return SkAlphaType in SkImageInfo
*/
SkAlphaType alphaType() const { return fInfo.alphaType(); }
/** Returns SkColorSpace associated with SkImageInfo. The
reference count of SkColorSpace is unchanged. The returned SkColorSpace is
immutable.
@return SkColorSpace, the range of colors, in SkImageInfo
*/
SkColorSpace* colorSpace() const { return fInfo.colorSpace(); }
/** Returns true if SkAlphaType is kOpaque_SkAlphaType.
Does not check if SkColorType allows alpha, or if any pixel value has
transparency.
@return true if SkImageInfo has opaque SkAlphaType
*/
bool isOpaque() const { return fInfo.isOpaque(); }
/** Returns SkIRect { 0, 0, width(), height() }.
@return integral rectangle from origin to width() and height()
*/
SkIRect bounds() const { return SkIRect::MakeWH(this->width(), this->height()); }
/** Returns number of pixels that fit on row. Should be greater than or equal to
width().
@return maximum pixels per row
*/
int rowBytesAsPixels() const { return int(fRowBytes >> this->shiftPerPixel()); }
/** Returns bit shift converting row bytes to row pixels.
Returns zero for kUnknown_SkColorType.
@return one of: 0, 1, 2, 3; left shift to convert pixels to bytes
*/
int shiftPerPixel() const { return fInfo.shiftPerPixel(); }
/** Returns minimum memory required for pixel storage.
Does not include unused memory on last row when rowBytesAsPixels() exceeds width().
Returns zero if result does not fit in size_t.
Returns zero if height() or width() is 0.
Returns height() times rowBytes() if colorType() is kUnknown_SkColorType.
@return size in bytes of image buffer
*/
size_t computeByteSize() const { return fInfo.computeByteSize(fRowBytes); }
/** Returns true if all pixels are opaque. SkColorType determines how pixels
are encoded, and whether pixel describes alpha. Returns true for SkColorType
without alpha in each pixel; for other SkColorType, returns true if all
pixels have alpha values equivalent to 1.0 or greater.
For SkColorType kRGB_565_SkColorType or kGray_8_SkColorType: always
returns true. For SkColorType kAlpha_8_SkColorType, kBGRA_8888_SkColorType,
kRGBA_8888_SkColorType: returns true if all pixel alpha values are 255.
For SkColorType kARGB_4444_SkColorType: returns true if all pixel alpha values are 15.
For kRGBA_F16_SkColorType: returns true if all pixel alpha values are 1.0 or
greater.
Returns false for kUnknown_SkColorType.
@return true if all pixels have opaque values or SkColorType is opaque
*/
bool computeIsOpaque() const;
/** Returns pixel at (x, y) as unpremultiplied color.
Returns black with alpha if SkColorType is kAlpha_8_SkColorType.
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined; and returns undefined values or may crash if
SK_RELEASE is defined. Fails if SkColorType is kUnknown_SkColorType or
pixel address is nullptr.
SkColorSpace in SkImageInfo is ignored. Some color precision may be lost in the
conversion to unpremultiplied color; original pixel data may have additional
precision.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return pixel converted to unpremultiplied color
*/
SkColor getColor(int x, int y) const;
/** Returns readable pixel address at (x, y). Returns nullptr if SkPixelRef is nullptr.
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined. Returns nullptr if SkColorType is kUnknown_SkColorType.
Performs a lookup of pixel size; for better performance, call
one of: addr8, addr16, addr32, addr64, or addrF16().
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable generic pointer to pixel
*/
const void* addr(int x, int y) const {
return (const char*)fPixels + fInfo.computeOffset(x, y, fRowBytes);
}
/** Returns readable base pixel address. Result is addressable as unsigned 8-bit bytes.
Will trigger an assert() if SkColorType is not kAlpha_8_SkColorType or
kGray_8_SkColorType, and is built with SK_DEBUG defined.
One byte corresponds to one pixel.
@return readable unsigned 8-bit pointer to pixels
*/
const uint8_t* addr8() const {
SkASSERT(1 == fInfo.bytesPerPixel());
return reinterpret_cast<const uint8_t*>(fPixels);
}
/** Returns readable base pixel address. Result is addressable as unsigned 16-bit words.
Will trigger an assert() if SkColorType is not kRGB_565_SkColorType or
kARGB_4444_SkColorType, and is built with SK_DEBUG defined.
One word corresponds to one pixel.
@return readable unsigned 16-bit pointer to pixels
*/
const uint16_t* addr16() const {
SkASSERT(2 == fInfo.bytesPerPixel());
return reinterpret_cast<const uint16_t*>(fPixels);
}
/** Returns readable base pixel address. Result is addressable as unsigned 32-bit words.
Will trigger an assert() if SkColorType is not kRGBA_8888_SkColorType or
kBGRA_8888_SkColorType, and is built with SK_DEBUG defined.
One word corresponds to one pixel.
@return readable unsigned 32-bit pointer to pixels
*/
const uint32_t* addr32() const {
SkASSERT(4 == fInfo.bytesPerPixel());
return reinterpret_cast<const uint32_t*>(fPixels);
}
/** Returns readable base pixel address. Result is addressable as unsigned 64-bit words.
Will trigger an assert() if SkColorType is not kRGBA_F16_SkColorType and is built
with SK_DEBUG defined.
One word corresponds to one pixel.
@return readable unsigned 64-bit pointer to pixels
*/
const uint64_t* addr64() const {
SkASSERT(8 == fInfo.bytesPerPixel());
return reinterpret_cast<const uint64_t*>(fPixels);
}
/** Returns readable base pixel address. Result is addressable as unsigned 16-bit words.
Will trigger an assert() if SkColorType is not kRGBA_F16_SkColorType and is built
with SK_DEBUG defined.
Each word represents one color component encoded as a half float.
Four words correspond to one pixel.
@return readable unsigned 16-bit pointer to first component of pixels
*/
const uint16_t* addrF16() const {
SkASSERT(8 == fInfo.bytesPerPixel());
SkASSERT(kRGBA_F16_SkColorType == fInfo.colorType());
return reinterpret_cast<const uint16_t*>(fPixels);
}
/** Returns readable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined.
Will trigger an assert() if SkColorType is not kAlpha_8_SkColorType or
kGray_8_SkColorType, and is built with SK_DEBUG defined.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable unsigned 8-bit pointer to pixel at (x, y)
*/
const uint8_t* addr8(int x, int y) const {
SkASSERT((unsigned)x < (unsigned)fInfo.width());
SkASSERT((unsigned)y < (unsigned)fInfo.height());
return (const uint8_t*)((const char*)this->addr8() + y * fRowBytes + (x << 0));
}
/** Returns readable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined.
Will trigger an assert() if SkColorType is not kRGB_565_SkColorType or
kARGB_4444_SkColorType, and is built with SK_DEBUG defined.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable unsigned 16-bit pointer to pixel at (x, y)
*/
const uint16_t* addr16(int x, int y) const {
SkASSERT((unsigned)x < (unsigned)fInfo.width());
SkASSERT((unsigned)y < (unsigned)fInfo.height());
return (const uint16_t*)((const char*)this->addr16() + y * fRowBytes + (x << 1));
}
/** Returns readable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined.
Will trigger an assert() if SkColorType is not kRGBA_8888_SkColorType or
kBGRA_8888_SkColorType, and is built with SK_DEBUG defined.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable unsigned 32-bit pointer to pixel at (x, y)
*/
const uint32_t* addr32(int x, int y) const {
SkASSERT((unsigned)x < (unsigned)fInfo.width());
SkASSERT((unsigned)y < (unsigned)fInfo.height());
return (const uint32_t*)((const char*)this->addr32() + y * fRowBytes + (x << 2));
}
/** Returns readable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined.
Will trigger an assert() if SkColorType is not kRGBA_F16_SkColorType and is built
with SK_DEBUG defined.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable unsigned 64-bit pointer to pixel at (x, y)
*/
const uint64_t* addr64(int x, int y) const {
SkASSERT((unsigned)x < (unsigned)fInfo.width());
SkASSERT((unsigned)y < (unsigned)fInfo.height());
return (const uint64_t*)((const char*)this->addr64() + y * fRowBytes + (x << 3));
}
/** Returns readable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined.
Will trigger an assert() if SkColorType is not kRGBA_F16_SkColorType and is built
with SK_DEBUG defined.
Each unsigned 16-bit word represents one color component encoded as a half float.
Four words correspond to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return readable unsigned 16-bit pointer to pixel component at (x, y)
*/
const uint16_t* addrF16(int x, int y) const {
SkASSERT(kRGBA_F16_SkColorType == fInfo.colorType());
return reinterpret_cast<const uint16_t*>(this->addr64(x, y));
}
/** Returns writable base pixel address.
@return writable generic base pointer to pixels
*/
void* writable_addr() const { return const_cast<void*>(fPixels); }
/** Returns writable pixel address at (x, y).
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined. Returns zero if SkColorType is kUnknown_SkColorType.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable generic pointer to pixel
*/
void* writable_addr(int x, int y) const {
return const_cast<void*>(this->addr(x, y));
}
/** Returns writable pixel address at (x, y). Result is addressable as unsigned
8-bit bytes. Will trigger an assert() if SkColorType is not kAlpha_8_SkColorType
or kGray_8_SkColorType, and is built with SK_DEBUG defined.
One byte corresponds to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable unsigned 8-bit pointer to pixels
*/
uint8_t* writable_addr8(int x, int y) const {
return const_cast<uint8_t*>(this->addr8(x, y));
}
/** Returns writable_addr pixel address at (x, y). Result is addressable as unsigned
16-bit words. Will trigger an assert() if SkColorType is not kRGB_565_SkColorType
or kARGB_4444_SkColorType, and is built with SK_DEBUG defined.
One word corresponds to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable unsigned 16-bit pointer to pixel
*/
uint16_t* writable_addr16(int x, int y) const {
return const_cast<uint16_t*>(this->addr16(x, y));
}
/** Returns writable pixel address at (x, y). Result is addressable as unsigned
32-bit words. Will trigger an assert() if SkColorType is not
kRGBA_8888_SkColorType or kBGRA_8888_SkColorType, and is built with SK_DEBUG
defined.
One word corresponds to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable unsigned 32-bit pointer to pixel
*/
uint32_t* writable_addr32(int x, int y) const {
return const_cast<uint32_t*>(this->addr32(x, y));
}
/** Returns writable pixel address at (x, y). Result is addressable as unsigned
64-bit words. Will trigger an assert() if SkColorType is not
kRGBA_F16_SkColorType and is built with SK_DEBUG defined.
One word corresponds to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable unsigned 64-bit pointer to pixel
*/
uint64_t* writable_addr64(int x, int y) const {
return const_cast<uint64_t*>(this->addr64(x, y));
}
/** Returns writable pixel address at (x, y). Result is addressable as unsigned
16-bit words. Will trigger an assert() if SkColorType is not
kRGBA_F16_SkColorType and is built with SK_DEBUG defined.
Each word represents one color component encoded as a half float.
Four words correspond to one pixel.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return writable unsigned 16-bit pointer to first component of pixel
*/
uint16_t* writable_addrF16(int x, int y) const {
return reinterpret_cast<uint16_t*>(writable_addr64(x, y));
}
/** Copies a SkRect of pixels to dstPixels. Copy starts at (srcX, srcY), and does not
exceed SkPixmap (width(), height()).
dstInfo specifies width, height, SkColorType, SkAlphaType, and
SkColorSpace of destination. dstRowBytes specifics the gap from one destination
row to the next. Returns true if pixels are copied. Returns false if
dstInfo.addr() equals nullptr, or dstRowBytes is less than dstInfo.minRowBytes().
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType() must match.
If SkPixmap colorType() is kGray_8_SkColorType, dstInfo.colorSpace() must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dstInfo.alphaType() must
match. If SkPixmap colorSpace() is nullptr, dstInfo.colorSpace() must match. Returns
false if pixel conversion is not possible.
srcX and srcY may be negative to copy only top or left of source. Returns
false if width() or height() is zero or negative. Returns false if:
abs(srcX) >= Pixmap width(), or if abs(srcY) >= Pixmap height().
If behavior is SkTransferFunctionBehavior::kRespect: converts source
pixels to a linear space before converting to dstInfo.
If behavior is SkTransferFunctionBehavior::kIgnore: source
pixels are treated as if they are linear, regardless of how they are encoded.
@param dstInfo destination width, height, SkColorType, SkAlphaType, SkColorSpace
@param dstPixels destination pixel storage
@param dstRowBytes destination row length
@param srcX column index whose absolute value is less than width()
@param srcY row index whose absolute value is less than height()
@param behavior one of: SkTransferFunctionBehavior::kRespect,
SkTransferFunctionBehavior::kIgnore
@return true if pixels are copied to dstPixels
*/
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
int srcX, int srcY, SkTransferFunctionBehavior behavior) const;
/** Copies a SkRect of pixels to dstPixels. Copy starts at (0, 0), and does not
exceed SkPixmap (width(), height()).
dstInfo specifies width, height, SkColorType, SkAlphaType, and
SkColorSpace of destination. dstRowBytes specifics the gap from one destination
row to the next. Returns true if pixels are copied. Returns false if
dstInfo.addr() equals nullptr, or dstRowBytes is less than dstInfo.minRowBytes().
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType() must match.
If SkPixmap colorType() is kGray_8_SkColorType, dstInfo.colorSpace() must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dstInfo.alphaType() must
match. If SkPixmap colorSpace() is nullptr, dstInfo.colorSpace() must match. Returns
false if pixel conversion is not possible.
Returns false if SkPixmap width() or height() is zero or negative.
@param dstInfo destination width, height, SkColorType, SkAlphaType, SkColorSpace
@param dstPixels destination pixel storage
@param dstRowBytes destination row length
@return true if pixels are copied to dstPixels
*/
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes) const {
return this->readPixels(dstInfo, dstPixels, dstRowBytes, 0, 0);
}
/** Copies a SkRect of pixels to dstPixels. Copy starts at (srcX, srcY), and does not
exceed SkPixmap (width(), height()).
dstInfo specifies width, height, SkColorType, SkAlphaType, and
SkColorSpace of destination. dstRowBytes specifics the gap from one destination
row to the next. Returns true if pixels are copied. Returns false if
dstInfo.addr() equals nullptr, or dstRowBytes is less than dstInfo.minRowBytes().
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType() must match.
If SkPixmap colorType() is kGray_8_SkColorType, dstInfo.colorSpace() must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dstInfo.alphaType() must
match. If SkPixmap colorSpace() is nullptr, dstInfo.colorSpace() must match. Returns
false if pixel conversion is not possible.
srcX and srcY may be negative to copy only top or left of source. Returns
false if SkPixmap width() or height() is zero or negative. Returns false if:
abs(srcX) >= Pixmap width(), or if abs(srcY) >= Pixmap height().
@param dstInfo destination width, height, SkColorType, SkAlphaType, SkColorSpace
@param dstPixels destination pixel storage
@param dstRowBytes destination row length
@param srcX column index whose absolute value is less than width()
@param srcY row index whose absolute value is less than height()
@return true if pixels are copied to dstPixels
*/
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, int srcX,
int srcY) const {
return this->readPixels(dstInfo, dstPixels, dstRowBytes, srcX, srcY,
SkTransferFunctionBehavior::kRespect);
}
/** Copies a SkRect of pixels to dst. Copy starts at (srcX, srcY), and does not
exceed SkPixmap (width(), height()). dst specifies width, height, SkColorType,
SkAlphaType, and SkColorSpace of destination. Returns true if pixels are copied.
Returns false if dst.addr() equals nullptr, or dst.rowBytes() is less than
dst SkImageInfo::minRowBytes.
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dst.info().colorType must match.
If SkPixmap colorType() is kGray_8_SkColorType, dst.info().colorSpace must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dst.info().alphaType must
match. If SkPixmap colorSpace() is nullptr, dst.info().colorSpace must match. Returns
false if pixel conversion is not possible.
srcX and srcY may be negative to copy only top or left of source. Returns
false SkPixmap width() or height() is zero or negative. Returns false if:
abs(srcX) >= Pixmap width(), or if abs(srcY) >= Pixmap height().
@param dst SkImageInfo and pixel address to write to
@param srcX column index whose absolute value is less than width()
@param srcY row index whose absolute value is less than height()
@return true if pixels are copied to dst
*/
bool readPixels(const SkPixmap& dst, int srcX, int srcY) const {
return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), srcX, srcY);
}
/** Copies pixels inside bounds() to dst. dst specifies width, height, SkColorType,
SkAlphaType, and SkColorSpace of destination. Returns true if pixels are copied.
Returns false if dst.addr() equals nullptr, or dst.rowBytes() is less than
dst SkImageInfo::minRowBytes.
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dst SkColorType must match.
If SkPixmap colorType() is kGray_8_SkColorType, dst SkColorSpace must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dst SkAlphaType must
match. If SkPixmap colorSpace() is nullptr, dst SkColorSpace must match. Returns
false if pixel conversion is not possible.
Returns false if SkPixmap width() or height() is zero or negative.
@param dst SkImageInfo and pixel address to write to
@return true if pixels are copied to dst
*/
bool readPixels(const SkPixmap& dst) const {
return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), 0, 0);
}
/** Copies SkBitmap to dst, scaling pixels to fit dst.width() and dst.height(), and
converting pixels to match dst.colorType() and dst.alphaType(). Returns true if
pixels are copied. Returns false if dst.addr() is nullptr, or dst.rowBytes() is
less than dst SkImageInfo::minRowBytes.
Pixels are copied only if pixel conversion is possible. If SkPixmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dst SkColorType must match.
If SkPixmap colorType() is kGray_8_SkColorType, dst SkColorSpace must match.
If SkPixmap alphaType() is kOpaque_SkAlphaType, dst SkAlphaType must
match. If SkPixmap colorSpace() is nullptr, dst SkColorSpace must match. Returns
false if pixel conversion is not possible.
Returns false if SkBitmap width() or height() is zero or negative.
Scales the image, with filterQuality, to match dst.width() and dst.height().
filterQuality kNone_SkFilterQuality is fastest, typically implemented with
nearest neighbor filter. kLow_SkFilterQuality is typically implemented with
bilerp filter. kMedium_SkFilterQuality is typically implemented with
bilerp filter, and Filter_Quality_MipMap when size is reduced.
kHigh_SkFilterQuality is slowest, typically implemented with Filter_Quality_BiCubic.
@param dst SkImageInfo and pixel address to write to
@param filterQuality one of: kNone_SkFilterQuality, kLow_SkFilterQuality,
kMedium_SkFilterQuality, kHigh_SkFilterQuality
@return true if pixels are scaled to fit dst
*/
bool scalePixels(const SkPixmap& dst, SkFilterQuality filterQuality) const;
/** Writes color to pixels bounded by subset; returns true on success.
Returns false if colorType() is kUnknown_SkColorType, or if subset does
not intersect bounds().
@param color unpremultiplied color to write
@param subset bounding integer SkRect of written pixels
@return true if pixels are changed
*/
bool erase(SkColor color, const SkIRect& subset) const;
/** Writes color to pixels inside bounds(); returns true on success.
Returns false if colorType() is kUnknown_SkColorType, or if bounds()
is empty.
@param color unpremultiplied color to write
@return true if pixels are changed
*/
bool erase(SkColor color) const { return this->erase(color, this->bounds()); }
/** Writes color to pixels bounded by subset; returns true on success.
if subset is nullptr, writes colors pixels inside bounds(). Returns false if
colorType() is kUnknown_SkColorType, if subset is not nullptr and does
not intersect bounds(), or if subset is nullptr and bounds() is empty.
@param color unpremultiplied color to write
@param subset bounding integer SkRect of pixels to write; may be nullptr
@return true if pixels are changed
*/
bool erase(const SkColor4f& color, const SkIRect* subset = nullptr) const;
private:
const void* fPixels;
size_t fRowBytes;
SkImageInfo fInfo;
friend class SkPixmapPriv;
};
#endif