#Topic Pixmap #Alias Pixmap_Reference #Subtopic Overview #Subtopic Subtopics #Populate ## ## #Class SkPixmap Pixmap provides a utility to pair SkImageInfo with pixels and row bytes. Pixmap is a low level class which provides convenience functions to access raster destinations. Canvas can not draw Pixmap, nor does Pixmap provide a direct drawing destination. Use Bitmap to draw pixels referenced by Pixmap; use Surface to draw into pixels referenced by Pixmap. Pixmap does not try to manage the lifetime of the pixel memory. Use Pixel_Ref to manage pixel memory; Pixel_Ref is safe across threads. #Subtopic Related_Functions #Populate ## #Subtopic Constructors #Populate ## #Subtopic Member_Functions #Populate ## #Subtopic Initialization #Line # sets fields for use ## # ------------------------------------------------------------------------------ #Method SkPixmap() #In Initialization #Line # constructs with default values ## Creates an empty Pixmap 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 Pixmap has been created. #Return empty Pixmap ## #Example void draw(SkCanvas* canvas) { const char* alphas[] = {"Unknown", "Opaque", "Premul", "Unpremul"}; const char* colors[] = {"Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16"}; SkPixmap pixmap; for (int i = 0; i < 2; ++i) { SkDebugf("width: %2d height: %2d", pixmap.width(), pixmap.height()); SkDebugf(" color: k%s_SkColorType", colors[pixmap.colorType()]); SkDebugf(" alpha: k%s_SkAlphaType\n", alphas[pixmap.alphaType()]); pixmap.reset(SkImageInfo::Make(25, 35, kRGBA_8888_SkColorType, kOpaque_SkAlphaType), nullptr, 0); } } #StdOut width: 0 height: 0 color: kUnknown_SkColorType alpha: kUnknown_SkAlphaType width: 25 height: 35 color: kRGBA_8888_SkColorType alpha: kOpaque_SkAlphaType ## ## #SeeAlso SkPixmap(const SkImageInfo& info, const void* addr, size_t rowBytes) reset() SkAlphaType SkColorType ## # ------------------------------------------------------------------------------ #Method SkPixmap(const SkImageInfo& info, const void* addr, size_t rowBytes) #In Initialization #Line # constructs from Image_Info, pixels ## Creates Pixmap 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 Pixmap goes out of scope, addr is unaffected. Pixmap may be later modified by reset() to change its size, pixel type, or storage. #Param info width, height, SkAlphaType, SkColorType of Image_Info ## #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 Pixmap ## #Example #Image 3 #Description SkImage::MakeRasterCopy takes const SkPixmap& as an argument. The example constructs a SkPixmap from the brace-delimited parameters. ## SkDebugf("image alpha only = %s\n", image->isAlphaOnly() ? "true" : "false"); SkPMColor pmColors = 0; sk_sp<SkImage> copy = SkImage::MakeRasterCopy({SkImageInfo::MakeA8(1, 1), (uint8_t*)&pmColors, 1}); SkDebugf("copy alpha only = %s\n", copy->isAlphaOnly() ? "true" : "false"); #StdOut image alpha only = false copy alpha only = true ## ## #SeeAlso SkPixmap() reset() SkAlphaType SkColorType ## # ------------------------------------------------------------------------------ #Method void reset() #In Initialization #Line # reuses existing Pixmap with replacement values ## 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. #Example void draw(SkCanvas* canvas) { const char* alphas[] = {"Unknown", "Opaque", "Premul", "Unpremul"}; const char* colors[] = {"Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16"}; SkPixmap pixmap(SkImageInfo::Make(25, 35, kRGBA_8888_SkColorType, kOpaque_SkAlphaType), nullptr, 0); for (int i = 0; i < 2; ++i) { SkDebugf("width: %2d height: %2d", pixmap.width(), pixmap.height()); SkDebugf(" color: k%s_SkColorType", colors[pixmap.colorType()]); SkDebugf(" alpha: k%s_SkAlphaType\n", alphas[pixmap.alphaType()]); pixmap.reset(); } } #StdOut width: 25 height: 35 color: kRGBA_8888_SkColorType alpha: kOpaque_SkAlphaType width: 0 height: 0 color: kUnknown_SkColorType alpha: kUnknown_SkAlphaType ## ## #SeeAlso SkPixmap() SkAlphaType SkColorType ## # ------------------------------------------------------------------------------ #Method void reset(const SkImageInfo& info, const void* addr, size_t rowBytes) #In Initialization 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 Pixmap goes out of scope, addr is unaffected. #Param info width, height, SkAlphaType, SkColorType of Image_Info ## #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 ## #Example #Image 4 #Height 64 void draw(SkCanvas* canvas) { std::vector<int32_t> pixels; pixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); int x = 0; for (auto colorType : { kRGBA_8888_SkColorType, kBGRA_8888_SkColorType } ) { pixmap.reset(SkImageInfo::Make(image->width(), image->height(), colorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); SkBitmap bitmap; bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, x, 0); x += 128; } } ## #SeeAlso SkPixmap(const SkImageInfo& info, const void* addr, size_t rowBytes) reset() SkAlphaType SkColorType ## # ------------------------------------------------------------------------------ #Method void setColorSpace(sk_sp<SkColorSpace> colorSpace) #In Initialization #Line # sets Image_Info Color_Space ## Changes Color_Space in Image_Info; preserves width, height, SkAlphaType, and SkColorType in Image, and leaves pixel address and row bytes unchanged. Color_Space reference count is incremented. #Param colorSpace Color_Space moved to Image_Info ## #Example void draw(SkCanvas* canvas) { SkPixmap pixmap; sk_sp<SkColorSpace> colorSpace1 = SkColorSpace::MakeRGB(SkColorSpace::kLinear_RenderTargetGamma, SkColorSpace::kRec2020_Gamut); SkDebugf("is %sunique\n", colorSpace1->unique() ? "" : "not "); pixmap.setColorSpace(colorSpace1); SkDebugf("is %sunique\n", colorSpace1->unique() ? "" : "not "); } #StdOut is unique is not unique ## ## #SeeAlso Color_Space SkImageInfo::makeColorSpace ## # ------------------------------------------------------------------------------ #Method bool SK_WARN_UNUSED_RESULT reset(const SkMask& mask) #In Initialization Sets width, height, pixel address, and row bytes to Mask properties, if Mask format is SkMask::kA8_Format; and returns true. Otherwise sets width, height, row bytes to zero; pixel address to nullptr; SkColorType to kUnknown_SkColorType; and SkAlphaType to kUnknown_SkAlphaType; and returns false. Failing to read the return value generates a compile time warning. #Param mask Mask containing pixels and dimensions ## #Return true if set to Mask properties ## #Example const int width = 2; const int height = 2; uint8_t bytes[] = { 0, 1, 2, 3, 4, 5, 6, 7 }; SkMask mask; mask.fFormat = SkMask::kA8_Format; mask.fBounds = {0, 0, width, height}; mask.fImage = bytes; mask.fRowBytes = (width + 7) >> 3; SkPixmap pixmap; bool success = pixmap.reset(mask); SkDebugf("success: %s width: %d height: %d\n", success ? "true " : "false", pixmap.width(), pixmap.height()); mask.fFormat = SkMask::kBW_Format; success = pixmap.reset(mask); SkDebugf("success: %s width: %d height: %d\n", success ? "true " : "false", pixmap.width(), pixmap.height()); #StdOut success: true width: 2 height: 2 success: false width: 0 height: 0 ## ## #SeeAlso Mask reset() ## # ------------------------------------------------------------------------------ #Method bool SK_WARN_UNUSED_RESULT extractSubset(SkPixmap* subset, const SkIRect& area) const #In Initialization #Line # sets pointer to portion of original ## Sets subset width, height, pixel address to intersection of Pixmap 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 Pixmap ## #Return true if intersection of Pixmap and area is not empty ## #Example #Image 3 #Height 128 void draw(SkCanvas* canvas) { std::vector<int32_t> pixels; pixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); SkPixmap inset; if (pixmap.extractSubset(&inset, {128, 128, 512, 512})) { SkBitmap bitmap; bitmap.installPixels(inset); canvas->drawBitmap(bitmap, 0, 0); } } ## #SeeAlso reset() SkIRect::intersect ## #Subtopic Initialization ## #Subtopic Image_Info_Access #Line # returns all or part of Image_Info ## # ------------------------------------------------------------------------------ #Method const SkImageInfo& info() const #In Image_Info_Access #Line # returns Image_Info ## Returns width, height, Alpha_Type, Color_Type, and Color_Space. #Return reference to ImageInfo ## #Example #Image 3 std::vector<int32_t> pixels; pixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); SkPixmap inset; if (pixmap.extractSubset(&inset, {128, 128, 512, 512})) { const SkImageInfo& info = inset.info(); const char* alphas[] = {"Unknown", "Opaque", "Premul", "Unpremul"}; const char* colors[] = {"Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16"}; SkDebugf("width: %d height: %d color: %s alpha: %s\n", info.width(), info.height(), colors[info.colorType()], alphas[info.alphaType()]); } #StdOut width: 384 height: 384 color: BGRA_8888 alpha: Opaque ## ## #SeeAlso Image_Info ## # ------------------------------------------------------------------------------ #Method size_t rowBytes() const #In Image_Info_Access #Line # returns interval between rows in bytes ## Returns row bytes, the interval from one pixel row to the next. Row bytes is at least as large as: #Formula width() * info().bytesPerPixel() ## . Returns zero if colorType is kUnknown_SkColorType. It is up to the Bitmap creator to ensure that row bytes is a useful value. #Return byte length of pixel row ## #Example SkPixmap badPixmap = {SkImageInfo::MakeA8(4, 4), nullptr, 2}; SkPixmap okPixmap = {SkImageInfo::MakeA8(4, 4), nullptr, 8}; for (auto& pixmap : { badPixmap, okPixmap } ) { SkDebugf("rowBytes: %d minRowBytes: %d\n", pixmap.rowBytes(), pixmap.info().minRowBytes()); } #StdOut rowBytes: 2 minRowBytes: 4 rowBytes: 8 minRowBytes: 4 ## ## #SeeAlso addr() info() SkImageInfo::minRowBytes ## # ------------------------------------------------------------------------------ #Method const void* addr() const #In Image_Info_Access #Line # returns readable pixel address as void pointer ## Returns pixel address, the base address corresponding to the pixel origin. It is up to the Pixmap creator to ensure that pixel address is a useful value. #Return pixel address ## #Example #Image 3 std::vector<int32_t> pixels; pixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); SkDebugf("pixels address: 0x%llx\n", pixmap.addr()); SkPixmap inset; if (pixmap.extractSubset(&inset, {128, 128, 512, 512})) { SkDebugf("inset address: 0x%llx\n", inset.addr()); } #StdOut #Volatile pixels address: 0x7f2a440bb010 inset address: 0x7f2a440fb210 ## ## #SeeAlso addr(int x, int y) addr8 addr16 addr32 addr64 info() rowBytes() ## # ------------------------------------------------------------------------------ #Method int width() const #In Image_Info_Access #Line # returns pixel column count ## Returns pixel count in each pixel row. Should be equal or less than: #Formula rowBytes() / info().bytesPerPixel() ## . #Return pixel width in Image_Info ## #Example SkImageInfo info = SkImageInfo::MakeA8(16, 32); SkPixmap pixmap(info, nullptr, 64); SkDebugf("pixmap width: %d info width: %d\n", pixmap.width(), info.width()); #StdOut pixmap width: 16 info width: 16 ## ## #SeeAlso height() SkImageInfo::width() ## # ------------------------------------------------------------------------------ #Method int height() const #In Image_Info_Access #Line # returns pixel row count ## Returns pixel row count. #Return pixel height in Image_Info ## #Example SkPixmap pixmap(SkImageInfo::MakeA8(16, 32), nullptr, 64); SkDebugf("pixmap height: %d info height: %d\n", pixmap.height(), pixmap.info().height()); #StdOut pixmap height: 32 info height: 32 ## ## #SeeAlso width() ImageInfo::height() ## # ------------------------------------------------------------------------------ #Method SkColorType colorType() const #In Image_Info_Access #Line # returns Image_Info Color_Type ## Returns Color_Type, 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 Color_Type in Image_Info ## #Example const char* colors[] = {"Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16"}; SkPixmap pixmap(SkImageInfo::MakeA8(16, 32), nullptr, 64); SkDebugf("color type: k" "%s" "_SkColorType\n", colors[pixmap.colorType()]); #StdOut color type: kAlpha_8_SkColorType ## ## #SeeAlso alphaType() SkImageInfo::colorType ## # ------------------------------------------------------------------------------ #Method SkAlphaType alphaType() const #In Image_Info_Access #Line # returns Image_Info Alpha_Type ## Returns Alpha_Type, one of: kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType. #Return Alpha_Type in Image_Info ## #Example const char* alphas[] = {"Unknown", "Opaque", "Premul", "Unpremul"}; SkPixmap pixmap(SkImageInfo::MakeA8(16, 32), nullptr, 64); SkDebugf("alpha type: k" "%s" "_SkAlphaType\n", alphas[pixmap.alphaType()]); #StdOut alpha type: kPremul_SkAlphaType ## ## #SeeAlso colorType() SkImageInfo::alphaType ## # ------------------------------------------------------------------------------ #Method SkColorSpace* colorSpace() const #In Image_Info_Access #Line # returns Image_Info Color_Space ## Returns Color_Space associated with Image_Info. The reference count of Color_Space is unchanged. The returned Color_Space is immutable. #Return Color_Space, the range of colors, in Image_Info ## #Example #Description SkColorSpace::MakeSRGBLinear creates Color_Space with linear gamma and an sRGB gamut. This Color_Space gamma is not close to sRGB gamma. ## SkPixmap pixmap(SkImageInfo::MakeN32(16, 32, kPremul_SkAlphaType, SkColorSpace::MakeSRGBLinear()), nullptr, 64); SkColorSpace* colorSpace = pixmap.colorSpace(); SkDebugf("gammaCloseToSRGB: %s gammaIsLinear: %s isSRGB: %s\n", colorSpace->gammaCloseToSRGB() ? "true" : "false", colorSpace->gammaIsLinear() ? "true" : "false", colorSpace->isSRGB() ? "true" : "false"); #StdOut gammaCloseToSRGB: false gammaIsLinear: true isSRGB: false ## ## #SeeAlso Color_Space SkImageInfo::colorSpace ## # ------------------------------------------------------------------------------ #Method bool isOpaque() const #In Image_Info_Access #Line # returns true if Image_Info describes opaque pixels ## Returns true if Alpha_Type is kOpaque_SkAlphaType. Does not check if Color_Type allows Alpha, or if any pixel value has transparency. #Return true if Image_Info has opaque Alpha_Type ## #Example #Description isOpaque ignores whether all pixels are opaque or not. ## std::vector<uint32_t> pixels; const int height = 2; const int width = 2; pixels.resize(height * width * 4); SkPixmap pixmap(SkImageInfo::Make(width, height, kN32_SkColorType, kPremul_SkAlphaType), (const void*) &pixels.front(), width * 4); for (int index = 0; index < 2; ++index) { pixmap.erase(0x00000000); SkDebugf("isOpaque: %s\n", pixmap.isOpaque() ? "true" : "false"); pixmap.erase(0xFFFFFFFF); SkDebugf("isOpaque: %s\n", pixmap.isOpaque() ? "true" : "false"); pixmap.reset(pixmap.info().makeAlphaType(kOpaque_SkAlphaType), (const void*) &pixels.front(), width * 4); } #StdOut isOpaque: false isOpaque: false isOpaque: true isOpaque: true ## ## #SeeAlso computeIsOpaque SkImageInfo::isOpaque ## # ------------------------------------------------------------------------------ #Method SkIRect bounds() const #In Image_Info_Access #Line # returns width and height as Rectangle ## Returns IRect { 0, 0, width(), height() }. #Return integral rectangle from origin to width() and height() ## #Example for (int width : { 0, 2 } ) { for (int height : { 0, 2 } ) { SkPixmap pixmap(SkImageInfo::MakeA8(width, height), nullptr, width); SkDebugf("width: %d height: %d empty: %s\n", width, height, pixmap.bounds().isEmpty() ? "true" : "false"); } } #StdOut width: 0 height: 0 empty: true width: 0 height: 2 empty: true width: 2 height: 0 empty: true width: 2 height: 2 empty: false ## ## #SeeAlso height() width() IRect ## # ------------------------------------------------------------------------------ #Method int rowBytesAsPixels() const #In Image_Info_Access #Line # returns interval between rows in pixels ## Returns number of pixels that fit on row. Should be greater than or equal to width(). #Return maximum pixels per row ## #Example for (int rowBytes : { 4, 5, 6, 7, 8} ) { SkPixmap pixmap(SkImageInfo::MakeN32(1, 1, kPremul_SkAlphaType), nullptr, rowBytes); SkDebugf("rowBytes: %d rowBytesAsPixels: %d\n", rowBytes, pixmap.rowBytesAsPixels()); } #StdOut rowBytes: 4 rowBytesAsPixels: 1 rowBytes: 5 rowBytesAsPixels: 1 rowBytes: 6 rowBytesAsPixels: 1 rowBytes: 7 rowBytesAsPixels: 1 rowBytes: 8 rowBytesAsPixels: 2 ## ## #SeeAlso rowBytes shiftPerPixel width SkImageInfo::bytesPerPixel ## # ------------------------------------------------------------------------------ #Method int shiftPerPixel() const #In Image_Info_Access #Line # returns bit shift from pixels to bytes ## 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 ## #Example const char* colors[] = {"Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16"}; SkImageInfo info = SkImageInfo::MakeA8(1, 1); for (SkColorType colorType : { kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kBGRA_8888_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType } ) { SkPixmap pixmap(info.makeColorType(colorType), nullptr, 4); SkDebugf("color: k" "%s" "_SkColorType" "%*s" "bytesPerPixel: %d shiftPerPixel: %d\n", colors[colorType], 10 - strlen(colors[colorType]), " ", pixmap.info().bytesPerPixel(), pixmap.shiftPerPixel()); } #StdOut color: kUnknown_SkColorType bytesPerPixel: 0 shiftPerPixel: 0 color: kAlpha_8_SkColorType bytesPerPixel: 1 shiftPerPixel: 0 color: kRGB_565_SkColorType bytesPerPixel: 2 shiftPerPixel: 1 color: kARGB_4444_SkColorType bytesPerPixel: 2 shiftPerPixel: 1 color: kRGBA_8888_SkColorType bytesPerPixel: 4 shiftPerPixel: 2 color: kBGRA_8888_SkColorType bytesPerPixel: 4 shiftPerPixel: 2 color: kGray_8_SkColorType bytesPerPixel: 1 shiftPerPixel: 0 color: kRGBA_F16_SkColorType bytesPerPixel: 8 shiftPerPixel: 3 ## ## #SeeAlso rowBytes rowBytesAsPixels width SkImageInfo::bytesPerPixel ## # ------------------------------------------------------------------------------ #Method size_t computeByteSize() const #In Image_Info_Access #Line # returns size required for pixels ## 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 ## #Example SkPixmap pixmap; for (int width : { 1, 1000, 1000000 } ) { for (int height: { 1, 1000, 1000000 } ) { SkImageInfo imageInfo = SkImageInfo::MakeN32(width, height, kPremul_SkAlphaType); pixmap.reset(imageInfo, nullptr, width * 5); SkDebugf("width: %7d height: %7d computeByteSize: %13lld\n", width, height, pixmap.computeByteSize()); } } #StdOut width: 1 height: 1 computeByteSize: 4 width: 1 height: 1000 computeByteSize: 4999 width: 1 height: 1000000 computeByteSize: 4999999 width: 1000 height: 1 computeByteSize: 4000 width: 1000 height: 1000 computeByteSize: 4999000 width: 1000 height: 1000000 computeByteSize: 4999999000 width: 1000000 height: 1 computeByteSize: 4000000 width: 1000000 height: 1000 computeByteSize: 4999000000 width: 1000000 height: 1000000 computeByteSize: 4999999000000 ## ## #SeeAlso SkImageInfo::computeByteSize ## #Subtopic Image_Info_Access ## #Subtopic Reader #Line # examine pixel value ## # ------------------------------------------------------------------------------ #Method bool computeIsOpaque() const #In Reader #Line # returns true if all pixels are opaque ## Returns true if all pixels are opaque. Color_Type determines how pixels are encoded, and whether pixel describes Alpha. Returns true for Color_Types without alpha in each pixel; for other Color_Types, returns true if all pixels have alpha values equivalent to 1.0 or greater. For Color_Types kRGB_565_SkColorType or kGray_8_SkColorType: always returns true. For Color_Types kAlpha_8_SkColorType, kBGRA_8888_SkColorType, kRGBA_8888_SkColorType: returns true if all pixel Alpha values are 255. For Color_Type 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 Color_Type is opaque ## #Example std::vector<uint32_t> pixels; const int height = 2; const int width = 2; pixels.resize(height * width * 4); SkPixmap pixmap(SkImageInfo::Make(width, height, kN32_SkColorType, kPremul_SkAlphaType), (const void*) &pixels.front(), width * 4); for (int index = 0; index < 2; ++index) { pixmap.erase(0x00000000); SkDebugf("computeIsOpaque: %s\n", pixmap.computeIsOpaque() ? "true" : "false"); pixmap.erase(0xFFFFFFFF); SkDebugf("computeIsOpaque: %s\n", pixmap.computeIsOpaque() ? "true" : "false"); pixmap.reset(pixmap.info().makeAlphaType(kOpaque_SkAlphaType), (const void*) &pixels.front(), width * 4); } #StdOut computeIsOpaque: false computeIsOpaque: true computeIsOpaque: false computeIsOpaque: true ## ## #SeeAlso isOpaque Color_Type Alpha ## # ------------------------------------------------------------------------------ #Method SkColor getColor(int x, int y) const #In Reader #Line # returns one pixel as Unpremultiplied Color ## Returns pixel at (x, y) as Unpremultiplied Color. Returns black with Alpha if Color_Type 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 Color_Type is kUnknown_SkColorType or pixel address is nullptr. Color_Space in Image_Info 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 ## #Example const int w = 4; const int h = 4; std::vector<SkPMColor> storage; storage.resize(w * h); SkDebugf("Premultiplied:\n"); for (int y = 0; y < h; ++y) { SkDebugf("(0, %d) ", y); for (int x = 0; x < w; ++x) { int a = 0xFF * (x + y) / (w - 1 + h - 1); storage[x + y * w] = SkPackARGB32(a, a * x / (w - 1), a * y / (h - 1), a); SkDebugf("0x%08x%c", storage[x + y * w], x == w - 1 ? '\n' : ' '); } } SkPixmap pixmap(SkImageInfo::MakeN32(w, h, kPremul_SkAlphaType), &storage.front(), w * 4); SkDebugf("Unpremultiplied:\n"); for (int y = 0; y < h; ++y) { SkDebugf("(0, %d) ", y); for (int x = 0; x < w; ++x) { SkDebugf("0x%08x%c", pixmap.getColor(x, y), x == w - 1 ? '\n' : ' '); } } #StdOut Premultiplied: (0, 0) 0x00000000 0x2a0e002a 0x55380055 0x7f7f007f (0, 1) 0x2a000e2a 0x551c1c55 0x7f542a7f 0xaaaa38aa (0, 2) 0x55003855 0x7f2a547f 0xaa7171aa 0xd4d48dd4 (0, 3) 0x7f007f7f 0xaa38aaaa 0xd48dd4d4 0xffffffff Unpremultiplied: (0, 0) 0x00000000 0x2a5500ff 0x55a800ff 0x7fff00ff (0, 1) 0x2a0055ff 0x555454ff 0x7fa954ff 0xaaff54ff (0, 2) 0x5500a8ff 0x7f54a9ff 0xaaaaaaff 0xd4ffaaff (0, 3) 0x7f00ffff 0xaa54ffff 0xd4aaffff 0xffffffff ## ## #SeeAlso addr() readPixels ## #Subtopic Reader ## #Subtopic Readable_Address #Line # returns read only pixels ## # ------------------------------------------------------------------------------ #Method const void* addr(int x, int y) const #In Readable_Address Returns readable pixel address at (x, y). Returns nullptr if Pixel_Ref 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 Color_Type 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 ## #Example const int w = 4; const int h = 4; std::vector<SkPMColor> storage; storage.resize(w * h); SkPixmap pixmap(SkImageInfo::MakeN32(w, h, kPremul_SkAlphaType), &storage.front(), w * 4); SkDebugf("pixmap.addr(1, 2) %c= &storage[1 + 2 * w]\n", pixmap.addr(1, 2) == &storage[1 + 2 * w] ? '=' : '!'); #StdOut pixmap.addr(1, 2) == &storage[1 + 2 * w] ## ## #SeeAlso addr8 addr16 addr32 addr64 addrF16 getColor writable_addr SkBitmap::getAddr ## # ------------------------------------------------------------------------------ #Method const uint8_t* addr8() const #In Readable_Address #Line # returns readable pixel address as 8-bit pointer ## Returns readable base pixel address. Result is addressable as unsigned 8-bit bytes. Will trigger an assert() if Color_Type 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 ## #Example const int w = 4; const int h = 4; uint8_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kGray_8_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr8() %c= storage\n", pixmap.addr8() == storage ? '=' : '!'); #StdOut pixmap.addr8() == storage ## ## #SeeAlso addr() addr16 addr32 addr64 addrF16 getColor writable_addr writable_addr8 ## # ------------------------------------------------------------------------------ #Method const uint16_t* addr16() const #In Readable_Address #Line # returns readable pixel address as 16-bit pointer ## Returns readable base pixel address. Result is addressable as unsigned 16-bit words. Will trigger an assert() if Color_Type 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 ## #Example const int w = 4; const int h = 4; uint16_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kARGB_4444_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr16() %c= storage\n", pixmap.addr16() == storage ? '=' : '!'); #StdOut pixmap.addr16() == storage ## ## #SeeAlso addr() addr8 addr32 addr64 addrF16 getColor writable_addr writable_addr16 ## # ------------------------------------------------------------------------------ #Method const uint32_t* addr32() const #In Readable_Address #Line # returns readable pixel address as 32-bit pointer ## Returns readable base pixel address. Result is addressable as unsigned 32-bit words. Will trigger an assert() if Color_Type 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 ## #Example const int w = 4; const int h = 4; uint32_t storage[w * h]; SkPixmap pixmap(SkImageInfo::MakeN32(w, h, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr32() %c= storage\n", pixmap.addr32() == storage ? '=' : '!'); #StdOut pixmap.addr32() == storage ## ## #SeeAlso addr() addr8 addr16 addr64 addrF16 getColor writable_addr writable_addr32 ## # ------------------------------------------------------------------------------ #Method const uint64_t* addr64() const #In Readable_Address #Line # returns readable pixel address as 64-bit pointer ## Returns readable base pixel address. Result is addressable as unsigned 64-bit words. Will trigger an assert() if Color_Type 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 ## #Example const int w = 4; const int h = 4; uint64_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr64() %c= storage\n", pixmap.addr64() == storage ? '=' : '!'); #StdOut pixmap.addr64() == storage ## ## #SeeAlso addr() addr8 addr16 addr32 addrF16 getColor writable_addr writable_addr64 ## # ------------------------------------------------------------------------------ #Method const uint16_t* addrF16() const #In Readable_Address #Line # returns readable pixel component address as 16-bit pointer ## Returns readable base pixel address. Result is addressable as unsigned 16-bit words. Will trigger an assert() if Color_Type 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 ## #Example const int w = 4; const int h = 4; uint16_t storage[w * h * 4]; SkPixmap pixmap(SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType), storage, w * 4 * sizeof(storage[0])); SkDebugf("pixmap.addrF16() %c= storage\n", pixmap.addrF16() == storage ? '=' : '!'); #StdOut pixmap.addrF16() == storage ## ## #SeeAlso addr() addr8 addr16 addr32 addr64 getColor writable_addr writable_addrF16 ## # ------------------------------------------------------------------------------ #Method const uint8_t* addr8(int x, int y) const #In Readable_Address 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 Color_Type 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) ## #Example const int w = 4; const int h = 4; uint8_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kGray_8_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr8(1, 2) %c= &storage[1 + 2 * w]\n", pixmap.addr8(1, 2) == &storage[1 + 2 * w] ? '=' : '!'); #StdOut pixmap.addr8(1, 2) == &storage[1 + 2 * w] ## ## #SeeAlso addr() addr16 addr32 addr64 addrF16 getColor writable_addr writable_addr8 ## # ------------------------------------------------------------------------------ #Method const uint16_t* addr16(int x, int y) const #In Readable_Address 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 Color_Type 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) ## #Example const int w = 4; const int h = 4; uint16_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kARGB_4444_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr16(1, 2) %c= &storage[1 + 2 * w]\n", pixmap.addr16(1, 2) == &storage[1 + 2 * w] ? '=' : '!'); #StdOut pixmap.addr16(1, 2) == &storage[1 + 2 * w] ## ## #SeeAlso addr() addr8 addr32 addr64 addrF16 getColor writable_addr writable_addr16 ## # ------------------------------------------------------------------------------ #Method const uint32_t* addr32(int x, int y) const #In Readable_Address 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 Color_Type 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) ## #Example const int w = 4; const int h = 4; uint32_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kRGBA_8888_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr32(1, 2) %c= &storage[1 + 2 * w]\n", pixmap.addr32(1, 2) == &storage[1 + 2 * w] ? '=' : '!'); #StdOut pixmap.addr32(1, 2) == &storage[1 + 2 * w] ## ## #SeeAlso addr() addr8 addr16 addr64 addrF16 getColor writable_addr writable_addr64 ## # ------------------------------------------------------------------------------ #Method const uint64_t* addr64(int x, int y) const #In Readable_Address 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 Color_Type 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) ## #Example const int w = 4; const int h = 4; uint64_t storage[w * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType), storage, w * sizeof(storage[0])); SkDebugf("pixmap.addr64(1, 2) %c= &storage[1 + 2 * w]\n", pixmap.addr64(1, 2) == &storage[1 + 2 * w] ? '=' : '!'); #StdOut pixmap.addr64(1, 2) == &storage[1 + 2 * w] ## ## #SeeAlso addr() addr8 addr16 addr32 addrF16 getColor writable_addr writable_addr64 ## # ------------------------------------------------------------------------------ #Method const uint16_t* addrF16(int x, int y) const #In Readable_Address 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 Color_Type 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) ## #Example const int w = 4; const int h = 4; const int wordsPerPixel = 4; const int rowWords = w * wordsPerPixel; uint16_t storage[rowWords * h]; SkPixmap pixmap(SkImageInfo::Make(w, h, kRGBA_F16_SkColorType, kPremul_SkAlphaType), storage, rowWords * sizeof(storage[0])); SkDebugf("pixmap.addrF16(1, 2) %c= &storage[1 * wordsPerPixel + 2 * rowWords]\n", pixmap.addrF16(1, 2) == &storage[1 * wordsPerPixel + 2 * rowWords] ? '=' : '!'); #StdOut pixmap.addrF16(1, 2) == &storage[1 * wordsPerPixel + 2 * rowWords] ## ## #SeeAlso addr() addr8 addr16 addr32 addr64 getColor writable_addr writable_addrF16 ## #Subtopic Readable_Address ## #Subtopic Writable_Address #Line # returns writable pixels ## # ------------------------------------------------------------------------------ #Method void* writable_addr() const #In Writable_Address #Line # returns writable pixel address as void pointer ## Returns writable base pixel address. #Return writable generic base pointer to pixels ## #Example const int w = 4; const int h = 4; SkPMColor storage[w * h * 4]; SkPixmap pixmap(SkImageInfo::MakeN32(w, h, kPremul_SkAlphaType), storage, w * 4); SkDebugf("pixmap.writable_addr() %c= (void *)storage\n", pixmap.writable_addr() == (void *)storage ? '=' : '!'); pixmap.erase(0x00000000); *(SkPMColor*)pixmap.writable_addr() = 0xFFFFFFFF; SkDebugf("pixmap.getColor(0, 1) %c= 0x00000000\n", pixmap.getColor(0, 1) == 0x00000000 ? '=' : '!'); SkDebugf("pixmap.getColor(0, 0) %c= 0xFFFFFFFF\n", pixmap.getColor(0, 0) == 0xFFFFFFFF ? '=' : '!'); #StdOut pixmap.writable_addr() == (void *)storage pixmap.getColor(0, 1) == 0x00000000 pixmap.getColor(0, 0) == 0xFFFFFFFF ## ## #SeeAlso writable_addr8 writable_addr16 writable_addr32 writable_addr64 writable_addrF16 addr() ## # ------------------------------------------------------------------------------ #Method void* writable_addr(int x, int y) const #In Writable_Address 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 Color_Type 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 ## #Example const int w = 4; const int h = 4; SkPMColor storage[w * h * 4]; SkPixmap pixmap(SkImageInfo::MakeN32(w, h, kPremul_SkAlphaType), storage, w * 4); SkDebugf("pixmap.writable_addr() %c= (void *)storage\n", pixmap.writable_addr() == (void *)storage ? '=' : '!'); pixmap.erase(0x00000000); *(SkPMColor*)pixmap.writable_addr(1, 2) = 0xFFFFFFFF; SkDebugf("pixmap.getColor(0, 0) %c= 0x00000000\n", pixmap.getColor(0, 0) == 0x00000000 ? '=' : '!'); SkDebugf("pixmap.getColor(1, 2) %c= 0xFFFFFFFF\n", pixmap.getColor(1, 2) == 0xFFFFFFFF ? '=' : '!'); #StdOut pixmap.writable_addr() == (void *)storage pixmap.getColor(0, 0) == 0x00000000 pixmap.getColor(1, 2) == 0xFFFFFFFF ## ## #SeeAlso writable_addr8 writable_addr16 writable_addr32 writable_addr64 writable_addrF16 addr() ## # ------------------------------------------------------------------------------ #Method uint8_t* writable_addr8(int x, int y) const #In Writable_Address #Line # returns writable pixel address as 8-bit pointer ## Returns writable pixel address at (x, y). Result is addressable as unsigned 8-bit bytes. Will trigger an assert() if Color_Type 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 ## #Example #Height 64 #Description Altering pixels after drawing Bitmap is not guaranteed to affect subsequent drawing on all platforms. Adding a second SkBitmap::installPixels after editing pixel memory is safer. ## void draw(SkCanvas* canvas) { uint8_t storage[][5] = {{ 0, 0, 64, 0, 0}, { 0, 128, 255, 128, 0}, {64, 255, 255, 255, 64}, { 0, 128, 255, 128, 0}, { 0, 0, 64, 0, 0}}; SkImageInfo imageInfo = SkImageInfo::Make(5, 5, kGray_8_SkColorType, kPremul_SkAlphaType); SkPixmap pixmap(imageInfo, storage[0], 5); SkBitmap bitmap; bitmap.installPixels(pixmap); canvas->scale(10, 10); canvas->drawBitmap(bitmap, 0, 0); *pixmap.writable_addr8(2, 2) = 0; // bitmap.installPixels(pixmap); // uncomment to fix on GPU canvas->drawBitmap(bitmap, 10, 0); } ## #SeeAlso writable_addr writable_addr16 writable_addr32 writable_addr64 writable_addrF16 addr() addr8 ## # ------------------------------------------------------------------------------ #Method uint16_t* writable_addr16(int x, int y) const #In Writable_Address #Line # returns writable pixel address as 16-bit pointer ## Returns writable_addr pixel address at (x, y). Result is addressable as unsigned 16-bit words. Will trigger an assert() if Color_Type 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 ## #Example #Description Draw a five by five bitmap, and draw it again with a center black pixel. The low nibble of the 16-bit word is Alpha. ## #Height 64 uint16_t storage[][5] = {{ 0xCABF, 0xDABE, 0xCA9D, 0xC96C, 0xA39B }, { 0xACEE, 0xA87C, 0x893A, 0x4779, 0x8708 }, { 0x4B7C, 0x255B, 0x2559, 0x2557, 0x4656 }, { 0x9099, 0x8128, 0x2557, 0x4124, 0x3323 }, { 0x7547, 0x5505, 0x4434, 0x2012, 0x0000 }}; SkImageInfo imageInfo = SkImageInfo::Make(5, 5, kARGB_4444_SkColorType, kPremul_SkAlphaType); SkPixmap pixmap(imageInfo, storage[0], sizeof(storage) / 5); SkBitmap bitmap; bitmap.installPixels(pixmap); canvas->scale(10, 10); canvas->drawBitmap(bitmap, 0, 0); *pixmap.writable_addr16(2, 2) = 0x000F; bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 10, 0); ## #SeeAlso writable_addr writable_addr8 writable_addr32 writable_addr64 writable_addrF16 addr() addr16 ## # ------------------------------------------------------------------------------ #Method uint32_t* writable_addr32(int x, int y) const #In Writable_Address #Line # returns writable pixel address as 32-bit pointer ## Returns writable pixel address at (x, y). Result is addressable as unsigned 32-bit words. Will trigger an assert() if Color_Type 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 ## #Example #Image 4 #Height 72 std::vector<int32_t> pixels; pixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(SkImageInfo::Make(image->width(), image->height(), kN32_SkColorType, image->alphaType()), (const void*) &pixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); for (int y = 0; y < pixmap.height() / 2; ++y) { for (int x = 0; x < pixmap.width(); ++x) { if ((x & 4) == (y & 4)) { SkTSwap(*pixmap.writable_addr32(x, y), *pixmap.writable_addr32(pixmap.width() - x, pixmap.height() - y)); } } } SkBitmap bitmap; bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); ## #SeeAlso writable_addr writable_addr8 writable_addr16 writable_addr64 writable_addrF16 addr() addr32 ## # ------------------------------------------------------------------------------ #Method uint64_t* writable_addr64(int x, int y) const #In Writable_Address #Line # returns writable pixel address as 64-bit pointer ## Returns writable pixel address at (x, y). Result is addressable as unsigned 64-bit words. Will trigger an assert() if Color_Type 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 ## #Example #Height 40 SkImageInfo info = SkImageInfo::Make(3, 3, kRGBA_F16_SkColorType, kPremul_SkAlphaType); uint64_t storage[9]; SkPixmap pixmap(info, storage, 3 * sizeof(uint64_t)); SkColor4f c4 { 1, 0.45f, 0.25f, 0.65f }; pixmap.erase(c4); SkBitmap bitmap; canvas->scale(10, 10); bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); *pixmap.writable_addr64(1, 1) |= 0x00ff000000000000LL; bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 10, 0); ## #SeeAlso writable_addr writable_addr8 writable_addr16 writable_addr32 writable_addrF16 addr() addr64 ## # ------------------------------------------------------------------------------ #Method uint16_t* writable_addrF16(int x, int y) const #In Writable_Address #Line # returns writable pixel component address as 16-bit pointer ## Returns writable pixel address at (x, y). Result is addressable as unsigned 16-bit words. Will trigger an assert() if Color_Type 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 ## #Example #Height 64 #Description Left bitmap is drawn with two pixels defined in half float format. Right bitmap is drawn after overwriting bottom half float color with top half float color. ## SkImageInfo info = SkImageInfo::Make(1, 2, kRGBA_F16_SkColorType, kPremul_SkAlphaType); uint16_t storage[2][4]; SkPixmap pixmap(info, storage[0], sizeof(uint64_t)); SkIRect topPixelBounds = {0, 0, 1, 1}; pixmap.erase({ 0.65f, 0.45f, 0.25f, 1 }, &topPixelBounds); SkIRect bottomPixelBounds = {0, 1, 1, 2}; pixmap.erase({ 0.25f, 0.65f, 0.45f, 1 }, &bottomPixelBounds); SkBitmap bitmap; canvas->scale(20, 20); bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); uint16_t* pixel2 = pixmap.writable_addrF16(0, 1); for (int i = 0; i < 4; ++i) { pixel2[i] = storage[0][i]; } bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 4, 0); ## #SeeAlso writable_addr writable_addr8 writable_addr16 writable_addr32 writable_addr64 addr() addrF16 ## #Subtopic Writable_Address ## #Subtopic Writer #Line # copy to pixel values ## # ------------------------------------------------------------------------------ #Method bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, int srcX, int srcY, SkTransferFunctionBehavior behavior) const #In Writer #Line # copies and converts pixels ## Copies a Rect of pixels to dstPixels. Copy starts at (srcX, srcY), and does not exceed Pixmap (width(), height()). dstInfo specifies width, height, Color_Type, Alpha_Type, and Color_Space 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType must match. If Pixmap colorType is kGray_8_SkColorType, dstInfo.colorSpace must match. If Pixmap alphaType is kOpaque_SkAlphaType, dstInfo.alphaType must match. If Pixmap 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: #Formula abs(srcX) >= Pixmap width() ## , or if #Formula 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, Color_Type, Alpha_Type, Color_Space ## #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 ## #Example #ToDo example doesn't do anything interesting since info colorSpace is nullptr ## #Image 3 void draw(SkCanvas* canvas) { SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height(), canvas->imageInfo().colorSpace() ? SkColorSpace::MakeSRGB() : nullptr); std::vector<int32_t> srcPixels; srcPixels.resize(image->height() * image->width() * 4); SkPixmap pixmap(info, (const void*) &srcPixels.front(), image->width() * 4); image->readPixels(pixmap, 0, 0); SkTransferFunctionBehavior behavior = canvas->imageInfo().colorSpace() ? SkTransferFunctionBehavior::kRespect : SkTransferFunctionBehavior::kIgnore; std::vector<int32_t> dstPixels; dstPixels.resize(image->height() * image->width() * 4); int offset = 0; for (auto behavior : { SkTransferFunctionBehavior::kRespect, SkTransferFunctionBehavior::kIgnore} ) { pixmap.readPixels(info, &dstPixels.front(), image->width() * 4, offset, 0, behavior); offset += 128; } SkBitmap bitmap; SkPixmap dstmap(info, &dstPixels.front(), image->width() * 4); bitmap.installPixels(dstmap); canvas->drawBitmap(bitmap, 0, 0); } ## #SeeAlso erase SkBitmap::readPixels SkCanvas::drawBitmap SkCanvas::readPixels SkImage::readPixels SkSurface::readPixels ## # ------------------------------------------------------------------------------ #Method bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes) const #In Writer Copies a Rect of pixels to dstPixels. Copy starts at (0, 0), and does not exceed Pixmap (width(), height()). dstInfo specifies width, height, Color_Type, Alpha_Type, and Color_Space 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType must match. If Pixmap colorType is kGray_8_SkColorType, dstInfo.colorSpace must match. If Pixmap alphaType is kOpaque_SkAlphaType, dstInfo.alphaType must match. If Pixmap colorSpace is nullptr, dstInfo.colorSpace must match. Returns false if pixel conversion is not possible. Returns false if Pixmap width() or height() is zero or negative. #Param dstInfo destination width, height, Color_Type, Alpha_Type, Color_Space ## #Param dstPixels destination pixel storage ## #Param dstRowBytes destination row length ## #Return true if pixels are copied to dstPixels ## #Example #Height 128 #Description Transferring the gradient from 8 bits per component to 4 bits per component creates visible banding. ## std::vector<int32_t> pixels; const int width = 256; const int height = 64; pixels.resize(height * width * 4); SkImageInfo srcInfo = SkImageInfo::MakeN32Premul(width, height); SkPixmap srcPixmap(srcInfo, (const void*) &pixels.front(), width * 4); SkColor gradColors[] = { 0xFFAA3300, 0x7F881122 }; SkPoint gradPoints[] = { { 0, 0 }, { 256, 0 } }; SkPaint paint; paint.setShader(SkGradientShader::MakeLinear(gradPoints, gradColors, nullptr, SK_ARRAY_COUNT(gradColors), SkShader::kClamp_TileMode)); SkBitmap bitmap; bitmap.installPixels(srcPixmap); SkCanvas srcCanvas(bitmap); srcCanvas.drawRect(SkRect::MakeWH(width, height), paint); canvas->drawBitmap(bitmap, 0, 0); std::vector<int32_t> dstPixels; dstPixels.resize(height * width * 2); SkImageInfo dstInfo = srcInfo.makeColorType(kARGB_4444_SkColorType); srcPixmap.readPixels(dstInfo, &dstPixels.front(), width * 2); SkPixmap dstPixmap(dstInfo, &dstPixels.front(), width * 2); bitmap.installPixels(dstPixmap); canvas->drawBitmap(bitmap, 0, 128); ## #SeeAlso erase SkBitmap::readPixels SkCanvas::drawBitmap SkCanvas::readPixels SkImage::readPixels SkSurface::readPixels ## # ------------------------------------------------------------------------------ #Method bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes, int srcX, int srcY) const #In Writer Copies a Rect of pixels to dstPixels. Copy starts at (srcX, srcY), and does not exceed Pixmap (width(), height()). dstInfo specifies width, height, Color_Type, Alpha_Type, and Color_Space 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType must match. If Pixmap colorType is kGray_8_SkColorType, dstInfo.colorSpace must match. If Pixmap alphaType is kOpaque_SkAlphaType, dstInfo.alphaType must match. If Pixmap 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 Pixmap width() or height() is zero or negative. Returns false if: #Formula abs(srcX) >= Pixmap width() ## , or if #Formula abs(srcY) >= Pixmap height() ## . #Param dstInfo destination width, height, Color_Type, Alpha_Type, Color_Space ## #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 ## #Example #Image 3 void draw(SkCanvas* canvas) { SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height()); std::vector<int32_t> srcPixels; const int rowBytes = image->width() * 4; srcPixels.resize(image->height() * rowBytes); SkPixmap pixmap(info, (const void*) &srcPixels.front(), rowBytes); image->readPixels(pixmap, 0, 0); for (int offset : { 32, 64, 96 } ) { std::vector<int32_t> dstPixels; dstPixels.resize(image->height() * rowBytes); pixmap.readPixels(info, &dstPixels.front(), rowBytes, offset, 0); SkBitmap bitmap; SkPixmap dstmap(info, &dstPixels.front(), rowBytes); bitmap.installPixels(dstmap); canvas->translate(32, 32); canvas->drawBitmap(bitmap, 0, 0); } } ## #SeeAlso erase SkBitmap::readPixels SkCanvas::drawBitmap SkCanvas::readPixels SkImage::readPixels SkSurface::readPixels ## # ------------------------------------------------------------------------------ #Method bool readPixels(const SkPixmap& dst, int srcX, int srcY) const #In Writer Copies a Rect of pixels to dst. Copy starts at (srcX, srcY), and does not exceed Pixmap (width(), height()). dst specifies width, height, Color_Type, Alpha_Type, and Color_Space 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dst.info().colorType must match. If Pixmap colorType is kGray_8_SkColorType, dst.info().colorSpace must match. If Pixmap alphaType is kOpaque_SkAlphaType, dst.info().alphaType must match. If Pixmap 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 Pixmap width() or height() is zero or negative. Returns false if: #Formula abs(srcX) >= Pixmap width() ## , or if #Formula abs(srcY) >= Pixmap height() ## . #Param dst Image_Info 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 ## #Example #Image 3 void draw(SkCanvas* canvas) { SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height()); std::vector<int32_t> srcPixels; const int rowBytes = image->width() * 4; srcPixels.resize(image->height() * rowBytes); SkPixmap pixmap(info, (const void*) &srcPixels.front(), rowBytes); image->readPixels(pixmap, 0, 0); for (int offset : { 32, 64, 96 } ) { std::vector<int32_t> dstPixels; dstPixels.resize(image->height() * rowBytes); SkPixmap dstmap(info, &dstPixels.front(), rowBytes); pixmap.readPixels(dstmap, offset, 0); SkBitmap bitmap; bitmap.installPixels(dstmap); canvas->translate(32, 32); canvas->drawBitmap(bitmap, 0, 0); } } ## #SeeAlso erase SkBitmap::readPixels SkCanvas::drawBitmap SkCanvas::readPixels SkImage::readPixels SkSurface::readPixels ## # ------------------------------------------------------------------------------ #Method bool readPixels(const SkPixmap& dst) const #In Writer Copies pixels inside bounds() to dst. dst specifies width, height, Color_Type, Alpha_Type, and Color_Space 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dst Color_Type must match. If Pixmap colorType is kGray_8_SkColorType, dst Color_Space must match. If Pixmap alphaType is kOpaque_SkAlphaType, dst Alpha_Type must match. If Pixmap colorSpace is nullptr, dst Color_Space must match. Returns false if pixel conversion is not possible. Returns false if Pixmap width() or height() is zero or negative. #Param dst Image_Info and pixel address to write to ## #Return true if pixels are copied to dst ## #Example #Image 3 void draw(SkCanvas* canvas) { SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height()); std::vector<int32_t> srcPixels; const int rowBytes = image->width() * 4; srcPixels.resize(image->height() * rowBytes); SkPixmap pixmap(info, (const void*) &srcPixels.front(), rowBytes); image->readPixels(pixmap, 0, 0); for (int index = 0; index < 3; ++index ) { std::vector<int32_t> dstPixels; dstPixels.resize(image->height() * rowBytes); SkPixmap dstmap(info, &dstPixels.front(), rowBytes); pixmap.readPixels(dstmap); SkBitmap bitmap; bitmap.installPixels(dstmap); canvas->translate(32, 32); canvas->drawBitmap(bitmap, 0, 0); } } ## #SeeAlso erase SkBitmap::readPixels SkCanvas::drawBitmap SkCanvas::readPixels SkImage::readPixels SkSurface::readPixels ## # ------------------------------------------------------------------------------ #Method bool scalePixels(const SkPixmap& dst, SkFilterQuality filterQuality) const #In Writer #Line # scales and converts pixels ## Copies Bitmap 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 Pixmap colorType is kGray_8_SkColorType, or kAlpha_8_SkColorType; dst Color_Type must match. If Pixmap colorType is kGray_8_SkColorType, dst Color_Space must match. If Pixmap alphaType is kOpaque_SkAlphaType, dst Alpha_Type must match. If Pixmap colorSpace is nullptr, dst Color_Space must match. Returns false if pixel conversion is not possible. Returns false if Bitmap 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 Filter_Quality_Nearest_Neighbor. kLow_SkFilterQuality is typically implemented with Filter_Quality_Bilerp. kMedium_SkFilterQuality is typically implemented with Filter_Quality_Bilerp, and Filter_Quality_MipMap when size is reduced. kHigh_SkFilterQuality is slowest, typically implemented with Filter_Quality_BiCubic. #Param dst Image_Info 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 ## #Example #Image 3 void draw(SkCanvas* canvas) { SkImageInfo info = SkImageInfo::MakeN32Premul(image->width(), image->height()); std::vector<int32_t> srcPixels; int rowBytes = image->width() * 4; srcPixels.resize(image->height() * rowBytes); SkPixmap pixmap(info, (const void*) &srcPixels.front(), rowBytes); image->readPixels(pixmap, 0, 0); for (int offset : { 32, 64, 96 } ) { info = SkImageInfo::MakeN32Premul(image->width() + offset, image->height()); rowBytes = info.width() * 4; std::vector<int32_t> dstPixels; dstPixels.resize(image->height() * rowBytes); SkPixmap dstmap(info, &dstPixels.front(), rowBytes); pixmap.scalePixels(dstmap, kMedium_SkFilterQuality); SkBitmap bitmap; bitmap.installPixels(dstmap); canvas->translate(32, 32); canvas->drawBitmap(bitmap, 0, 0); } } ## #SeeAlso SkCanvas::drawBitmap SkImage::scalePixels ## # ------------------------------------------------------------------------------ #Method bool erase(SkColor color, const SkIRect& subset) const #In Writer #Line # writes Color to pixels ## 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 Rect of written pixels ## #Return true if pixels are changed ## #Example #Height 50 uint32_t storage[2]; SkImageInfo info = SkImageInfo::MakeN32Premul(1, 2); SkPixmap pixmap(info, storage, info.minRowBytes()); pixmap.erase(SK_ColorBLUE, {0, 0, 1, 1}); pixmap.erase(SK_ColorRED, {0, 1, 1, 2}); SkBitmap bitmap; canvas->scale(20, 20); bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); ## #SeeAlso SkBitmap::erase SkCanvas::clear SkCanvas::drawColor ## # ------------------------------------------------------------------------------ #Method bool erase(SkColor color) const #In Writer 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 ## #Example #Height 50 uint32_t storage[2]; SkImageInfo info = SkImageInfo::MakeN32Premul(1, 2); SkPixmap pixmap(info, storage, info.minRowBytes()); pixmap.erase(SK_ColorBLUE); SkBitmap bitmap; canvas->scale(20, 20); bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); ## #SeeAlso SkBitmap::erase SkCanvas::clear SkCanvas::drawColor ## # ------------------------------------------------------------------------------ #Method bool erase(const SkColor4f& color, const SkIRect* subset = nullptr) const #In Writer 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 Rect of pixels to write; may be nullptr ## #Return true if pixels are changed ## #Example #Height 50 uint32_t storage[2]; SkImageInfo info = SkImageInfo::MakeN32Premul(1, 2); SkPixmap pixmap(info, storage, info.minRowBytes()); SkIRect topPixelBounds = {0, 0, 1, 1}; pixmap.erase({ 0.65f, 0.45f, 0.25f, 1 }, &topPixelBounds); SkIRect bottomPixelBounds = {0, 1, 1, 2}; pixmap.erase({ 0.25f, 0.65f, 0.45f, 1 }, &bottomPixelBounds); SkBitmap bitmap; canvas->scale(20, 20); bitmap.installPixels(pixmap); canvas->drawBitmap(bitmap, 0, 0); ## #SeeAlso SkBitmap::erase SkCanvas::clear SkCanvas::drawColor ## #Subtopic Writer ## #Class SkPixmap ## #Topic Pixmap ##