| #Topic Image_Info |
| #Alias Image_Info_Reference |
| |
| Image_Info specifies the dimensions and encoding of the pixels in a Bitmap. |
| The dimensions are integral width and height. The encoding is how pixel |
| bits describe Color_Alpha, transparency; Color components red, blue, |
| and green; and Color_Space, the range and linearity of colors. |
| |
| Image_Info describes an uncompressed raster pixels. In contrast, Image |
| additionally describes compressed pixels like PNG, and Surface describes |
| destinations on the GPU. Image and Surface may be specified by Image_Info, |
| but Image and Surface may not contain Image_Info. |
| |
| #Subtopic Overview |
| #Subtopic Subtopic |
| #Populate |
| ## |
| ## |
| |
| #Subtopic Constant |
| #Populate |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Alpha_Type |
| #Line # encoding for pixel transparency ## |
| #Alias Alpha_Type |
| #Alias Alpha_Types |
| |
| #PhraseDef list_of_alpha_types |
| kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, |
| kUnpremul_SkAlphaType |
| ## |
| |
| #Enum SkAlphaType |
| #Line # encoding for pixel transparency ## |
| |
| #Code |
| enum SkAlphaType { |
| kUnknown_SkAlphaType, |
| kOpaque_SkAlphaType, |
| kPremul_SkAlphaType, |
| kUnpremul_SkAlphaType, |
| kLastEnum_SkAlphaType = kUnpremul_SkAlphaType, |
| }; |
| ## |
| |
| Describes how to interpret the alpha component of a pixel. A pixel may |
| be opaque, or Color_Alpha, describing multiple levels of transparency. |
| |
| In simple blending, Color_Alpha weights the draw color and the destination |
| color to create a new color. If alpha describes a weight from zero to one: |
| |
| #Formula |
| new color = draw color * alpha + destination color * (1 - alpha) |
| ## |
| |
| In practice alpha is encoded in two or more bits, where 1.0 equals all bits set. |
| |
| Color_RGB may have Color_Alpha included in each component value; the stored |
| value is the original Color_RGB multiplied by Color_Alpha. Premultiplied color |
| components improve performance. |
| |
| #Const kUnknown_SkAlphaType 0 |
| Alpha_Type is uninitialized. |
| ## |
| #Const kOpaque_SkAlphaType 1 |
| Pixels are opaque. The Color_Type must have no explicit alpha |
| component, or all alpha components must be set to their maximum value. |
| ## |
| #Const kPremul_SkAlphaType 2 |
| Pixels have alpha premultiplied into color components. |
| Surface pixels must be premultiplied. |
| ## |
| #Const kUnpremul_SkAlphaType 3 |
| Pixel color component values are independent of alpha value. |
| Images generated from encoded data like PNG do not premultiply pixel color |
| components. kUnpremul_SkAlphaType is supported for Image pixels, but not for |
| Surface pixels. |
| ## |
| |
| #NoExample |
| ## |
| |
| #SeeAlso SkColorType SkColorSpace |
| |
| #Enum SkAlphaType ## |
| |
| #Subtopic Opaque |
| |
| Use Opaque as a hint to optimize drawing when alpha component |
| of all pixel is set to its maximum value of 1.0; all alpha component bits are set. |
| If Image_Info is set to Opaque but all alpha values are not 1.0, results are |
| undefined. |
| |
| #Example |
| #Height 64 |
| #Description |
| SkPreMultiplyARGB parameter a is set to 255, its maximum value, and is interpreted |
| as Color_Alpha of 1.0. kOpaque_SkAlphaType may be set to improve performance. |
| If SkPreMultiplyARGB parameter a is set to a value smaller than 255, |
| kPremul_SkAlphaType must be used instead to avoid undefined results. |
| The four displayed values are the original component values, though not necessarily |
| in the same order. |
| ## |
| SkPMColor color = SkPreMultiplyARGB(255, 50, 100, 150); |
| SkString s; |
| s.printf("%u %u %u %u", SkColorGetA(color), SkColorGetR(color), |
| SkColorGetG(color), SkColorGetB(color)); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| canvas->drawString(s, 10, 62, paint); |
| canvas->scale(50, 50); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(1, 1, kN32_SkColorType, kOpaque_SkAlphaType); |
| if (bitmap.installPixels(imageInfo, (void*) &color, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 0, 0); |
| } |
| ## |
| |
| #Subtopic Opaque ## |
| |
| #Subtopic Premul |
| |
| Use Premul when stored color components are the original color multiplied by the |
| alpha component. The alpha component range of 0.0 to 1.0 is achieved by dividing |
| the integer bit value by the maximum bit value. |
| |
| #Formula |
| stored color = original color * alpha / max alpha |
| ## |
| |
| The color component must be equal to or smaller than the alpha component, |
| or the results are undefined. |
| |
| #Example |
| #Description |
| SkPreMultiplyARGB parameter a is set to 150, less than its maximum value, and is |
| interpreted as Color_Alpha of about 0.6. kPremul_SkAlphaType must be set, since |
| SkPreMultiplyARGB parameter a is set to a value smaller than 255, |
| to avoid undefined results. |
| The four displayed values reflect that the alpha component has been multiplied |
| by the original color. |
| ## |
| #Height 64 |
| SkPMColor color = SkPreMultiplyARGB(150, 50, 100, 150); |
| SkString s; |
| s.printf("%u %u %u %u", SkColorGetA(color), SkColorGetR(color), |
| SkColorGetG(color), SkColorGetB(color)); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| canvas->drawString(s, 10, 62, paint); |
| canvas->scale(50, 50); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(1, 1, kN32_SkColorType, kPremul_SkAlphaType); |
| if (bitmap.installPixels(imageInfo, (void*) &color, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 0, 0); |
| } |
| ## |
| |
| #Subtopic Premul ## |
| |
| #Subtopic Unpremul |
| |
| Use Unpremul if stored color components are not divided by the alpha component. |
| Some drawing destinations may not support Unpremul. |
| |
| #Bug 7079 |
| #Example |
| #Height 64 |
| #Description |
| SkColorSetARGB parameter a is set to 150, less than its maximum value, and is |
| interpreted as Color_Alpha of about 0.6. color is not premultiplied; |
| color components may have values greater than color alpha. |
| The four displayed values are the original component values, though not necessarily |
| in the same order. |
| ## |
| SkColor color = SkColorSetARGB(150, 50, 100, 255); |
| SkString s; |
| s.printf("%u %u %u %u", SkColorGetA(color), SkColorGetR(color), |
| SkColorGetG(color), SkColorGetB(color)); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| canvas->drawString(s, 10, 62, paint); |
| canvas->scale(50, 50); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(1, 1, kN32_SkColorType, kUnpremul_SkAlphaType); |
| if (bitmap.installPixels(imageInfo, (void*) &color, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 0, 0); |
| } |
| ## |
| |
| #Subtopic Unpremul ## |
| |
| #Method static inline bool SkAlphaTypeIsOpaque(SkAlphaType at) |
| #In Property |
| #Line # returns if Alpha_Type equals kOpaque_SkAlphaType ## |
| |
| Returns true if Alpha_Type equals kOpaque_SkAlphaType. kOpaque_SkAlphaType is a |
| hint that the Color_Type is opaque, or that all Color_Alpha values are set to |
| their 1.0 equivalent. If Alpha_Type is kOpaque_SkAlphaType, and Color_Type is not |
| opaque, then the result of drawing any pixel with a Color_Alpha value less than |
| 1.0 is undefined. |
| |
| #Param at one of: #list_of_alpha_types# |
| ## |
| #Return true if at equals kOpaque_SkAlphaType ## |
| #NoExample |
| ## |
| ## |
| |
| #Subtopic Alpha_Type ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Color_Type |
| #Line # encoding for pixel color ## |
| #Alias Color_Type |
| #Alias Color_Types |
| |
| #PhraseDef list_of_color_types |
| 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 |
| ## |
| |
| #Subtopic Native |
| #Alias Native_Color_Type |
| #Substitute native SkColorType |
| ## |
| |
| #Enum SkColorType |
| #Line # encoding for pixel color ## |
| |
| #Code |
| enum SkColorType { |
| 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, |
| |
| kLastEnum_SkColorType = kRGBA_F16_SkColorType, |
| ###$ |
| #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A) |
| kN32_SkColorType = kBGRA_8888_SkColorType, |
| #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A) |
| kN32_SkColorType = kRGBA_8888_SkColorType, |
| #else |
| #error "SK_*32_SHIFT values must correspond to BGRA or RGBA byte order" |
| #endif |
| $$$# |
| }; |
| #Code ## |
| |
| Describes how pixel bits encode color. A pixel may be an alpha mask, a |
| gray level, Color_RGB, or Color_ARGB. |
| |
| kN32_SkColorType selects the native 32-bit Color_ARGB format. On Little_Endian |
| processors, pixels containing 8-bit Color_ARGB components pack into 32-bit |
| kBGRA_8888_SkColorType. On Big_Endian processors, pixels pack into 32-bit |
| kRGBA_8888_SkColorType. |
| |
| #Const kUnknown_SkColorType 0 |
| Color_Type is uninitialized; encoding format and size is unknown. |
| ## |
| #Const kAlpha_8_SkColorType 1 |
| Encodes Color_Alpha as Alpha_8 pixel in an 8-bit byte. |
| ## |
| #Const kRGB_565_SkColorType 2 |
| Encodes Color_RGB as BGR_565 pixel in a 16-bit word. |
| ## |
| #Const kARGB_4444_SkColorType 3 |
| Encodes Color_ARGB as ABGR_4444 pixel in a 16-bit word. |
| ## |
| #Const kRGBA_8888_SkColorType 4 |
| Encodes Color_ARGB as RGBA_8888 pixel in a 32-bit word. |
| ## |
| #Const kRGB_888x_SkColorType 5 |
| Encodes Color_RGB as RGB_888x pixel in a 32-bit word. |
| ## |
| #Const kBGRA_8888_SkColorType 6 |
| Encodes Color_ARGB as BGRA_8888 pixel in a 32-bit word. |
| ## |
| #Const kRGBA_1010102_SkColorType 7 |
| Encodes Color_ARGB as RGBA_1010102 pixel in a 32-bit word. |
| ## |
| #Const kRGB_101010x_SkColorType 8 |
| Encodes Color_RGB as RGB_101010x pixel in a 32-bit word. |
| ## |
| #Const kGray_8_SkColorType 9 |
| Encodes Color_Gray as Gray_8 in an 8-bit byte. |
| ## |
| #Const kRGBA_F16_SkColorType 10 |
| Encodes Color_ARGB as RGBA_F16 in a 64-bit word. |
| ## |
| |
| #ToDo can be 4 or 6; how to document? ## |
| #Const kN32_SkColorType 4 |
| Encodes Color_ARGB as either RGBA_8888 or BGRA_8888, whichever |
| is native to the platform. |
| ## |
| |
| #NoExample |
| ## |
| |
| #SeeAlso SkAlphaType SkColorSpace |
| |
| #Enum SkColorType ## |
| |
| #Subtopic Alpha_8 |
| |
| Alpha_8 is an 8-bit byte pixel encoding that represents transparency. A value of zero is |
| completely transparent; a value of 255 is completely opaque. Bitmap with Alpha_8 |
| pixels does not visibly draw, because its pixels have no color information. |
| The paired SkAlphaType is ignored. |
| |
| #Example |
| #Description |
| Alpha_8 pixels can modify another draw. orangePaint fills the bounds of bitmap, |
| with its transparency set to alpha8 pixel value. |
| ## |
| #Height 64 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kAlpha_8_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| SkPaint orangePaint; |
| orangePaint.setARGB(0xFF, 0xFF, 0xA5, 0x00); |
| canvas->drawBitmap(bitmap, 0, 0, &orangePaint); |
| uint8_t alpha8[] = { 0xFF, 0xBB, 0x77, 0x33 }; |
| SkPixmap alphaPixmap(imageInfo, &alpha8, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(alphaPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2, &orangePaint); |
| } |
| ## |
| ## |
| |
| #Subtopic BGR_565 |
| |
| BGR_565 is a 16-bit word pixel encoding that contains five bits of blue, |
| six bits of green, and five bits of red. BGR_565 is fully opaque as if its |
| Color_Alpha was set to one, and should always be paired with kOpaque_SkAlphaType. |
| |
| #Illustration |
| |
| #Example |
| #Height 96 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGB_565_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack565 = [](unsigned r, unsigned g, unsigned b) -> uint16_t { |
| return (b << 0) | (g << 5) | (r << 11); |
| }; |
| uint16_t red565[] = { pack565(0x1F, 0x00, 0x00), pack565(0x17, 0x00, 0x00), |
| pack565(0x0F, 0x00, 0x00), pack565(0x07, 0x00, 0x00) }; |
| uint16_t blue565[] = { pack565(0x00, 0x00, 0x1F), pack565(0x00, 0x00, 0x17), |
| pack565(0x00, 0x00, 0x0F), pack565(0x00, 0x00, 0x07) }; |
| SkPixmap redPixmap(imageInfo, &red565, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(redPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blue565, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(bluePixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic ABGR_4444 |
| |
| ABGR_4444 is a 16-bit word pixel encoding that contains four bits of alpha, |
| four bits of blue, four bits of green, and four bits of red. |
| |
| #Illustration |
| |
| If paired with kPremul_SkAlphaType: blue, green, and red components are |
| premultiplied by the alpha value. If blue, green, or red is greater than alpha, |
| the drawn result is undefined. |
| |
| If paired with kUnpremul_SkAlphaType: alpha, blue, green, and red components |
| may have any value. There may be a performance penalty with unpremultipled |
| pixels. |
| |
| If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; |
| blue, green, and red components are fully opaque. If any alpha component is |
| less than 15, the drawn result is undefined. |
| |
| #Bug 7648 |
| |
| #Example |
| #Height 96 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kARGB_4444_SkColorType, kPremul_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack4444 = [](unsigned a, unsigned r, unsigned g, unsigned b) -> uint16_t { |
| return (a << 0) | (b << 4) | (g << 8) | (r << 12); |
| }; |
| uint16_t red4444[] = { pack4444(0xF, 0xF, 0x0, 0x0), pack4444(0xF, 0xb, 0x0, 0x0), |
| pack4444(0xF, 0x7, 0x0, 0x0), pack4444(0xF, 0x3, 0x0, 0x0) }; |
| uint16_t blue4444[] = { pack4444(0xF, 0x0, 0x0, 0xF), pack4444(0xF, 0x0, 0x0, 0xb), |
| pack4444(0xF, 0x0, 0x0, 0x7), pack4444(0xF, 0x0, 0x0, 0x3) }; |
| SkPixmap redPixmap(imageInfo, &red4444, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(redPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blue4444, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(bluePixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic RGBA_8888 |
| |
| RGBA_8888 is a 32-bit word pixel encoding that contains eight bits of red, |
| eight bits of green, eight bits of blue, and eight bits of alpha. |
| |
| #Illustration |
| |
| If paired with kPremul_SkAlphaType: red, green, and blue components are |
| premultiplied by the alpha value. If red, green, or blue is greater than alpha, |
| the drawn result is undefined. |
| |
| If paired with kUnpremul_SkAlphaType: alpha, red, green, and blue components |
| may have any value. There may be a performance penalty with unpremultipled |
| pixels. |
| |
| If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; |
| red, green, and blue components are fully opaque. If any alpha component is |
| less than 255, the drawn result is undefined. |
| |
| On Big_Endian platforms, RGBA_8888 is the native Color_Type, and will have |
| the best performance. Use kN32_SkColorType to choose the best Color_Type for |
| the platform at compile time. |
| |
| #Example |
| #Height 96 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGBA_8888_SkColorType, kPremul_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack8888 = [](unsigned a, unsigned r, unsigned g, unsigned b) -> uint32_t { |
| return (r << 0) | (g << 8) | (b << 16) | (a << 24); |
| }; |
| uint32_t red8888[] = { pack8888(0xFF, 0xFF, 0x0, 0x0), pack8888(0xFF, 0xbb, 0x0, 0x0), |
| pack8888(0xFF, 0x77, 0x0, 0x0), pack8888(0xFF, 0x33, 0x0, 0x0) }; |
| uint32_t blue8888[] = { pack8888(0xFF, 0x0, 0x0, 0x0FF), pack8888(0xFF, 0x0, 0x0, 0x0bb), |
| pack8888(0xFF, 0x0, 0x0, 0x077), pack8888(0xFF, 0x0, 0x0, 0x033) }; |
| SkPixmap redPixmap(imageInfo, &red8888, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(redPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blue8888, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(bluePixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic RGB_888x |
| |
| RGB_888x is a 32-bit word pixel encoding that contains eight bits of red, |
| eight bits of green, eight bits of blue, and eight unused bits. RGB_888x is fully |
| opaque as if its Color_Alpha was set to one, and should always be paired with |
| kOpaque_SkAlphaType. |
| |
| #Illustration |
| |
| #Example |
| #Bug 7645 |
| #Height 96 |
| #Platform cpu |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGB_888x_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack888 = [](unsigned r, unsigned g, unsigned b) -> uint32_t { |
| return (r << 0) | (g << 8) | (b << 16); |
| }; |
| uint32_t red888[] = { pack888(0xFF, 0x00, 0x00), pack888(0xbb, 0x00, 0x00), |
| pack888(0x77, 0x00, 0x00), pack888(0x33, 0x00, 0x00) }; |
| uint32_t blue888[] = { pack888(0x00, 0x00, 0xFF), pack888(0x00, 0x00, 0xbb), |
| pack888(0x00, 0x00, 0x77), pack888(0x00, 0x00, 0x33) }; |
| if (bitmap.installPixels(imageInfo, (void*) red888, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| if (bitmap.installPixels(imageInfo, (void*) blue888, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic BGRA_8888 |
| |
| BGRA_8888 is a 32-bit word pixel encoding that contains eight bits of blue, |
| eight bits of green, eight bits of red, and eight bits of alpha. |
| |
| #Illustration |
| |
| If paired with kPremul_SkAlphaType: blue, green, and red components are |
| premultiplied by the alpha value. If blue, green, or red is greater than alpha, |
| the drawn result is undefined. |
| |
| If paired with kUnpremul_SkAlphaType: blue, green, red, and alpha components |
| may have any value. There may be a performance penalty with unpremultipled |
| pixels. |
| |
| If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; |
| blue, green, and red components are fully opaque. If any alpha component is |
| less than 255, the drawn result is undefined. |
| |
| On Little_Endian platforms, BGRA_8888 is the native Color_Type, and will have |
| the best performance. Use kN32_SkColorType to choose the best Color_Type for |
| the platform at compile time. |
| |
| #Example |
| #Height 96 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kBGRA_8888_SkColorType, kPremul_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack8888 = [](unsigned a, unsigned r, unsigned g, unsigned b) -> uint32_t { |
| return (b << 0) | (g << 8) | (r << 16) | (a << 24); |
| }; |
| uint32_t red8888[] = { pack8888(0xFF, 0xFF, 0x0, 0x0), pack8888(0xFF, 0xbb, 0x0, 0x0), |
| pack8888(0xFF, 0x99, 0x0, 0x0), pack8888(0xFF, 0x55, 0x0, 0x0) }; |
| uint32_t blue8888[] = { pack8888(0xFF, 0x0, 0x0, 0x0FF), pack8888(0xFF, 0x0, 0x0, 0x0bb), |
| pack8888(0xFF, 0x0, 0x0, 0x099), pack8888(0xFF, 0x0, 0x0, 0x055) }; |
| SkPixmap redPixmap(imageInfo, &red8888, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(redPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blue8888, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(bluePixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic RGBA_1010102 |
| |
| RGBA_1010102 is a 32-bit word pixel encoding that contains ten bits of red, |
| ten bits of green, ten bits of blue, and two bits of alpha. Possible alpha |
| values are zero: fully transparent; one: 33% opaque; two: 67% opaque; |
| three: fully opaque. |
| |
| #Illustration |
| |
| If paired with kPremul_SkAlphaType: red, green, and blue components are |
| premultiplied by the alpha value. If red, green, or blue is greater than the |
| alpha replicated to ten bits, the drawn result is undefined. |
| |
| If paired with kUnpremul_SkAlphaType: alpha, red, green, and blue components |
| may have any value. There may be a performance penalty with unpremultipled |
| pixels. |
| |
| If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; |
| red, green, and blue components are fully opaque. If any alpha component is |
| less than 3, the drawn result is undefined. |
| |
| #Example |
| #Bug 7645 |
| #Height 96 |
| #Platform cpu |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGBA_1010102_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack1010102 = [](unsigned r, unsigned g, unsigned b, unsigned a) -> uint32_t { |
| return (r << 0) | (g << 10) | (b << 20) | (a << 30); |
| }; |
| uint32_t redBits[] = { pack1010102(0x3FF, 0x000, 0x000, 0x3), |
| pack1010102(0x2ff, 0x000, 0x000, 0x3), |
| pack1010102(0x1ff, 0x000, 0x000, 0x3), |
| pack1010102(0x0ff, 0x000, 0x000, 0x3) }; |
| uint32_t blueBits[] = { pack1010102(0x000, 0x000, 0x3FF, 0x3), |
| pack1010102(0x000, 0x000, 0x2ff, 0x3), |
| pack1010102(0x000, 0x000, 0x1ff, 0x3), |
| pack1010102(0x000, 0x000, 0x0ff, 0x3) }; |
| if (bitmap.installPixels(imageInfo, (void*) redBits, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blueBits, imageInfo.minRowBytes()); |
| if (bitmap.installPixels(imageInfo, (void*) blueBits, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic RGB_101010x |
| |
| RGB_101010x is a 32-bit word pixel encoding that contains ten bits of red, |
| ten bits of green, ten bits of blue, and two unused bits. RGB_101010x is fully |
| opaque as if its Color_Alpha was set to one, and should always be paired with |
| kOpaque_SkAlphaType. |
| |
| #Illustration |
| |
| #Example |
| #Bug 7645 |
| #Height 96 |
| #Platform cpu |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGB_101010x_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto pack101010x = [](unsigned r, unsigned g, unsigned b) -> uint32_t { |
| return (r << 0) | (g << 10) | (b << 20); |
| }; |
| uint32_t redBits[] = { pack101010x(0x3FF, 0x000, 0x000), pack101010x(0x2ff, 0x000, 0x000), |
| pack101010x(0x1ff, 0x000, 0x000), pack101010x(0x0ff, 0x000, 0x000) }; |
| uint32_t blueBits[] = { pack101010x(0x000, 0x000, 0x3FF), pack101010x(0x000, 0x000, 0x2ff), |
| pack101010x(0x000, 0x000, 0x1ff), pack101010x(0x000, 0x000, 0x0ff) }; |
| if (bitmap.installPixels(imageInfo, (void*) redBits, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, &blueBits, imageInfo.minRowBytes()); |
| if (bitmap.installPixels(imageInfo, (void*) blueBits, imageInfo.minRowBytes())) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| ## |
| ## |
| |
| #Subtopic Gray_8 |
| |
| Gray_8 is an 8-bit byte pixel encoding that represents equal values for red, |
| blue, and green, reprsenting colors from black to white. Gray_8 is fully |
| opaque as if its Color_Alpha was set to one, and should always be paired with |
| kOpaque_SkAlphaType. |
| |
| #Example |
| #Height 64 |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kGray_8_SkColorType, kOpaque_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| uint8_t gray8[] = { 0xFF, 0xBB, 0x77, 0x33 }; |
| SkPixmap grayPixmap(imageInfo, &gray8, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(grayPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| ## |
| ## |
| |
| #Subtopic RGBA_F16 |
| |
| RGBA_F16 is a 64-bit word pixel encoding that contains sixteen bits of blue, |
| sixteen bits of green, sixteen bits of red, and sixteen bits of alpha. |
| |
| Each component encodes a floating point value using |
| #A Half floats # https://www.khronos.org/opengl/wiki/Small_Float_Formats ## |
| . Meaningful colors are represented by the range 0.0 to 1.0, although smaller |
| and larger values may be useful when used in combination with Transfer_Mode. |
| |
| #Illustration |
| |
| If paired with kPremul_SkAlphaType: blue, green, and red components are |
| premultiplied by the alpha value. If blue, green, or red is greater than alpha, |
| the drawn result is undefined. |
| |
| If paired with kUnpremul_SkAlphaType: blue, green, red, and alpha components |
| may have any value. There may be a performance penalty with unpremultipled |
| pixels. |
| |
| If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; |
| blue, green, and red components are fully opaque. If any alpha component is |
| less than 255, the drawn result is undefined. |
| |
| #ToDo |
| FloatToHalf should be replaced with SkFloatToHalf if/when that's made public |
| ## |
| |
| #Example |
| #Height 96 |
| #Function |
| union FloatUIntUnion { |
| uint32_t fUInt; |
| float fFloat; |
| }; |
| |
| uint16_t FloatToHalf(float f) { |
| static const FloatUIntUnion magic = { 15 << 23 }; |
| static const uint32_t round_mask = ~0xfffu; |
| FloatUIntUnion floatUnion; |
| floatUnion.fFloat = f; |
| uint32_t sign = floatUnion.fUInt & 0x80000000u; |
| floatUnion.fUInt ^= sign; |
| floatUnion.fUInt &= round_mask; |
| floatUnion.fFloat *= magic.fFloat; |
| floatUnion.fUInt -= round_mask; |
| return (floatUnion.fUInt >> 13) | (sign >> 16); |
| } |
| ## |
| |
| void draw(SkCanvas* canvas) { |
| canvas->scale(16, 16); |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(2, 2, kRGBA_F16_SkColorType, kPremul_SkAlphaType); |
| bitmap.allocPixels(imageInfo); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorGREEN); |
| canvas->drawBitmap(bitmap, 0, 0); |
| auto H = [](float c) -> uint16_t { |
| return FloatToHalf(c); |
| }; |
| // R G B A |
| uint16_t red_f16[][4] = { { H(1.0f), H(0.0f), H(0.0f), H(1.0f) }, |
| { H(.75f), H(0.0f), H(0.0f), H(1.0f) }, |
| { H(.50f), H(0.0f), H(0.0f), H(1.0f) }, |
| { H(.25f), H(0.0f), H(0.0f), H(1.0f) } }; |
| uint16_t blue_f16[][4] = { { H(0.0f), H(0.0f), H(1.0f), H(1.0f) }, |
| { H(0.0f), H(0.0f), H(.75f), H(1.0f) }, |
| { H(0.0f), H(0.0f), H(.50f), H(1.0f) }, |
| { H(0.0f), H(0.0f), H(.25f), H(1.0f) } }; |
| SkPixmap redPixmap(imageInfo, red_f16, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(redPixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 2, 2); |
| } |
| SkPixmap bluePixmap(imageInfo, blue_f16, imageInfo.minRowBytes()); |
| if (bitmap.writePixels(bluePixmap, 0, 0)) { |
| canvas->drawBitmap(bitmap, 4, 4); |
| } |
| } |
| ## |
| ## |
| |
| #Subtopic Color_Type ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method int SkColorTypeBytesPerPixel(SkColorType ct) |
| #In Property |
| #Line # returns Color_Type byte size ## |
| |
| Returns the number of bytes required to store a pixel, including unused padding. |
| Returns zero if ct is kUnknown_SkColorType or invalid. |
| |
| #Param ct one of: #list_of_color_types# |
| ## |
| |
| #Return bytes per pixel ## |
| |
| #Example |
| #Height 192 |
| const char* colors[] = { "Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", |
| "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16" }; |
| SkPaint paint; |
| paint.setTypeface(SkTypeface::MakeFromName("monospace", SkFontStyle())); |
| paint.setAntiAlias(true); |
| paint.setTextSize(10); |
| int y = 15; |
| canvas->drawString(" colorType bytes", 10, y, paint); |
| for (SkColorType colorType : { #list_of_color_types# |
| } ) { |
| int result = SkColorTypeBytesPerPixel(colorType); |
| SkString string; |
| string.printf("%13s %4d", colors[(int) colorType], result); |
| canvas->drawString(string, 10, y += 14, paint); |
| } |
| ## |
| #SeeAlso SkImageInfo::bytesPerPixel |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool SkColorTypeIsAlwaysOpaque(SkColorType ct) |
| #In Property |
| #Line # returns if Color_Type includes Color_Alpha ## |
| |
| Returns true if Color_Type always decodes Color_Alpha to 1.0, making the pixel |
| fully opaque. If true, Color_Type does not reserve bits to encode Color_Alpha. |
| |
| #Param ct one of: #list_of_color_types# |
| ## |
| |
| #Return true if Color_Alpha is always set to 1.0 ## |
| |
| #Example |
| #Height 192 |
| const char* colors[] = { "Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", |
| "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16" }; |
| SkPaint paint; |
| paint.setTypeface(SkTypeface::MakeFromName("monospace", SkFontStyle())); |
| paint.setAntiAlias(true); |
| paint.setTextSize(10); |
| int y = 15; |
| canvas->drawString(" colorType bytes", 10, y, paint); |
| for (SkColorType colorType : { #list_of_color_types# |
| } ) { |
| bool result = SkColorTypeIsAlwaysOpaque(colorType); |
| SkString string; |
| string.printf("%13s %6s", colors[(int) colorType], result ? "true" : "false"); |
| canvas->drawString(string, 10, y += 14, paint); |
| } |
| ## |
| #SeeAlso SkColorTypeValidateAlphaType |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType, |
| SkAlphaType* canonical = nullptr) |
| #In Property |
| #Line # returns if Alpha_Type is valid ## |
| |
| Returns true if canonical can be set to a valid Alpha_Type for colorType. If |
| there is more than one valid canonical Alpha_Type, set to alphaType, if valid. |
| If true is returned and canonical is not nullptr, store valid Alpha_Type. |
| |
| Returns false only if alphaType is kUnknown_SkAlphaType, color type is not |
| kUnknown_SkColorType, and Color_Type is not always opaque. If false is returned, |
| canonical is ignored. |
| |
| For kUnknown_SkColorType: set canonical to kUnknown_SkAlphaType and return true. |
| For kAlpha_8_SkColorType: set canonical to kPremul_SkAlphaType or |
| kOpaque_SkAlphaType and return true if alphaType is not kUnknown_SkAlphaType. |
| For kRGB_565_SkColorType, kRGB_888x_SkColorType, kRGB_101010x_SkColorType, and |
| kGray_8_SkColorType: set canonical to kOpaque_SkAlphaType and return true. |
| For kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kBGRA_8888_SkColorType, |
| kRGBA_1010102_SkColorType, and kRGBA_F16_SkColorType: set canonical to alphaType |
| and return true if alphaType is not kUnknown_SkAlphaType. |
| |
| #Param colorType one of: #list_of_color_types# |
| ## |
| #Param alphaType one of: #list_of_alpha_types# |
| ## |
| #Param canonical storage for Alpha_Type ## |
| |
| #Return true if valid Alpha_Type can be associated with colorType ## |
| |
| #Example |
| #Height 640 |
| const char* colors[] = { "Unknown", "Alpha_8", "RGB_565", "ARGB_4444", "RGBA_8888", "RGB_888x", |
| "BGRA_8888", "RGBA_1010102", "RGB_101010x", "Gray_8", "RGBA_F16" }; |
| const char* alphas[] = {"Unknown ", "Opaque ", "Premul ", "Unpremul"}; |
| SkAlphaType alphaTypes[] = { #list_of_alpha_types# |
| }; |
| SkPaint paint; |
| paint.setTypeface(SkTypeface::MakeFromName("monospace", SkFontStyle())); |
| paint.setAntiAlias(true); |
| paint.setTextSize(10); |
| int y = 15; |
| canvas->drawString(" colorType alphaType canonical", 10, y, paint); |
| for (SkColorType colorType : { #list_of_color_types# |
| } ) { |
| for (SkAlphaType alphaType : alphaTypes) { |
| SkAlphaType canonicalAlphaType = kUnknown_SkAlphaType; |
| bool result = SkColorTypeValidateAlphaType(colorType, alphaType, &canonicalAlphaType); |
| SkString string; |
| string.printf("%13s %10s %10s", colors[(int) colorType], alphas[(int) alphaType], |
| result ? alphas[(int) canonicalAlphaType] : "------ "); |
| canvas->drawString(string, 10, y += 14, paint); |
| } |
| } |
| ## |
| #SeeAlso SkColorTypeIsAlwaysOpaque |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic YUV_ColorSpace |
| #Alias YUV_ColorSpace |
| #Enum SkYUVColorSpace |
| #Line # color range of YUV pixels ## |
| |
| #Code |
| enum SkYUVColorSpace { |
| kJPEG_SkYUVColorSpace, |
| kRec601_SkYUVColorSpace, |
| kRec709_SkYUVColorSpace, |
| kLastEnum_SkYUVColorSpace = kRec709_SkYUVColorSpace, |
| }; |
| ## |
| |
| Describes color range of YUV pixels. The color mapping from YUV to RGB varies |
| depending on the source. YUV pixels may be generated by JPEG images, standard |
| video streams, or high definition video streams. Each has its own mapping from |
| YUV and RGB. |
| |
| JPEG YUV values encode the full range of 0 to 255 for all three components. |
| Video YUV values range from 16 to 235 for all three components. Details of |
| encoding and conversion to RGB are described in |
| #A YCbCr color space # https://en.wikipedia.org/wiki/YCbCr ## |
| . |
| |
| #Const kJPEG_SkYUVColorSpace 0 |
| Describes standard JPEG color space; |
| #A CCIR 601 # https://en.wikipedia.org/wiki/Rec._601 ## |
| with full range of 0 to 255 for components. |
| ## |
| #Const kRec601_SkYUVColorSpace 1 |
| Describes standard used by SDTV; |
| #A CCIR 601 # https://en.wikipedia.org/wiki/Rec._601 ## |
| with studio range of 16 to 235 range for components. |
| ## |
| #Const kRec709_SkYUVColorSpace 2 |
| Describes standard used by HDTV; |
| #A Rec. 709 # http://en.wikipedia.org/wiki/Rec._709 ## |
| with studio range of 16 to 235 range for components. |
| ## |
| |
| #NoExample |
| ## |
| |
| #SeeAlso SkImage::MakeFromYUVTexturesCopy SkImage::MakeFromNV12TexturesCopy |
| |
| #Enum SkYUVColorSpace ## |
| #Subtopic YUV_ColorSpace ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Struct SkImageInfo |
| |
| Describes pixel dimensions and encoding. Bitmap, Image, PixMap, and Surface |
| can be created from Image_Info. Image_Info can be retrieved from Bitmap and |
| Pixmap, but not from Image and Surface. For example, Image and Surface |
| implementations may defer pixel depth, so may not completely specify Image_Info. |
| |
| Image_Info contains dimensions, the pixel integral width and height. It encodes |
| how pixel bits describe Color_Alpha, transparency; Color components red, blue, |
| and green; and Color_Space, the range and linearity of colors. |
| |
| #Subtopic Member_Function |
| #Populate |
| ## |
| |
| #Subtopic Related_Function |
| #Populate |
| ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Constructor |
| #Populate |
| ## |
| |
| #Method SkImageInfo() |
| |
| #In Constructor |
| #Line # creates with zero dimensions, kUnknown_SkColorType, kUnknown_SkAlphaType ## |
| Creates an empty Image_Info with kUnknown_SkColorType, kUnknown_SkAlphaType, |
| a width and height of zero, and no Color_Space. |
| |
| #Return empty Image_Info ## |
| |
| #Example |
| #Height 32 |
| #Description |
| An empty Image_Info may be passed to SkCanvas::accessTopLayerPixels as storage |
| for the Canvas actual Image_Info. |
| ## |
| SkImageInfo imageInfo; |
| size_t rowBytes; |
| SkIPoint origin; |
| (void) canvas->accessTopLayerPixels(&imageInfo, &rowBytes, &origin); |
| const char* alphaType[] = { "Unknown", "Opaque", "Premul", "Unpremul" }; |
| SkString string; |
| string.printf("k%s_SkAlphaType", alphaType[(int) imageInfo.alphaType()]); |
| SkPaint paint; |
| canvas->drawString(string, 20, 20, paint); |
| ## |
| |
| #SeeAlso Make MakeN32 MakeS32 MakeA8 |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at, |
| sk_sp<SkColorSpace> cs = nullptr) |
| #In Constructor |
| #Line # creates Image_Info from dimensions, Color_Type, Alpha_Type, Color_Space ## |
| Creates Image_Info from integral dimensions width and height, Color_Type ct, |
| Alpha_Type at, and optionally Color_Space cs. |
| |
| If Color_Space cs is nullptr and Image_Info is part of drawing source: Color_Space |
| defaults to sRGB, mapping into Surface Color_Space. |
| |
| Parameters are not validated to see if their values are legal, or that the |
| combination is supported. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| #Param ct one of: #list_of_color_types# |
| ## |
| #Param at one of: #list_of_alpha_types# |
| ## |
| #Param cs range of colors; may be nullptr ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 48 |
| uint8_t storage[][5] = {{ 0xCA, 0xDA, 0xCA, 0xC9, 0xA3 }, |
| { 0xAC, 0xA8, 0x89, 0xA7, 0x87 }, |
| { 0x9B, 0xB5, 0xE5, 0x95, 0x46 }, |
| { 0x90, 0x81, 0xC5, 0x71, 0x33 }, |
| { 0x75, 0x55, 0x44, 0x40, 0x30 }}; |
| SkImageInfo imageInfo = SkImageInfo::Make(5, 5, kGray_8_SkColorType, kOpaque_SkAlphaType); |
| SkPixmap pixmap(imageInfo, storage[0], sizeof(storage) / 5); |
| SkBitmap bitmap; |
| bitmap.installPixels(pixmap); |
| canvas->scale(8, 8); |
| canvas->drawBitmap(bitmap, 0, 0); |
| ## |
| |
| #SeeAlso MakeN32 MakeN32Premul MakeS32 MakeA8 |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeN32(int width, int height, SkAlphaType at, |
| sk_sp<SkColorSpace> cs = nullptr) |
| #In Constructor |
| #Line # creates Image_Info with Native_Color_Type ## |
| Creates Image_Info from integral dimensions width and height, kN32_SkColorType, |
| Alpha_Type at, and optionally Color_Space cs. kN32_SkColorType will equal either |
| kBGRA_8888_SkColorType or kRGBA_8888_SkColorType, whichever is optimal. |
| |
| If Color_Space cs is nullptr and Image_Info is part of drawing source: Color_Space |
| defaults to sRGB, mapping into Surface Color_Space. |
| |
| Parameters are not validated to see if their values are legal, or that the |
| combination is supported. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| #Param at one of: #list_of_alpha_types# |
| ## |
| #Param cs range of colors; may be nullptr ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 128 |
| SkBitmap bitmap; |
| bitmap.allocPixels(SkImageInfo::MakeN32(16, 16, kPremul_SkAlphaType)); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorWHITE); |
| SkPaint paint; |
| offscreen.drawString("g", 0, 10, paint); |
| canvas->scale(8, 8); |
| canvas->drawBitmap(bitmap, 0, 0); |
| ## |
| |
| #SeeAlso Make MakeN32Premul MakeS32 MakeA8 |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeS32(int width, int height, SkAlphaType at) |
| |
| #In Constructor |
| #Line # creates Image_Info with Native_Color_Type, sRGB Color_Space ## |
| Creates Image_Info from integral dimensions width and height, kN32_SkColorType, |
| Alpha_Type at, with sRGB Color_Space. |
| |
| Parameters are not validated to see if their values are legal, or that the |
| combination is supported. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| #Param at one of: #list_of_alpha_types# |
| ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Set sRGB |
| #Height 128 |
| #Description |
| Top gradient is drawn to offscreen without Color_Space. It is darker than middle |
| gradient, drawn to offscreen with sRGB Color_Space. Bottom gradient shares bits |
| with middle, but does not specify the Color_Space in noColorSpaceBitmap. A source |
| without Color_Space is treated as sRGB; the bottom gradient is identical to the |
| middle gradient. |
| ## |
| const int width = 256; |
| const int height = 32; |
| SkImageInfo info = SkImageInfo::MakeN32Premul(width, height); |
| SkColor gradColors[] = { 0xFFAA0055, 0xFF11CC88 }; |
| SkPoint gradPoints[] = { { 0, 0 }, { width, 0 } }; |
| SkPaint gradPaint; |
| gradPaint.setShader(SkGradientShader::MakeLinear(gradPoints, gradColors, nullptr, |
| SK_ARRAY_COUNT(gradColors), SkShader::kClamp_TileMode)); |
| SkBitmap bitmap; |
| bitmap.allocPixels(SkImageInfo::MakeN32(width, height, kPremul_SkAlphaType)); |
| SkCanvas offscreen(bitmap); |
| offscreen.drawRect(SkRect::MakeWH(width, height), gradPaint); |
| canvas->drawBitmap(bitmap, 0, 0); |
| bitmap.allocPixels(SkImageInfo::MakeS32(width, height, kPremul_SkAlphaType)); |
| SkCanvas sRGBOffscreen(bitmap); |
| sRGBOffscreen.drawRect(SkRect::MakeWH(width, height), gradPaint); |
| canvas->drawBitmap(bitmap, 0, 48); |
| SkBitmap noColorSpaceBitmap; |
| noColorSpaceBitmap.setInfo(SkImageInfo::MakeN32(width, height, kPremul_SkAlphaType)); |
| noColorSpaceBitmap.setPixels(bitmap.getAddr(0, 0)); |
| canvas->drawBitmap(noColorSpaceBitmap, 0, 96); |
| ## |
| |
| #SeeAlso Make MakeN32 MakeN32Premul MakeA8 |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeN32Premul(int width, int height, sk_sp<SkColorSpace> cs = nullptr) |
| |
| #In Constructor |
| #Line # creates Image_Info with Native_Color_Type, kPremul_SkAlphaType ## |
| Creates Image_Info from integral dimensions width and height, kN32_SkColorType, |
| kPremul_SkAlphaType, with optional Color_Space. |
| |
| If Color_Space cs is nullptr and Image_Info is part of drawing source: Color_Space |
| defaults to sRGB, mapping into Surface Color_Space. |
| |
| Parameters are not validated to see if their values are legal, or that the |
| combination is supported. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| #Param cs range of colors; may be nullptr ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 128 |
| SkBitmap bitmap; |
| bitmap.allocPixels(SkImageInfo::MakeN32Premul(18, 18)); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorWHITE); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextSize(15); |
| offscreen.drawString("\xF0\x9F\x98\xB8", 1, 15, paint); |
| canvas->scale(6, 6); |
| canvas->drawBitmap(bitmap, 0, 0); |
| ## |
| |
| #SeeAlso MakeN32 MakeS32 MakeA8 Make |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeN32Premul(const SkISize& size) |
| |
| #In Constructor |
| Creates Image_Info from integral dimensions width and height, kN32_SkColorType, |
| kPremul_SkAlphaType, with Color_Space set to nullptr. |
| |
| If Image_Info is part of drawing source: Color_Space defaults to sRGB, mapping |
| into Surface Color_Space. |
| |
| Parameters are not validated to see if their values are legal, or that the |
| combination is supported. |
| |
| #Param size width and height, each must be zero or greater ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 128 |
| SkBitmap bitmap; |
| bitmap.allocPixels(SkImageInfo::MakeN32Premul({18, 18})); |
| SkCanvas offscreen(bitmap); |
| offscreen.clear(SK_ColorWHITE); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextSize(15); |
| offscreen.drawString("\xF0\x9F\x98\xB9", 1, 15, paint); |
| canvas->scale(6, 6); |
| canvas->drawBitmap(bitmap, 0, 0); |
| ## |
| |
| #SeeAlso MakeN32 MakeS32 MakeA8 Make |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeA8(int width, int height) |
| |
| #In Constructor |
| #Line # creates Image_Info with kAlpha_8_SkColorType, kPremul_SkAlphaType ## |
| Creates Image_Info from integral dimensions width and height, kAlpha_8_SkColorType, |
| kPremul_SkAlphaType, with Color_Space set to nullptr. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 64 |
| uint8_t pixels[][8] = { { 0x00, 0x00, 0x3f, 0x00, 0x00, 0x00, 0x00, 0x00}, |
| { 0x00, 0x7f, 0xff, 0x3f, 0x3f, 0x7f, 0x3f, 0x00}, |
| { 0x3f, 0xff, 0x7f, 0x00, 0x7f, 0xff, 0x7f, 0x00}, |
| { 0x00, 0x3f, 0x00, 0x00, 0x3f, 0x7f, 0x3f, 0x00}, |
| { 0x3f, 0x7f, 0x7f, 0x3f, 0x00, 0x00, 0x00, 0x00}, |
| { 0x7f, 0xff, 0xff, 0x7f, 0x00, 0x3f, 0x7f, 0x3f}, |
| { 0x7f, 0xff, 0xff, 0x7f, 0x00, 0x7f, 0xff, 0x7f}, |
| { 0x3f, 0x7f, 0x7f, 0x3f, 0x00, 0x3f, 0x7f, 0x3f} }; |
| SkBitmap bitmap; |
| bitmap.installPixels(SkImageInfo::MakeA8(8, 8), |
| (void*) pixels, sizeof(pixels[0])); |
| SkPaint paint; |
| canvas->scale(4, 4); |
| for (auto color : { SK_ColorRED, SK_ColorBLUE, 0xFF007F00} ) { |
| paint.setColor(color); |
| canvas->drawBitmap(bitmap, 0, 0, &paint); |
| canvas->translate(12, 0); |
| } |
| ## |
| |
| #SeeAlso MakeN32 MakeS32 Make |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeUnknown(int width, int height) |
| |
| #In Constructor |
| #Line # creates Image_Info with kUnknown_SkColorType, kUnknown_SkAlphaType ## |
| Creates Image_Info from integral dimensions width and height, kUnknown_SkColorType, |
| kUnknown_SkAlphaType, with Color_Space set to nullptr. |
| |
| Returned Image_Info as part of source does not draw, and as part of destination |
| can not be drawn to. |
| |
| #Param width pixel column count; must be zero or greater ## |
| #Param height pixel row count; must be zero or greater ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 32 |
| #Width 384 |
| SkImageInfo info; // default constructor |
| SkString string; |
| string.printf("SkImageInfo() %c= SkImageInfo::MakeUnknown(0, 0)", |
| info == SkImageInfo::MakeUnknown(0, 0) ? '=' : '!'); |
| SkPaint paint; |
| canvas->drawString(string, 0, 12, paint); |
| ## |
| |
| #SeeAlso SkImageInfo() MakeN32 MakeS32 Make |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static SkImageInfo MakeUnknown() |
| |
| #In Constructor |
| Creates Image_Info from integral dimensions width and height set to zero, |
| kUnknown_SkColorType, kUnknown_SkAlphaType, with Color_Space set to nullptr. |
| |
| Returned Image_Info as part of source does not draw, and as part of destination |
| can not be drawn to. |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 32 |
| #Width 384 |
| SkImageInfo info; // default constructor |
| SkString string; |
| string.printf("SkImageInfo() %c= SkImageInfo::MakeUnknown()", |
| info == SkImageInfo::MakeUnknown() ? '=' : '!'); |
| SkPaint paint; |
| canvas->drawString(string, 0, 12, paint); |
| ## |
| |
| #SeeAlso SkImageInfo() MakeN32 MakeS32 Make |
| |
| #Method ## |
| |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Property |
| #Populate |
| #Line # metrics and attributes ## |
| ## |
| |
| #Method int width() const |
| #In Property |
| #Line # returns pixel column count ## |
| Returns pixel count in each row. |
| |
| #Return pixel width ## |
| |
| #Example |
| #Image 4 |
| #Height 96 |
| canvas->translate(10, 10); |
| canvas->drawBitmap(source, 0, 0); |
| SkImageInfo imageInfo = source.info(); |
| canvas->translate(0, imageInfo.height()); |
| SkPaint paint; |
| paint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawLine(0, 10, imageInfo.width(), 10, paint); |
| canvas->drawString("width", imageInfo.width() / 2, 25, paint); |
| ## |
| |
| #SeeAlso height SkBitmap::width SkPixelRef::width SkImage::width SkSurface::width |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method int height() const |
| #In Property |
| #Line # returns pixel row count ## |
| Returns pixel row count. |
| |
| #Return pixel height ## |
| |
| #Example |
| #Image 4 |
| #Height 96 |
| canvas->translate(10, 20); |
| canvas->drawBitmap(source, 0, 0); |
| SkImageInfo imageInfo = source.info(); |
| SkPaint paint; |
| paint.setTextAlign(SkPaint::kCenter_Align); |
| paint.setVerticalText(true); |
| canvas->drawLine(imageInfo.width() + 10, 0, imageInfo.width() + 10, imageInfo.height(), paint); |
| canvas->drawString("height", imageInfo.width() + 25, imageInfo.height() / 2, paint); |
| ## |
| |
| #SeeAlso width SkBitmap::height SkPixelRef::height SkImage::height SkSurface::height |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkColorType colorType() const |
| #In Property |
| #Line # returns Color_Type ## |
| Returns Color_Type, one of: #list_of_color_types#. |
| |
| #Return Color_Type ## |
| |
| #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(16, 32); |
| SkDebugf("color type: k" "%s" "_SkColorType\n", colors[info.colorType()]); |
| #StdOut |
| color type: kAlpha_8_SkColorType |
| ## |
| ## |
| |
| #SeeAlso alphaType SkPixmap::colorType SkBitmap::colorType |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkAlphaType alphaType() const |
| #In Property |
| #Line # Returns Alpha_Type ## |
| Returns Alpha_Type, one of: #list_of_alpha_types#. |
| |
| #Return Alpha_Type ## |
| |
| #Example |
| const char* alphas[] = {"Unknown", "Opaque", "Premul", "Unpremul"}; |
| SkImageInfo info = SkImageInfo::MakeA8(16, 32); |
| SkDebugf("alpha type: k" "%s" "_SkAlphaType\n", alphas[info.alphaType()]); |
| #StdOut |
| alpha type: kPremul_SkAlphaType |
| ## |
| ## |
| |
| #SeeAlso colorType SkPixmap::alphaType SkBitmap::alphaType |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkColorSpace* colorSpace() const |
| #In Property |
| #Line # returns Color_Space ## |
| Returns Color_Space, the range of colors. The reference count of |
| Color_Space is unchanged. The returned Color_Space is immutable. |
| |
| #Return Color_Space, or nullptr ## |
| |
| #Example |
| #Description |
| SkColorSpace::MakeSRGBLinear creates Color_Space with linear gamma |
| and an sRGB gamut. This Color_Space gamma is not close to sRGB gamma. |
| ## |
| SkImageInfo info = SkImageInfo::MakeN32(16, 32, kPremul_SkAlphaType, |
| SkColorSpace::MakeSRGBLinear()); |
| SkColorSpace* colorSpace = info.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 SkPixmap::colorSpace SkBitmap::colorSpace |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method sk_sp<SkColorSpace> refColorSpace() const |
| #In Property |
| #Line # returns Color_Space ## |
| Returns smart pointer to Color_Space, the range of colors. The smart pointer |
| tracks the number of objects sharing this Color_Space reference so the memory |
| is released when the owners destruct. |
| |
| The returned Color_Space is immutable. |
| |
| #Return Color_Space wrapped in a smart pointer ## |
| |
| #Example |
| SkImageInfo info1 = SkImageInfo::MakeN32(16, 32, kPremul_SkAlphaType, |
| SkColorSpace::MakeSRGBLinear()); |
| SkImageInfo info2 = SkImageInfo::MakeN32(16, 32, kPremul_SkAlphaType, |
| info1.refColorSpace()); |
| SkColorSpace* colorSpace = info2.colorSpace(); |
| SkDebugf("gammaCloseToSRGB: %s gammaIsLinear: %s isSRGB: %s\n", |
| colorSpace->gammaCloseToSRGB() ? "true" : "false", |
| colorSpace->gammaIsLinear() ? "true" : "false", |
| colorSpace->isSRGB() ? "true" : "false"); |
| ## |
| |
| #SeeAlso Color_Space SkBitmap::refColorSpace |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isEmpty() const |
| #In Property |
| #Line # returns if dimensions contain pixels ## |
| |
| Returns if Image_Info describes an empty area of pixels by checking if either |
| width or height is zero or smaller. |
| |
| #Return true if either dimension is zero or smaller ## |
| |
| #Example |
| for (int width : { 0, 2 } ) { |
| for (int height : { 0, 2 } ) { |
| SkImageInfo imageInfo= SkImageInfo::MakeA8(width, height); |
| SkDebugf("width: %d height: %d empty: %s\n", width, height, |
| imageInfo.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 dimensions bounds SkBitmap::empty SkPixmap::bounds |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool isOpaque() const |
| #In Property |
| #Line # returns if Alpha_Type is kOpaque_SkAlphaType ## |
| |
| Returns true if Alpha_Type is set to hint that all pixels are opaque; their |
| Color_Alpha value is implicitly or explicitly 1.0. If true, and all pixels are |
| not opaque, Skia may draw incorrectly. |
| |
| Does not check if Color_Type allows Alpha, or if any pixel value has |
| transparency. |
| |
| #Return true if Alpha_Type is kOpaque_SkAlphaType ## |
| |
| #Example |
| const int height = 2; |
| const int width = 2; |
| SkBitmap bitmap; |
| SkImageInfo imageInfo = SkImageInfo::Make(width, height, kN32_SkColorType, kPremul_SkAlphaType); |
| bitmap.setInfo(imageInfo); |
| for (int index = 0; index < 2; ++index) { |
| bitmap.allocPixels(); |
| bitmap.eraseColor(0x00000000); |
| SkDebugf("isOpaque: %s\n", imageInfo.isOpaque() ? "true" : "false"); |
| bitmap.eraseColor(0xFFFFFFFF); |
| SkDebugf("isOpaque: %s\n", imageInfo.isOpaque() ? "true" : "false"); |
| imageInfo = imageInfo.makeAlphaType(kOpaque_SkAlphaType); |
| bitmap.setInfo(imageInfo); |
| } |
| #StdOut |
| isOpaque: false |
| isOpaque: false |
| isOpaque: true |
| isOpaque: true |
| ## |
| ## |
| |
| #SeeAlso Color_Alpha SkColorTypeValidateAlphaType SkBitmap::isOpaque SkImage::isOpaque SkPixmap::isOpaque |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkISize dimensions() const |
| #In Property |
| #Line # returns width() and height() ## |
| |
| Returns ISize { width(), height() }. |
| |
| #Return integral size of width() and height() ## |
| |
| #Example |
| const int height = 2; |
| const int width = 2; |
| SkImageInfo imageInfo = SkImageInfo::Make(width, height, kN32_SkColorType, kPremul_SkAlphaType); |
| SkISize dimensions = imageInfo.dimensions(); |
| SkIRect bounds = imageInfo.bounds(); |
| SkIRect dimensionsAsBounds = SkIRect::MakeSize(dimensions); |
| SkDebugf("dimensionsAsBounds %c= bounds\n", dimensionsAsBounds == bounds ? '=' : '!'); |
| #StdOut |
| dimensionsAsBounds == bounds |
| ## |
| ## |
| |
| #SeeAlso width height bounds SkBitmap::dimensions |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkIRect bounds() const |
| #In Property |
| #Line # returns width() and height() as Rectangle ## |
| Returns IRect { 0, 0, width(), height() }. |
| |
| #Return integral rectangle from origin to width() and height() ## |
| |
| #Example |
| #Height 64 |
| #Image 4 |
| canvas->scale(.5f, .5f); |
| SkImageInfo imageInfo = source.info(); |
| SkIRect bounds = imageInfo.bounds(); |
| for (int x : { 0, bounds.width() } ) { |
| for (int y : { 0, bounds.height() } ) { |
| canvas->drawBitmap(source, x, y); |
| } |
| } |
| ## |
| |
| #SeeAlso width height dimensions |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool gammaCloseToSRGB() const |
| #In Property |
| #Line # Returns if Color_Space gamma is approximately the same as sRGB ## |
| |
| Returns true if associated Color_Space is not nullptr, and Color_Space gamma |
| is approximately the same as sRGB. |
| This includes the |
| ###$ |
| $A sRGB transfer function $ https://en.wikipedia.org/wiki/SRGB#The_sRGB_transfer_function_(%22gamma%22) $$ |
| $$$# |
| as well as a gamma curve described by a 2.2 exponent. |
| |
| #Return true if Color_Space gamma is approximately the same as sRGB ## |
| |
| #Example |
| #Height 144 |
| const int width = 256; |
| const int height = 64; |
| auto drawLabel = [=](const char* what, bool closeToSRGB) -> void { |
| SkString string; |
| string.printf("%s gamma is %s" "close to sRGB", what, closeToSRGB ? "" : "not "); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawString(string, width / 2, 56, paint); |
| }; |
| SkColor gradColors[] = { 0xFFFF7F00, 0xFF00FF7F, 0xFF0000FF, 0xFF7F7FFF }; |
| SkPoint gradPoints[] = { { 0, 0 }, { width, 0 }, { width * 2, 0 }, { width * 3, 0 } }; |
| SkPaint gradPaint; |
| gradPaint.setShader(SkGradientShader::MakeLinear(gradPoints, gradColors, nullptr, |
| SK_ARRAY_COUNT(gradColors), SkShader::kClamp_TileMode)); |
| canvas->drawRect(SkRect::MakeWH(width, height), gradPaint); |
| drawLabel("canvas", canvas->imageInfo().gammaCloseToSRGB()); |
| SkBitmap bitmap; |
| SkImageInfo offscreenInfo = SkImageInfo::MakeS32(width, height, kPremul_SkAlphaType); |
| bitmap.allocPixels(offscreenInfo); |
| SkCanvas sRGBOffscreen(bitmap); |
| sRGBOffscreen.drawRect(SkRect::MakeWH(width, height), gradPaint); |
| canvas->translate(0, 80); |
| canvas->drawBitmap(bitmap, 0, 0); |
| drawLabel("offscreen", offscreenInfo.gammaCloseToSRGB()); |
| ## |
| |
| #SeeAlso SkColorSpace::gammaCloseToSRGB |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkImageInfo makeWH(int newWidth, int newHeight) const |
| #In Constructor |
| #Line # creates Image_Info with changed dimensions ## |
| Creates Image_Info with the same Color_Type, Color_Space, and Alpha_Type, |
| with dimensions set to width and height. |
| |
| #Param newWidth pixel column count; must be zero or greater ## |
| #Param newHeight pixel row count; must be zero or greater ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 144 |
| #Image 3 |
| SkImageInfo canvasImageInfo = canvas->imageInfo(); |
| SkRect canvasBounds = SkRect::Make(canvasImageInfo.bounds()); |
| canvas->drawBitmapRect(source, source.bounds(), canvasBounds, nullptr); |
| SkImageInfo insetImageInfo = |
| canvasImageInfo.makeWH(canvasBounds.width() / 2, canvasBounds.height() / 2); |
| SkBitmap inset; |
| inset.allocPixels(insetImageInfo); |
| SkCanvas offscreen(inset); |
| offscreen.drawBitmapRect(source, source.bounds(), SkRect::Make(inset.bounds()), nullptr); |
| canvas->drawBitmap(inset, canvasBounds.width() / 4, canvasBounds.height() / 4); |
| ## |
| |
| #SeeAlso Make makeAlphaType makeColorSpace makeColorType |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkImageInfo makeAlphaType(SkAlphaType newAlphaType) const |
| #In Constructor |
| #Line # creates Image_Info with changed Alpha_Type ## |
| Creates Image_Info with same Color_Type, Color_Space, width, and height, |
| with Alpha_Type set to newAlphaType. |
| |
| Created Image_Info contains newAlphaType even if it is incompatible with |
| Color_Type, in which case Alpha_Type in Image_Info is ignored. |
| |
| #Param newAlphaType one of: #list_of_alpha_types# |
| ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Image 3 |
| const int width = 256; |
| const int height = 128; |
| SkColor pixels[height][width]; |
| for (int y = 0; y < height; ++y) { |
| for (int x = 0; x < width; ++x) { |
| int red = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarSin((x * 4 + y) * 0.03f))); |
| int blue = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarCos((x * 3 + y) * 0.04f))); |
| int green = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarSin((x * 2 + y) * 0.05f))); |
| int alpha = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarCos((x * 1 + y) * 0.006f))); |
| pixels[y][x] = |
| SkColorSetARGB(alpha, red * alpha / 255, green * alpha / 255, blue * alpha / 255); |
| } |
| } |
| SkBitmap bitmap; |
| SkImageInfo info = SkImageInfo::Make(width, height, kBGRA_8888_SkColorType, kPremul_SkAlphaType); |
| bitmap.installPixels(info, (void*) pixels, sizeof(SkColor) * width); |
| canvas->drawBitmap(source, 0, 0); |
| canvas->drawBitmap(bitmap, 0, 0); |
| SkImageInfo unpremulInfo = info.makeAlphaType(kUnpremul_SkAlphaType); |
| bitmap.installPixels(unpremulInfo, (void*) pixels, sizeof(SkColor) * width); |
| canvas->drawBitmap(bitmap, 0, 128); |
| ## |
| |
| #SeeAlso Make MakeA8 makeColorType makeColorSpace |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkImageInfo makeColorType(SkColorType newColorType) const |
| #In Constructor |
| #Line # creates Image_Info with changed Color_Type ## |
| Creates Image_Info with same Alpha_Type, Color_Space, width, and height, |
| with Color_Type set to newColorType. |
| |
| #Param newColorType one of: #list_of_color_types# |
| ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| const int width = 256; |
| const int height = 128; |
| SkColor pixels[height][width]; |
| for (int y = 0; y < height; ++y) { |
| for (int x = 0; x < width; ++x) { |
| int red = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarSin((x * 4 + y) * 0.03f))); |
| int blue = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarCos((x * 3 + y) * 0.04f))); |
| int green = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarSin((x * 2 + y) * 0.05f))); |
| int alpha = SkScalarRoundToInt(255 * SkScalarAbs(SkScalarCos((x * 1 + y) * 0.006f))); |
| pixels[y][x] = |
| SkColorSetARGB(alpha, red * alpha / 255, green * alpha / 255, blue * alpha / 255); |
| } |
| } |
| SkBitmap bitmap; |
| SkImageInfo info = SkImageInfo::Make(width, height, kBGRA_8888_SkColorType, kPremul_SkAlphaType); |
| bitmap.installPixels(info, (void*) pixels, sizeof(SkColor) * width); |
| canvas->drawBitmap(source, 0, 0); |
| canvas->drawBitmap(bitmap, 0, 0); |
| SkImageInfo rgbaInfo = info.makeColorType(kRGBA_8888_SkColorType); |
| bitmap.installPixels(rgbaInfo, (void*) pixels, sizeof(SkColor) * width); |
| canvas->drawBitmap(bitmap, 0, 128); |
| ## |
| |
| #SeeAlso Make makeAlphaType makeColorSpace |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method SkImageInfo makeColorSpace(sk_sp<SkColorSpace> cs) const |
| #In Constructor |
| #Line # creates Image_Info with changed Color_Space ## |
| Creates Image_Info with same Alpha_Type, Color_Type, width, and height, |
| with Color_Space set to cs. |
| |
| #Param cs range of colors; may be nullptr ## |
| |
| #Return created Image_Info ## |
| |
| #Example |
| #Height 224 |
| const int width = 256; |
| const int height = 64; |
| auto drawLabel = [=](const char* what, bool closeToSRGB) -> void { |
| SkString string; |
| string.printf("%s gamma is %s" "close to sRGB", what, closeToSRGB ? "" : "not "); |
| SkPaint paint; |
| paint.setAntiAlias(true); |
| paint.setTextAlign(SkPaint::kCenter_Align); |
| canvas->drawString(string, width / 2, 56, paint); |
| }; |
| SkColor gradColors[] = { 0xFFFF7F00, 0xFF00FF7F, 0xFF0000FF, 0xFF7F7FFF }; |
| SkPoint gradPoints[] = { { 0, 0 }, { width, 0 }, { width * 2, 0 }, { width * 3, 0 } }; |
| SkPaint gradPaint; |
| gradPaint.setShader(SkGradientShader::MakeLinear(gradPoints, gradColors, nullptr, |
| SK_ARRAY_COUNT(gradColors), SkShader::kClamp_TileMode)); |
| canvas->drawRect(SkRect::MakeWH(width, height), gradPaint); |
| drawLabel("canvas", canvas->imageInfo().gammaCloseToSRGB()); |
| SkBitmap bitmap; |
| SkImageInfo offscreenInfo = SkImageInfo::MakeS32(width, height, kPremul_SkAlphaType); |
| bitmap.allocPixels(offscreenInfo); |
| SkCanvas sRGBOffscreen(bitmap); |
| sRGBOffscreen.drawRect(SkRect::MakeWH(width, height), gradPaint); |
| canvas->translate(0, 80); |
| canvas->drawBitmap(bitmap, 0, 0); |
| drawLabel("offscreen", offscreenInfo.gammaCloseToSRGB()); |
| SkImageInfo linearGamma = |
| offscreenInfo.makeColorSpace(offscreenInfo.colorSpace()->makeLinearGamma()); |
| bitmap.allocPixels(linearGamma); |
| SkCanvas lgOffscreen(bitmap); |
| lgOffscreen.drawRect(SkRect::MakeWH(width, height), gradPaint); |
| canvas->translate(0, 80); |
| canvas->drawBitmap(bitmap, 0, 0); |
| drawLabel("linear", linearGamma.gammaCloseToSRGB()); |
| ## |
| |
| #SeeAlso Make MakeS32 makeAlphaType makeColorType |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method int bytesPerPixel() const |
| #In Property |
| #Line # returns number of bytes in pixel based on Color_Type ## |
| Returns number of bytes per pixel required by Color_Type. |
| Returns zero if colorType( is kUnknown_SkColorType. |
| |
| #Return bytes in pixel ## |
| |
| #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"}; |
| for (SkColorType colorType : { #list_of_color_types# |
| } ) { |
| SkImageInfo info = SkImageInfo::Make(1, 1, colorType, kOpaque_SkAlphaType); |
| SkDebugf("color: k" "%s" "_SkColorType" "%*s" "bytesPerPixel: %d\n", |
| colors[colorType], 13 - strlen(colors[colorType]), " ", |
| info.bytesPerPixel()); |
| } |
| #StdOut |
| color: kUnknown_SkColorType bytesPerPixel: 0 |
| color: kAlpha_8_SkColorType bytesPerPixel: 1 |
| color: kRGB_565_SkColorType bytesPerPixel: 2 |
| color: kARGB_4444_SkColorType bytesPerPixel: 2 |
| color: kRGBA_8888_SkColorType bytesPerPixel: 4 |
| color: kRGB_888x_SkColorType bytesPerPixel: 4 |
| color: kBGRA_8888_SkColorType bytesPerPixel: 4 |
| color: kRGBA_1010102_SkColorType bytesPerPixel: 4 |
| color: kRGB_101010x_SkColorType bytesPerPixel: 4 |
| color: kGray_8_SkColorType bytesPerPixel: 1 |
| color: kRGBA_F16_SkColorType bytesPerPixel: 8 |
| ## |
| ## |
| |
| #SeeAlso width shiftPerPixel SkBitmap::bytesPerPixel |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method int shiftPerPixel() const |
| #In Property |
| #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"}; |
| for (SkColorType colorType : { #list_of_color_types# |
| } ) { |
| SkImageInfo info = SkImageInfo::Make(1, 1, colorType, kOpaque_SkAlphaType); |
| SkDebugf("color: k" "%s" "_SkColorType" "%*s" "shiftPerPixel: %d\n", |
| colors[colorType], 14 - strlen(colors[colorType]), " ", |
| info.shiftPerPixel()); |
| } |
| #StdOut |
| color: kUnknown_SkColorType shiftPerPixel: 0 |
| color: kAlpha_8_SkColorType shiftPerPixel: 0 |
| color: kRGB_565_SkColorType shiftPerPixel: 1 |
| color: kARGB_4444_SkColorType shiftPerPixel: 1 |
| color: kRGBA_8888_SkColorType shiftPerPixel: 2 |
| color: kRGB_888x_SkColorType shiftPerPixel: 2 |
| color: kBGRA_8888_SkColorType shiftPerPixel: 2 |
| color: kRGBA_1010102_SkColorType shiftPerPixel: 2 |
| color: kRGB_101010x_SkColorType shiftPerPixel: 2 |
| color: kGray_8_SkColorType shiftPerPixel: 0 |
| color: kRGBA_F16_SkColorType shiftPerPixel: 3 |
| ## |
| ## |
| |
| #SeeAlso bytesPerPixel minRowBytes SkBitmap::shiftPerPixel SkPixmap::shiftPerPixel |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method uint64_t minRowBytes64() const |
| #In Property |
| #Line # returns width() times bytesPerPixel in 64 bits ## |
| |
| Returns minimum bytes per row, computed from pixel width() and Color_Type, which |
| specifies bytesPerPixel(). Bitmap maximum value for row bytes must be representable |
| as a positive value in a 32-bit signed integer. |
| |
| #Return width() times bytesPerPixel as unsigned 64-bit integer ## |
| |
| #Example |
| for (int shift = 24; shift < 32; ++shift) { |
| int width = 1 << shift; |
| SkImageInfo imageInfo = |
| SkImageInfo::Make(width, 1, kRGBA_F16_SkColorType, kPremul_SkAlphaType); |
| uint64_t minRowBytes = imageInfo.minRowBytes64(); |
| bool widthTooLarge = (uint64_t) (int32_t) minRowBytes != minRowBytes; |
| SkDebugf("RGBA_F16 width %d (0x%08x) %s\n", |
| width, width, widthTooLarge ? "too large" : "OK"); |
| } |
| #StdOut |
| RGBA_F16 width 16777216 (0x01000000) OK |
| RGBA_F16 width 33554432 (0x02000000) OK |
| RGBA_F16 width 67108864 (0x04000000) OK |
| RGBA_F16 width 134217728 (0x08000000) OK |
| RGBA_F16 width 268435456 (0x10000000) too large |
| RGBA_F16 width 536870912 (0x20000000) too large |
| RGBA_F16 width 1073741824 (0x40000000) too large |
| RGBA_F16 width -2147483648 (0x80000000) too large |
| ## |
| ## |
| |
| #SeeAlso minRowBytes computeByteSize computeMinByteSize validRowBytes |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t minRowBytes() const |
| #In Property |
| #Line # returns width() times bytesPerPixel in 32 bits ## |
| |
| Returns minimum bytes per row, computed from pixel width() and Color_Type, which |
| specifies bytesPerPixel(). Bitmap maximum value for row bytes must be representable |
| as a positive value in a 32-bit signed integer. |
| |
| #Return width() times bytesPerPixel as signed 32-bit integer ## |
| |
| #Example |
| for (int shift = 24; shift < 32; ++shift) { |
| int width = 1 << shift; |
| SkImageInfo imageInfo = |
| SkImageInfo::Make(width, 1, kRGBA_F16_SkColorType, kPremul_SkAlphaType); |
| size_t minRowBytes = imageInfo.minRowBytes(); |
| bool widthTooLarge = !minRowBytes; |
| SkDebugf("RGBA_F16 width %d (0x%08x) %s\n", |
| width, width, widthTooLarge ? "too large" : "OK"); |
| } |
| #StdOut |
| RGBA_F16 width 16777216 (0x01000000) OK |
| RGBA_F16 width 33554432 (0x02000000) OK |
| RGBA_F16 width 67108864 (0x04000000) OK |
| RGBA_F16 width 134217728 (0x08000000) OK |
| RGBA_F16 width 268435456 (0x10000000) too large |
| RGBA_F16 width 536870912 (0x20000000) too large |
| RGBA_F16 width 1073741824 (0x40000000) too large |
| RGBA_F16 width -2147483648 (0x80000000) too large |
| ## |
| ## |
| |
| #SeeAlso minRowBytes64 computeByteSize computeMinByteSize validRowBytes |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t computeOffset(int x, int y, size_t rowBytes) const |
| #In Utility |
| #Line # returns byte offset within pixel array ## |
| |
| Returns byte offset of pixel from pixel base address. |
| |
| Asserts in debug build if x or y is outside of bounds. Does not assert if |
| rowBytes is smaller than minRowBytes, even though result may be incorrect. |
| |
| #Param x column index, zero or greater, and less than width() ## |
| #Param y row index, zero or greater, and less than height() ## |
| #Param rowBytes size of pixel row or larger ## |
| |
| #Return offset within pixel array ## |
| |
| #Example |
| #Height 128 |
| uint8_t pixels[][12] = { { 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, 0x00}, |
| { 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00}, |
| { 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00}, |
| { 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0x00, 0xFF, 0xFF}, |
| { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, |
| { 0x00, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0x00}, |
| { 0x00, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x00}, |
| { 0x00, 0x00, 0xFF, 0x00, 0x00, 0xFF, 0x00, 0x00} }; |
| SkImageInfo imageInfo = SkImageInfo::MakeA8(8, 8); |
| SkBitmap bitmap; |
| bitmap.installPixels(imageInfo, (void*) pixels, sizeof(pixels[0])); |
| SkPaint paint; |
| paint.setColor(SK_ColorRED); |
| canvas->drawBitmapRect(bitmap, SkRect::MakeWH(8, 8), SkRect::MakeWH(32, 32), &paint); |
| size_t offset = imageInfo.computeOffset(2, 3, sizeof(pixels[0])); |
| pixels[0][offset] = 0x7F; |
| offset = imageInfo.computeOffset(5, 3, sizeof(pixels[0])); |
| pixels[0][offset] = 0x7F; |
| bitmap.installPixels(imageInfo, (void*) pixels, sizeof(pixels[0])); |
| canvas->drawBitmapRect(bitmap, SkRect::MakeWH(8, 8), SkRect::MakeWH(128, 128), &paint); |
| ## |
| |
| #SeeAlso height width minRowBytes computeByteSize |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Operator |
| #Populate |
| ## |
| |
| #Method bool operator==(const SkImageInfo& other)_const |
| #Line # compares Image_Info for equality ## |
| |
| Compares Image_Info with other, and returns true if width, height, Color_Type, |
| Alpha_Type, and Color_Space are equivalent. |
| |
| #Param other Image_Info to compare ## |
| |
| #Return true if Image_Info equals other ## |
| |
| #Example |
| SkImageInfo info1 = SkImageInfo::Make(10, 20, kGray_8_SkColorType, kPremul_SkAlphaType);
|
| SkImageInfo info2 = SkImageInfo::Make(20, 10, kAlpha_8_SkColorType, kUnpremul_SkAlphaType);
|
| SkDebugf("info1 %c= info2\n", info1 == info2 ? '=' : '!');
|
| info2 = info2.makeWH(10, 20);
|
| SkDebugf("info1 %c= info2\n", info1 == info2 ? '=' : '!');
|
| info2 = info2.makeColorType(kGray_8_SkColorType);
|
| SkDebugf("info1 %c= info2\n", info1 == info2 ? '=' : '!');
|
| info2 = info2.makeAlphaType(kPremul_SkAlphaType);
|
| SkDebugf("info1 %c= info2\n", info1 == info2 ? '=' : '!');
|
| #StdOut
|
| info1 != info2
|
| info1 != info2
|
| info1 != info2
|
| info1 == info2
|
| ##
|
| ## |
| |
| #SeeAlso operator!=(const SkImageInfo& other)_const SkColorSpace::Equals |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool operator!=(const SkImageInfo& other)_const |
| #Line # compares Image_Info for inequality ## |
| |
| Compares Image_Info with other, and returns true if width, height, Color_Type, |
| Alpha_Type, and Color_Space are equivalent. |
| |
| #Param other Image_Info to compare ## |
| |
| #Return true if Image_Info is not equal to other ## |
| |
| #Example |
| SkImageInfo info1 = SkImageInfo::Make(10, 20, kGray_8_SkColorType, kPremul_SkAlphaType);
|
| SkImageInfo info2 = SkImageInfo::Make(20, 10, kAlpha_8_SkColorType, kUnpremul_SkAlphaType);
|
| SkDebugf("info1 %c= info2\n", info1 != info2 ? '!' : '=');
|
| info2 = info2.makeWH(10, 20);
|
| SkDebugf("info1 %c= info2\n", info1 != info2 ? '!' : '=');
|
| info2 = info2.makeColorType(kGray_8_SkColorType);
|
| SkDebugf("info1 %c= info2\n", info1 != info2 ? '!' : '=');
|
| info2 = info2.makeAlphaType(kPremul_SkAlphaType);
|
| SkDebugf("info1 %c= info2\n", info1 != info2 ? '!' : '=');
|
| #StdOut
|
| info1 != info2
|
| info1 != info2
|
| info1 != info2
|
| info1 == info2
|
| ##
|
| ## |
| |
| #SeeAlso operator==(const SkImageInfo& other)_const SkColorSpace::Equals |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t computeByteSize(size_t rowBytes) const |
| #In Utility |
| #Line # memory required by pixel buffer with given row bytes ## |
| Returns storage required by pixel array, given Image_Info dimensions, Color_Type, |
| and rowBytes. rowBytes is assumed to be at least as large as minRowBytes(). |
| |
| Returns zero if height is zero. |
| Returns SK_MaxSizeT if answer exceeds the range of size_t. |
| |
| #Param rowBytes size of pixel row or larger ## |
| |
| #Return memory required by pixel buffer ## |
| |
| #Example |
| #Height 130 |
| SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
|
| const size_t size = info.computeByteSize(100000);
|
| SkAutoTMalloc<SkPMColor> storage(size);
|
| SkPMColor* pixels = storage.get();
|
| SkBitmap bitmap;
|
| bitmap.setInfo(info);
|
| bitmap.setPixels(pixels);
|
| bitmap.eraseColor(SK_ColorRED);
|
| canvas->scale(50, 50);
|
| canvas->rotate(8);
|
| canvas->drawBitmap(bitmap, 2, 0); |
| ## |
| |
| #SeeAlso computeMinByteSize validRowBytes |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method size_t computeMinByteSize() const |
| #In Utility |
| #Line # least memory required by pixel buffer ## |
| Returns storage required by pixel array, given Image_Info dimensions, and |
| Color_Type. Uses minRowBytes() to compute bytes for pixel row. |
| |
| Returns zero if height is zero. |
| Returns SK_MaxSizeT if answer exceeds the range of size_t. |
| |
| #Return least memory required by pixel buffer ## |
| |
| #Example |
| #Height 130 |
| SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
|
| const size_t size = info.computeMinByteSize();
|
| SkAutoTMalloc<SkPMColor> storage(size);
|
| SkPMColor* pixels = storage.get();
|
| SkBitmap bitmap;
|
| bitmap.setInfo(info);
|
| bitmap.setPixels(pixels);
|
| bitmap.eraseColor(SK_ColorRED);
|
| canvas->scale(50, 50);
|
| canvas->rotate(8);
|
| canvas->drawBitmap(bitmap, 2, 0); |
| ## |
| |
| #SeeAlso computeByteSize validRowBytes |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method static bool ByteSizeOverflowed(size_t byteSize) |
| #In Utility |
| #Line # checks result of computeByteSize and computeMinByteSize ## |
| Returns true if byteSize equals SK_MaxSizeT. computeByteSize and |
| computeMinByteSize return SK_MaxSizeT if size_t can not hold buffer size. |
| |
| #Param byteSize result of computeByteSize or computeMinByteSize ## |
| |
| #Return true if computeByteSize or computeMinByteSize result exceeds size_t ## |
| |
| #Example |
| SkImageInfo info = SkImageInfo::MakeN32Premul(2, 1000000000);
|
| for (size_t rowBytes = 100000000; rowBytes < 10000000000000LL; rowBytes *= 10) {
|
| const size_t size = info.computeByteSize(rowBytes);
|
| SkDebugf("rowBytes:%llu size:%llu overflowed:%s\n", rowBytes, size,
|
| SkImageInfo::ByteSizeOverflowed(size) ? "true" : "false");
|
| }
|
| #StdOut
|
| rowBytes:100000000 size:99999999900000008 overflowed:false
|
| rowBytes:1000000000 size:999999999000000008 overflowed:false
|
| rowBytes:10000000000 size:9999999990000000008 overflowed:false
|
| rowBytes:100000000000 size:18446744073709551615 overflowed:true
|
| rowBytes:1000000000000 size:18446744073709551615 overflowed:true
|
| ##
|
| ## |
| |
| #SeeAlso computeByteSize computeMinByteSize validRowBytes |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method bool validRowBytes(size_t rowBytes) const |
| #In Utility |
| #Line # checks if row bytes is large enough to contain pixel row ## |
| Returns true if rowBytes is smaller than width times pixel size. |
| |
| #Param rowBytes size of pixel row or larger ## |
| |
| #Return true if rowBytes is large enough to contain pixel row ## |
| |
| #Example |
| SkImageInfo info = SkImageInfo::MakeN32Premul(16, 8);
|
| for (size_t rowBytes = 60; rowBytes < 72; rowBytes += sizeof(SkPMColor)) {
|
| SkDebugf("validRowBytes(%llu): %s\n", rowBytes, info.validRowBytes(rowBytes) ?
|
| "true" : "false");
|
| }
|
| #StdOut
|
| validRowBytes(60): false
|
| validRowBytes(64): true
|
| validRowBytes(68): true
|
| ##
|
| ## |
| |
| #SeeAlso ByteSizeOverflowed computeByteSize computeMinByteSize |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| |
| #Method void reset() |
| #In Constructor |
| #Line # sets zero dimensions, kUnknown_SkColorType, kUnknown_SkAlphaType ## |
| Creates an empty Image_Info with kUnknown_SkColorType, kUnknown_SkAlphaType, |
| a width and height of zero, and no Color_Space. |
| |
| #Example |
| SkImageInfo info = SkImageInfo::MakeN32Premul(16, 8);
|
| SkImageInfo copy = info;
|
| SkDebugf("info %c= copy\n", info == copy ? '=' : '!');
|
| copy.reset();
|
| SkDebugf("info %c= reset copy\n", info == copy ? '=' : '!');
|
| SkDebugf("SkImageInfo() %c= reset copy\n", SkImageInfo() == copy ? '=' : '!');
|
| #StdOut
|
| info == copy
|
| info != reset copy
|
| SkImageInfo() == reset copy
|
| ##
|
| ## |
| |
| #SeeAlso SkImageInfo() |
| |
| #Method ## |
| |
| # ------------------------------------------------------------------------------ |
| #Subtopic Utility |
| #Populate |
| #Line # rarely called management functions ## |
| ## |
| |
| #Method void validate() const |
| #In Utility |
| #Line # asserts if Image_Info is invalid (debug only) ## |
| Asserts if internal values are illegal or inconsistent. Only available if |
| SK_DEBUG is defined at compile time. |
| |
| #NoExample |
| ## |
| |
| #SeeAlso validRowBytes SkBitmap::validate |
| |
| #Method ## |
| |
| #Struct SkImageInfo ## |
| |
| #Topic Image_Info ## |
