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Diffstat (limited to 'site/user/api/SkImageInfo_Reference.md')
| -rw-r--r-- | site/user/api/SkImageInfo_Reference.md | 98 |
1 files changed, 71 insertions, 27 deletions
diff --git a/site/user/api/SkImageInfo_Reference.md b/site/user/api/SkImageInfo_Reference.md index 611ae68d5d..743907ff54 100644 --- a/site/user/api/SkImageInfo_Reference.md +++ b/site/user/api/SkImageInfo_Reference.md @@ -112,40 +112,43 @@ SkImageInfo related constants are defined by <code>enum</code>, <code>enum class <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel with half floats for red, green, blue, alpha; in 64-bit word</td> </tr> <tr> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRGBA_F32_SkColorType'>kRGBA_F32_SkColorType</a></td> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel using C float for red, green, blue, alpha; in 128-bit word</td> + </tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRGB_101010x_SkColorType'>kRGB_101010x_SkColorType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel with 10 bits each for red, green, blue; in 32-bit word</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRGB_565_SkColorType'>kRGB_565_SkColorType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel with 5 bits red, 6 bits green, 5 bits blue, in 16-bit word</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRGB_888x_SkColorType'>kRGB_888x_SkColorType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel with 8 bits each for red, green, blue; in 32-bit word</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRec601_SkYUVColorSpace'>kRec601_SkYUVColorSpace</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>describes SDTV range</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kRec709_SkYUVColorSpace'>kRec709_SkYUVColorSpace</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>describes HDTV range</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kUnknown_SkAlphaType'>kUnknown_SkAlphaType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>uninitialized</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kUnknown_SkColorType'>kUnknown_SkColorType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>uninitialized</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#kUnpremul_SkAlphaType'>kUnpremul_SkAlphaType</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>pixel components are independent of <a href='SkColor_Reference#Alpha'>Alpha</a></td> </tr> </table> - ## <a name='Alpha_Type'>Alpha Type</a> ## <a name='SkAlphaType'>Enum SkAlphaType</a> @@ -333,8 +336,8 @@ true if <a href='#SkAlphaTypeIsOpaque_at'>at</a> equals <a href='#kOpaque_SkAlph <a href='#kRGB_101010x_SkColorType'>kRGB_101010x_SkColorType</a>, <a href='#kGray_8_SkColorType'>kGray_8_SkColorType</a>, <a href='#kRGBA_F16_SkColorType'>kRGBA_F16_SkColorType</a>, - - <a href='#kLastEnum_SkColorType'>kLastEnum_SkColorType</a> = <a href='#kRGBA_F16_SkColorType'>kRGBA_F16_SkColorType</a>, + <a href='#kRGBA_F32_SkColorType'>kRGBA_F32_SkColorType</a>, + <a href='#kLastEnum_SkColorType'>kLastEnum_SkColorType</a> = <a href='#kRGBA_F32_SkColorType'>kRGBA_F32_SkColorType</a>, #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A) <a href='#kN32_SkColorType'>kN32_SkColorType</a> = <a href='#kBGRA_8888_SkColorType'>kBGRA_8888_SkColorType</a>, #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A) @@ -456,18 +459,29 @@ blue, and green, representing colors from black to white. <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGBA_F16'>Color Type RGBA F16</a> </td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> Stores 64-bit word pixel encoding that contains 16 bits of blue, -16 bits of green, 16 bits of red, and 16 bits of alpha. +16 bits of green, 16 bits of red, and 16 bits of alpha. Each component +is encoded as a half float. </td> </tr> <tr> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='kRGBA_F32_SkColorType'><code>kRGBA_F32_SkColorType</code></a></td> + <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>11</td> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGBA_F32'>Color Type RGBA F32</a> </td> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> +Stores 128-bit word pixel encoding that contains 32 bits of blue, +32 bits of green, 32 bits of red, and 32 bits of alpha. Each component +is encoded as a single precision float. +</td> + </tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='kLastEnum_SkColorType'><code>kLastEnum_SkColorType</code></a></td> - <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>10</td> + <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>11</td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '> Used by tests to iterate through all valid values. </td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a name='kN32_SkColorType'><code>kN32_SkColorType</code></a></td> <td style='text-align: center; border: 2px solid #dddddd; padding: 8px; '>4 or 6</td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '></td> @@ -701,7 +715,7 @@ opaque as if its <a href='SkColor_Reference#Alpha'>Color Alpha</a> was set to on ## <a name='Color_Type_RGBA_F16'>Color Type RGBA F16</a> <a href='#kRGBA_F16_SkColorType'>kRGBA_F16_SkColorType</a> encodes ARGB into a 64-bit word. Each component: -blue, green, red, and alpha; use 16 bits, describing a floating point value. +blue, green, red, and alpha; use 16 bits, describing a floating point value, from -65500 to 65000 with 3.31 decimal digits of precision. At present, <a href='SkColor_Reference#Color'>Color</a> in <a href='SkPaint_Reference#Paint'>Paint</a> does not provide enough precision or range to @@ -723,11 +737,42 @@ pixels. If paired with <a href='#kOpaque_SkAlphaType'>kOpaque_SkAlphaType</a>: 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. +less than one, the drawn result is undefined. ### Example -<div><fiddle-embed name="788ac33198103a14a5076dc3e03f2f4b"></fiddle-embed></div> +<div><fiddle-embed name="dd81527bbdf5eaae7dd21ac04ab84f9e"></fiddle-embed></div> + +### See Also + +<a href='SkColor4f_Reference#SkColor4f'>SkColor4f</a> + +## <a name='Color_Type_RGBA_F32'>Color Type RGBA F32</a> + +<a href='#kRGBA_F32_SkColorType'>kRGBA_F32_SkColorType</a> encodes ARGB into a 128-bit word. Each component: +blue, green, red, and alpha; use 32 bits, describing a floating point value, +from -3.402823e+38 to 3.402823e+38 with 7.225 decimal digits of precision. + +At present, <a href='SkColor_Reference#Color'>Color</a> in <a href='SkPaint_Reference#Paint'>Paint</a> does not provide enough precision or range to +draw all colors possible to a <a href='#kRGBA_F32_SkColorType'>kRGBA_F32_SkColorType</a> <a href='SkSurface_Reference#Surface'>Surface</a>. + +Each component encodes a floating point value using <a href='https://en.wikipedia.org/wiki/Single-precision_floating-point_format'>single-precision floats</a></a> . +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 <a href='undocumented#Transfer_Mode'>Transfer Mode</a>. + + + +If paired with <a href='#kPremul_SkAlphaType'>kPremul_SkAlphaType</a>: blue, green, and red components are +<a href='undocumented#Premultiply'>Premultiplied</a> by the alpha value. If blue, green, or red is greater than alpha, +the drawn result is undefined. + +If paired with <a href='#kUnpremul_SkAlphaType'>kUnpremul_SkAlphaType</a>: blue, green, red, and alpha components +may have any value. There may be a performance penalty with <a href='undocumented#Unpremultiply'>Unpremultiplied</a> +pixels. + +If paired with <a href='#kOpaque_SkAlphaType'>kOpaque_SkAlphaType</a>: all alpha component values are at the maximum; +blue, green, and red components are fully opaque. If any alpha component is +less than one, the drawn result is undefined. ### See Also @@ -942,6 +987,7 @@ SkImageInfo related constants are defined by <code>enum</code>, <code>enum class <tr><th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Topic</th> <th style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>Description</th></tr> </table> + Describes pixel dimensions and encoding. <a href='SkBitmap_Reference#Bitmap'>Bitmap</a>, <a href='SkImage_Reference#Image'>Image</a>, PixMap, and <a href='SkSurface_Reference#Surface'>Surface</a> can be created from <a href='#Image_Info'>Image Info</a>. <a href='#Image_Info'>Image Info</a> can be retrieved from <a href='SkBitmap_Reference#Bitmap'>Bitmap</a> and <a href='SkPixmap_Reference#Pixmap'>Pixmap</a>, but not from <a href='SkImage_Reference#Image'>Image</a> and <a href='SkSurface_Reference#Surface'>Surface</a>. For example, <a href='SkImage_Reference#Image'>Image</a> and <a href='SkSurface_Reference#Surface'>Surface</a> @@ -1104,7 +1150,6 @@ SkImageInfo member functions read and modify the structure properties. </tr> </table> - ## <a name='Related_Function'>Related Function</a> @@ -1161,32 +1206,35 @@ SkImageInfo global, <code>struct</code>, and <code>class</code> related member f <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>encodes ARGB as half floats</td> </tr> <tr style='background-color: #f0f0f0; '> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGBA_F32'>Color Type RGBA F32</a></td> + <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>encodes ARGB as single precision floats</td> + </tr> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGB_101010'>Color Type RGB 101010</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>encodes RGB ten bits per color component</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGB_565'>Color Type RGB 565</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>encodes RGB in 16 bits</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Color_Type_RGB_888'>Color Type RGB 888</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>encodes RGB in 32 bits</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Property'>Property</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>metrics and attributes</td> </tr> - <tr style='background-color: #f0f0f0; '> + <tr> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#Utility'>Utility</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>rarely called management functions</td> </tr> - <tr> + <tr style='background-color: #f0f0f0; '> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '><a href='#YUV_ColorSpace'>YUV ColorSpace</a></td> <td style='text-align: left; border: 2px solid #dddddd; padding: 8px; '>color range of YUV pixels</td> </tr> </table> - ## <a name='Constructor'>Constructor</a> @@ -1260,7 +1308,6 @@ SkImageInfo can be constructed or initialized by these functions, including C++ </tr> </table> - <a name='SkImageInfo_empty_constructor'></a> ## SkImageInfo @@ -1695,7 +1742,6 @@ created <a href='#Image_Info'>Image Info</a> </tr> </table> - <a name='SkImageInfo_width'></a> ## width @@ -2382,7 +2428,6 @@ SkImageInfo operators inline class member functions with arithmetic equivalents. </tr> </table> - <a name='SkImageInfo_equal1_operator'></a> ## operator== @@ -2673,7 +2718,6 @@ SkImageInfo() == reset copy </tr> </table> - <a name='SkImageInfo_validate'></a> ## validate |