[squeak-dev] The Inbox: Graphics-nice.285.mczTobias Pape Das.Linux at gmx.deWed Jan 1 22:07:02 UTC 2014
On 01.01.2014, at 19:55, commits at source.squeak.org wrote: > Nicolas Cellier uploaded a new version of Graphics to project The Inbox: > http://source.squeak.org/inbox/Graphics-nice.285.mcz > > ==================== Summary ==================== > > Name: Graphics-nice.285 > Author: nice > Time: 1 January 2014, 8:53:32.416 pm > UUID: 04aee02d-83ae-4b4d-aed9-968a6a7487db > Ancestors: Graphics-nice.284 > > Change Color implementation from 10 bits per (rgb) component to 8 bits per component. > Several considerations motivate this change: > - no Graphic output is using 10 bits; Au contraire! http://lmgtfy.com/?q=10+bit+graphics https://nvidia.custhelp.com/app/answers/detail/a_id/3011/~/10-bit-per-color-support-on-nvidia-geforce-gpus http://www.luminous-landscape.com/reviews/accessories/10bit.shtml http://www.amd.com/us/Documents/10-Bit.pdf Best -Tobias > - alpha channel is already stored using 8 bits; > - 8 bits matches nowadays most used 32 bits depth Form - thus it's an optimization. > Note that the tolerance for testing Color components has to be increased to a value >= (1/255), I suggest 0.005. > > =============== Diff against Graphics-nice.284 =============== > > Item was added: > + (PackageInfo named: 'Graphics') preamble: '"Change color components from 10 to 8 bits" > + Color allSubInstancesDo: > + [:c | > + | rgb | > + rgb := c instVarNamed: ''rgb''. > + rgb := (rgb bitAnd: 16r3FC00000) >> 2 + (rgb bitAnd: 16rFF000) >> 2 + (rgb bitAnd: 16r3FC) >> 2. > + c instVarNamed: ''rgb'' put: rgb; flushCache].'! > > Item was changed: > ----- Method: Color class>>initialize (in category 'class initialization') ----- > initialize > "Color initialize" > > "Details: Externally, the red, green, and blue components of color > are floats in the range [0.0..1.0]. Internally, they are represented > as integers in the range [0..ComponentMask] packing into a > small integer to save space and to allow fast hashing and > equality testing. > > For a general description of color representations for computer > graphics, including the relationship between the RGB and HSV > color models used here, see Chapter 17 of Foley and van Dam, > Fundamentals of Interactive Computer Graphics, Addison-Wesley, > 1982." > > + ComponentMask := 255. > + HalfComponentMask := 128. "used to round up in integer calculations" > + ComponentMax := 255.0. "a Float used to normalize components" > + RedShift := 16. > + GreenShift := 8. > - ComponentMask := 1023. > - HalfComponentMask := 512. "used to round up in integer calculations" > - ComponentMax := 1023.0. "a Float used to normalize components" > - RedShift := 20. > - GreenShift := 10. > BlueShift := 0. > > PureRed := self r: 1 g: 0 b: 0. > PureGreen := self r: 0 g: 1 b: 0. > PureBlue := self r: 0 g: 0 b: 1. > PureYellow := self r: 1 g: 1 b: 0. > PureCyan := self r: 0 g: 1 b: 1. > PureMagenta := self r: 1 g: 0 b: 1. > > RandomStream := Random new. > > self initializeIndexedColors. > self initializeGrayToIndexMap. > self initializeNames. > self initializeHighLights. > ! > > Item was changed: > ----- Method: Color class>>initializeGrayToIndexMap (in category 'class initialization') ----- > initializeGrayToIndexMap > "Build an array of gray values available in the 8-bit colormap. This array is indexed by a gray level between black (1) and white (256) and returns the pixel value for the corresponding gray level." > "Note: This method must be called after initializeIndexedColors, since it uses IndexedColors." > "Color initializeGrayToIndexMap" > > | grayLevels grayIndices c distToClosest dist indexOfClosest | > "record the level and index of each gray in the 8-bit color table" > grayLevels := OrderedCollection new. > grayIndices := OrderedCollection new. > "Note: skip the first entry, which is reserved for transparent" > 2 to: IndexedColors size do: [:i | > c := IndexedColors at: i. > c saturation = 0.0 ifTrue: [ "c is a gray" > + grayLevels add: c privateBlue. "top 8 bits; R, G, and B are the same" > - grayLevels add: (c privateBlue) >> 2. "top 8 bits; R, G, and B are the same" > grayIndices add: i - 1]]. "pixel values are zero-based" > grayLevels := grayLevels asArray. > grayIndices := grayIndices asArray. > > "for each gray level in [0..255], select the closest match" > GrayToIndexMap := ByteArray new: 256. > 0 to: 255 do: [:level | > distToClosest := 10000. "greater than distance to any real gray" > 1 to: grayLevels size do: [:i | > dist := (level - (grayLevels at: i)) abs. > dist < distToClosest ifTrue: [ > distToClosest := dist. > indexOfClosest := grayIndices at: i]]. > GrayToIndexMap at: (level + 1) put: indexOfClosest]. > ! > > Item was changed: > ----- Method: Color>>asHTMLColor (in category 'conversions') ----- > asHTMLColor > + ^'#' , (rgb printStringBase: 16 length: 6 padded: true)! > - | s | > - s := '#000000' copy. > - s at: 2 put: (Character digitValue: ((rgb bitShift: -6 - RedShift) bitAnd: 15)). > - s at: 3 put: (Character digitValue: ((rgb bitShift: -2 - RedShift) bitAnd: 15)). > - s at: 4 put: (Character digitValue: ((rgb bitShift: -6 - GreenShift) bitAnd: 15)). > - s at: 5 put: (Character digitValue: ((rgb bitShift: -2 - GreenShift) bitAnd: 15)). > - s at: 6 put: (Character digitValue: ((rgb bitShift: -6 - BlueShift) bitAnd: 15)). > - s at: 7 put: (Character digitValue: ((rgb bitShift: -2 - BlueShift) bitAnd: 15)). > - ^ s! > > Item was changed: > ----- Method: Color>>closestPixelValue1 (in category 'conversions') ----- > closestPixelValue1 > "Return the nearest approximation to this color for a monochrome Form." > > "fast special cases" > rgb = 0 ifTrue: [^ 1]. "black" > + rgb = 16rFFFFFFF ifTrue: [^ 0]. "white" > - rgb = 16r3FFFFFFF ifTrue: [^ 0]. "white" > > self luminance > 0.5 > ifTrue: [^ 0] "white" > ifFalse: [^ 1]. "black" > ! > > Item was changed: > ----- Method: Color>>closestPixelValue2 (in category 'conversions') ----- > closestPixelValue2 > "Return the nearest approximation to this color for a 2-bit deep Form." > > | lum | > "fast special cases" > rgb = 0 ifTrue: [^ 1]. "black" > + rgb = 16rFFFFFFF ifTrue: [^ 2]. "opaque white" > - rgb = 16r3FFFFFFF ifTrue: [^ 2]. "opaque white" > > lum := self luminance. > lum < 0.2 ifTrue: [^ 1]. "black" > lum > 0.6 ifTrue: [^ 2]. "opaque white" > ^ 3 "50% gray" > ! > > Item was changed: > ----- Method: Color>>closestPixelValue4 (in category 'conversions') ----- > closestPixelValue4 > "Return the nearest approximation to this color for a 4-bit deep Form." > > | bIndex | > "fast special cases" > rgb = 0 ifTrue: [^ 1]. "black" > + rgb = 16rFFFFFFF ifTrue: [^ 2]. "opaque white" > - rgb = 16r3FFFFFFF ifTrue: [^ 2]. "opaque white" > > rgb = PureRed privateRGB ifTrue: [^ 4]. > rgb = PureGreen privateRGB ifTrue: [^ 5]. > rgb = PureBlue privateRGB ifTrue: [^ 6]. > rgb = PureCyan privateRGB ifTrue: [^ 7]. > rgb = PureYellow privateRGB ifTrue: [^ 8]. > rgb = PureMagenta privateRGB ifTrue: [^ 9]. > > bIndex := (self luminance * 8.0) rounded. "bIndex in [0..8]" > ^ #( > 1 "black" > 10 "1/8 gray" > 11 "2/8 gray" > 12 "3/8 gray" > 3 "4/8 gray" > 13 "5/8 gray" > 14 "6/8 gray" > 15 "7/8 gray" > 2 "opaque white" > ) at: bIndex + 1. > ! > > Item was changed: > ----- Method: Color>>closestPixelValue8 (in category 'conversions') ----- > closestPixelValue8 > "Return the nearest approximation to this color for an 8-bit deep Form." > > "fast special cases" > rgb = 0 ifTrue: [^ 1]. "black" > + rgb = 16rFFFFFFF ifTrue: [^ 255]. "white" > - rgb = 16r3FFFFFFF ifTrue: [^ 255]. "white" > > self saturation < 0.2 ifTrue: [ > + ^ GrayToIndexMap at: self privateGreen + 1. "nearest gray" > - ^ GrayToIndexMap at: (self privateGreen >> 2) + 1. "nearest gray" > ] ifFalse: [ > "compute nearest entry in the color cube" > ^ 40 + > ((((self privateRed * 5) + HalfComponentMask) // ComponentMask) * 36) + > ((((self privateBlue * 5) + HalfComponentMask) // ComponentMask) * 6) + > (((self privateGreen * 5) + HalfComponentMask) // ComponentMask)]. > ! > > Item was changed: > ----- Method: Color>>pixelValueForDepth: (in category 'conversions') ----- > pixelValueForDepth: d > "Returns an integer representing the bits that appear in a single pixel of this color in a Form of the given depth. The depth must be one of 1, 2, 4, 8, 16, or 32. Contrast with pixelWordForDepth: and bitPatternForDepth:, which return either a 32-bit word packed with the given pixel value or a multiple-word Bitmap containing a pattern. The inverse is the class message colorFromPixelValue:depth:" > "Details: For depths of 8 or less, the result is a colorMap index. For depths of 16 and 32, it is a direct color value with 5 or 8 bits per color component." > "Transparency: The pixel value zero is reserved for transparent. For depths greater than 8, black maps to the darkest possible blue." > > | val | > d > 8 "most common case" > ifTrue: > [d = 32 ifTrue: [ > "eight bits per component; top 8 bits set to all ones (opaque alpha)" > + ^rgb = 0 ifTrue: [16rFF000001] ifFalse: [rgb bitOr: 16rFF000000]]. > - val := (LargePositiveInteger new: 4) > - at: 4 put: 16rFF; > - at: 3 put: ((rgb bitShift: -22) bitAnd: 16rFF); > - at: 2 put: ((rgb bitShift: -12) bitAnd: 16rFF); > - at: 1 put: ((rgb bitShift: -2) bitAnd: 16rFF); > - normalize. "normalize is not necessary as long as SmallInteger maxVal highBit < 32, but let's be future proof" > - ^val < 16rFF000001 ifTrue: [16rFF000001] ifFalse: [val]]. > > d = 16 ifTrue: [ > "five bits per component; top bits ignored" > + val := (((rgb bitShift: -9) bitAnd: 16r7C00) bitOr: > + ((rgb bitShift: -6) bitAnd: 16r03E0)) bitOr: > + ((rgb bitShift: -3) bitAnd: 16r001F). > - val := (((rgb bitShift: -15) bitAnd: 16r7C00) bitOr: > - ((rgb bitShift: -10) bitAnd: 16r03E0)) bitOr: > - ((rgb bitShift: -5) bitAnd: 16r001F). > ^val < 1 ifTrue: [1] ifFalse: [val]]. > > d = 12 ifTrue: [ "for indexing a color map with 4 bits per color component" > + val := (((rgb bitShift: -12) bitAnd: 16r0F00) bitOr: > + ((rgb bitShift: -8) bitAnd: 16r00F0)) bitOr: > + ((rgb bitShift: -4) bitAnd: 16r000F). > - val := (((rgb bitShift: -18) bitAnd: 16r0F00) bitOr: > - ((rgb bitShift: -12) bitAnd: 16r00F0)) bitOr: > - ((rgb bitShift: -6) bitAnd: 16r000F). > ^val < 1 ifTrue: [1] ifFalse: [val]]. > > d = 9 ifTrue: [ "for indexing a color map with 3 bits per color component" > + val := (((rgb bitShift: -15) bitAnd: 16r01C0) bitOr: > + ((rgb bitShift: -10) bitAnd: 16r0038)) bitOr: > + ((rgb bitShift: -5) bitAnd: 16r0007). > - val := (((rgb bitShift: -21) bitAnd: 16r01C0) bitOr: > - ((rgb bitShift: -14) bitAnd: 16r0038)) bitOr: > - ((rgb bitShift: -7) bitAnd: 16r0007). > ^val < 1 ifTrue: [1] ifFalse: [val]]]. > d = 8 ifTrue: [^ self closestPixelValue8]. > d = 4 ifTrue: [^ self closestPixelValue4]. > d = 2 ifTrue: [^ self closestPixelValue2].. > d = 1 ifTrue: [^ self closestPixelValue1]. > > self error: 'unknown pixel depth: ', d printString > ! > > Item was added: > + (PackageInfo named: 'Graphics') postscript: '"The cache might hold incorrect values during 10->8 bits per component transition" > + Color allSubInstancesDo: [:c | c flushCache].'! > > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 1665 bytes Desc: Message signed with OpenPGP using GPGMail Url : http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20140101/af67aa2b/signature.pgp
More information about the Squeak-dev mailing list |