[squeak-dev] The Trunk: Graphics-jmv.74.mcz

Juan Vuletich uploaded a new version of Graphics to project The Trunk:
http://source.squeak.org/trunk/Graphics-jmv.74.mcz

==================== Summary ====================

Name: Graphics-jmv.74
Author: jmv
Time: 7 September 2009, 9:38:11 am
UUID: 41940759-1507-4bbf-9788-3234f1174099
Ancestors: Graphics-ar.73

Always do the second BitBlt pass for AA StrikeFonts if destDepth=32, as it might happen that the destination has transparent pixels that we need to make opaque.

Remove the (now unused) #properAlphaForBlackText preference.

Set the correct alpha value in colormaps used for AA StrikeFonts (This will only have effect when a bug in rule rgbAdd in Bitblt is fixed)

=============== Diff against Graphics-ar.73 ===============

Item was added:
+ ----- Method: BitBlt class>>initialize (in category 'class initialization') -----
+ initialize
+ self recreateColorMaps!

Item was changed:
  ----- Method: BitBlt>>installStrikeFont:foregroundColor:backgroundColor: (in category 'private') -----
  installStrikeFont: aStrikeFont foregroundColor: foregroundColor backgroundColor: backgroundColor
  | lastSourceDepth targetColor |
  sourceForm ifNotNil:[lastSourceDepth := sourceForm depth].
  sourceForm := aStrikeFont glyphs.
 
  "Ignore any halftone pattern since we use a color map approach here"
  halftoneForm := nil.
  sourceY := 0.
  height := aStrikeFont height.
 
  sourceForm depth = 1 ifTrue: [
  self combinationRule: Form paint.
  (colorMap notNil and:[lastSourceDepth = sourceForm depth]) ifFalse: [
  "Set up color map for a different source depth (color font)"
  "Uses caching for reasonable efficiency"
  colorMap := self cachedFontColormapFrom: sourceForm depth to: destForm depth.
  colorMap at: 1 put: (destForm pixelValueFor: backgroundColor)].
  colorMap at: 2 put: (destForm pixelValueFor: foregroundColor).
  ]
  ifFalse: [
  (Preferences subPixelRenderFonts and: [ foregroundColor = Color black or: [ Preferences subPixelRenderColorFonts ]]) ifTrue: [
  destForm depth > 8 ifTrue: [
  "rgbMul is equivalent to component alpha blend if text is black (only faster, hehe)"
  self combinationRule: 37. "RGBMul"
+ colorMap := (destForm depth = 32 or: [ (foregroundColor = Color black) not ]) ifTrue: [
- colorMap := (Preferences properAlphaForBlackText or: [ (foregroundColor = Color black) not ]) ifTrue: [
  "rgbMul / rgbAdd IS component alpha blend for any color of text (neat trick, eh!!)"
  "This colorMap is to be used on the second pass with rule 20 (rgbAdd)
  See #displayString:from:to:at:strikeFont:kern:"
+ "Note: In 32bpp we always need the second pass, as the source could have transparent pixels, and we need to add to the alpha channel"
  self colorConvertingMap: foregroundColor from: sourceForm depth to: destForm depth keepSubPixelAA: true]]
  ifFalse: [
  self combinationRule: 25. "Paint"
  targetColor := foregroundColor = Color black ifFalse: [ foregroundColor ].
  colorMap := self colorConvertingMap: targetColor from: sourceForm depth to: destForm depth keepSubPixelAA: true]
  ]
  ifFalse: [
  "Do not use rule 34 for 16bpp display. TTCFont uses it, but it builds a glyphs cache for each color used!!"
  self combinationRule: (destForm depth = 32 ifTrue: [34 "alphaBlendScaled"] ifFalse: [25 "Paint"]).
  colorMap := self colorConvertingMap: foregroundColor from: sourceForm depth to: destForm depth keepSubPixelAA: false
  ]
  ].!

Item was changed:
  ----- Method: Color class>>computeRGBColorConvertingMap:to:keepSubPixelAA: (in category 'colormaps') -----
  computeRGBColorConvertingMap: targetColor to: destDepth keepSubPixelAA: keepSubPix
  "Builds a colormap intended to convert from subpixelAA black values to targetColor values.
  keepSubPix
  ifTrue: [ Answer colors that also include subpixelAA ]
  ifFalse: [
  Take fullpixel luminance level. Apply it to targetColor.
  I.e. answer colors with NO subpixelAA ]"
 
  | mask map c bitsPerColor r g b f v |
 
  destDepth > 8
+ ifTrue: [bitsPerColor := 5]  "retain maximum color resolution"
+ ifFalse: [bitsPerColor := 4].
- ifTrue: [bitsPerColor _ 5]  "retain maximum color resolution"
- ifFalse: [bitsPerColor _ 4].
  "Usually a bit less is enough, but make it configurable"
  bitsPerColor _ bitsPerColor min: Preferences aaFontsColormapDepth.
+ mask := (1 bitShift: bitsPerColor) - 1.
- mask _ (1 bitShift: bitsPerColor) - 1.
  map _ Bitmap new: (1 bitShift: (3 * bitsPerColor)).
  0 to: map size - 1 do: [:i |
+ r := (i bitShift: 0 - (2 * bitsPerColor)) bitAnd: mask.
+ g := (i bitShift: 0 - bitsPerColor) bitAnd: mask.
+ b := (i bitShift: 0) bitAnd: mask.
+ f := 1.0 - (r + g + b / 3.0 / mask).
+ c := targetColor notNil
- r _ (i bitShift: 0 - (2 * bitsPerColor)) bitAnd: mask.
- g _ (i bitShift: 0 - bitsPerColor) bitAnd: mask.
- b _ (i bitShift: 0) bitAnd: mask.
- f _ 1.0 - (r + g + b / 3.0 / mask).
- c _ targetColor notNil
  ifTrue: [
  (keepSubPix and: [destDepth > 8]) ifTrue: [
  Color
  r: 1.0 - (r/mask) * targetColor red
  g: 1.0 - (g/mask) * targetColor green
+ b: 1.0 - (b/mask) * targetColor blue
+ alpha: f * targetColor alpha "alpha will be ignored below, in #pixelValueForDepth: if destDepth ~= 32" ]
- b: 1.0 - (b/mask) * targetColor blue ]
  ifFalse: [
  destDepth = 32
+ ifTrue: [ targetColor * f alpha: f * targetColor alpha ]
- ifTrue: [ targetColor * f alpha: f ]
  ifFalse: [ targetColor alphaMixed: f*1.5 with: Color white ]]]
+ ifFalse: [ Color r: r g: g b: b range: mask]. "This is currently used only to keep some SubPixelAA on destDepth = 8, using a single pass of rule 25"
+ v := destDepth = 32
- ifFalse: [ Color r: r g: g b: b range: mask].
- v _ destDepth = 32
  ifTrue: [ c pixelValueForDepth: destDepth]
  ifFalse: [
  f < 0.1
  ifTrue: [ 0 ]
  ifFalse: [ c pixelValueForDepth: destDepth ]].
  map at: i + 1 put: v ].
  ^ map!