The Trunk: Graphics-tpr.226.mcz

tim Rowledge uploaded a new version of Graphics to project The Trunk:
http://source.squeak.org/trunk/Graphics-tpr.226.mcz

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

Name: Graphics-tpr.226
Author: tpr
Time: 23 September 2013, 12:42:11.34 pm
UUID: 842c37b1-aab4-41a7-b8ff-1411a96c4590
Ancestors: Graphics-tpr.225

A first step in improvingthe characterscanner tree(s);
mostly split out kerning and non-kerning scanning. Also add some guide comments for later parts of the work, so some methods are only changed in comment.

=============== Diff against Graphics-tpr.225 ===============

Item was added:
+ ----- Method: AbstractFont>>isPairKerningCapable (in category 'testing') -----
+ isPairKerningCapable
+ "a hopefully temporary test method; better factoring of scan/measure/display should remove the need for it.
+ Only FreeType fonts would currently add this to return true"
+       ^false!

Item was removed:
- ----- Method: AbstractFont>>widthAndKernedWidthOfLeft:right:into: (in category 'kerning') -----
- widthAndKernedWidthOfLeft: leftCharacter right: rightCharacterOrNil into: aTwoElementArray
-       "Set the first element of aTwoElementArray to the width of leftCharacter and
-       the second element to the width of left character when kerned with
-       rightCharacterOrNil. Answer aTwoElementArray"
-       | w k |
-       w := self widthOf: leftCharacter.
-       rightCharacterOrNil isNil
-               ifTrue:[
-                       aTwoElementArray
-                               at: 1 put: w;
-                               at: 2 put: w]
-               ifFalse:[
-                       k := self kerningLeft: leftCharacter right: rightCharacterOrNil.
-                       aTwoElementArray
-                               at: 1 put: w;
-                               at: 2 put: w+k].
-       ^aTwoElementArray
-       !

Item was changed:
  ----- Method: CharacterScanner>>basicScanCharactersFrom:to:in:rightX:stopConditions:kern: (in category 'scanning') -----
+ basicScanCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
+       "In ancient days this would have called primitive 103 to scan a string with StrikeFont, but time moves on. See historicalScanCharactersFrom:to:in:rightX:stopConditions:kern: if you're curious. This code handles the newer shape of CharacterScanner but does *no* pair kerning.
+       There is a pretty deep assumption of simple ASCII strings and characters - beware"
+       | ascii nextDestX char |
- basicScanCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
-       "Primitive. This is the inner loop of text display--but see
-       scanCharactersFrom: to:rightX: which would get the string,
-       stopConditions and displaying from the instance. March through source
-       String from startIndex to stopIndex. If any character is flagged with a
-       non-nil entry in stops, then return the corresponding value. Determine
-       width of each character from xTable, indexed by map.
-       If dextX would exceed rightX, then return stops at: 258.
-       Advance destX by the width of the character. If stopIndex has been
-       reached, then return stops at: 257. Optional.
-       See Object documentation whatIsAPrimitive."
-       | ascii nextDestX char  floatDestX widthAndKernedWidth nextChar atEndOfRun |
-       <primitive: 103>
        lastIndex := startIndex.
-       floatDestX := destX.
-       widthAndKernedWidth := Array new: 2.
-       atEndOfRun := false.
        [lastIndex <= stopIndex]
+               whileTrue: [
+                       "get the character value"
+                       char := sourceString at: lastIndex.
-               whileTrue:
-                       [char := (sourceString at: lastIndex).
                        ascii := char asciiValue + 1.
+                       "if there is an entry in 'stops' for this value, return it"
+                       (stops at: ascii)
+                               ifNotNil: [^ stops at: ascii].
+                       "bump nextDestX by the width of the current character"
+                       nextDestX := destX + (font widthOf: char).
+                       "if the next x is past the right edge, return crossedX"
+                       nextDestX > rightX
+                               ifTrue: [^ stops crossedX].
+                       "update destX and incorporate thr kernDelta"
+                       destX := nextDestX + kernDelta.
-                       (stops at: ascii) == nil ifFalse: [^stops at: ascii].
-                       "Note: The following is querying the font about the width
-                       since the primitive may have failed due to a non-trivial
-                       mapping of characters to glyphs or a non-existing xTable."
-                       nextChar := (lastIndex + 1 <= stopIndex)
-                               ifTrue:[sourceString at: lastIndex + 1]
-                               ifFalse:[
-                                       atEndOfRun := true.
-                                       "if there is a next char in sourceString, then get the kern
-                                       and store it in pendingKernX"
-                                       lastIndex + 1 <= sourceString size
-                                               ifTrue:[sourceString at: lastIndex + 1]
-                                               ifFalse:[       nil]].
-                       font
-                               widthAndKernedWidthOfLeft: char
-                               right: nextChar
-                               into: widthAndKernedWidth.
-                       nextDestX := floatDestX + (widthAndKernedWidth at: 1).
-                       nextDestX > rightX ifTrue: [^stops crossedX].
-                       floatDestX := floatDestX + kernDelta + (widthAndKernedWidth at: 2).
-                       atEndOfRun
-                               ifTrue:[
-                                       pendingKernX := (widthAndKernedWidth at: 2) - (widthAndKernedWidth at: 1).
-                                       floatDestX := floatDestX - pendingKernX].
-                       destX := floatDestX.
                        lastIndex := lastIndex + 1].
        lastIndex := stopIndex.
+       ^ stops endOfRun!
-       ^stops endOfRun!

Item was added:
+ ----- Method: CharacterScanner>>basicScanKernableCharactersFrom:to:in:rightX:stopConditions:kern: (in category 'scanning') -----
+ basicScanKernableCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
+       "In ancient days this would have called primitive 103 to scan a string with StrikeFont, but time moves on. See historicalScanCharactersFrom:to:in:rightX:stopConditions:kern: if you're curious. This code handles the newer shape of CharacterScanner and provides some support for fonts that have pair-kerning; this may be removable with some better factoring.
+       There is a pretty deep assumption of simple ASCII strings and characters - beware"
+       | ascii nextDestX char floatDestX widthAndKernedWidth nextCharOrNil atEndOfRun |
+       lastIndex := startIndex.
+       floatDestX := destX.
+       widthAndKernedWidth := Array new: 2.
+       atEndOfRun := false.
+       [lastIndex <= stopIndex]
+               whileTrue: [
+                       "get the character value"
+                       char := sourceString at: lastIndex.
+                       ascii := char asciiValue + 1.
+                       "if there is an entry in 'stops' for this value, return it"
+                       (stops at: ascii)
+                               ifNotNil: [^ stops at: ascii].
+                       "get the next character..."
+                       nextCharOrNil := lastIndex + 1 <= stopIndex
+                                               ifTrue: [sourceString at: lastIndex + 1]
+                                               ifFalse: ["if we're at or past the stopIndex, see if there is anything in the full string"
+                                                       atEndOfRun := true.
+                                                       lastIndex + 1 <= sourceString size
+                                                               ifTrue: [sourceString at: lastIndex + 1]].
+                       "get the font's kerning info for the pair of current character and next character"
+                       "for almost all fonts in common use this is a waste of time since they don't support pair kerning and both values are #widthOf: char"
+                       font
+                               widthAndKernedWidthOfLeft: char
+                               right: nextCharOrNil
+                               into: widthAndKernedWidth.
+                       "bump nextDestX by the width of the current character"
+                       nextDestX := floatDestX
+                                               + (widthAndKernedWidth at: 1).
+                       "if the next x is past the right edge, return crossedX"
+                       nextDestX > rightX
+                               ifTrue: [^ stops crossedX].
+                       "bump floatDestX by the *kerned* width of the current
+                       character, which is where the *next* char will go"
+                       floatDestX := floatDestX + kernDelta
+                                               + (widthAndKernedWidth at: 2).
+                       "if we are at the end of this run we keep track of the
+                       character-kern-delta for possible later use and then rather
+                       insanely remove that character-kern-delta from floatDestX,
+                       making it equivalent to (old floatDestX) + kernDelta +
+                       width-of-character - no idea why"
+                       atEndOfRun
+                               ifTrue: [pendingKernX := (widthAndKernedWidth at: 2)
+                                                               - (widthAndKernedWidth at: 1).
+                                       floatDestX := floatDestX - pendingKernX].
+                       "save the next x for next time around the loop"
+                       destX := floatDestX.
+                       lastIndex := lastIndex + 1].
+       lastIndex := stopIndex.
+       ^ stops endOfRun!

Item was added:
+ ----- Method: CharacterScanner>>historicalScanCharactersFrom:to:in:rightX:stopConditions:kern: (in category 'scanning') -----
+ historicalScanCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
+       "Primitive. This is the inner loop of text display--but see
+       scanCharactersFrom: to:rightX: which would get the string,
+       stopConditions and displaying from the instance. March through source
+       String from startIndex to stopIndex. If any character is flagged with a
+       non-nil entry in stops, then return the corresponding value. Determine
+       width of each character from xTable, indexed by map.
+       If dextX would exceed rightX, then return stops at: 258.
+       Advance destX by the width of the character. If stopIndex has been
+       reached, then return stops at: 257. Optional.
+       See Object documentation whatIsAPrimitive.
+       Historical note: this primitive has been unusable since about Squeak 2.8 when the shape of the CharracterScanner class changed. It is left here as a reminder that the actual primitive still needs supporting in the VM to keep old images such as Scratch1.4 alive - tpr"
+       | ascii nextDestX char |
+       <primitive: 103>
+       lastIndex _ startIndex.
+       [lastIndex <= stopIndex]
+               whileTrue:
+                       [char _ (sourceString at: lastIndex).
+                       ascii _ char asciiValue + 1.
+                       (stops at: ascii) == nil ifFalse: [^stops at: ascii].
+                       "Note: The following is querying the font about the width
+                       since the primitive may have failed due to a non-trivial
+                       mapping of characters to glyphs or a non-existing xTable."
+                       nextDestX _ destX + (font widthOf: char).
+                       nextDestX > rightX ifTrue: [^stops at: CrossedX].
+                       destX _ nextDestX + kernDelta.
+                       lastIndex _ lastIndex + 1].
+       lastIndex _ stopIndex.
+       ^stops at: EndOfRun
+ !

Item was changed:
  ----- Method: CharacterScanner>>isBreakableAtIndex: (in category 'scanner methods') -----
  isBreakableAtIndex: index
+ "appears t obe unused - cf MultiCharacterScanner>isBreakableAt:in:in"
-
        ^ (EncodedCharSet at: ((text at: index) leadingChar + 1)) isBreakableAt: index in: text.
  !

Item was changed:
  ----- Method: CharacterScanner>>scanCharactersFrom:to:in:rightX:stopConditions:kern: (in category 'scanning') -----
+ scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
- scanCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
-
        | startEncoding selector |
+       sourceString isByteString
+               ifTrue: [font isPairKerningCapable
+                               ifTrue: [^ self
+                                               basicScanKernableCharactersFrom: startIndex
+                                               to: (stopIndex min: sourceString size)
+                                               in: sourceString
+                                               rightX: rightX
+                                               stopConditions: stops
+                                               kern: kernDelta]
+                               ifFalse: [^ self
+                                               basicScanCharactersFrom: startIndex
+                                               to: (stopIndex min: sourceString size)
+                                               in: sourceString
+                                               rightX: rightX
+                                               stopConditions: stops
+                                               kern: kernDelta]].
+       sourceString isWideString
+               ifTrue: [startIndex > stopIndex
+                               ifTrue: [lastIndex := stopIndex.
+                                       ^ stops endOfRun].
+                       startEncoding := (sourceString at: startIndex) leadingChar.
+                       selector := EncodedCharSet scanSelectorAt: startEncoding.
+                       ^ self
+                               perform: selector
+                               withArguments: (Array
+                                               with: startIndex
+                                               with: stopIndex
+                                               with: sourceString
+                                               with: rightX
+                                               with: stops
+                                               with: kernDelta)].
+       ^ stops endOfRun!
-       (sourceString isByteString) ifTrue: [^ self basicScanCharactersFrom: startIndex to: (stopIndex min: sourceString size) in: sourceString rightX: rightX stopConditions: stops kern: kernDelta.].
-
-       (sourceString isWideString) ifTrue: [
-               startIndex > stopIndex ifTrue: [lastIndex := stopIndex. ^ stops endOfRun].
-               startEncoding :=  (sourceString at: startIndex) leadingChar.
-               selector := EncodedCharSet scanSelectorAt: startEncoding.
-               ^ self perform: selector withArguments: (Array with: startIndex with: stopIndex with: sourceString with: rightX with: stops with: kernDelta).
-       ].
-
-       ^ stops endOfRun
- !

Item was removed:
- ----- Method: CharacterScanner>>scanMultiCharactersCombiningFrom:to:in:rightX:stopConditions:kern: (in category 'scanner methods') -----
- scanMultiCharactersCombiningFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta
-       "Implement a workaround for unicode composing.
-       a MultiCharacterScanner should better be used to handle combination."
-
-       ^self scanMultiCharactersFrom: startIndex to: stopIndex in: sourceString rightX: rightX stopConditions: stops kern: kernDelta!

On 23-09-2013, at 1:34 PM, Nicolas Cellier <[hidden email]> wrote:

> Please tim, := assignments would be much appreciated :)

I wasn't aware of not using them, but fortunately it's only in a virtually-dead method. Oh, I see - it was like that before I renamed it to preserve it temporarily.


tim
--
tim Rowledge; [hidden email]; http://www.rowledge.org/tim
Useful random insult:- Has a pulse, but that's about all.

On 23-09-2013, at 2:14 PM, Nicolas Cellier <[hidden email]> wrote:

> The update did not work for me because widthAndKernedWidthOfLeft:right:into: was removed before its senders were changed.

> Unfortunately some TextMorph decided to update in between…

Damn. And all that work that was intended to prevent order dependency goes up in smoke…

So how do we rescind a change? What else do I need to know to solve this?

tim
--
tim Rowledge; [hidden email]; http://www.rowledge.org/tim

The generation of random numbers is too important to be left to chance.

The first variant is easier, and it will also work for those who have managed to update to tpr.226.


Levente

On Tue, 24 Sep 2013, Nicolas Cellier wrote:

The simplest thing that could work:
restart after Graphics-tpr.226, restore the removed method publish Graphics-tpr.227.mcz.
browse latest update mcm, update at least Graphics to Graphics-tpr.227, publish (store) the update mcm in trunk
Then remove the method again and publish Graphics-tpr.228 in trunk

Or a variant:
restart before Graphics-tpr.226, replay all changes but the remove, publish Graphics-tpr.227.mcz.
browse mcm update, update graphics package, publish mcm update
Merge Graphics-tpr.226, publish Graphics-tpr.228 in trunk


2013/9/24 tim Rowledge <[hidden email]>

      On 23-09-2013, at 2:14 PM, Nicolas Cellier <[hidden email]> wrote:

      > The update did not work for me because widthAndKernedWidthOfLeft:right:into: was removed before its senders were changed.
> Unfortunately some TextMorph decided to update in between…

Damn. And all that work that was intended to prevent order dependency goes up in smoke…

So how do we rescind a change? What else do I need to know to solve this?


tim
--
tim Rowledge; [hidden email]; http://www.rowledge.org/tim
The generation of random numbers is too important to be left to chance.

But wait a minute before touching the update map, I have to first fix update-nice.246 which broke build.squeak.org

2013/9/24 Levente Uzonyi <[hidden email]>

The first variant is easier, and it will also work for those who have managed to update to tpr.226.


Levente

On Tue, 24 Sep 2013, Nicolas Cellier wrote:

The simplest thing that could work:
restart after Graphics-tpr.226, restore the removed method publish Graphics-tpr.227.mcz.
browse latest update mcm, update at least Graphics to Graphics-tpr.227, publish (store) the update mcm in trunk
Then remove the method again and publish Graphics-tpr.228 in trunk

Or a variant:
restart before Graphics-tpr.226, replay all changes but the remove, publish Graphics-tpr.227.mcz.
browse mcm update, update graphics package, publish mcm update
Merge Graphics-tpr.226, publish Graphics-tpr.228 in trunk


2013/9/24 tim Rowledge <[hidden email]>

      On 23-09-2013, at 2:14 PM, Nicolas Cellier <[hidden email]> wrote:

      > The update did not work for me because widthAndKernedWidthOfLeft:right:into: was removed before its senders were changed.
> Unfortunately some TextMorph decided to update in between…

Damn. And all that work that was intended to prevent order dependency goes up in smoke…

So how do we rescind a change? What else do I need to know to solve this?


tim
--
tim Rowledge; [hidden email]; http://www.rowledge.org/tim
The generation of random numbers is too important to be left to chance.

Now I'm puzzled. My image still has the widthAndKernedWidthOfLeft:right:into: method. So far as I can tell it wasn't removed at any point. I see in your debug log that a StrikeFont dNU'd when sent it but I cannot see how that would happen - all my code did was modify it.

tim
--
tim Rowledge; [hidden email]; http://www.rowledge.org/tim

Oxymorons: Silent scream