Possible bug, Rotated text changes sizes (width)

Demivec · **Posted:** Sun Feb 07, 2010 8:44 pm

In doing some experiments with the DrawRotatedText() function I ran across a bug.

The bug results in the wrong size for rotated text, that is the text size increases for some reason, at least in width.

I wanted to post it in the coding forum first to make sure I wasn't overlooking something that would be causing this effect.

The code below draws non-rotated text and place a box around it using the dimensions returned from TextWidth() and TextHeight(). It's width is 92 pixels.
Rotated text is drawn using an angle of zero, it's width matches the previously drawn text, being 92 pixels.
Rotated text is then drawn using an angle of 0.2 . It's width mysteriously increases by 6 pixels, become 98 pixels. It also shifts down by 2 pixels.

It would seem the shifting doesn't relate to the rotation amount because it should keep the upper-left pixel in the same position or one that is slightly higher. The length change is likewise peculiar.

Code:

Define sizeX = 110, sizeY = 40

If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And StartDrawing(ImageOutput(0))
      Box(0, 0, sizeX, sizeY, RGB(255, 255, 255))
      
      Define text.s="X>>>  O  >>>X"
      
      Define tx = TextWidth(text)
      Define ty = TextHeight(text)
      
      ;draw standard text
      DrawText(5,5,text)
      ;outline text with box to highlight dimensions (again)
      DrawingMode(#PB_2DDrawing_Outlined)
      Box(5,5,tx,ty,$FFFF00)
 
      ;draw rotated text with no rotation
      DrawRotatedText(5, 5 + ty, text, 0, #Black)
      ;draw rotated text using a very small angle
      DrawRotatedText(5, 5 + ty, text, 0.2, #Magenta) ; <== text has become wider?
    StopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

Thorium · **Joined:** Sat Aug 15, 2009 6:59 pm **Posts:** 1024

Isn't that just normal, that if you rotate something it's bounding box becomes bigger?

freak · **Posted:** Sun Feb 07, 2010 9:39 pm

Rotating only works with TrueType fonts on Windows. If your font isn't a TrueType font then the command will try to load one that matches as close as possible. This is where the difference comes from.

Demivec · **Posted:** Mon Feb 08, 2010 2:40 am

freak wrote:

Rotating only works with TrueType fonts on Windows. If your font isn't a TrueType font then the command will try to load one that matches as close as possible. This is where the difference comes from.

That's helpful to know. So I should make sure I use a TrueType font so everything should work better.

Below is the same code from above with one major change. It loads and uses the "Courier New" TrueType font. Now the rotated text (by 0.2 degrees) is drawn skinnier by 3 pixels and is drawn lower on the screen by 4 pixels. I'm confused, I thought using a Truetype would fix it but it just went off in another direction. Does anyone have a TrueType font that can be used with the code below so that the rotated version does not have it's width shrunk or expanded and won't draw the text below it's anchor point (the top left)?

Any insight would be appreciated.

Code:

Define sizeX = 110, sizeY = 40, px = 2, py = 2

If Not LoadFont(0,"Courier New",10,#PB_Font_Bold): End: EndIf

If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And StartDrawing(ImageOutput(0))
      Box(0, 0, sizeX, sizeY, RGB(255, 255, 255))
      DrawingFont(FontID(0))  ;use TrueType font    
      Define text.s="X>>>  O  >>>X"
      
      Define tx = TextWidth(text)
      Define ty = TextHeight(text)

      ;draw standard text
      DrawText(px,py,text)
      ;outline text with box to highlight dimensions (again)
      DrawingMode(#PB_2DDrawing_Outlined)
      Box(px, py, tx, ty, $FFFF00)
 
      ;draw rotated text with no rotation
      DrawRotatedText(px, py + ty, text, 0, #Black)
      ;draw rotated text using a very small angle
      DrawRotatedText(px, py + ty, text, -0.2, #Magenta) ; <== text has become skinnier?
    StopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

Thorium wrote:

Isn't that just normal, that if you rotate something it's bounding box becomes bigger?

That is true. That is why I used the smallest rotation that would cause a change in the font rendering, 0.2 degrees. I think the change in the bounding box size should be negligible.

skywalk · **Posted:** Tue Jul 10, 2012 8:20 pm

I think Consolas works on Windows 7, but isn't native to XP.

Code:

;If Not LoadFont(0,"Consolas",10,#PB_Font_Bold): End: EndIf
If Not LoadFont(0,"Consolas",10,#PB_Font_HighQuality): End: EndIf

Danilo · **Joined:** Sat Apr 26, 2003 8:26 am **Posts:** 1290

Demivec wrote:

Any insight would be appreciated.

Code:

Define sizeX = 110, sizeY = 40, px = 2, py = 2

If Not LoadFont(0,"Courier New",10,#PB_Font_Bold): End: EndIf

If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And StartDrawing(ImageOutput(0))
      Box(0, 0, sizeX, sizeY, RGB(255, 255, 255))
      DrawingFont(FontID(0))  ;use TrueType font    
      Define text.s="X>>>  O  >>>X"
      
      Define tx = TextWidth(text)
      Define ty = TextHeight(text)

      ;draw standard text
      DrawText(px,py,text)
      ;outline text with box to highlight dimensions (again)
      DrawingMode(#PB_2DDrawing_Outlined)
      Box(px, py, tx, ty, $FFFF00)
 
      ;draw rotated text with no rotation
      DrawRotatedText(px, py + ty, text, 0, #Black)
      ;draw rotated text using a very small angle
      DrawRotatedText(px, py + ty, text, -0.2, #Magenta) ; <== text has become skinnier?
    StopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

You are right, it happens with flag #PB_Font_Bold. Other flags like Italic and Strikeout work correctly.

Works with gDrawing (GDI+):

Code:

XIncludeFile "gDrawing.pbi"

Define sizeX = 510, sizeY = 140, px = 2, py = 2

;If Not LoadFont(0,"Courier New",10,#PB_Font_Bold): End: EndIf

;If Not LoadFont(0,"Consolas",10,#PB_Font_Bold): End: EndIf
;If Not LoadFont(0,"Consolas",10,#PB_Font_HighQuality): End: EndIf
gInit()
If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And gStartDrawing(ImageOutput(0))
      gBox(0, 0, sizeX, sizeY, RGBA(255, 255, 255,255))
      gSetFont("Courier New",40,#PB_Font_Bold)  ;use TrueType font
      Define text.s="X>>>  O  >>>X"
      
      Define tx = gTextWidth(text)
      Define ty = gTextHeight(text)

      ;draw standard text
      gDrawText(px,py,text,RGBA(0,0,0,255))
      ;outline text with box to highlight dimensions (again)
      gDrawingMode(#PB_2DDrawing_Outlined)
      gBox(px, py, tx, ty, $FFFFFF00)
      gDrawingMode(#PB_2DDrawing_Default)
 
      ;draw rotated text with no rotation
      gDrawRotatedText(px, py + ty, text, 0, #Black|$FF000000)
      ;draw rotated text using a very small angle
      gDrawRotatedText(px, py + ty, text, 0.5, #Magenta|$FF000000) ; <== text has become skinnier?
    gStopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

Danilo · **Joined:** Sat Apr 26, 2003 8:26 am **Posts:** 1290

Try with bigger font on Windows:

Code:

Define sizeX = 1810, sizeY = 440, px = 2, py = 2

If Not LoadFont(0,"Courier New",110): End: EndIf
;If Not LoadFont(0,"Consolas",110): End: EndIf

If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And StartDrawing(ImageOutput(0))
      Box(0, 0, sizeX, sizeY, RGB(255, 255, 255))
      DrawingFont(FontID(0))  ;use TrueType font    
      Define text.s="X>>>  O  >>>X"
      
      Define tx = TextWidth(text)
      Define ty = TextHeight(text)

      ;draw standard text
      ;DrawingMode(#PB_2DDrawing_Transparent)
      DrawText(px,py,text)
      ;outline text with box to highlight dimensions (again)
      DrawingMode(#PB_2DDrawing_Outlined)
      Box(px, py, tx, ty, $FFFF00)
 
      ;draw rotated text with no rotation
      DrawRotatedText(px, py + ty, text, 0, #Black)
      ;draw rotated text using a very small angle
      DrawRotatedText(px, py + ty, text, -0.2, #Magenta) ; <== text has become skinnier?
    StopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

No #PB_Font_Bold flag.
-0.2 degree rotation only and it shows big offset in y-coordinate.
Maybe rotation origin is at -500,0?
Looks wrong, like another bug.

Puffolino · **Joined:** Thu Jan 05, 2012 12:27 am **Posts:** 45

Danilo wrote:

-0.2 degree rotation only and it shows big offset in y-coordinate.
Maybe rotation origin is at -500,0?
Looks wrong, like another bug.

The problem is seen here already when using 0.1 (independent if +0.1° or -0.1°, rotation angles between -0.099999 and +0.099999 will work because they get rounded to 0.0)

Danilo · **Joined:** Sat Apr 26, 2003 8:26 am **Posts:** 1290

Danilo wrote:

Try with bigger font on Windows:

Code:

Define sizeX = 1810, sizeY = 440, px = 2, py = 2

If Not LoadFont(0,"Courier New",110): End: EndIf
;If Not LoadFont(0,"Consolas",110): End: EndIf

If OpenWindow(0, 0, 0, sizeX, sizeY, "2DDrawing Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  If CreateImage(0, sizeX, sizeY) And StartDrawing(ImageOutput(0))
      Box(0, 0, sizeX, sizeY, RGB(255, 255, 255))
      DrawingFont(FontID(0))  ;use TrueType font    
      Define text.s="X>>>  O  >>>X"
      
      Define tx = TextWidth(text)
      Define ty = TextHeight(text)

      ;draw standard text
      ;DrawingMode(#PB_2DDrawing_Transparent)
      DrawText(px,py,text)
      ;outline text with box to highlight dimensions (again)
      DrawingMode(#PB_2DDrawing_Outlined)
      Box(px, py, tx, ty, $FFFF00)
 
      ;draw rotated text with no rotation
      DrawRotatedText(px, py + ty, text, 0, #Black)
      ;draw rotated text using a very small angle
      DrawRotatedText(px, py + ty, text, -0.2, #Magenta) ; <== text has become skinnier?
    StopDrawing()
    ImageGadget(0, 0, 0, sizeX, sizeY, ImageID(0))
  EndIf
  
  Define event
  Repeat
    event = WaitWindowEvent()
  Until event = #PB_Event_CloseWindow
EndIf

No #PB_Font_Bold flag.
-0.2 degree rotation only and it shows big offset in y-coordinate.
Maybe rotation origin is at -500,0?
Looks wrong, like another bug.

What do you think, freak?

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Possible bug, Rotated text changes sizes (width)

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