ImageFont Glyph Positioning Problem

BlitzMax Forums/BlitzMax Beginners Area/ImageFont Glyph Positioning Problem

Firstdeathmaker

(Posted 2008) [#1]

Hi,

I´ve got a problem with TImageFont. I wrote a function that takes an image:TImage, a font:TImageFont and a given text:String and puts the text on the image. (It´s for variable ingame buttons). And because my image has also Alpha, I need to perform everything through Readpixel / Writepixel.

Currently I go into the ImageFont and take the different Glyphs as Images to render them on my button. But the positions of the Glyphs are wrong somehow.

Does anybody know how I get the offsets of the Glyphs?

My code:

Function RenderButton:TImage(button:TImage,font:TImageFont,text:String)
	SetImageFont font
	Local map:TPixmap = LockImage(button)
	
	Local textposx:Int = (button.width - TextWidth(text))/2
	Local textposy:Int = (button.height - TextHeight(text))/2
	Local x:Int
	
	For Local i:Int = 0 Until text.length
		Local n:Int = font.CharToGlyph(text[i])
		If n<0 Continue
		
		Local glyph:TImageGlyph=font.LoadGlyph(n)
		Local image:TImage=glyph._image
			
		If image
			Local frame:TImageFrame=image.Frame(0)
			If frame		
				'frame.Draw 0,0,image.width,image.height,x+tx,y+ty
				'Auf den eigendlichen Button rendern
				Local map2:TPixmap = LockImage(image,0,1,0)
				For Local x0:Int=0 Until image.width
				For Local x1:Int=0 Until image.height
				
					Local px0:Int = x0+x+textposx+glyph._x
					Local px1:Int = x1+textposy+glyph._y
					
					If px0>0 And px1>0 And px0<button.width And px1<button.height 'Secure against buffer overrun
						Local c1:Int = ReadPixel(map2,x0,x1)
						Local c2:Int = ReadPixel(map,px0,px1)
	
						Local a1:Int=c1 Shr 24
						Local rgb1:Long = (c1 Shl 8) Shr 8
						
						Local a2:Int=c2 Shr 24
						Local rgb2:Long= (c2 Shl 8) Shr 8
	
						Local r1:Int=((c1 Shl 8) Shr 8)/$10000
						Local g1:Int=((c1 Shl 16) Shr 16)/$100
						Local b1:Int=((c1 Shl 24) Shr 24)
			
						Local r2:Int=((c2 Shl 8) Shr 8)/$10000
						Local g2:Int=((c2 Shl 16) Shr 16)/$100
						Local b2:Int=((c2 Shl 24) Shr 24)
						
						Local r3:Int=((a1*r1) + (255-a1)*r2)/255
						Local g3:Int=((a1*g1) + (255-a1)*g2)/255
						Local b3:Int=((a1*b1) + (255-a1)*b2)/255
						
						Local c3:Int = a2*$1000000 + r3*$10000 + g3*$100 + b3
					
						WritePixel(map,px0,px1,c3)
					EndIf
				Next
				Next
				UnlockImage(image)
			EndIf
			x:+glyph.Advance()
		EndIf
	Next
	
	UnlockImage button
	Return button
End Function

thx

EDIT: Problem solved, code ^ is now working (if anybody needs)