Pixmap manipulation and code optimisation

BlitzMax Forums/BlitzMax Beginners Area/Pixmap manipulation and code optimisation

Grisu

(Posted 2006) [#1]

Hi!

I use this piece of code to read all image files in a loop.
Resize them down to ICONSIZE and create a iconstrip out of them all.

1.
Can I manipulate the shrinked pixmap?
I'd like to add a black 1 pixel border to the resized images. before I paste them to the imagestip itself.
In BP I simply would use the imagebuffer and draw the black border lines onto it. But with bmx and pixmaps I have no idea.

2.
Can this whole process be done faster. I don't need the globalpixmap or the other media in memory for later use.

The Iconsize is I use currently is 96 x 96 pixels.
The whole strip is 12.576+ x 96 pixels large!

 Global Fullpixmap:TPixmap=CreatePixmap(((MAXFOLGEN)*ICONSIZE),ICONSIZE,PF_BGR888,1) 

 For Local i=0 To MAXFOLGEN-1  
    Local tmppixmap:TPixMap=LoadPixmap("media/"+i+".jpg") ' Load media files 
    fullpixmap.paste(ResizePixmap(tmppixmap,ICONSIZE,ICONSIZE),i*ICONSIZE,0) 'and paste them to the global pixmap
 Next 
 
 ' Output 
 SavePixmapPNG(fullpixmap, "stripimg.png",9 )

FlameDuck

(Posted 2006) [#2]

Looks pretty good to me. You can use Readpixel and Writepixel to draw to Pixmaps.

Grisu

(Posted 2006) [#3]

Thanks for the hint!

I think using "Drawimagerect" would be faster than using paste?

ImaginaryHuman

(Posted 2006) [#4]

You can have a pixmap that is 2 pixels wider and taller than the source data, clear it to black, then paste your pixmaps to 1,1. Then paste that whole pixmap into your strip.

Grisu

(Posted 2006) [#5]

How do I clear a pixmap to full black please?

setcolor 0,0,0
cls pixmap :)

BlackSp1der

(Posted 2006) [#6]

full black?
with createpixmap

Pixmap:TPixmap=CreatePixmap(Pixmap.Width,Pixmap.Height,Pixmap.Format)

BlackSp1der

(Posted 2006) [#7]

and what you want to do?, add 1 pixel extra to the image? or cut 1 pixel?

anyway you can use pixmapwindow

resize image to 96x96 and cut 1 pixel of image

 For Local i=0 Until MAXFOLGEN
    Local tmppixmap:TPixMap=LoadPixmap("media/"+i+".jpg") ' Load media files 
    fullpixmap.paste(PixmapWindow(ResizePixmap(tmppixmap,ICONSIZE,ICONSIZE),1,1,ICONSIZE-2,ICONSIZE-2),1+i*ICONSIZE,1) 'and paste them to the global pixmap
 Next 
 
 ' Output 
 SavePixmapPNG(fullpixmap, "stripimg.png",9 )

resize image to 94x94 (1 pixel border)

    fullpixmap.paste(ResizePixmap(tmppixmap,ICONSIZE-2,ICONSIZE-2),1+i*ICONSIZE,1)

Grisu

(Posted 2006) [#8]

Thanks.

What is a 'virtual' window inside the pixmap?

ImaginaryHuman

(Posted 2006) [#9]

Normally a pixmap has its own memory buffer to store pixels, attached to the header information that describes the width, height, pitch etc.

An alternative is that you have this header information pointing to some other pre-existing block of memory, that is associated with some other pixmap. So the two pixmap headers sort of share the same pixmap pixels. Then using that `window within a pixmap`, you can just deal with what is within that window, like a clipped window, and ignore what's outside of it.

Grisu

(Posted 2006) [#10]

Ah, ok. Thank you again.
They should put such text into the docs... :)