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Thread: how to draw a image of size 600x400

  1. #1
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    Default how to draw a image of size 600x400

    hi,

    can anyone say me how to draw an image of size 600x400. i tried as follows
    Qt Code:
    1. QPainter p( this );
    2. uint x,y;
    3. x=550;
    4. y=500;
    5. QImage image(x,y,32 );
    6. image.setAlphaBuffer( true );
    7. for ( uint j =0; j <x; j++ )
    8. {
    9. for ( uint i =0; i <y; i++ )
    10. {
    11. QRgb pixel;
    12. pixel = qRgb(0,0,255);
    13. image.setPixel( i, j, pixel );
    14. }
    15. }
    16. p.drawImage(QPoint(0,0),image,0);
    To copy to clipboard, switch view to plain text mode 

    when i executed this it said the following error:
    "
    QImage::scanLine: Index 500 out of range
    Segmentation fault ".

    but i can succesfuly draw an image of size 500x500.
    can anyone say me why is that so ..

    thanks in advance,

    saravanan

  2. #2
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    Default Re: how to draw a image of size 600x400

    Hi,

    seems to that you have to swap i and j:
    Qt Code:
    1. image.setPixel( j, i, pixel );
    To copy to clipboard, switch view to plain text mode 

    Lykurg


    EDIT: or you must say j<y and i<x.

  3. #3
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    Default Re: how to draw a image of size 600x400

    hi,

    thank you for the reply.now i got it working.

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