Fun with SetWorldTransform

Environment: VC6, MFC

This code will show you how useful SetWorldTransform can be. The code will enable you to do things such as:

  • Scale to 1/2 of the original size
  • Translate right by 3/4 inch
  • Rotate 30 degrees counterclockwise
  • Shear along the x-axis with a proportionality constant of 1.0
  • Reflect about a horizontal axis

The code was originally part of the MS SDK, but I have enhanced and converted it to MFC to make it easier to understand.

// The Key part to the source code is using 'SetWorldTransform'
// and setting up the XFORM structure

XFORM xForm;

SetGraphicsMode ( pDC->GetSafeHdc (), GM_ADVANCED );
pDC->SetMapMode ( MM_LOENGLISH );

xForm.eM11 = (FLOAT) 0.5;
xForm.eM12 = (FLOAT) 0.0;
xForm.eM21 = (FLOAT) 0.0;
xForm.eM22 = (FLOAT) 0.5;
xForm.eDx  = (FLOAT) 0.0;
xForm.eDy  = (FLOAT) 0.0;
SetWorldTransform ( pDC->GetSafeHdc (), &xForm );

Downloads

Download demo project - 8 Kb
Download source - 22 Kb


Comments

  • Doubt regarding combination of these operations.

    Posted by Legacy on 08/20/2003 12:00am

    Originally posted by: Chandra Prakash Joshi

    In ur example you have shown all the transform operation with respect to the original image. Suppose i want a rectangular(not square) image to rotate 90 degree than zoom 200% than reflect along x axis and than again rotate it -90 degree. and unfortunately i can't use array for storing the list of transformations done on my image. Any suggestion or idea will be of gr8 Help.. ThankU.

    Reply
  • WinNT only...

    Posted by Legacy on 08/14/2003 12:00am

    Originally posted by: Oliver

    Good demonstration of world transformation. Thank you!

    Maybe you should point out that this example code works on WinNT only since SetWorldTransform is unsupported on non-NT systems.
    The usefulness of a function set that does not work on all Win platforms is a point that should be discussed.

    Oliver.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Companies undertaking an IT project need to find the right balance between cost and functionality. It's important to start by determining whether to build a solution from scratch, buy an out-of-the-box solution, or a combination of both. In reality, most projects will require some system tailoring to meet business requirements. Decision-makers must understand how much software development is enough and craft a detailed implementation plan to ensure the project's success. This white paper examines the different …

  • According to technology research firm Gartner, cloud computing will become the bulk of new IT spend by 20161. By the end of 2017, Gartner predicts that nearly half of large enterprises will have hybrid cloud deployments1. Learn how you can use these trends to your advantage by offering cloud and hybrid data solutions to your customers.

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date