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  • Your email address will not be published.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

  • Live Event Date: October 29, 2014 @ 11:00 a.m. ET / 8:00 a.m. PT Are you interested in building a cognitive application using the power of IBM Watson? Need a platform that provides speed and ease for rapidly deploying this application? Join Chris Madison, Watson Solution Architect, as he walks through the process of building a Watson powered application on IBM Bluemix. Chris will talk about the new Watson Services just released on IBM bluemix, but more importantly he will do a step by step cognitive …

  • Live Event Date: November 13, 2014 @ 2:00 p.m. ET / 11:00 a.m. PT APIs can be a great source of competitive advantage. The practice of exposing backend services as APIs has become pervasive, however their use varies widely across companies and industries. Some companies leverage APIs to create internal, operational and development efficiencies, while others use them to drive ancillary revenue channels. Many companies successfully support both public and private programs from the same API by varying levels …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds