- Coordinate Systems
- Transformation Types
- The <tt>Matrix</tt> Class and Transformation
- The <tt>Graphics</tt> Class and Transformation
- Global, Local, and Composite Transformations
- Image Transformation
- Color Transformation and the Color Matrix
- Matrix Operations in Image Processing
- Text Transformation
- The Significance of Transformation Order
- Summary
This chapter is from the book
This chapter is from the book
This chapter is from the book
In Chapter 5 we discussed how to use the ScaleTransform, RotateTransform, and TranslateTransform methods to transform text. We can also use a transformation matrix to transform text.
We create a Matrix object with the transformation properties and apply it to the surface using the Transform property of the Graphics object. Listing 10.21 creates a Matrix object and sets it as the Transform property. We then call DrawString, which draws the text on the form. To test this code, add the code to a form’s paint event handler.
Listing 10.21 Text transformation example
Graphics g = e.Graphics;
string str =
"Colors, fonts, and text are common" +
" elements of graphics programming." +
"In this chapter, you learned " +
" about the colors, fonts, and text" +
" representations in the "+
".NET Framework class library. "+
"You learned how to create "+
"these elements and use them in GDI+.";
// Create a Matrix object
Matrix M = new Matrix(1, 0, 0.5f, 1, 0, 0);
g.RotateTransform(45.0f,
System.Drawing.Drawing2D.MatrixOrder.Prepend);
g.TranslateTransform(-20, -70);
g.Transform = M;
g.DrawString(str,
new Font("Verdana", 10),
new SolidBrush(Color.Blue),
new Rectangle(50,20,200,300) );
Figure 10.30 shows the outcome of Listing 10.21.
)
Figure 10.30. Using the transformation matrix to transform text
We can apply shearing and other effects by changing the values of Matrix. For example, if we change Matrix as follows:
Matrix M = new Matrix(1, 0.5f, 0, 1, 0, 0);
the new code will generate Figure 10.31.
)
Figure 10.31. Using the transformation matrix to shear text
We can reverse the text just by changing the value of the Matrix object as follows:
Matrix M = new Matrix(1, 1, 1, -1, 0, 0);
with the results shown in Figure 10.32.
)
Figure 10.32. Using the transformation matrix to reverse text