void Path(Painter& sw)
{
sw.Translate(52, 52);
for(int i = 0; i < 2; i++) {
sw.Rectangle(20, 20, 60, 60);
sw.Move(0, 0);
sw.Cubic(99, 0, 50, 50, 99, 99);
sw.Cubic(0, 99, 50, 50, 0, 0);
sw.EvenOdd(i).Fill(Green());
sw.Stroke(1, Black());
sw.Translate(120, 0);
}
}
void Div(Painter& sw)
{
sw.Character(100, 100, 'O', Arial(100))
.Character(100, 150, 'O', Arial(100))
.Fill(Black());
sw.Translate(200, 0);
sw.Character(100, 100, 'O', Arial(100))
.Div()
.Character(100, 150, 'O', Arial(100))
.Fill(Black());
}
void Paint(Painter& Painter, Portfolio& Portfolio)
{
/*For this example, we'll move the origin to the center to make things
a little easier to see. The most important thing to know is that by
default Belle uses the bottom-left corner of the canvas as the origin and
not the top-left corner (with reversed y) as many graphics libraries do.
While this is a bit unconventional, it allows for the x and y dimensions
to be treated the same and makes for clearer code.*/
Painter.Translate(Dimensions / 2.0);
//Draw a silhouette of the untransformed shape.
DrawShape(Painter, Colors::gray, Colors::lightgray);
//For each page show a different example of using affine transformations.
switch(Painter.GetPageNumber())
{
case 0: //Page 1
//Just show the gray coordinate axis...
break;
case 1: //Page 2
//Show a translation over 1.3 and up 1.8.
Painter.Translate(Vector(1.3, 1.8));
DrawShape(Painter);
Painter.Revert();
break;
case 2: //Page 3
//Show a rotation of 30 degrees.
Painter.Rotate(30.0 * Deg); /*(Deg is just a unit that converts degrees
to radians when multiplying and radians to degress when dividing).*/
DrawShape(Painter);
Painter.Revert();
break;
case 3: //Page 4
//Show a scaling of 1.5.
Painter.Scale(1.5);
DrawShape(Painter);
Painter.Revert();
break;
case 4: //Page 5
/*Scaling and translating is not the same as translating and scaling.
This is related to the fact that matrix multiplication is not generally
commutative.*/
Painter.Translate(Vector(1, 1)); //Translate-scale
Painter.Scale(2.0);
DrawShape(Painter, Colors::green);
Painter.Revert(2); /*(Revert defaults to undoing one transformation, but
you can specify any number of previous transformations to revert at
once.)*/
Painter.Scale(2.0); //Scale-translate
Painter.Translate(Vector(1, 1));
DrawShape(Painter, Colors::red);
Painter.Revert(2);
break;
case 5: //Page 6
/*For the same underlying reason, rotating and translating is not the
same as translating and rotating.*/
Painter.Translate(Vector(1, 1)); //Translate-rotate
Painter.Rotate(30.0 * Deg);
DrawShape(Painter, Colors::green);
Painter.Revert(2);
Painter.Rotate(30.0 * Deg); //Rotate-translate
Painter.Translate(Vector(1, 1));
DrawShape(Painter, Colors::red);
Painter.Revert(2);
break;
case 6: //Page 7
//However, scaling and rotation happen to be commutative.
Painter.Scale(2.0); //Scale-rotate
Painter.Rotate(30.0 * Deg);
DrawShape(Painter, Colors::green);
Painter.Revert(2);
Painter.Rotate(30.0 * Deg); //Rotate-scale
Painter.Scale(2.0);
DrawShape(Painter, Colors::green);
Painter.Revert(2);
break;
case 7: //Page 8
/*Occasionally, one may find a need to scale by different amounts in the
x- and y- dimensions. This is typically done to create a mirror image.*/
Painter.Scale(Vector(-1.0, 1.0)); //Horizontal mirror
DrawShape(Painter, Colors::lightgreen);
Painter.Revert();
DrawShape(Painter, Colors::green); //Original
break;
case 8: //Page 9
{
/*You can also create an affine transformation using the Affine object,
and call Transform with the object.
The TranslateScaleRotate method on Affine can be used to position an
object at a given size and angle. It is equivalent to multiplying by
a Translate, Scale, and Rotate in that order (though the scale and
rotation order could be flipped per the result shown on page 7).*/
Affine a = Affine::TranslateScaleRotate(Vector(1, 1), 2.0, 30.0 * Deg);
Painter.Transform(a);
DrawShape(Painter, Colors::green);
Painter.Revert();
Affine b = (Affine::Translate(Vector(1, 1)) * Affine::Scale(2.0)) *
Affine::Rotate(30.0 * Deg);
Painter.Transform(b);
DrawShape(Painter, Colors::green);
Painter.Revert();
Painter.Translate(Vector(1, 1));
Painter.Scale(2.0);
Painter.Rotate(30.0 * Deg);
DrawShape(Painter, Colors::green);
Painter.Revert(3);
}
break;
case 9: //Page 10
/*You can easily change units from the default inches to another unit.
The following creates a horizontal unit-sized vector in Centimeters and
converts that to Inches. The x-component is thus the relative scale.*/
Painter.Scale(Inches(Centimeters(1.0, 0.0)).x);
DrawShape(Painter);
Painter.Revert();
break;
}
Painter.Revert(); //Revert the page centering transformation.
}
