gg/src/gx/camera.go

package gx

// Implements the camera component
// for the main window.
type Camera struct {
	Transform
}

// Returns the matrix satysfying camera
// position, scale and rotation to apply
// it to the objects to get the real
// transform to display on the screen.
// (Should implement buffering it so we do not
//  need to calculate it each time for each object. )
func (c *Camera)RealMatrix(
	e *Engine,
) Matrix {
	g := &Matrix{}

	g.Scale(
		c.S.X,
		c.S.Y,
	)

	g.Translate(
		-c.P.X,
		c.P.Y,
	)
	g.Rotate(-c.R)

	g.Translate(
		c.RA.X,
		-c.RA.Y,
	)

	return *g
}