gg/cmd/test/camera.go

package main

import "surdeus.su/core/gg/ox"
import "surdeus.su/core/gg/mx"
import "surdeus.su/core/gg"

import "log"

var (
	camera *Camera
)

type Camera struct {
	ox.Camera
	ScaleSpeed mx.Float
	RotationSpeed mx.Float
}

func NewCamera() *Camera {
	camera := &Camera{}
	camera.Camera = ox.NewCamera()
	camera.ScaleSpeed = 5.
	camera.RotationSpeed = .3
	return camera
}

func (cam *Camera) OnUpdate(c gg.Context) {
	dt := c.Engine().DT().Seconds()
	mov := c.Events().Mouse.Move
	wheel := c.Events().Mouse.Wheel
	shiftPressed := c.Engine().IsPressed(gg.KeyShift)
	d := float64(1.)
	if shiftPressed {
		d *= -1
	}

	// Moving.
	if mov != nil && c.Engine().IsButtoned(
			gg.MouseButtonRight,
	) {
		cam.Move(mov.AbsDelta)
	}

	for _, btn := range c.Events().Mouse.Downs {
		switch btn.MouseButton {
		case gg.MouseButtonLeft :
			t := NewTri(ox.T().SetPosition(
				c.Engine().GetAbsCursorPosition(),
			))
			t.Spawned = true
			c.Engine().Spawn(t)
		}
	}


	// Scale.
	if wheel != nil {
		k := 1.5
		log.Println(wheel.Offset.Y)
		if wheel.Offset.Y < 0 {
			k = 1/k
		}

		cam.Scale(mx.V2(
			k,
			//wheel.Offset.Y * dt * cam.ScaleSpeed * 40,
		))
	}

	// Scale and rotation.
	for _, key := range c.Engine().GetKeyboardKeys() {
		switch key {
		case gg.KeyF:
			cam.AddScale(mx.VX(d*cam.ScaleSpeed * dt))
		case gg.KeyG:
			cam.AddScale(mx.VY(d*cam.ScaleSpeed * dt))
		case gg.KeyR:
			cam.Rotate(d*mx.Pi * cam.RotationSpeed * dt)
		}
	}
}