gg/ox/rect.go

package ox

import (
	//"github.com/hajimehoshi/ebiten/v2"
	//"github.com/hajimehoshi/ebiten/v2/vector"
	//"fmt"
	//"image"
)
import "surdeus.su/core/gg"
import "surdeus.su/core/gg/mx"

// The type describes rectangle geometry with
// way to move, rotate and scale it.
type Rectangle struct {
	ObjectImpl
	Transform
	Width, Height mx.Float
}

// Return points of vertices of the rectangle.
func (r Rectangle) Vertices() mx.Vectors {
	t := r.Transform
	wh := mx.Vector{r.Width, r.Height}
	t.SetAround(t.GetAround().Mul(wh))
	m := t.GetMatrice()
	p1 := mx.Vector{0, 0}.Apply(m)
	p2 := mx.Vector{wh.X, 0}.Apply(m)
	p3 := mx.Vector{wh.X, wh.Y}.Apply(m)
	p4 := mx.Vector{0, wh.Y}.Apply(m)
	return mx.Vectors{p1, p2, p3, p4}
}

func (r Rectangle) Edges() mx.Lines {
	vs := r.Vertices()
	return mx.Lines{
		mx.Line{vs[0], vs[1]},
		mx.Line{vs[1], vs[2]},
		mx.Line{vs[2], vs[3]},
		mx.Line{vs[3], vs[0]},
	}
}

// Get 2 triangles that the rectangle consists of.
func (r Rectangle) MakeTriangles() mx.Triangles {
	pts := r.Vertices()
	p1 := pts[0]
	p2 := pts[1]
	p3 := pts[2]
	p4 := pts[3]
	
	return mx.Triangles{
		mx.Triangle{p1, p2, p3},
		mx.Triangle{p1, p4, p3},
	}
}

// Check whether the rectangle contains the point.
func (r Rectangle) ContainsPoint(pt mx.Vector) bool {
	return r.MakeTriangles().ContainsPoint(pt)
}

// Get the points that are contained in the rectangle.
func (r Rectangle) GetContainedPoints(
	pts mx.Vectors,
) (mx.Vectors) {
	return r.MakeTriangles().GetContainedPoints(pts)
}

// The type describes rectangle that can be drawn.
type DrawableRectangle struct {
	Rectangle
	Drawity
}

func (r *DrawableRectangle) Draw(c gg.Context) *gg.Drawing {
	tri := &DrawableTriangles{}
	tri.Drawity = r.Drawity
	tri.Triangles = r.MakeTriangles()
	return tri.Draw(c)
	
	/*// Use the Color as base image if no is provided.
	//var did bool
	if r.Images[0] == nil {
		r.Images[0] = NewImage(1, 1)
		r.Images[0].Set(0, 0, r.Color)
	} 
	
	w, h := r.Images[0].Size()
	
	// Drawing with shader.
	c.DrawRectShader(w, h, r.Shader, &ebiten.DrawRectShaderOptions{
		GeoM: m,
		Images: r.Images,
		Uniforms: r.Uniforms,
	})*/
	return nil
}