gg/rect.go

package gg

import (
	//"github.com/hajimehoshi/ebiten/v2"
	//"github.com/hajimehoshi/ebiten/v2/vector"
	//"fmt"
	//"image"
)

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

// Return points of vertices of the rectangle.
func (r Rectangle) Vertices() Vertices {
	t := r.Transform
	wh := V(r.Width, r.Height)
	t.Around = t.Around.Scale(wh)
	m := t.Matrix()
	p1 := V(0, 0).Apply(m)
	p2 := V(wh.X, 0).Apply(m)
	p3 := V(wh.X, wh.Y).Apply(m)
	p4 := V(0, wh.Y).Apply(m)
	return Vertices{p1, p2, p3, p4}
}

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

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

// Check whether the rectangle contains the point.
func (r Rectangle) ContainedPoints(pts Points) (Points) {
	return r.MakeTriangles().ContainedPoints(pts)
}

// The type describes rectangle that can be drawn.
type DrawableRectangle struct {
	Rectangle
	ShaderOptions
	
	// Solid color of the rectangle.
	// Will be ignored if the Shader
	// field is not nil.
	Colority
}

func (r *DrawableRectangle) Draw(c *Context) []EVertex {
	return (&DrawableTriangles{
		Colority: r.Colority,
		Triangles: r.MakeTriangles(),
	}).MakeEVertices(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
}