vector/vector_test.go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package vector

// TODO: add tests for NaN and Inf coordinates.

import (
	"image"
	"image/draw"
	"testing"

	"golang.org/x/image/math/f32"
)

func TestBasicPath(t *testing.T) {
	want := []byte{
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0xd4, 0xdd, 0xc5, 0xab, 0x63, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x9f, 0xff, 0xff, 0xff, 0xff, 0xfb, 0xb3, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x60, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf1, 0x5b, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5b, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf1, 0x20, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x9f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xb3, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x5f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfb, 0x12, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x63, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xab, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x9f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc5, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x5f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xdd, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf4, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	}

	z := NewRasterizer(16, 16)
	z.MoveTo(f32.Vec2{2, 2})
	z.QuadTo(f32.Vec2{14, 2}, f32.Vec2{14, 14})
	z.LineTo(f32.Vec2{5, 14})
	z.ClosePath()

	dst := image.NewAlpha(z.Bounds())
	z.DrawOp = draw.Src
	z.Draw(dst, dst.Bounds(), image.Opaque, image.Point{})

	got := dst.Pix
	if len(got) != len(want) {
		t.Fatalf("len(got)=%d and len(want)=%d differ", len(got), len(want))
	}
	for i := range got {
		delta := int(got[i]) - int(want[i])
		// The +/- 2 allows different implementations to give different
		// rounding errors.
		if delta < -2 || +2 < delta {
			t.Errorf("i=%d: got %#02x, want %#02x", i, got[i], want[i])
		}
	}
}