package draw_test

import (
	"fmt"
	"image"
	"image/color"
	"image/draw"
	"math"
)

func ExampleDrawer_floydSteinberg() {
	const width = 130
	const height = 50

	im := image.NewGray(image.Rectangle{Max: image.Point{X: width, Y: height}})
	for x := 0; x < width; x++ {
		for y := 0; y < height; y++ {
			dist := math.Sqrt(math.Pow(float64(x-width/2), 2)/3+math.Pow(float64(y-height/2), 2)) / (height / 1.5) * 255

			if err != nil {
				t.Fatal(err)
			}
			err = diff(convertToNRGBA(m0), m1)
			if err != nil {
				t.Error(err)
			}
		})
	}
}

func BenchmarkEncodeGray(b *testing.B) {
	img := image.NewGray(image.Rect(0, 0, 640, 480))
	b.SetBytes(640 * 480 * 1)
	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		Encode(io.Discard, img)
	}
}

type pool struct {
	b *EncoderBuffer
}

					uint8(13 * x % 0x100),
					uint8(11 * y % 0x100),
					uint8((11*x + 13*y) % 0x100),
					uint8((31*x + 37*y) % 0x100),
				})
			}
		}
		src = src1
	case color.GrayModel:
		src1 := image.NewGray(image.Rect(0, 0, srcw, srch))
		for y := 0; y < srch; y++ {
			for x := 0; x < srcw; x++ {
				src1.SetGray(x, y, color.Gray{
					uint8((11*x + 13*y) % 0x100),
				})
			}
		}
		src = src1

			continue
		}
	}
}

// TestWriteGrayscale tests that a grayscale images survives a round-trip
// through encode/decode cycle.
func TestWriteGrayscale(t *testing.T) {
	m0 := image.NewGray(image.Rect(0, 0, 32, 32))
	for i := range m0.Pix {
		m0.Pix[i] = uint8(i)
	}
	var buf bytes.Buffer
	if err := Encode(&buf, m0, nil); err != nil {
		t.Fatal(err)
	}
	m1, err := Decode(&buf)