Subversion Repositories openrisc

// Copyright 2009 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 png

import (
        "bytes"
        "fmt"
        "image"
        "image/color"
        "io/ioutil"
        "testing"
)

func diff(m0, m1 image.Image) error {
        b0, b1 := m0.Bounds(), m1.Bounds()
        if !b0.Size().Eq(b1.Size()) {
                return fmt.Errorf("dimensions differ: %v vs %v", b0, b1)
        }
        dx := b1.Min.X - b0.Min.X
        dy := b1.Min.Y - b0.Min.Y
        for y := b0.Min.Y; y < b0.Max.Y; y++ {
                for x := b0.Min.X; x < b0.Max.X; x++ {
                        c0 := m0.At(x, y)
                        c1 := m1.At(x+dx, y+dy)
                        r0, g0, b0, a0 := c0.RGBA()
                        r1, g1, b1, a1 := c1.RGBA()
                        if r0 != r1 || g0 != g1 || b0 != b1 || a0 != a1 {
                                return fmt.Errorf("colors differ at (%d, %d): %v vs %v", x, y, c0, c1)
                        }
                }
        }
        return nil
}

func encodeDecode(m image.Image) (image.Image, error) {
        var b bytes.Buffer
        err := Encode(&b, m)
        if err != nil {
                return nil, err
        }
        m, err = Decode(&b)
        if err != nil {
                return nil, err
        }
        return m, nil
}

func TestWriter(t *testing.T) {
        // The filenames variable is declared in reader_test.go.
        names := filenames
        if testing.Short() {
                names = filenamesShort
        }
        for _, fn := range names {
                qfn := "testdata/pngsuite/" + fn + ".png"
                // Read the image.
                m0, err := readPNG(qfn)
                if err != nil {
                        t.Error(fn, err)
                        continue
                }
                // Read the image again, encode it, and decode it.
                m1, err := readPNG(qfn)
                if err != nil {
                        t.Error(fn, err)
                        return
                }
                m2, err := encodeDecode(m1)
                if err != nil {
                        t.Error(fn, err)
                        return
                }
                // Compare the two.
                err = diff(m0, m2)
                if err != nil {
                        t.Error(fn, err)
                        continue
                }
        }
}

func TestSubImage(t *testing.T) {
        m0 := image.NewRGBA(image.Rect(0, 0, 256, 256))
        for y := 0; y < 256; y++ {
                for x := 0; x < 256; x++ {
                        m0.Set(x, y, color.RGBA{uint8(x), uint8(y), 0, 255})
                }
        }
        m0 = m0.SubImage(image.Rect(50, 30, 250, 130)).(*image.RGBA)
        m1, err := encodeDecode(m0)
        if err != nil {
                t.Error(err)
                return
        }
        err = diff(m0, m1)
        if err != nil {
                t.Error(err)
                return
        }
}

func BenchmarkEncodePaletted(b *testing.B) {
        b.StopTimer()
        img := image.NewPaletted(image.Rect(0, 0, 640, 480), color.Palette{
                color.RGBA{0, 0, 0, 255},
                color.RGBA{255, 255, 255, 255},
        })
        b.SetBytes(640 * 480 * 1)
        b.StartTimer()
        for i := 0; i < b.N; i++ {
                Encode(ioutil.Discard, img)
        }
}

func BenchmarkEncodeRGBOpaque(b *testing.B) {
        b.StopTimer()
        img := image.NewRGBA(image.Rect(0, 0, 640, 480))
        // Set all pixels to 0xFF alpha to force opaque mode.
        bo := img.Bounds()
        for y := bo.Min.Y; y < bo.Max.Y; y++ {
                for x := bo.Min.X; x < bo.Max.X; x++ {
                        img.Set(x, y, color.RGBA{0, 0, 0, 255})
                }
        }
        if !img.Opaque() {
                b.Fatal("expected image to be opaque")
        }
        b.SetBytes(640 * 480 * 4)
        b.StartTimer()
        for i := 0; i < b.N; i++ {
                Encode(ioutil.Discard, img)
        }
}

func BenchmarkEncodeRGBA(b *testing.B) {
        b.StopTimer()
        img := image.NewRGBA(image.Rect(0, 0, 640, 480))
        if img.Opaque() {
                b.Fatal("expected image to not be opaque")
        }
        b.SetBytes(640 * 480 * 4)
        b.StartTimer()
        for i := 0; i < b.N; i++ {
                Encode(ioutil.Discard, img)
        }
}