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 (
        "bufio"
        "fmt"
        "image"
        "image/color"
        "io"
        "os"
        "strings"
        "testing"
)

var filenames = []string{
        "basn0g01",
        "basn0g01-30",
        "basn0g02",
        "basn0g02-29",
        "basn0g04",
        "basn0g04-31",
        "basn0g08",
        "basn0g16",
        "basn2c08",
        "basn2c16",
        "basn3p01",
        "basn3p02",
        "basn3p04",
        "basn3p08",
        "basn3p08-trns",
        "basn4a08",
        "basn4a16",
        "basn6a08",
        "basn6a16",
}

var filenamesShort = []string{
        "basn0g01",
        "basn0g04-31",
        "basn6a16",
}

func readPNG(filename string) (image.Image, error) {
        f, err := os.Open(filename)
        if err != nil {
                return nil, err
        }
        defer f.Close()
        return Decode(f)
}

// An approximation of the sng command-line tool.
func sng(w io.WriteCloser, filename string, png image.Image) {
        defer w.Close()
        bounds := png.Bounds()
        cm := png.ColorModel()
        var bitdepth int
        switch cm {
        case color.RGBAModel, color.NRGBAModel, color.AlphaModel, color.GrayModel:
                bitdepth = 8
        default:
                bitdepth = 16
        }
        cpm, _ := cm.(color.Palette)
        var paletted *image.Paletted
        if cpm != nil {
                switch {
                case len(cpm) <= 2:
                        bitdepth = 1
                case len(cpm) <= 4:
                        bitdepth = 2
                case len(cpm) <= 16:
                        bitdepth = 4
                default:
                        bitdepth = 8
                }
                paletted = png.(*image.Paletted)
        }

        // Write the filename and IHDR.
        io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
        fmt.Fprintf(w, "    width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
        switch {
        case cm == color.RGBAModel, cm == color.RGBA64Model:
                io.WriteString(w, "    using color;\n")
        case cm == color.NRGBAModel, cm == color.NRGBA64Model:
                io.WriteString(w, "    using color alpha;\n")
        case cm == color.GrayModel, cm == color.Gray16Model:
                io.WriteString(w, "    using grayscale;\n")
        case cpm != nil:
                io.WriteString(w, "    using color palette;\n")
        default:
                io.WriteString(w, "unknown PNG decoder color model\n")
        }
        io.WriteString(w, "}\n")

        // We fake a gAMA output. The test files have a gAMA chunk but the go PNG parser ignores it
        // (the PNG spec section 11.3 says "Ancillary chunks may be ignored by a decoder").
        io.WriteString(w, "gAMA {1.0000}\n")

        // Write the PLTE and tRNS (if applicable).
        if cpm != nil {
                lastAlpha := -1
                io.WriteString(w, "PLTE {\n")
                for i, c := range cpm {
                        r, g, b, a := c.RGBA()
                        if a != 0xffff {
                                lastAlpha = i
                        }
                        r >>= 8
                        g >>= 8
                        b >>= 8
                        fmt.Fprintf(w, "    (%3d,%3d,%3d)     # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
                }
                io.WriteString(w, "}\n")
                if lastAlpha != -1 {
                        io.WriteString(w, "tRNS {\n")
                        for i := 0; i <= lastAlpha; i++ {
                                _, _, _, a := cpm[i].RGBA()
                                a >>= 8
                                fmt.Fprintf(w, " %d", a)
                        }
                        io.WriteString(w, "}\n")
                }
        }

        // Write the IMAGE.
        io.WriteString(w, "IMAGE {\n    pixels hex\n")
        for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
                switch {
                case cm == color.GrayModel:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                gray := png.At(x, y).(color.Gray)
                                fmt.Fprintf(w, "%02x", gray.Y)
                        }
                case cm == color.Gray16Model:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                gray16 := png.At(x, y).(color.Gray16)
                                fmt.Fprintf(w, "%04x ", gray16.Y)
                        }
                case cm == color.RGBAModel:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                rgba := png.At(x, y).(color.RGBA)
                                fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
                        }
                case cm == color.RGBA64Model:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                rgba64 := png.At(x, y).(color.RGBA64)
                                fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
                        }
                case cm == color.NRGBAModel:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                nrgba := png.At(x, y).(color.NRGBA)
                                fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
                        }
                case cm == color.NRGBA64Model:
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                nrgba64 := png.At(x, y).(color.NRGBA64)
                                fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
                        }
                case cpm != nil:
                        var b, c int
                        for x := bounds.Min.X; x < bounds.Max.X; x++ {
                                b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
                                c++
                                if c == 8/bitdepth {
                                        fmt.Fprintf(w, "%02x", b)
                                        b = 0
                                        c = 0
                                }
                        }
                }
                io.WriteString(w, "\n")
        }
        io.WriteString(w, "}\n")
}

func TestReader(t *testing.T) {
        names := filenames
        if testing.Short() {
                names = filenamesShort
        }
        for _, fn := range names {
                // Read the .png file.
                img, err := readPNG("testdata/pngsuite/" + fn + ".png")
                if err != nil {
                        t.Error(fn, err)
                        continue
                }

                if fn == "basn4a16" {
                        // basn4a16.sng is gray + alpha but sng() will produce true color + alpha
                        // so we just check a single random pixel.
                        c := img.At(2, 1).(color.NRGBA64)
                        if c.R != 0x11a7 || c.G != 0x11a7 || c.B != 0x11a7 || c.A != 0x1085 {
                                t.Error(fn, fmt.Errorf("wrong pixel value at (2, 1): %x", c))
                        }
                        continue
                }

                piper, pipew := io.Pipe()
                pb := bufio.NewReader(piper)
                go sng(pipew, fn, img)
                defer piper.Close()

                // Read the .sng file.
                sf, err := os.Open("testdata/pngsuite/" + fn + ".sng")
                if err != nil {
                        t.Error(fn, err)
                        continue
                }
                defer sf.Close()
                sb := bufio.NewReader(sf)
                if err != nil {
                        t.Error(fn, err)
                        continue
                }

                // Compare the two, in SNG format, line by line.
                for {
                        ps, perr := pb.ReadString('\n')
                        ss, serr := sb.ReadString('\n')
                        if perr == io.EOF && serr == io.EOF {
                                break
                        }
                        if perr != nil {
                                t.Error(fn, perr)
                                break
                        }
                        if serr != nil {
                                t.Error(fn, serr)
                                break
                        }
                        if ps != ss {
                                t.Errorf("%s: Mismatch\n%sversus\n%s\n", fn, ps, ss)
                                break
                        }
                }
        }
}

var readerErrors = []struct {
        file string
        err  string
}{
        {"invalid-zlib.png", "zlib checksum error"},
        {"invalid-crc32.png", "invalid checksum"},
        {"invalid-noend.png", "unexpected EOF"},
        {"invalid-trunc.png", "unexpected EOF"},
}

func TestReaderError(t *testing.T) {
        for _, tt := range readerErrors {
                img, err := readPNG("testdata/" + tt.file)
                if err == nil {
                        t.Errorf("decoding %s: missing error", tt.file)
                        continue
                }
                if !strings.Contains(err.Error(), tt.err) {
                        t.Errorf("decoding %s: %s, want %s", tt.file, err, tt.err)
                }
                if img != nil {
                        t.Errorf("decoding %s: have image + error", tt.file)
                }
        }
}