351 lines
8.0 KiB
Go
351 lines
8.0 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package png
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import (
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"bufio"
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"fmt"
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"image"
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"image/color"
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"io"
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"io/ioutil"
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"os"
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"strings"
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"testing"
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)
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var filenames = []string{
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"basn0g01",
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"basn0g01-30",
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"basn0g02",
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"basn0g02-29",
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"basn0g04",
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"basn0g04-31",
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"basn0g08",
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"basn0g16",
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"basn2c08",
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"basn2c16",
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"basn3p01",
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"basn3p02",
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"basn3p04",
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"basn3p08",
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"basn3p08-trns",
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"basn4a08",
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"basn4a16",
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"basn6a08",
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"basn6a16",
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}
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var filenamesPaletted = []string{
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"basn3p01",
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"basn3p02",
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"basn3p04",
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"basn3p08",
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"basn3p08-trns",
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}
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var filenamesShort = []string{
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"basn0g01",
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"basn0g04-31",
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"basn6a16",
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}
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func readPNG(filename string) (image.Image, error) {
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f, err := os.Open(filename)
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if err != nil {
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return nil, err
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}
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defer f.Close()
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return Decode(f)
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}
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// An approximation of the sng command-line tool.
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func sng(w io.WriteCloser, filename string, png image.Image) {
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defer w.Close()
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bounds := png.Bounds()
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cm := png.ColorModel()
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var bitdepth int
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switch cm {
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case color.RGBAModel, color.NRGBAModel, color.AlphaModel, color.GrayModel:
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bitdepth = 8
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default:
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bitdepth = 16
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}
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cpm, _ := cm.(color.Palette)
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var paletted *image.Paletted
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if cpm != nil {
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switch {
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case len(cpm) <= 2:
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bitdepth = 1
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case len(cpm) <= 4:
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bitdepth = 2
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case len(cpm) <= 16:
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bitdepth = 4
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default:
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bitdepth = 8
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}
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paletted = png.(*image.Paletted)
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}
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// Write the filename and IHDR.
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io.WriteString(w, "#SNG: from "+filename+".png\nIHDR {\n")
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fmt.Fprintf(w, " width: %d; height: %d; bitdepth: %d;\n", bounds.Dx(), bounds.Dy(), bitdepth)
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switch {
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case cm == color.RGBAModel, cm == color.RGBA64Model:
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io.WriteString(w, " using color;\n")
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case cm == color.NRGBAModel, cm == color.NRGBA64Model:
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io.WriteString(w, " using color alpha;\n")
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case cm == color.GrayModel, cm == color.Gray16Model:
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io.WriteString(w, " using grayscale;\n")
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case cpm != nil:
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io.WriteString(w, " using color palette;\n")
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default:
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io.WriteString(w, "unknown PNG decoder color model\n")
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}
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io.WriteString(w, "}\n")
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// We fake a gAMA output. The test files have a gAMA chunk but the go PNG parser ignores it
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// (the PNG spec section 11.3 says "Ancillary chunks may be ignored by a decoder").
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io.WriteString(w, "gAMA {1.0000}\n")
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// Write the PLTE and tRNS (if applicable).
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if cpm != nil {
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lastAlpha := -1
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io.WriteString(w, "PLTE {\n")
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for i, c := range cpm {
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var r, g, b, a uint8
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switch c := c.(type) {
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case color.RGBA:
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r, g, b, a = c.R, c.G, c.B, 0xff
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case color.NRGBA:
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r, g, b, a = c.R, c.G, c.B, c.A
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default:
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panic("unknown palette color type")
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}
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if a != 0xff {
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lastAlpha = i
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}
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fmt.Fprintf(w, " (%3d,%3d,%3d) # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
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}
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io.WriteString(w, "}\n")
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if lastAlpha != -1 {
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io.WriteString(w, "tRNS {\n")
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for i := 0; i <= lastAlpha; i++ {
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_, _, _, a := cpm[i].RGBA()
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a >>= 8
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fmt.Fprintf(w, " %d", a)
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}
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io.WriteString(w, "}\n")
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}
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}
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// Write the IMAGE.
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io.WriteString(w, "IMAGE {\n pixels hex\n")
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for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
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switch {
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case cm == color.GrayModel:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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gray := png.At(x, y).(color.Gray)
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fmt.Fprintf(w, "%02x", gray.Y)
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}
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case cm == color.Gray16Model:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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gray16 := png.At(x, y).(color.Gray16)
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fmt.Fprintf(w, "%04x ", gray16.Y)
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}
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case cm == color.RGBAModel:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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rgba := png.At(x, y).(color.RGBA)
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fmt.Fprintf(w, "%02x%02x%02x ", rgba.R, rgba.G, rgba.B)
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}
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case cm == color.RGBA64Model:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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rgba64 := png.At(x, y).(color.RGBA64)
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fmt.Fprintf(w, "%04x%04x%04x ", rgba64.R, rgba64.G, rgba64.B)
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}
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case cm == color.NRGBAModel:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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nrgba := png.At(x, y).(color.NRGBA)
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fmt.Fprintf(w, "%02x%02x%02x%02x ", nrgba.R, nrgba.G, nrgba.B, nrgba.A)
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}
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case cm == color.NRGBA64Model:
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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nrgba64 := png.At(x, y).(color.NRGBA64)
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fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
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}
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case cpm != nil:
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var b, c int
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for x := bounds.Min.X; x < bounds.Max.X; x++ {
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b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
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c++
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if c == 8/bitdepth {
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fmt.Fprintf(w, "%02x", b)
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b = 0
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c = 0
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}
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}
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}
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io.WriteString(w, "\n")
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}
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io.WriteString(w, "}\n")
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}
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func TestReader(t *testing.T) {
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names := filenames
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if testing.Short() {
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names = filenamesShort
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}
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for _, fn := range names {
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// Read the .png file.
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img, err := readPNG("testdata/pngsuite/" + fn + ".png")
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if err != nil {
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t.Error(fn, err)
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continue
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}
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if fn == "basn4a16" {
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// basn4a16.sng is gray + alpha but sng() will produce true color + alpha
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// so we just check a single random pixel.
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c := img.At(2, 1).(color.NRGBA64)
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if c.R != 0x11a7 || c.G != 0x11a7 || c.B != 0x11a7 || c.A != 0x1085 {
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t.Error(fn, fmt.Errorf("wrong pixel value at (2, 1): %x", c))
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}
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continue
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}
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piper, pipew := io.Pipe()
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pb := bufio.NewScanner(piper)
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go sng(pipew, fn, img)
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defer piper.Close()
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// Read the .sng file.
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sf, err := os.Open("testdata/pngsuite/" + fn + ".sng")
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if err != nil {
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t.Error(fn, err)
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continue
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}
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defer sf.Close()
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sb := bufio.NewScanner(sf)
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if err != nil {
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t.Error(fn, err)
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continue
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}
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// Compare the two, in SNG format, line by line.
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for {
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pdone := pb.Scan()
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sdone := sb.Scan()
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if pdone && sdone {
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break
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}
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if pdone || sdone {
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t.Errorf("%s: Different sizes", fn)
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break
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}
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ps := pb.Text()
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ss := sb.Text()
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if ps != ss {
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t.Errorf("%s: Mismatch\n%sversus\n%s\n", fn, ps, ss)
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break
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}
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}
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if pb.Err() != nil {
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t.Error(fn, pb.Err())
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}
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if sb.Err() != nil {
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t.Error(fn, sb.Err())
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}
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}
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}
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var readerErrors = []struct {
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file string
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err string
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}{
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{"invalid-zlib.png", "zlib: invalid checksum"},
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{"invalid-crc32.png", "invalid checksum"},
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{"invalid-noend.png", "unexpected EOF"},
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{"invalid-trunc.png", "unexpected EOF"},
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}
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func TestReaderError(t *testing.T) {
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for _, tt := range readerErrors {
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img, err := readPNG("testdata/" + tt.file)
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if err == nil {
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t.Errorf("decoding %s: missing error", tt.file)
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continue
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}
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if !strings.Contains(err.Error(), tt.err) {
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t.Errorf("decoding %s: %s, want %s", tt.file, err, tt.err)
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}
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if img != nil {
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t.Errorf("decoding %s: have image + error", tt.file)
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}
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}
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}
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func TestPalettedDecodeConfig(t *testing.T) {
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for _, fn := range filenamesPaletted {
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f, err := os.Open("testdata/pngsuite/" + fn + ".png")
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if err != nil {
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t.Errorf("%s: open failed: %v", fn, err)
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continue
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}
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defer f.Close()
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cfg, err := DecodeConfig(f)
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if err != nil {
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t.Errorf("%s: %v", fn, err)
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continue
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}
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pal, ok := cfg.ColorModel.(color.Palette)
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if !ok {
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t.Errorf("%s: expected paletted color model", fn)
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continue
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}
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if pal == nil {
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t.Errorf("%s: palette not initialized", fn)
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continue
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}
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}
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}
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func benchmarkDecode(b *testing.B, filename string, bytesPerPixel int) {
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b.StopTimer()
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data, err := ioutil.ReadFile(filename)
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if err != nil {
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b.Fatal(err)
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}
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s := string(data)
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cfg, err := DecodeConfig(strings.NewReader(s))
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if err != nil {
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b.Fatal(err)
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}
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b.SetBytes(int64(cfg.Width * cfg.Height * bytesPerPixel))
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b.StartTimer()
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for i := 0; i < b.N; i++ {
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Decode(strings.NewReader(s))
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}
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}
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func BenchmarkDecodeGray(b *testing.B) {
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benchmarkDecode(b, "testdata/benchGray.png", 1)
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}
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func BenchmarkDecodeNRGBAGradient(b *testing.B) {
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benchmarkDecode(b, "testdata/benchNRGBA-gradient.png", 4)
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}
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func BenchmarkDecodeNRGBAOpaque(b *testing.B) {
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benchmarkDecode(b, "testdata/benchNRGBA-opaque.png", 4)
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}
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func BenchmarkDecodePaletted(b *testing.B) {
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benchmarkDecode(b, "testdata/benchPaletted.png", 1)
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}
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func BenchmarkDecodeRGB(b *testing.B) {
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benchmarkDecode(b, "testdata/benchRGB.png", 4)
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}
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