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// Copyright 2014 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 portable
import (
"image"
"image/color"
"image/draw"
"image/png"
"math"
"os"
"runtime"
"testing"
"golang.org/x/mobile/event/size"
"golang.org/x/mobile/exp/f32"
"golang.org/x/mobile/geom"
)
func TestAffine(t *testing.T) {
if runtime.GOOS == "android" || runtime.GOOS == "ios" {
t.Skipf("testdata not available on %s", runtime.GOOS)
}
f, err := os.Open("../../../testdata/testpattern.png")
if err != nil {
t.Fatal(err)
}
defer f.Close()
srcOrig, _, err := image.Decode(f)
if err != nil {
t.Fatal(err)
}
src := image.NewRGBA(srcOrig.Bounds())
draw.Draw(src, src.Rect, srcOrig, srcOrig.Bounds().Min, draw.Src)
const (
pixW = 100
pixH = 100
ptW = geom.Pt(50)
ptH = geom.Pt(50)
)
sz := size.Event{
WidthPx: pixW,
HeightPx: pixH,
WidthPt: ptW,
HeightPt: ptH,
PixelsPerPt: float32(pixW) / float32(ptW),
}
got := image.NewRGBA(image.Rect(0, 0, pixW, pixH))
blue := image.NewUniform(color.RGBA{B: 0xff, A: 0xff})
draw.Draw(got, got.Bounds(), blue, image.Point{}, draw.Src)
b := src.Bounds()
b.Min.X += 10
b.Max.Y /= 2
var a f32.Affine
a.Identity()
a.Scale(&a, sz.PixelsPerPt, sz.PixelsPerPt)
a.Translate(&a, 0, 24)
a.Rotate(&a, float32(math.Asin(12./20)))
// See commentary in the render method defined in portable.go.
a.Scale(&a, 40/float32(b.Dx()), 20/float32(b.Dy()))
a.Inverse(&a)
affine(got, src, b, nil, &a, draw.Over)
ptTopLeft := geom.Point{0, 24}
ptBottomRight := geom.Point{12 + 32, 16}
drawCross(got, 0, 0)
drawCross(got, int(ptTopLeft.X.Px(sz.PixelsPerPt)), int(ptTopLeft.Y.Px(sz.PixelsPerPt)))
drawCross(got, int(ptBottomRight.X.Px(sz.PixelsPerPt)), int(ptBottomRight.Y.Px(sz.PixelsPerPt)))
drawCross(got, pixW-1, pixH-1)
const wantPath = "../../../testdata/testpattern-window.png"
f, err = os.Open(wantPath)
if err != nil {
t.Fatal(err)
}
defer f.Close()
wantSrc, _, err := image.Decode(f)
if err != nil {
t.Fatal(err)
}
want, ok := wantSrc.(*image.RGBA)
if !ok {
b := wantSrc.Bounds()
want = image.NewRGBA(b)
draw.Draw(want, b, wantSrc, b.Min, draw.Src)
}
if !imageEq(got, want) {
gotPath, err := writeTempPNG("testpattern-window-got", got)
if err != nil {
t.Fatal(err)
}
t.Errorf("got\n%s\nwant\n%s", gotPath, wantPath)
}
}
func TestAffineMask(t *testing.T) {
if runtime.GOOS == "android" || runtime.GOOS == "ios" {
t.Skipf("testdata not available on %s", runtime.GOOS)
}
f, err := os.Open("../../../testdata/testpattern.png")
if err != nil {
t.Fatal(err)
}
defer f.Close()
srcOrig, _, err := image.Decode(f)
if err != nil {
t.Fatal(err)
}
b := srcOrig.Bounds()
src := image.NewRGBA(b)
draw.Draw(src, src.Rect, srcOrig, b.Min, draw.Src)
mask := image.NewAlpha(b)
for y := b.Min.Y; y < b.Max.Y; y++ {
for x := b.Min.X; x < b.Max.X; x++ {
mask.Set(x, y, color.Alpha{A: uint8(x - b.Min.X)})
}
}
want := image.NewRGBA(b)
draw.DrawMask(want, want.Rect, src, b.Min, mask, b.Min, draw.Src)
a := new(f32.Affine)
a.Identity()
got := image.NewRGBA(b)
affine(got, src, b, mask, a, draw.Src)
if !imageEq(got, want) {
gotPath, err := writeTempPNG("testpattern-mask-got", got)
if err != nil {
t.Fatal(err)
}
wantPath, err := writeTempPNG("testpattern-mask-want", want)
if err != nil {
t.Fatal(err)
}
t.Errorf("got\n%s\nwant\n%s", gotPath, wantPath)
}
}
func writeTempPNG(prefix string, m image.Image) (string, error) {
f, err := os.CreateTemp("", prefix+"-")
if err != nil {
return "", err
}
f.Close()
path := f.Name() + ".png"
f, err = os.Create(path)
if err != nil {
return "", err
}
if err := png.Encode(f, m); err != nil {
f.Close()
return "", err
}
return path, f.Close()
}
func drawCross(m *image.RGBA, x, y int) {
c := color.RGBA{0xff, 0, 0, 0xff} // red
m.SetRGBA(x+0, y-2, c)
m.SetRGBA(x+0, y-1, c)
m.SetRGBA(x-2, y+0, c)
m.SetRGBA(x-1, y+0, c)
m.SetRGBA(x+0, y+0, c)
m.SetRGBA(x+1, y+0, c)
m.SetRGBA(x+2, y+0, c)
m.SetRGBA(x+0, y+1, c)
m.SetRGBA(x+0, y+2, c)
}
func eqEpsilon(x, y uint8) bool {
const epsilon = 9
return x-y < epsilon || y-x < epsilon
}
func colorEq(c0, c1 color.RGBA) bool {
return eqEpsilon(c0.R, c1.R) && eqEpsilon(c0.G, c1.G) && eqEpsilon(c0.B, c1.B) && eqEpsilon(c0.A, c1.A)
}
func imageEq(m0, m1 *image.RGBA) bool {
b0 := m0.Bounds()
b1 := m1.Bounds()
if b0 != b1 {
return false
}
badPx := 0
for y := b0.Min.Y; y < b0.Max.Y; y++ {
for x := b0.Min.X; x < b0.Max.X; x++ {
c0, c1 := m0.At(x, y).(color.RGBA), m1.At(x, y).(color.RGBA)
if !colorEq(c0, c1) {
badPx++
}
}
}
badFrac := float64(badPx) / float64(b0.Dx()*b0.Dy())
return badFrac < 0.01
}
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