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// Copyright 2011 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 draw
import (
"image"
"testing"
)
type clipTest struct {
desc string
r, dr, sr, mr image.Rectangle
sp, mp image.Point
nilMask bool
r0 image.Rectangle
sp0, mp0 image.Point
}
var clipTests = []clipTest{
// The following tests all have a nil mask.
{
"basic",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 100, 100),
image.ZR,
image.ZP,
image.ZP,
true,
image.Rect(0, 0, 100, 100),
image.ZP,
image.ZP,
},
{
"clip dr",
image.Rect(0, 0, 100, 100),
image.Rect(40, 40, 60, 60),
image.Rect(0, 0, 100, 100),
image.ZR,
image.ZP,
image.ZP,
true,
image.Rect(40, 40, 60, 60),
image.Pt(40, 40),
image.ZP,
},
{
"clip sr",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 100, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.ZP,
image.ZP,
true,
image.Rect(20, 20, 80, 80),
image.Pt(20, 20),
image.ZP,
},
{
"clip dr and sr",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.ZP,
image.ZP,
true,
image.Rect(20, 20, 50, 80),
image.Pt(20, 20),
image.ZP,
},
{
"clip dr and sr, sp outside sr (top-left)",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.Pt(15, 8),
image.ZP,
true,
image.Rect(5, 12, 50, 72),
image.Pt(20, 20),
image.ZP,
},
{
"clip dr and sr, sp outside sr (middle-left)",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.Pt(15, 66),
image.ZP,
true,
image.Rect(5, 0, 50, 14),
image.Pt(20, 66),
image.ZP,
},
{
"clip dr and sr, sp outside sr (bottom-left)",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.Pt(15, 91),
image.ZP,
true,
image.ZR,
image.Pt(15, 91),
image.ZP,
},
{
"clip dr and sr, sp inside sr",
image.Rect(0, 0, 100, 100),
image.Rect(0, 0, 50, 100),
image.Rect(20, 20, 80, 80),
image.ZR,
image.Pt(44, 33),
image.ZP,
true,
image.Rect(0, 0, 36, 47),
image.Pt(44, 33),
image.ZP,
},
// The following tests all have a non-nil mask.
{
"basic mask",
image.Rect(0, 0, 80, 80),
image.Rect(20, 0, 100, 80),
image.Rect(0, 0, 50, 49),
image.Rect(0, 0, 46, 47),
image.ZP,
image.ZP,
false,
image.Rect(20, 0, 46, 47),
image.Pt(20, 0),
image.Pt(20, 0),
},
// TODO(nigeltao): write more tests.
}
func TestClip(t *testing.T) {
dst0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
src0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
mask0 := image.NewRGBA(image.Rect(0, 0, 100, 100))
for _, c := range clipTests {
dst := dst0.SubImage(c.dr).(*image.RGBA)
src := src0.SubImage(c.sr).(*image.RGBA)
var mask image.Image
if !c.nilMask {
mask = mask0.SubImage(c.mr)
}
r, sp, mp := c.r, c.sp, c.mp
clip(dst, &r, src, &sp, mask, &mp)
// Check that the actual results equal the expected results.
if !c.r0.Eq(r) {
t.Errorf("%s: clip rectangle want %v got %v", c.desc, c.r0, r)
continue
}
if !c.sp0.Eq(sp) {
t.Errorf("%s: sp want %v got %v", c.desc, c.sp0, sp)
continue
}
if !c.nilMask {
if !c.mp0.Eq(mp) {
t.Errorf("%s: mp want %v got %v", c.desc, c.mp0, mp)
continue
}
}
// Check that the clipped rectangle is contained by the dst / src / mask
// rectangles, in their respective co-ordinate spaces.
if !r.In(c.dr) {
t.Errorf("%s: c.dr %v does not contain r %v", c.desc, c.dr, r)
}
// sr is r translated into src's co-ordinate space.
sr := r.Add(c.sp.Sub(c.dr.Min))
if !sr.In(c.sr) {
t.Errorf("%s: c.sr %v does not contain sr %v", c.desc, c.sr, sr)
}
if !c.nilMask {
// mr is r translated into mask's co-ordinate space.
mr := r.Add(c.mp.Sub(c.dr.Min))
if !mr.In(c.mr) {
t.Errorf("%s: c.mr %v does not contain mr %v", c.desc, c.mr, mr)
}
}
}
}
func TestClipWithNilMP(t *testing.T) {
src := image.NewRGBA(image.Rect(0, 0, 100, 100))
// dst must be smaller than src for clipping to occur
dst := image.NewRGBA(image.Rect(50, 50, 100, 100))
r := image.Rect(0, 0, 100, 100)
sp := image.ZP
// issue 9177: floydSteinberg.Draw passes nil for mp, which used to cause clip to panic
clip(dst, &r, src, &sp, nil, nil)
}