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-rw-r--r--src/image/draw/clip_test.go205
1 files changed, 205 insertions, 0 deletions
diff --git a/src/image/draw/clip_test.go b/src/image/draw/clip_test.go
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+++ b/src/image/draw/clip_test.go
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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),
+ },
+ {
+ "clip sr and mr",
+ image.Rect(0, 0, 100, 100),
+ image.Rect(0, 0, 100, 100),
+ image.Rect(23, 23, 55, 86),
+ image.Rect(44, 44, 87, 58),
+ image.Pt(10, 10),
+ image.Pt(11, 11),
+ false,
+ image.Rect(33, 33, 45, 47),
+ image.Pt(43, 43),
+ image.Pt(44, 44),
+ },
+}
+
+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)
+ r, sp, mp := c.r, c.sp, c.mp
+ if c.nilMask {
+ clip(dst, &r, src, &sp, nil, nil)
+ } else {
+ clip(dst, &r, src, &sp, mask0.SubImage(c.mr), &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 coordinate 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 coordinate 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 coordinate 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)
+ }
+ }
+ }
+}