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Diffstat (limited to 'src/image/draw/clip_test.go')
| -rw-r--r-- | src/image/draw/clip_test.go | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/image/draw/clip_test.go b/src/image/draw/clip_test.go new file mode 100644 index 000000000..65381f72f --- /dev/null +++ b/src/image/draw/clip_test.go @@ -0,0 +1,193 @@ +// 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) + } + } + } +} |