// 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) } } } }