1 /*
2  * Copyright 2011 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "SkCanvas.h"
9 #include "SkCubicClipper.h"
10 #include "SkGeometry.h"
11 #include "SkPaint.h"
12 #include "SkPath.h"
13 #include "Test.h"
14 
15 // Currently the supersampler blitter uses int16_t for its index into an array
16 // the width of the clip. Test that we don't crash/assert if we try to draw
17 // with a device/clip that is larger.
test_giantClip()18 static void test_giantClip() {
19     SkBitmap bm;
20     bm.allocN32Pixels(64919, 1);
21     SkCanvas canvas(bm);
22     canvas.clear(SK_ColorTRANSPARENT);
23 
24     SkPath path;
25     path.moveTo(0, 0); path.lineTo(1, 0); path.lineTo(33, 1);
26     SkPaint paint;
27     paint.setAntiAlias(true);
28     canvas.drawPath(path, paint);
29 }
30 
PrintCurve(const char * name,const SkPoint crv[4])31 static void PrintCurve(const char *name, const SkPoint crv[4]) {
32     SkDebugf("%s: %.10g, %.10g, %.10g, %.10g, %.10g, %.10g, %.10g, %.10g\n",
33             name,
34             (float)crv[0].fX, (float)crv[0].fY,
35             (float)crv[1].fX, (float)crv[1].fY,
36             (float)crv[2].fX, (float)crv[2].fY,
37             (float)crv[3].fX, (float)crv[3].fY);
38 
39 }
40 
41 
CurvesAreEqual(const SkPoint c0[4],const SkPoint c1[4],float tol)42 static bool CurvesAreEqual(const SkPoint c0[4],
43                            const SkPoint c1[4],
44                            float tol) {
45     for (int i = 0; i < 4; i++) {
46         if (SkScalarAbs(c0[i].fX - c1[i].fX) > tol ||
47             SkScalarAbs(c0[i].fY - c1[i].fY) > tol
48         ) {
49             PrintCurve("c0", c0);
50             PrintCurve("c1", c1);
51             return false;
52         }
53     }
54     return true;
55 }
56 
57 
SetCurve(float x0,float y0,float x1,float y1,float x2,float y2,float x3,float y3,SkPoint crv[4])58 static SkPoint* SetCurve(float x0, float y0,
59                          float x1, float y1,
60                          float x2, float y2,
61                          float x3, float y3,
62                          SkPoint crv[4]) {
63     crv[0].fX = x0;   crv[0].fY = y0;
64     crv[1].fX = x1;   crv[1].fY = y1;
65     crv[2].fX = x2;   crv[2].fY = y2;
66     crv[3].fX = x3;   crv[3].fY = y3;
67     return crv;
68 }
69 
70 
DEF_TEST(ClipCubic,reporter)71 DEF_TEST(ClipCubic, reporter) {
72     static SkPoint crv[4] = {
73         { SkIntToScalar(0), SkIntToScalar(0)  },
74         { SkIntToScalar(2), SkIntToScalar(3)  },
75         { SkIntToScalar(1), SkIntToScalar(10) },
76         { SkIntToScalar(4), SkIntToScalar(12) }
77     };
78 
79     SkCubicClipper clipper;
80     SkPoint clipped[4], shouldbe[4];
81     SkIRect clipRect;
82     bool success;
83     const float tol = 1e-4f;
84 
85     // Test no clip, with plenty of room.
86     clipRect.set(-2, -2, 6, 14);
87     clipper.setClip(clipRect);
88     success = clipper.clipCubic(crv, clipped);
89     REPORTER_ASSERT(reporter, success == true);
90     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
91         0, 0, 2, 3, 1, 10, 4, 12, shouldbe), tol));
92 
93     // Test no clip, touching first point.
94     clipRect.set(-2, 0, 6, 14);
95     clipper.setClip(clipRect);
96     success = clipper.clipCubic(crv, clipped);
97     REPORTER_ASSERT(reporter, success == true);
98     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
99         0, 0, 2, 3, 1, 10, 4, 12, shouldbe), tol));
100 
101     // Test no clip, touching last point.
102     clipRect.set(-2, -2, 6, 12);
103     clipper.setClip(clipRect);
104     success = clipper.clipCubic(crv, clipped);
105     REPORTER_ASSERT(reporter, success == true);
106     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
107         0, 0, 2, 3, 1, 10, 4, 12, shouldbe), tol));
108 
109     // Test all clip.
110     clipRect.set(-2, 14, 6, 20);
111     clipper.setClip(clipRect);
112     success = clipper.clipCubic(crv, clipped);
113     REPORTER_ASSERT(reporter, success == false);
114 
115     // Test clip at 1.
116     clipRect.set(-2, 1, 6, 14);
117     clipper.setClip(clipRect);
118     success = clipper.clipCubic(crv, clipped);
119     REPORTER_ASSERT(reporter, success == true);
120     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
121         0.5126125216f, 1,
122         1.841195941f,  4.337081432f,
123         1.297019958f,  10.19801331f,
124         4,            12,
125         shouldbe), tol));
126 
127     // Test clip at 2.
128     clipRect.set(-2, 2, 6, 14);
129     clipper.setClip(clipRect);
130     success = clipper.clipCubic(crv, clipped);
131     REPORTER_ASSERT(reporter, success == true);
132     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
133         00.8412352204f, 2,
134         1.767683744f,   5.400758266f,
135         1.55052948f,    10.36701965f,
136         4,             12,
137         shouldbe), tol));
138 
139     // Test clip at 11.
140     clipRect.set(-2, -2, 6, 11);
141     clipper.setClip(clipRect);
142     success = clipper.clipCubic(crv, clipped);
143     REPORTER_ASSERT(reporter, success == true);
144     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
145         0,           0,
146         1.742904663f, 2.614356995f,
147         1.207521796f, 8.266430855f,
148         3.026495695f, 11,
149         shouldbe), tol));
150 
151     // Test clip at 10.
152     clipRect.set(-2, -2, 6, 10);
153     clipper.setClip(clipRect);
154     success = clipper.clipCubic(crv, clipped);
155     REPORTER_ASSERT(reporter, success == true);
156     REPORTER_ASSERT(reporter, CurvesAreEqual(clipped, SetCurve(
157         0,           0,
158         1.551193237f, 2.326789856f,
159         1.297736168f, 7.059780121f,
160         2.505550385f, 10,
161         shouldbe), tol));
162 
163     test_giantClip();
164 }
165