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 "SkBitmap.h"
9 #include "SkCanvas.h"
10 #include "SkPath.h"
11 #include "Test.h"
12
13 #define DIMENSION 32
14
drawAndTest(skiatest::Reporter * reporter,const SkPath & path,const SkPaint & paint,bool shouldDraw)15 static void drawAndTest(skiatest::Reporter* reporter, const SkPath& path,
16 const SkPaint& paint, bool shouldDraw) {
17 SkBitmap bm;
18 bm.allocN32Pixels(DIMENSION, DIMENSION);
19 SkASSERT(DIMENSION*4 == bm.rowBytes()); // ensure no padding on each row
20 bm.eraseColor(SK_ColorTRANSPARENT);
21
22 SkCanvas canvas(bm);
23 SkPaint p(paint);
24 p.setColor(SK_ColorWHITE);
25
26 canvas.drawPath(path, p);
27
28 size_t count = DIMENSION * DIMENSION;
29 const SkPMColor* ptr = bm.getAddr32(0, 0);
30
31 SkPMColor andValue = ~0U;
32 SkPMColor orValue = 0;
33 for (size_t i = 0; i < count; ++i) {
34 SkPMColor c = ptr[i];
35 andValue &= c;
36 orValue |= c;
37 }
38
39 // success means we drew everywhere or nowhere (depending on shouldDraw)
40 bool success = shouldDraw ? (~0U == andValue) : (0 == orValue);
41
42 if (!success) {
43 const char* str;
44 if (shouldDraw) {
45 str = "Path expected to draw everywhere, but didn't. ";
46 } else {
47 str = "Path expected to draw nowhere, but did. ";
48 }
49 ERRORF(reporter, "%s style[%d] cap[%d] join[%d] antialias[%d]"
50 " filltype[%d] ptcount[%d]", str, paint.getStyle(),
51 paint.getStrokeCap(), paint.getStrokeJoin(),
52 paint.isAntiAlias(), path.getFillType(), path.countPoints());
53 // uncomment this if you want to step in to see the failure
54 // canvas.drawPath(path, p);
55 }
56 }
57
58 enum DrawCaps {
59 kDontDrawCaps,
60 kDrawCaps
61 };
62
iter_paint(skiatest::Reporter * reporter,const SkPath & path,bool shouldDraw,DrawCaps drawCaps)63 static void iter_paint(skiatest::Reporter* reporter, const SkPath& path, bool shouldDraw,
64 DrawCaps drawCaps) {
65 static const SkPaint::Cap gCaps[] = {
66 SkPaint::kButt_Cap,
67 SkPaint::kRound_Cap,
68 SkPaint::kSquare_Cap
69 };
70 static const SkPaint::Join gJoins[] = {
71 SkPaint::kMiter_Join,
72 SkPaint::kRound_Join,
73 SkPaint::kBevel_Join
74 };
75 static const SkPaint::Style gStyles[] = {
76 SkPaint::kFill_Style,
77 SkPaint::kStroke_Style,
78 SkPaint::kStrokeAndFill_Style
79 };
80 for (size_t cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
81 for (size_t join = 0; join < SK_ARRAY_COUNT(gJoins); ++join) {
82 for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
83 if (drawCaps && SkPaint::kButt_Cap != gCaps[cap]
84 && SkPaint::kFill_Style != gStyles[style]) {
85 continue;
86 }
87
88 SkPaint paint;
89 paint.setStrokeWidth(SkIntToScalar(10));
90
91 paint.setStrokeCap(gCaps[cap]);
92 paint.setStrokeJoin(gJoins[join]);
93 paint.setStyle(gStyles[style]);
94
95 paint.setAntiAlias(false);
96 drawAndTest(reporter, path, paint, shouldDraw);
97 paint.setAntiAlias(true);
98 drawAndTest(reporter, path, paint, shouldDraw);
99 }
100 }
101 }
102 }
103
104 #define CX (SkIntToScalar(DIMENSION) / 2)
105 #define CY (SkIntToScalar(DIMENSION) / 2)
106
make_empty(SkPath *)107 static void make_empty(SkPath*) {}
make_M(SkPath * path)108 static void make_M(SkPath* path) { path->moveTo(CX, CY); }
make_MM(SkPath * path)109 static void make_MM(SkPath* path) { path->moveTo(CX, CY); path->moveTo(CX, CY); }
make_MZM(SkPath * path)110 static void make_MZM(SkPath* path) { path->moveTo(CX, CY); path->close(); path->moveTo(CX, CY); }
make_L(SkPath * path)111 static void make_L(SkPath* path) { path->moveTo(CX, CY); path->lineTo(CX, CY); }
make_Q(SkPath * path)112 static void make_Q(SkPath* path) { path->moveTo(CX, CY); path->quadTo(CX, CY, CX, CY); }
make_C(SkPath * path)113 static void make_C(SkPath* path) { path->moveTo(CX, CY); path->cubicTo(CX, CY, CX, CY, CX, CY); }
114
115 /* Two invariants are tested: How does an empty/degenerate path draw?
116 * - if the path is drawn inverse, it should draw everywhere
117 * - if the path is drawn non-inverse, it should draw nowhere
118 *
119 * Things to iterate on:
120 * - path (empty, degenerate line/quad/cubic w/ and w/o close
121 * - paint style
122 * - path filltype
123 * - path stroke variants (e.g. caps, joins, width)
124 */
test_emptydrawing(skiatest::Reporter * reporter)125 static void test_emptydrawing(skiatest::Reporter* reporter) {
126 static void (*gMakeProc[])(SkPath*) = {
127 make_empty, make_M, make_MM, make_MZM, make_L, make_Q, make_C
128 };
129 static SkPath::FillType gFills[] = {
130 SkPath::kWinding_FillType,
131 SkPath::kEvenOdd_FillType,
132 SkPath::kInverseWinding_FillType,
133 SkPath::kInverseEvenOdd_FillType
134 };
135 for (int doClose = 0; doClose < 2; ++doClose) {
136 for (size_t i = 0; i < SK_ARRAY_COUNT(gMakeProc); ++i) {
137 SkPath path;
138 gMakeProc[i](&path);
139 if (doClose) {
140 path.close();
141 }
142 /* zero length segments and close following moves draw round and square caps */
143 bool allowCaps = make_L == gMakeProc[i] || make_Q == gMakeProc[i]
144 || make_C == gMakeProc[i] || make_MZM == gMakeProc[i];
145 allowCaps |= SkToBool(doClose);
146 for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
147 path.setFillType(gFills[fill]);
148 bool shouldDraw = path.isInverseFillType();
149 iter_paint(reporter, path, shouldDraw, allowCaps ? kDrawCaps : kDontDrawCaps);
150 }
151 }
152 }
153 }
154
DEF_TEST(EmptyPath,reporter)155 DEF_TEST(EmptyPath, reporter) {
156 test_emptydrawing(reporter);
157 }
158