1 /*
2 * Copyright 2023 Google LLC
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 "include/core/SkBitmap.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkPathEffect.h"
11 #include "include/effects/SkDashPathEffect.h"
12 #include "include/gpu/ganesh/SkSurfaceGanesh.h"
13 #include "tests/Test.h"
14
15 // Draws a dashed circle with circumference 100, with an on-interval of 90 and an off-interval of
16 // 10, offset into the intervals by 25. This should draw a dash clockwise from 3:00 ending around
17 // 11:00, then the start of a second dash from 12:00 back to 3:00. In https://crbug.com/1495670, the
18 // math for intervals ending very near 2*pi introduced floating point error that prevented drawing
19 // the second dash.
DEF_GANESH_TEST_FOR_RENDERING_CONTEXTS(DashPathEffectTest_2PiInterval,reporter,contextInfo,CtsEnforcement::kApiLevel_V)20 DEF_GANESH_TEST_FOR_RENDERING_CONTEXTS(DashPathEffectTest_2PiInterval,
21 reporter,
22 contextInfo,
23 CtsEnforcement::kApiLevel_V) {
24 const float r = 50.0f / SK_ScalarPI;
25 const float centerX = ceilf(0.5f * r);
26 const float centerY = ceilf(r);
27 const float dashWidth = 10.0f;
28
29 SkImageInfo ii = SkImageInfo::Make(SkISize::Make(16, 16),
30 SkColorType::kRGBA_8888_SkColorType,
31 SkAlphaType::kPremul_SkAlphaType);
32 GrDirectContext* context = contextInfo.directContext();
33 sk_sp<SkSurface> surface = SkSurfaces::RenderTarget(context, skgpu::Budgeted::kYes, ii);
34 SkCanvas* canvas = surface->getCanvas();
35
36 SkPaint paint;
37 paint.setAntiAlias(true);
38 paint.setColor(SK_ColorRED);
39 paint.setStyle(SkPaint::kStroke_Style);
40 paint.setStrokeWidth(dashWidth);
41
42 constexpr float intervals[2] = {90.0f, 10.0f};
43 paint.setPathEffect(SkDashPathEffect::Make(intervals, 2, 25.0f));
44 canvas->drawCircle(centerX, centerY, r, paint);
45
46 // Check that we drew the second dash, which starts at the top of the circle.
47 SkBitmap bitmap;
48 SkPixmap pixmap;
49 bitmap.allocPixels(surface->imageInfo());
50 SkAssertResult(bitmap.peekPixels(&pixmap));
51 if (!surface->readPixels(pixmap, 0, 0)) {
52 ERRORF(reporter, "readPixels failed");
53 return;
54 }
55 SkColor topColor = pixmap.getColor(centerX + 1.0f, centerY - r);
56 REPORTER_ASSERT(reporter, topColor == SK_ColorRED);
57 }
58