1 /*
2 * Copyright 2020 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 "gm/gm.h"
9 #include "include/core/SkCanvas.h"
10 #include "include/core/SkPath.h"
11 #include "include/core/SkPoint.h"
12 #include "include/gpu/GrContextOptions.h"
13 #include "include/gpu/GrDirectContext.h"
14 #include "include/utils/SkRandom.h"
15 #include "src/gpu/GrCaps.h"
16 #include "src/gpu/GrDirectContextPriv.h"
17 #include "src/gpu/GrDrawingManager.h"
18 #include "src/gpu/GrRecordingContextPriv.h"
19 #include "src/gpu/ops/TessellationPathRenderer.h"
20
21 static constexpr float kStrokeWidth = 100;
22 static constexpr int kTestWidth = 120 * 4;
23 static constexpr int kTestHeight = 120 * 3 + 140;
24
draw_strokes(SkCanvas * canvas,SkRandom * rand,const SkPath & path,const SkPath & cubic)25 static void draw_strokes(SkCanvas* canvas, SkRandom* rand, const SkPath& path,
26 const SkPath& cubic) {
27 SkPaint strokePaint;
28 strokePaint.setAntiAlias(true);
29 strokePaint.setStrokeWidth(kStrokeWidth);
30 strokePaint.setStyle(SkPaint::kStroke_Style);
31
32 SkAutoCanvasRestore arc(canvas, true);
33 strokePaint.setStrokeJoin(SkPaint::kBevel_Join);
34 strokePaint.setColor(rand->nextU() | 0xff808080);
35 canvas->drawPath(path, strokePaint);
36
37 canvas->translate(120, 0);
38 strokePaint.setStrokeJoin(SkPaint::kRound_Join);
39 strokePaint.setColor(rand->nextU() | 0xff808080);
40 canvas->drawPath(path, strokePaint);
41
42 canvas->translate(120, 0);
43 strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
44 strokePaint.setColor(rand->nextU() | 0xff808080);
45 canvas->drawPath(path, strokePaint);
46
47 canvas->translate(120, 0);
48 strokePaint.setColor(rand->nextU() | 0xff808080);
49 canvas->drawPath(cubic, strokePaint);
50 }
51
draw_test(SkCanvas * canvas)52 static void draw_test(SkCanvas* canvas) {
53 SkRandom rand;
54
55 if (canvas->recordingContext() &&
56 canvas->recordingContext()->priv().caps()->shaderCaps()->tessellationSupport() &&
57 canvas->recordingContext()->priv().caps()->shaderCaps()->maxTessellationSegments() == 5) {
58 // The caller successfully overrode the max tessellation segments to 5. Indicate this in the
59 // background color.
60 canvas->clear(SkColorSetARGB(255, 64, 0, 0));
61 } else {
62 canvas->clear(SK_ColorBLACK);
63 }
64
65 SkAutoCanvasRestore arc(canvas, true);
66 canvas->translate(60, 60);
67
68 draw_strokes(canvas, &rand,
69 SkPath().lineTo(10,0).lineTo(10,10),
70 SkPath().cubicTo(10,0, 10,0, 10,10));
71 canvas->translate(0, 120);
72
73 draw_strokes(canvas, &rand,
74 SkPath().lineTo(0,-10).lineTo(0,10),
75 SkPath().cubicTo(0,-10, 0,-10, 0,10));
76 canvas->translate(0, 120);
77
78 draw_strokes(canvas, &rand,
79 SkPath().lineTo(0,-10).lineTo(10,-10).lineTo(10,10).lineTo(0,10),
80 SkPath().cubicTo(0,-10, 10,10, 0,10));
81 canvas->translate(0, 140);
82
83 draw_strokes(canvas, &rand,
84 SkPath().lineTo(0,-10).lineTo(10,-10).lineTo(10,0).lineTo(0,0),
85 SkPath().cubicTo(0,-10, 10,0, 0,0));
86 canvas->translate(0, 120);
87 }
88
DEF_SIMPLE_GM(widebuttcaps,canvas,kTestWidth,kTestHeight)89 DEF_SIMPLE_GM(widebuttcaps, canvas, kTestWidth, kTestHeight) {
90 canvas->clear(SK_ColorBLACK);
91 draw_test(canvas);
92 }
93
94 class WideButtCaps_tess_segs_5 : public skiagm::GM {
onShortName()95 SkString onShortName() override {
96 return SkString("widebuttcaps_tess_segs_5");
97 }
98
onISize()99 SkISize onISize() override {
100 return SkISize::Make(kTestWidth, kTestHeight);
101 }
102
103 // Pick a very small, odd (and better yet, prime) number of segments.
104 //
105 // - Odd because it makes the tessellation strip asymmetric, which will be important to test for
106 // future plans that involve drawing in reverse order.
107 //
108 // - >=4 because the tessellator code will just assume we have enough to combine a miter join
109 // and line in a single patch. (Requires 4 segments. Spec required minimum is 64.)
110 inline static constexpr int kMaxTessellationSegmentsOverride = 5;
111
modifyGrContextOptions(GrContextOptions * options)112 void modifyGrContextOptions(GrContextOptions* options) override {
113 options->fMaxTessellationSegmentsOverride = kMaxTessellationSegmentsOverride;
114 options->fAlwaysPreferHardwareTessellation = true;
115 // Only allow the tessellation path renderer.
116 options->fGpuPathRenderers = (GpuPathRenderers)((int)options->fGpuPathRenderers &
117 (int)GpuPathRenderers::kTessellation);
118 }
119
onDraw(SkCanvas * canvas,SkString * errorMsg)120 DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override {
121 auto dContext = GrAsDirectContext(canvas->recordingContext());
122 if (!dContext) {
123 *errorMsg = "GM relies on having access to a live direct context.";
124 return DrawResult::kSkip;
125 }
126
127 if (!dContext->priv().caps()->shaderCaps()->tessellationSupport() ||
128 !skgpu::v1::TessellationPathRenderer::IsSupported(*dContext->priv().caps())) {
129 errorMsg->set("Tessellation not supported.");
130 return DrawResult::kSkip;
131 }
132 auto opts = dContext->priv().drawingManager()->testingOnly_getOptionsForPathRendererChain();
133 if (!(opts.fGpuPathRenderers & GpuPathRenderers::kTessellation)) {
134 errorMsg->set("TessellationPathRenderer disabled.");
135 return DrawResult::kSkip;
136 }
137 if (dContext->priv().caps()->shaderCaps()->maxTessellationSegments() !=
138 kMaxTessellationSegmentsOverride) {
139 errorMsg->set("modifyGrContextOptions() did not limit maxTessellationSegments. "
140 "(Are you running viewer? If so use '--maxTessellationSegments 5'.)");
141 return DrawResult::kFail;
142 }
143 // Suppress a tessellator warning message that caps.maxTessellationSegments is too small.
144 GrRecordingContextPriv::AutoSuppressWarningMessages aswm(dContext);
145 draw_test(canvas);
146 return DrawResult::kOk;
147 }
148 };
149
150 DEF_GM( return new WideButtCaps_tess_segs_5; )
151