aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/windowrectangles.cpp
blob: 5266df2e087c4294222892debfb7c38cbac40c78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm.h"
#include "SkClipStack.h"
#include "SkRRect.h"

#if SK_SUPPORT_GPU
#  include "GrAppliedClip.h"
#  include "GrDrawContext.h"
#  include "GrDrawContextPriv.h"
#  include "GrFixedClip.h"
#  include "GrReducedClip.h"
#  include "GrRenderTargetPriv.h"
#  include "GrResourceProvider.h"
#  include "effects/GrTextureDomain.h"
#endif

constexpr static SkIRect kDeviceRect = {0, 0, 600, 600};
constexpr static SkIRect kLayerRect = {25, 25, 575, 575};
constexpr static SkIRect kCoverRect = {50, 50, 550, 550};

namespace skiagm {

////////////////////////////////////////////////////////////////////////////////////////////////////

class WindowRectanglesBaseGM : public GM {
protected:
    virtual void onCoverClipStack(const SkClipStack&, SkCanvas*) = 0;

private:
    SkISize onISize() override { return SkISize::Make(kDeviceRect.width(), kDeviceRect.height()); }
    void onDraw(SkCanvas*) final;
};

void WindowRectanglesBaseGM::onDraw(SkCanvas* canvas) {
    sk_tool_utils::draw_checkerboard(canvas, 0xffffffff, 0xffc6c3c6, 25);
    canvas->saveLayer(SkRect::Make(kLayerRect), nullptr);

    SkClipStack stack;
    stack.clipRect(SkRect::MakeXYWH(370.75, 80.25, 149, 100), SkMatrix::I(),
                   SkCanvas::kDifference_Op, false);
    stack.clipRect(SkRect::MakeXYWH(80.25, 420.75, 150, 100), SkMatrix::I(),
                   SkCanvas::kDifference_Op, true);
    stack.clipRRect(SkRRect::MakeRectXY(SkRect::MakeXYWH(200, 200, 200, 200), 60, 45),
                    SkMatrix::I(), SkCanvas::kDifference_Op, true);

    SkRRect nine;
    nine.setNinePatch(SkRect::MakeXYWH(550 - 30.25 - 100, 370.75, 100, 150), 12, 35, 23, 20);
    stack.clipRRect(nine, SkMatrix::I(), SkCanvas::kDifference_Op, true);

    SkRRect complx;
    SkVector complxRadii[4] = {{6, 4}, {8, 12}, {16, 24}, {48, 32}};
    complx.setRectRadii(SkRect::MakeXYWH(80.25, 80.75, 100, 149), complxRadii);
    stack.clipRRect(complx, SkMatrix::I(), SkCanvas::kDifference_Op, false);

    this->onCoverClipStack(stack, canvas);

    canvas->restore();
}

////////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * Draws a clip that will exercise window rectangles if they are supported.
 */
class WindowRectanglesGM : public WindowRectanglesBaseGM {
private:
    SkString onShortName() final { return SkString("windowrectangles"); }
    void onCoverClipStack(const SkClipStack&, SkCanvas*) final;
};

/**
 * This is a simple helper class for resetting a canvas's clip to our test’s SkClipStack.
 */
class ReplayClipStackVisitor final : public SkCanvasClipVisitor {
public:
    typedef SkCanvas::ClipOp Op;
    ReplayClipStackVisitor(SkCanvas* canvas) : fCanvas(canvas) {}
    void clipRect(const SkRect& r, Op op, bool aa) override { fCanvas->clipRect(r, op, aa); }
    void clipRRect(const SkRRect& rr, Op op, bool aa) override { fCanvas->clipRRect(rr, op, aa); }
    void clipPath(const SkPath&, Op, bool) override { SkFAIL("Not implemented"); }
private:
    SkCanvas* const fCanvas;
};

void WindowRectanglesGM::onCoverClipStack(const SkClipStack& stack, SkCanvas* canvas) {
    SkPaint paint;
    paint.setColor(0xff00aa80);

    // Set up the canvas's clip to match our SkClipStack.
    ReplayClipStackVisitor visitor(canvas);
    SkClipStack::Iter iter(stack, SkClipStack::Iter::kBottom_IterStart);
    for (const SkClipStack::Element* element = iter.next(); element; element = iter.next()) {
        element->replay(&visitor);
    }

    canvas->drawRect(SkRect::Make(kCoverRect), paint);
}

DEF_GM( return new WindowRectanglesGM(); )

////////////////////////////////////////////////////////////////////////////////////////////////////

#if SK_SUPPORT_GPU

constexpr static int kNumWindows = 8;

/**
 * Visualizes the mask (alpha or stencil) for a clip with several window rectangles. The purpose of
 * this test is to verify that window rectangles are being used during clip mask generation, and to
 * visualize where the window rectangles are placed.
 *
 * We use window rectangles when generating the clip mask because there is no need to invest time
 * defining those regions where window rectangles will be in effect during the actual draw anyway.
 *
 * This test works by filling the entire clip mask with a small checkerboard pattern before drawing
 * it, and then covering the mask with a solid color once it has been generated. The regions inside
 * window rectangles or outside the scissor should still have the initial checkerboard intact.
 */
class WindowRectanglesMaskGM : public WindowRectanglesBaseGM {
private:
    constexpr static int kMaskCheckerSize = 5;
    SkString onShortName() final { return SkString("windowrectangles_mask"); }
    void onCoverClipStack(const SkClipStack&, SkCanvas*) final;
    void visualizeAlphaMask(GrContext*, GrDrawContext*, const GrReducedClip&, const GrPaint&);
    void visualizeStencilMask(GrContext*, GrDrawContext*, const GrReducedClip&, const GrPaint&);
    void stencilCheckerboard(GrDrawContext*, bool flip);
    void fail(SkCanvas*);
};

/**
 * Base class for GrClips that visualize a clip mask.
 */
class MaskOnlyClipBase : public GrClip {
private:
    bool quickContains(const SkRect&) const final { return false; }
    bool isRRect(const SkRect& rtBounds, SkRRect* rr, bool* aa) const final { return false; }
    void getConservativeBounds(int width, int height, SkIRect* rect, bool* iior) const final {
        rect->set(0, 0, width, height);
        if (iior) {
            *iior = false;
        }
    }
};

/**
 * This class clips a cover by an alpha mask. We use it to visualize the alpha clip mask.
 */
class AlphaOnlyClip final : public MaskOnlyClipBase {
public:
    AlphaOnlyClip(GrTexture* mask, int x, int y) {
        int w = mask->width(), h = mask->height();
        fFP = GrDeviceSpaceTextureDecalFragmentProcessor::Make(mask, SkIRect::MakeWH(w, h), {x, y});
    }
private:
    bool apply(GrContext*, GrDrawContext*, bool, bool, GrAppliedClip* out) const override {
        out->addCoverageFP(fFP);
        return true;
    }
    sk_sp<GrFragmentProcessor> fFP;
};

/**
 * This class clips a cover by the stencil clip bit. We use it to visualize the stencil mask.
 */
class StencilOnlyClip final : public MaskOnlyClipBase {
private:
    bool apply(GrContext*, GrDrawContext*, bool, bool, GrAppliedClip* out) const override {
        out->addStencilClip();
        return true;
    }
};

void WindowRectanglesMaskGM::onCoverClipStack(const SkClipStack& stack, SkCanvas* canvas) {
    GrContext* ctx = canvas->getGrContext();
    GrDrawContext* dc = canvas->internal_private_accessTopLayerDrawContext();

    if (!ctx || !dc ||
        dc->accessRenderTarget()->renderTargetPriv().maxWindowRectangles() < kNumWindows) {
        this->fail(canvas);
        return;
    }

    const GrReducedClip reducedClip(stack, SkRect::Make(kCoverRect), kNumWindows);

    GrPaint paint;
    paint.setAntiAlias(true);
    if (!dc->isStencilBufferMultisampled()) {
        paint.setColor4f(GrColor4f(0, 0.25f, 1, 1));
        this->visualizeAlphaMask(ctx, dc, reducedClip, paint);
    } else {
        paint.setColor4f(GrColor4f(1, 0.25f, 0.25f, 1));
        this->visualizeStencilMask(ctx, dc, reducedClip, paint);
    }
}

void WindowRectanglesMaskGM::visualizeAlphaMask(GrContext* ctx, GrDrawContext* dc,
                                                const GrReducedClip& reducedClip,
                                                const GrPaint& paint) {
    sk_sp<GrDrawContext> maskDC(
        ctx->makeDrawContextWithFallback(SkBackingFit::kExact, kLayerRect.width(),
                                         kLayerRect.height(), kAlpha_8_GrPixelConfig, nullptr));
    if (!maskDC ||
        !ctx->resourceProvider()->attachStencilAttachment(maskDC->accessRenderTarget())) {
        return;
    }

    // Draw a checker pattern into the alpha mask so we can visualize the regions left untouched by
    // the clip mask generation.
    this->stencilCheckerboard(maskDC.get(), true);
    maskDC->clear(nullptr, GrColorPackA4(0xff), true);
    maskDC->drawContextPriv().drawAndStencilRect(StencilOnlyClip(), &GrUserStencilSettings::kUnused,
                                                 SkRegion::kDifference_Op, false, false,
                                                 SkMatrix::I(),
                                                 SkRect::MakeIWH(maskDC->width(), maskDC->height()));
    reducedClip.drawAlphaClipMask(maskDC.get());
    sk_sp<GrTexture> mask(maskDC->asTexture());

    int x = kCoverRect.x() - kLayerRect.x(),
        y = kCoverRect.y() - kLayerRect.y();

    // Now visualize the alpha mask by drawing a rect over the area where it is defined. The regions
    // inside window rectangles or outside the scissor should still have the initial checkerboard
    // intact. (This verifies we didn't spend any time modifying those pixels in the mask.)
    AlphaOnlyClip clip(mask.get(), x, y);
    dc->drawRect(clip, paint, SkMatrix::I(),
                 SkRect::Make(SkIRect::MakeXYWH(x, y, mask->width(), mask->height())));
}

void WindowRectanglesMaskGM::visualizeStencilMask(GrContext* ctx, GrDrawContext* dc,
                                                  const GrReducedClip& reducedClip,
                                                  const GrPaint& paint) {
    if (!ctx->resourceProvider()->attachStencilAttachment(dc->accessRenderTarget())) {
        return;
    }

    // Draw a checker pattern into the stencil buffer so we can visualize the regions left untouched
    // by the clip mask generation.
    this->stencilCheckerboard(dc, false);
    reducedClip.drawStencilClipMask(ctx, dc, {kLayerRect.x(), kLayerRect.y()});

    // Now visualize the stencil mask by covering the entire render target. The regions inside
    // window rectangless or outside the scissor should still have the initial checkerboard intact.
    // (This verifies we didn't spend any time modifying those pixels in the mask.)
    dc->drawPaint(StencilOnlyClip(), paint, SkMatrix::I());
}

void WindowRectanglesMaskGM::stencilCheckerboard(GrDrawContext* dc, bool flip) {
    constexpr static GrUserStencilSettings kSetClip(
        GrUserStencilSettings::StaticInit<
        0,
        GrUserStencilTest::kAlways,
        0,
        GrUserStencilOp::kSetClipBit,
        GrUserStencilOp::kKeep,
        0>()
    );

    dc->drawContextPriv().clearStencilClip(GrFixedClip::Disabled(), false);

    for (int y = 0; y < kLayerRect.height(); y += kMaskCheckerSize) {
        for (int x = (y & 1) == flip ? 0 : kMaskCheckerSize;
             x < kLayerRect.width(); x += 2 * kMaskCheckerSize) {
            SkIRect checker = SkIRect::MakeXYWH(x, y, kMaskCheckerSize, kMaskCheckerSize);
            dc->drawContextPriv().stencilRect(GrNoClip(), &kSetClip, false, SkMatrix::I(),
                                              SkRect::Make(checker));
        }
    }
}

void WindowRectanglesMaskGM::fail(SkCanvas* canvas) {
    SkPaint paint;
    paint.setAntiAlias(true);
    paint.setTextAlign(SkPaint::kCenter_Align);
    paint.setTextSize(20);
    sk_tool_utils::set_portable_typeface(&paint);

    SkString errorMsg;
    errorMsg.printf("Requires GPU with %i window rectangles", kNumWindows);

    canvas->clipRect(SkRect::Make(kCoverRect));
    canvas->clear(SK_ColorWHITE);
    canvas->drawText(errorMsg.c_str(), errorMsg.size(), SkIntToScalar(kCoverRect.centerX()),
                     SkIntToScalar(kCoverRect.centerY() - 10), paint);
}

DEF_GM( return new WindowRectanglesMaskGM(); )

#endif

}