Interactive Bevel Sample App

samplecode/SampleBevel.cpp

+/*
+ * 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 "SampleCode.h"
+#include "SkCanvas.h"
+#include "SkLightingShader.h"
+#include "SkNormalSource.h"
+#include "sk_tool_utils.h"
+
+
+class BevelView : public SampleView {
+public:
+    BevelView()
+        : fShapeBounds(SkRect::MakeWH(kShapeBoundsSize, kShapeBoundsSize))
+        , fRedLight(SkLights::Light::MakeDirectional(SkColor3f::Make(0.6f, 0.45f, 0.3f),
+                                                     SkVector3::Make(0.0f, -5.0f, 1.0f)))
+        , fBlueLight(SkLights::Light::MakeDirectional(SkColor3f::Make(0.3f, 0.45f, 0.6f),
+                                                      SkVector3::Make(0.0f, 5.0f, 1.0f))) {
+        this->setBGColor(0xFF666868); // Slightly colorized gray for contrast
+
+        // Lights
+        SkLights::Builder builder;
+        builder.add(fRedLight);
+        builder.add(fBlueLight);
+        builder.add(SkLights::Light::MakeAmbient(SkColor3f::Make(0.4f, 0.4f, 0.4f)));
+        fLights = builder.finish();
+
+        // Controls
+
+        SkScalar currY = kSliderHeight;
+
+        const SkScalar kWidthCtrlInitialPos = 0.2f;
+        fCtrlRangeRects[0] = SkRect::MakeXYWH(0.0f, currY,
+                                              kCtrlRange + kSliderWidth,
+                                              kSliderHeight);

[robertphillips, 2016/08/17 21:52:13]

Well, since Greg sort of brought it up, would it make sense/be possible to have
the ctrl rect structure parallel the ctrl range rects (i.e., have an array of
them)? The ctrl selection code in the onClick handler could then loop over the
array, fSelectedCtrlRect could be an int and, ideally, the parameter extraction
could be standardized.

[dvonbeck, 2016/08/17 22:10:22]

I am actually working on this for my next CL. I am building a cleaner way of
handling controls through a polymorphic pass-through of clicks so that I can
share code between sliders and a directional control I am building for the
lights. I can upload it to this one if you think it's necessary.

[robertphillips, 2016/08/18 14:40:41]

Okay - let's leave it for the follow on.

[dvonbeck, 2016/08/18 15:12:14]

Acknowledged.

+        fWidthCtrlRect = SkRect::MakeXYWH(kWidthCtrlInitialPos * kCtrlRange, currY,
+                                          kSliderWidth, kSliderHeight);
+        fBevelWidth = kBevelWidthMax * kWidthCtrlInitialPos;
+        currY += 2 * kSliderHeight;
+
+        const SkScalar kHeightCtrlInitialPos = 0.75f;
+        fCtrlRangeRects[1] = SkRect::MakeXYWH(0.0f, currY,
+                                              kCtrlRange + kSliderWidth,
+                                              kSliderHeight);
+        fHeightCtrlRect = SkRect::MakeXYWH(kHeightCtrlInitialPos * kCtrlRange, currY,
+                                           kSliderWidth, kSliderHeight);
+        // Mapping from (0, 1) to (-1, 1)
+        fBevelHeight = kBevelHeightMax * (kHeightCtrlInitialPos * 2.0f - 1.0f);
+        currY += 2 * kSliderHeight;
+
+        const SkScalar kTypeCtrlInitialPos = 1.0f / (2.0f * kBevelTypeCount);
+        fCtrlRangeRects[2] = SkRect::MakeXYWH(0.0f, currY,
+                                              kCtrlRange + kSliderWidth,
+                                              kSliderHeight);
+        fTypeCtrlRect = SkRect::MakeXYWH(kTypeCtrlInitialPos * kCtrlRange, currY,
+                                         kSliderWidth, kSliderHeight);
+        fBevelType = (SkNormalSource::BevelType) SkScalarFloorToInt(kTypeCtrlInitialPos);
+        currY += 2 * kSliderHeight;
+
+        fSelectedCtrlRect = nullptr;
+    }
+
+protected:
+    bool onQuery(SkEvent *evt) override {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "bevel");

[egdaniel, 2016/08/18 14:33:28]

We genearaly name samples with a capital letter and gm's with a lower case. So
make this a 'B'

[dvonbeck, 2016/08/18 15:12:14]

Done.

+            return true;
+        }
+
+        return this->INHERITED::onQuery(evt);
+    }
+
+    enum Shape {
+        kCircle_Shape,
+        kRect_Shape,
+    };
+    void drawShape(enum Shape shape, SkCanvas* canvas) {
+        canvas->save();
+
+        SkPaint paint;
+

[robertphillips, 2016/08/18 14:40:41]

We should probably be caching this and only recreating it when the parameters
change.

[dvonbeck, 2016/08/18 15:12:13]

Done.

+        sk_sp<SkNormalSource> normalSource = SkNormalSource::MakeBevel(fBevelType, fBevelWidth,
+                                                                       fBevelHeight);
+
+        paint.setShader(SkLightingShader::Make(nullptr, std::move(normalSource), fLights));
+        paint.setAntiAlias(true);
+        paint.setColor(0xFFDDDDDD);
+        switch (shape) {
+            case kCircle_Shape:
+                canvas->drawCircle(fShapeBounds.centerX(), fShapeBounds.centerY(),
+                                   fShapeBounds.width()/2.0f, paint);
+                break;
+            case kRect_Shape:
+                canvas->drawRect(fShapeBounds, paint);
+                break;
+            default:
+                SkDEBUGFAIL("Invalid shape enum for drawShape");
+        }
+
+        canvas->restore();
+    }
+
+    void onDrawContent(SkCanvas *canvas) override {
+
+        canvas->save();
+        canvas->resetMatrix(); // Force static controls and labels
+
+        // Draw controls
+
+        SkPaint ctrlRectPaint;
+        ctrlRectPaint.setColor(0xFFF3F3F3);
+        canvas->drawRect(fWidthCtrlRect, ctrlRectPaint);
+        canvas->drawRect(fHeightCtrlRect, ctrlRectPaint);
+        canvas->drawRect(fTypeCtrlRect, ctrlRectPaint);
+
+        SkPaint ctrlRectRangePaint;
+        ctrlRectRangePaint.setColor(0xFFFFFFFF);
+        ctrlRectRangePaint.setStyle(SkPaint::kStroke_Style);
+        ctrlRectRangePaint.setStrokeWidth(2.0f);
+
+        for (size_t i = 0; i < kNumControls; i++) {
+            canvas->drawRect(fCtrlRangeRects[i], ctrlRectRangePaint);
+        }
+
+        // Draw labels
+        constexpr SkScalar kTextSize = 12.0f;
+        SkString widthLabel, heightLabel, typeLabel;
+        SkPaint labelPaint;

[robertphillips, 2016/08/18 14:40:41]

Can we cache off the typeface and reuse it ?

[dvonbeck, 2016/08/18 15:12:14]

Done.

+        labelPaint.setTypeface(sk_tool_utils::create_portable_typeface("sans-serif",
+                                                                       SkFontStyle()));
+        labelPaint.setAntiAlias(true);
+        labelPaint.setColor(0xFFFFFFFF);
+        labelPaint.setTextSize(kTextSize);
+
+        widthLabel.appendf("BevelWidth: %f", fBevelWidth);
+        heightLabel.appendf("BevelHeight: %f", fBevelHeight);
+        typeLabel.append("BevelType: ");
+
+        switch (fBevelType) {
+            case SkNormalSource::BevelType::kLinear:
+                typeLabel.append("Linear");
+                break;
+            case SkNormalSource::BevelType::kRoundedIn:
+                typeLabel.append("RoundedIn");
+                break;
+            case SkNormalSource::BevelType::kRoundedOut:
+                typeLabel.append("RoundedOut");
+                break;
+        }
+
+        canvas->drawText(widthLabel.c_str(), widthLabel.size(), 0,
+                         fWidthCtrlRect.fTop - kTextSize/2.0f, labelPaint);
+        canvas->drawText(heightLabel.c_str(), heightLabel.size(), 0,
+                         fHeightCtrlRect.fTop - kTextSize/2.0f, labelPaint);
+        canvas->drawText(typeLabel.c_str(), typeLabel.size(), 0,
+                         fTypeCtrlRect.fTop - kTextSize/2.0f, labelPaint);
+
+        canvas->restore(); // Return to modified matrix when drawing shapes
+
+        // Draw shapes
+        SkScalar xPos = kCtrlRange + 25.0f;
+        SkScalar yPos = fShapeBounds.height();
+        for (Shape shape : { kCircle_Shape, kRect_Shape }) {
+            canvas->save();
+            canvas->translate(xPos, yPos);
+            this->drawShape(shape, canvas);
+            canvas->restore();
+
+            xPos += 1.2f * fShapeBounds.width();
+        }
+    }
+
+    SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
+        return new SkView::Click(this);
+    }
+
+    bool onClick(Click *click) override {
+        SkScalar x = click->fCurr.fX;
+        SkScalar y = click->fCurr.fY;
+
+        SkScalar dx = x - click->fPrev.fX;
+        SkScalar dy = y - click->fPrev.fY;
+
+        // Control deselection
+        if (Click::State::kUp_State == click->fState) {
+            fSelectedCtrlRect = nullptr;
+            return true;
+        }
+
+        // Control selection
+        if (nullptr == fSelectedCtrlRect && Click::State::kDown_State == click->fState) {
+            if (fWidthCtrlRect.contains(SkRect::MakeXYWH(x, y, 1, 1))) {
+                fSelectedCtrlRect = &fWidthCtrlRect;
+            } else if (fHeightCtrlRect.contains(SkRect::MakeXYWH(x, y, 1, 1))) {
+                fSelectedCtrlRect = &fHeightCtrlRect;
+            } else if (fTypeCtrlRect.contains(SkRect::MakeXYWH(x, y, 1, 1))) {
+                fSelectedCtrlRect = &fTypeCtrlRect;
+            }
+        }
+
+        // Control modification
+        if (nullptr != fSelectedCtrlRect) {
+            fSelectedCtrlRect->offsetTo(SkScalarPin(x, 0.0f, kCtrlRange), fSelectedCtrlRect->fTop);
+
+            fBevelHeight = (fHeightCtrlRect.fLeft / kCtrlRange) * kBevelHeightMax * 2.0f
+                           - kBevelHeightMax;
+            fBevelWidth = (fWidthCtrlRect.fLeft / kCtrlRange) * kBevelWidthMax;
+            fBevelType = (SkNormalSource::BevelType)SkTMin(
+                    SkScalarFloorToInt(kBevelTypeCount * fTypeCtrlRect.fLeft / kCtrlRange),
+                    kBevelTypeCount - 1);
+
+            // Snap type controls to 3 positions
+            fTypeCtrlRect.offsetTo(kCtrlRange * ( ((int)fBevelType)/SkIntToScalar(kBevelTypeCount)
+                                                  + 1.0f/(2.0f * kBevelTypeCount) ),
+                                   fTypeCtrlRect.fTop);
+
+            // Ensuring width is non-zero
+            fBevelWidth = SkMaxScalar(1.0f, fBevelWidth);
+
+            this->inval(nullptr);
+            return true;
+        }

[robertphillips, 2016/08/18 14:40:41]

should there be and else here ?

[dvonbeck, 2016/08/18 15:12:14]

Done.

+
+        // Moving light
+        if (nullptr == fSelectedCtrlRect) {
+            if (dx != 0 || dy != 0) {
+                float recipX = 1.0f / kAppWidth;
+                float recipY = 1.0f / kAppHeight;
+
+                if (0 == click->fModifierKeys) { // No modifier
+                    fBlueLight = SkLights::Light::MakeDirectional(fBlueLight.color(),
+                            SkVector3::Make((kAppWidth/2.0f - x) * recipX * -3.0f,
+                                            (kAppHeight/2.0f - y) * recipY * -3.0f,
+                                            1.0f));
+                } else if (1 == click->fModifierKeys) { // Shift key
+                    fRedLight = SkLights::Light::MakeDirectional(fRedLight.color(),
+                            SkVector3::Make((kAppWidth/2.0f - x) * recipX * -3.0f,
+                                            (kAppHeight/2.0f - y) * recipY * -3.0f,
+                                            1.0f));
+                }
+
+                SkLights::Builder builder;
+                builder.add(fRedLight);
+                builder.add(fBlueLight);
+                builder.add(SkLights::Light::MakeAmbient(
+                        SkColor3f::Make(0.4f, 0.4f, 0.4f)));
+                fLights = builder.finish();
+
+                this->inval(nullptr);
+            }
+            return true;
+        }
+
+        return true;
+    }
+
+private:
+    static constexpr int kNumTestRects = 3;
+
+    static constexpr SkScalar kAppWidth = 400.0f;
+    static constexpr SkScalar kAppHeight = 400.0f;
+    static constexpr SkScalar kShapeBoundsSize = 120.0f;
+
+    static constexpr SkScalar kCtrlRange = 150.0f;
+    static constexpr SkScalar kBevelWidthMax = kShapeBoundsSize;
+    static constexpr SkScalar kBevelHeightMax = 50.0f;
+    static constexpr int      kBevelTypeCount = 3;
+
+    static constexpr SkScalar kSliderHeight = 20.0f;
+    static constexpr SkScalar kSliderWidth = 10.0f;
+
+    const SkRect fShapeBounds;
+
+    static constexpr int kNumControls = 3;
+    SkRect fCtrlRangeRects[kNumControls];
+    SkRect* fSelectedCtrlRect;
+    SkRect fWidthCtrlRect;
+    SkRect fHeightCtrlRect;
+    SkRect fTypeCtrlRect;
+
+    SkScalar fBevelWidth;
+    SkScalar fBevelHeight;
+    SkNormalSource::BevelType fBevelType;
+
+    sk_sp<SkLights> fLights;
+    SkLights::Light fRedLight;
+    SkLights::Light fBlueLight;
+
+    typedef SampleView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new BevelView; }
+static SkViewRegister reg(MyFactory);
+