add GM case nonclosedpaths

gm/nonclosepaths.cpp

+/*
+ * Copyright 2013 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 "SkCanvas.h"
+#include "SkPath.h"
+
+namespace skiagm {
+

[robertphillips, 2013/11/08 14:18:50]

// This GM tests ...

+class NonClosePathsGM: public GM {
+public:
+    NonClosePathsGM() {}
+

[robertphillips, 2013/11/08 14:18:50]

Maybe make this ClosureType rather than NonCloseType?

+    enum NonCloseType {
+        TotalNonClose,    // The last point doesn't coincide with the first one in the contour.
+                          // The path looks not closed at all.
+

[robertphillips, 2013/11/08 14:18:50]

coincide -> coincides

+        FakeCloseCorner,  // The last point coincide with the first one at a corner.
+                          // The path looks like closed, but final rendering has 2 ends with cap.
+

[robertphillips, 2013/11/08 14:18:50]

coincide -> coincides

+        FakeCloseMiddle,  // The last point coincide with the first one in the middle of a line.

[robertphillips, 2013/11/08 14:18:50]

// The path looks closed, and the final rendering looks closed too. 
(i.e., remove the extra like)

+                          // The path looks like closed, and the final rendering looks closed too.
+
+        kNonCloseTypeCount
+    };
+
+protected:

[robertphillips, 2013/11/08 14:18:50]

SK_OVERRIDE

+    virtual SkString onShortName() {

[robertphillips, 2013/11/08 14:18:50]

nonclosedpaths (i.e., add 'd')

+        return SkString("nonclosepaths");
+    }
+

[robertphillips, 2013/11/08 14:18:50]

SK_OVERRIDE

+    virtual SkISize onISize() {

[robertphillips, 2013/11/08 14:18:50]

Does it need to be this big?

[yunchao, 2013/11/08 15:56:21]

Yeah, there are 12 * 18 + 3 cases, very one is 100 * 100 pixels. From
viewer.html for the output of skpdiff, the layout of nonclosedpaths is not bad.

+        return SkISize::Make(1220, 1920);
+    }
+

[robertphillips, 2013/11/08 14:18:50]

non-close path -> non-closed paths
for right angle is easier -> right angles make it easier

+    // Use rect-like geometry for non-close path, for right angle is easier to
+    // show the visual difference of lineCap and lineJoin.

[robertphillips, 2013/11/08 14:18:50]

We only use const references in Skia. If the object is non-const you need to use
a pointer.

Seems like this method could be static.

Why is the rect offset to 30,30. Why not have it start at 0,0?

[yunchao, 2013/11/08 15:56:21]

Because some cases are stroke-style, and the biggest strokeWidth is 50(half
would be 25). Set to (0, 0) may exceed the bounds.

+    void makePath(SkPath& path, NonCloseType type) {
+        if (FakeCloseMiddle == type) {
+            path.moveTo(30, 50);
+            path.lineTo(30, 30);
+        } else {
+            path.moveTo(30, 30);
+        }
+        path.lineTo(70, 30);
+        path.lineTo(70, 70);
+        path.lineTo(30, 70);
+        path.lineTo(30, 50);
+        if (FakeCloseCorner == type) {
+            path.lineTo(30, 30);
+        }
+    }
+
+    // set the location for the current test on the canvas

[robertphillips, 2013/11/08 14:18:50]

SetLocation for static member methods

+    static void setLocation(SkCanvas* canvas, int counter, int lineNum) {
+        SkScalar x = SK_Scalar1 * 100 * (counter % lineNum) + 10 + SK_Scalar1 / 4;
+        SkScalar y = SK_Scalar1 * 100 * (counter / lineNum) + 10 + 3 * SK_Scalar1 / 4;
+        canvas->translate(x, y);
+    }
+

[robertphillips, 2013/11/08 14:18:50]

SK_OVERRIDE

+    virtual void onDraw(SkCanvas* canvas) {

[robertphillips, 2013/11/08 14:18:50]

Maybe kStrokeWidths or gStrokeWidths?

+        static const int strokeWidth[] = {0, 10, 40, 50};

[robertphillips, 2013/11/08 14:18:50]

Maybe numWidths?

+        size_t size = SK_ARRAY_COUNT(strokeWidth);
+

[robertphillips, 2013/11/08 14:18:50]

Same here w.r.t. naming. Maybe prefix with a 'k' or 'g' and make plural?

+        static const SkPaint::Style testStyle[] = {
+            SkPaint::kStroke_Style, SkPaint::kStrokeAndFill_Style
+        };
+
+        static const SkPaint::Cap testCap[] = {
+            SkPaint::kButt_Cap, SkPaint::kRound_Cap, SkPaint::kSquare_Cap
+        };
+
+        static const SkPaint::Join testJoin[] = {
+            SkPaint::kMiter_Join, SkPaint::kRound_Join, SkPaint::kBevel_Join
+        };
+
+        static const NonCloseType testType[] = {
+            TotalNonClose, FakeCloseCorner, FakeCloseMiddle
+        };
+
+        int counter = 0;
+        SkPaint paint;
+        paint.setAntiAlias(true);
+
+        // For stroke style painter and fill-and-stroke style painter

[robertphillips, 2013/11/08 14:18:50]

pre-increments for these please (e.g., ++type)

+        for (size_t type = 0; type < kNonCloseTypeCount; type++) {
+            for (size_t style = 0; style < SK_ARRAY_COUNT(testStyle); style++) {
+                for (size_t cap = 0; cap < SK_ARRAY_COUNT(testCap); cap++) {
+                    for (size_t join = 0; join < SK_ARRAY_COUNT(testJoin); join++) {
+                        for (size_t width = 0; width < size; width++) {
+                            canvas->save();
+                            setLocation(canvas, counter, SkPaint::kJoinCount * size);
+
+                            SkPath path;

[robertphillips, 2013/11/08 14:18:50]

this->makePath

+                            makePath(path, testType[type]);
+
+                            paint.setStyle(testStyle[style]);
+                            paint.setStrokeCap(testCap[cap]);
+                            paint.setStrokeJoin(testJoin[join]);

[robertphillips, 2013/11/08 14:18:50]

SkIntToScalar instead of SkScalar

+                            paint.setStrokeWidth(SkScalar(strokeWidth[width]));
+
+                            canvas->drawPath(path, paint);
+                            canvas->restore();
+                            counter++;
+                        }
+                    }
+                }
+            }
+        }
+
+        // For fill style painter
+        for (size_t type = 0; type < kNonCloseTypeCount; type++) {
+            canvas->save();
+            setLocation(canvas, counter, SkPaint::kJoinCount * size);
+
+            SkPath path;

[robertphillips, 2013/11/08 14:18:50]

this->makePath

+            makePath(path, testType[type]);
+
+            paint.setStyle(SkPaint::kFill_Style);
+
+            canvas->drawPath(path, paint);
+            canvas->restore();
+            counter++;
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+

[robertphillips, 2013/11/08 14:18:50]

Please use DEF_GM macro instead here

+static GM* MyFactory(void*) { return new NonClosePathsGM; }
+static GMRegistry reg(MyFactory);
+
+}