add unittest for invariants for empty paths, still need to think about
hairlines in those cases
git-svn-id: http://skia.googlecode.com/svn/trunk@2919 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/EmptyPathTest.cpp b/tests/EmptyPathTest.cpp
new file mode 100644
index 0000000..59fafbb
--- /dev/null
+++ b/tests/EmptyPathTest.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+#include "SkPath.h"
+#include "SkCanvas.h"
+
+static void appendStr(SkString* str, const SkPaint& paint) {
+ str->appendf(" style[%d] cap[%d] join[%d] antialias[%d]",
+ paint.getStyle(), paint.getStrokeCap(),
+ paint.getStrokeJoin(), paint.isAntiAlias());
+}
+
+static void appendStr(SkString* str, const SkPath& path) {
+ str->appendf(" filltype[%d] ptcount[%d]",
+ path.getFillType(), path.countPoints());
+}
+
+#define DIMENSION 32
+
+static void drawAndTest(skiatest::Reporter* reporter, const SkPath& path,
+ const SkPaint& paint, bool shouldDraw) {
+ SkBitmap bm;
+ // explicitly specify a trim rowbytes, so we have no padding on each row
+ bm.setConfig(SkBitmap::kARGB_8888_Config, DIMENSION, DIMENSION, DIMENSION*4);
+ bm.allocPixels();
+ bm.eraseColor(0);
+
+ SkCanvas canvas(bm);
+ SkPaint p(paint);
+ p.setColor(SK_ColorWHITE);
+
+ canvas.drawPath(path, p);
+
+ size_t count = DIMENSION * DIMENSION;
+ const SkPMColor* ptr = bm.getAddr32(0, 0);
+
+ SkPMColor andValue = ~0;
+ SkPMColor orValue = 0;
+ for (size_t i = 0; i < count; ++i) {
+ SkPMColor c = ptr[i];
+ andValue &= c;
+ orValue |= c;
+ }
+
+ // success means we drew everywhere or nowhere (depending on shouldDraw)
+ bool success = shouldDraw ? (~0 == andValue) : (0 == orValue);
+
+ if (!success) {
+ SkString str;
+ if (shouldDraw) {
+ str.set("Path expected to draw everywhere, but didn't. ");
+ } else {
+ str.set("Path expected to draw nowhere, but did. ");
+ }
+ appendStr(&str, paint);
+ appendStr(&str, path);
+ reporter->report(str.c_str(), skiatest::Reporter::kFailed);
+
+// uncomment this if you want to step in to see the failure
+// canvas.drawPath(path, p);
+ }
+}
+
+static void iter_paint(skiatest::Reporter* reporter, const SkPath& path, bool shouldDraw) {
+ static const SkPaint::Cap gCaps[] = {
+ SkPaint::kButt_Cap,
+ SkPaint::kRound_Cap,
+ SkPaint::kSquare_Cap
+ };
+ static const SkPaint::Join gJoins[] = {
+ SkPaint::kMiter_Join,
+ SkPaint::kRound_Join,
+ SkPaint::kBevel_Join
+ };
+ static const SkPaint::Style gStyles[] = {
+ SkPaint::kFill_Style,
+ SkPaint::kStroke_Style,
+ SkPaint::kStrokeAndFill_Style
+ };
+ for (size_t cap = 0; cap < SK_ARRAY_COUNT(gCaps); ++cap) {
+ for (size_t join = 0; join < SK_ARRAY_COUNT(gJoins); ++join) {
+ for (size_t style = 0; style < SK_ARRAY_COUNT(gStyles); ++style) {
+ SkPaint paint;
+ paint.setStrokeWidth(SkIntToScalar(10));
+
+ paint.setStrokeCap(gCaps[cap]);
+ paint.setStrokeJoin(gJoins[join]);
+ paint.setStyle(gStyles[style]);
+
+ paint.setAntiAlias(false);
+ drawAndTest(reporter, path, paint, shouldDraw);
+ paint.setAntiAlias(true);
+ drawAndTest(reporter, path, paint, shouldDraw);
+ }
+ }
+ }
+}
+
+#define CX (SkIntToScalar(DIMENSION) / 2)
+#define CY (SkIntToScalar(DIMENSION) / 2)
+
+static void make_empty(SkPath* path) {}
+static void make_move(SkPath* path) { path->moveTo(CX, CY); }
+static void make_line(SkPath* path) { path->moveTo(CX, CY); path->lineTo(CX, CY); }
+static void make_quad(SkPath* path) { path->moveTo(CX, CY); path->quadTo(CX, CY, CX, CY); }
+static void make_cubic(SkPath* path) { path->moveTo(CX, CY); path->cubicTo(CX, CY, CX, CY, CX, CY); }
+
+/* Two invariants are tested: How does an empty/degenerate path draw?
+ * - if the path is drawn inverse, it should draw everywhere
+ * - if the path is drawn non-inverse, it should draw nowhere
+ *
+ * Things to iterate on:
+ * - path (empty, degenerate line/quad/cubic w/ and w/o close
+ * - paint style
+ * - path filltype
+ * - path stroke variants (e.g. caps, joins, width)
+ */
+static void test_emptydrawing(skiatest::Reporter* reporter) {
+ static void (*gMakeProc[])(SkPath*) = {
+ make_empty, make_move, make_line, make_quad, make_cubic
+ };
+ static SkPath::FillType gFills[] = {
+ SkPath::kWinding_FillType,
+ SkPath::kEvenOdd_FillType,
+ SkPath::kInverseWinding_FillType,
+ SkPath::kInverseEvenOdd_FillType
+ };
+ for (int doClose = 0; doClose < 2; ++doClose) {
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gMakeProc); ++i) {
+ SkPath path;
+ gMakeProc[i](&path);
+ if (doClose) {
+ path.close();
+ }
+ for (size_t fill = 0; fill < SK_ARRAY_COUNT(gFills); ++fill) {
+ path.setFillType(gFills[fill]);
+ bool shouldDraw = path.isInverseFillType();
+ iter_paint(reporter, path, shouldDraw);
+ }
+ }
+ }
+}
+
+static void TestEmptyPath(skiatest::Reporter* reporter) {
+ test_emptydrawing(reporter);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("EmptyPath", TestEmptyPathClass, TestEmptyPath)