Revert "Revert "Fix GrDefaultPathRender inversely wound path bug""

This reverts commit fc28138c0422637741ac2839914ef10c56438054.

Reason for revert: Suppression have landed for failing tests

Original change's description:
> Revert "Fix GrDefaultPathRender inversely wound path bug"
> 
> This reverts commit 511a9d49998ec6a74c375e6cfc55f660f7987c40.
> 
> Reason for revert: vulkan
> 
> Original change's description:
> > Fix GrDefaultPathRender inversely wound path bug
> > 
> > Bug: 769898
> > Change-Id: I3b1a43b1e114b35105493a0cfa01a1f01b65fa56
> > Reviewed-on: https://skia-review.googlesource.com/64065
> > Commit-Queue: Robert Phillips <robertphillips@google.com>
> > Reviewed-by: Brian Salomon <bsalomon@google.com>
> 
> TBR=bsalomon@google.com,robertphillips@google.com
> 
> Change-Id: Ib1a987294d14f0526bf5ff5a8fd90bbd5f6f3a0d
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 769898
> Reviewed-on: https://skia-review.googlesource.com/65201
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=bsalomon@google.com,robertphillips@google.com

Change-Id: I3a3543c46b3192f1ffd31a5566cf337dc03561a8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 769898
Reviewed-on: https://skia-review.googlesource.com/65202
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

1 files changed, 136 insertions, 0 deletions

diff --git a/tests/DefaultPathRendererTest.cpp b/tests/DefaultPathRendererTest.cpp
new file mode 100644
index 0000000000..d1e102bc5e
--- /dev/null
+++ b/tests/DefaultPathRendererTest.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2017 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"
+
+#if SK_SUPPORT_GPU
+#include "GrClip.h"
+#include "GrRenderTargetContext.h"
+#include "GrStyle.h"
+#include "GrTypesPriv.h"
+
+#include "effects/GrConstColorProcessor.h"
+
+static void allow_default_and_msaa(GrContextOptions* options) {
+    options->fGpuPathRenderers = GpuPathRenderers::kMSAA;
+}
+
+static void only_allow_default(GrContextOptions* options) {
+    options->fGpuPathRenderers = GpuPathRenderers::kNone;
+}
+
+static SkBitmap read_back(GrRenderTargetContext* rtc, int width, int height) {
+
+    SkImageInfo dstII = SkImageInfo::MakeN32Premul(width, height);
+
+    SkBitmap bm;
+    bm.allocPixels(dstII);
+
+    rtc->readPixels(dstII, bm.getAddr(0, 0), bm.rowBytes(), 0, 0, 0);
+
+    return bm;
+}
+
+static SkPath make_path(const SkRect& outer, int inset, SkPath::FillType fill) {
+    SkPath p;
+
+    p.addRect(outer, SkPath::kCW_Direction);
+    p.addRect(outer.makeInset(inset, inset), SkPath::kCCW_Direction);
+    p.setFillType(fill);
+    return p;
+}
+
+
+static const int kBigSize = 64; // This should be a power of 2
+static const int kPad = 3;
+
+// From crbug.com/769898:
+//   create an approx fit render target context that will have extra space (i.e., npot)
+//   draw an inverse wound concave path into it - forcing use of the stencil-using path renderer
+//   throw the RTC away so the backing GrSurface/GrStencilBuffer can be reused
+//   create a new render target context that will reuse the prior GrSurface
+//   draw a normally wound concave path that touches outside of the approx fit RTC's content rect
+//
+// When the bug manifests the GrDefaultPathRenderer/GrMSAAPathRenderer is/was leaving the stencil
+// buffer outside of the first content rect in a bad state and the second draw would be incorrect.
+
+static void run_test(GrContext* ctx, skiatest::Reporter* reporter) {
+    SkPath invPath = make_path(SkRect::MakeXYWH(0, 0, kBigSize, kBigSize),
+                               kBigSize/2-1, SkPath::kInverseWinding_FillType);
+    SkPath path = make_path(SkRect::MakeXYWH(0, 0, kBigSize, kBigSize),
+                            kPad, SkPath::kWinding_FillType);
+
+    GrStyle style(SkStrokeRec::kFill_InitStyle);
+
+    {
+        auto rtc =  ctx->makeDeferredRenderTargetContext(SkBackingFit::kApprox,
+                                                         kBigSize/2+1, kBigSize/2+1,
+                                                         kRGBA_8888_GrPixelConfig, nullptr);
+
+        rtc->clear(nullptr, GrColorPackRGBA(0x0, 0x0, 0x0, 0xFF), true);
+
+        GrPaint paint;
+
+        const GrColor4f color = { 1.0f, 0.0f, 0.0f, 1.0f };
+        auto fp = GrConstColorProcessor::Make(color, GrConstColorProcessor::kIgnore_InputMode);
+        paint.addColorFragmentProcessor(std::move(fp));
+
+        rtc->drawPath(GrNoClip(), std::move(paint), GrAA::kNo,
+                      SkMatrix::I(), invPath, style);
+
+        rtc->prepareForExternalIO(0, nullptr);
+    }
+
+    {
+        auto rtc = ctx->makeDeferredRenderTargetContext(SkBackingFit::kExact, kBigSize, kBigSize,
+                                                        kRGBA_8888_GrPixelConfig, nullptr);
+
+        rtc->clear(nullptr, GrColorPackRGBA(0x0, 0x0, 0x0, 0xFF), true);
+
+        GrPaint paint;
+
+        const GrColor4f color = { 0.0f, 1.0f, 0.0f, 1.0f };
+        auto fp = GrConstColorProcessor::Make(color, GrConstColorProcessor::kIgnore_InputMode);
+        paint.addColorFragmentProcessor(std::move(fp));
+
+        rtc->drawPath(GrNoClip(), std::move(paint), GrAA::kNo,
+                      SkMatrix::I(), path, style);
+
+        SkBitmap bm = read_back(rtc.get(), kBigSize, kBigSize);
+
+        bool correct = true;
+        for (int y = kBigSize/2+1; y < kBigSize-kPad-1 && correct; ++y) {
+            for (int x = kPad+1; x < kBigSize-kPad-1 && correct; ++x) {
+                correct = bm.getColor(x, y) == SK_ColorBLACK;
+                REPORTER_ASSERT(reporter, correct);
+            }
+        }
+    }
+
+}
+
+DEF_GPUTEST_FOR_CONTEXTS(GrDefaultPathRendererTest,
+                         sk_gpu_test::GrContextFactory::IsRenderingContext,
+                         reporter, ctxInfo, only_allow_default) {
+    GrContext* ctx = ctxInfo.grContext();
+
+    run_test(ctx, reporter);
+}
+
+DEF_GPUTEST_FOR_CONTEXTS(GrMSAAPathRendererTest,
+                         sk_gpu_test::GrContextFactory::IsRenderingContext,
+                         reporter, ctxInfo, allow_default_and_msaa) {
+    GrContext* ctx = ctxInfo.grContext();
+
+    if (!ctx->caps()->sampleShadingSupport()) {   // The MSAAPathRenderer requires this
+        return;
+    }
+
+    run_test(ctx, reporter);
+}
+
+#endif