Add flag to avoid stencil buffers in Skia

Certain systems experience a leak in the GL driver associated with
stencil buffers. Attempts to avoid the leak (while still using stencil
buffers) dind't succeed. This patch adds a GrContextOption
fAvoidStencilBuffers. This disables certain path rendering modes, as
well as stencil based masking/clipping.

Bug: 713854
Change-Id: Ifa6c0f2bd5ee395547bda9165d6c79d197ae8b8b
Reviewed-on: https://skia-review.googlesource.com/15253
Commit-Queue: Eric Karl <ericrk@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>

4 files changed, 21 insertions, 5 deletions

diff --git a/tools/flags/SkCommonFlagsConfig.cpp b/tools/flags/SkCommonFlagsConfig.cpp
index 1e980d20e9..458962e007 100644
--- a/tools/flags/SkCommonFlagsConfig.cpp
+++ b/tools/flags/SkCommonFlagsConfig.cpp
@@ -64,6 +64,7 @@ static const struct {
     { "glsrgb",                "gpu", "api=gl,color=srgb" },
     { "glwide",                "gpu", "api=gl,color=f16_wide" },
     { "glnarrow",              "gpu", "api=gl,color=f16_narrow" },
+    { "glnostencils",          "gpu", "api=gl,stencils=false" },
     { "glessrgb",              "gpu", "api=gles,color=srgb" },
     { "gleswide",              "gpu", "api=gles,color=f16_wide" },
     { "glesnarrow",            "gpu", "api=gles,color=f16_narrow" },
@@ -151,6 +152,8 @@ static const char configExtendedHelp[] =
     "\t    Use NV_path_rendering OpenGL and OpenGL ES extension.\n"
     "\tsamples\ttype: int\tdefault: 0.\n"
     "\t    Use multisampling with N samples.\n"
+    "\tstencils\ttype: bool\tdefault: true.\n"
+    "\t    Allow the use of stencil buffers.\n"
     "\n"
     "Predefined configs:\n\n"
     // Help text for pre-defined configs is auto-generated from gPredefinedConfigs
@@ -181,7 +184,7 @@ SkCommandLineConfig::~SkCommandLineConfig() {
 SkCommandLineConfigGpu::SkCommandLineConfigGpu(
     const SkString& tag, const SkTArray<SkString>& viaParts, ContextType contextType, bool useNVPR,
     bool useInstanced, bool useDIText, int samples, SkColorType colorType,
-    sk_sp<SkColorSpace> colorSpace)
+    sk_sp<SkColorSpace> colorSpace, bool useStencilBuffers)
         : SkCommandLineConfig(tag, SkString("gpu"), viaParts)
         , fContextType(contextType)
         , fContextOverrides(ContextOverrides::kNone)
@@ -210,6 +213,9 @@ SkCommandLineConfigGpu::SkCommandLineConfigGpu(
         fContextOverrides |= ContextOverrides::kRequireSRGBSupport;
         fContextOverrides |= ContextOverrides::kAllowSRGBWithoutDecodeControl;
     }
+    if (!useStencilBuffers) {
+        fContextOverrides |= ContextOverrides::kAvoidStencilBuffers;
+    }
 }
 static bool parse_option_int(const SkString& value, int* outInt) {
     if (value.isEmpty()) {
@@ -370,6 +376,8 @@ SkCommandLineConfigGpu* parse_command_line_config_gpu(const SkString& tag,
     bool seenColor = false;
     SkColorType colorType = kRGBA_8888_SkColorType;
     sk_sp<SkColorSpace> colorSpace = nullptr;
+    bool seenUseStencils = false;
+    bool useStencils = true;
 
     SkTArray<SkString> optionParts;
     SkStrSplit(options.c_str(), ",", kStrict_SkStrSplitMode, &optionParts);
@@ -400,6 +408,9 @@ SkCommandLineConfigGpu* parse_command_line_config_gpu(const SkString& tag,
         } else if (key.equals("color") && !seenColor) {
             valueOk = parse_option_gpu_color(value, &colorType, &colorSpace);
             seenColor = true;
+        } else if (key.equals("stencils") && !seenUseStencils) {
+            valueOk = parse_option_bool(value, &useStencils);
+            seenUseStencils = true;
         }
         if (!valueOk) {
             return nullptr;
@@ -409,7 +420,7 @@ SkCommandLineConfigGpu* parse_command_line_config_gpu(const SkString& tag,
         return nullptr;
     }
     return new SkCommandLineConfigGpu(tag, vias, contextType, useNVPR, useInstanced, useDIText,
-                                      samples, colorType, colorSpace);
+                                      samples, colorType, colorSpace, useStencils);
 }
 #endif
 
diff --git a/tools/flags/SkCommonFlagsConfig.h b/tools/flags/SkCommonFlagsConfig.h
index e6ebefd864..a3c3b38cd4 100644
--- a/tools/flags/SkCommonFlagsConfig.h
+++ b/tools/flags/SkCommonFlagsConfig.h
@@ -55,7 +55,8 @@ class SkCommandLineConfigGpu : public SkCommandLineConfig {
     typedef sk_gpu_test::GrContextFactory::ContextOverrides ContextOverrides;
     SkCommandLineConfigGpu(const SkString& tag, const SkTArray<SkString>& viaParts,
                            ContextType contextType, bool useNVPR, bool useInstanced, bool useDIText,
-                           int samples, SkColorType colorType, sk_sp<SkColorSpace> colorSpace);
+                           int samples, SkColorType colorType, sk_sp<SkColorSpace> colorSpace,
+                           bool useStencilBuffers);
     const SkCommandLineConfigGpu* asConfigGpu() const override { return this; }
     ContextType getContextType() const { return fContextType; }
     ContextOverrides getContextOverrides() const { return fContextOverrides; }
diff --git a/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 6ed89542c9..e02bc1b371 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -230,6 +230,9 @@ ContextInfo GrContextFactory::getContextInfoInternal(ContextType type, ContextOv
     if (ContextOverrides::kAllowSRGBWithoutDecodeControl & overrides) {
         grOptions.fRequireDecodeDisableForSRGB = false;
     }
+    if (ContextOverrides::kAvoidStencilBuffers & overrides) {
+        grOptions.fAvoidStencilBuffers = true;
+    }
     sk_sp<GrContext> grCtx(GrContext::Create(backend, backendContext, grOptions));
     if (!grCtx.get()) {
         return ContextInfo();
diff --git a/tools/gpu/GrContextFactory.h b/tools/gpu/GrContextFactory.h
index 0067e52144..eb54b50bbb 100644
--- a/tools/gpu/GrContextFactory.h
+++ b/tools/gpu/GrContextFactory.h
@@ -94,9 +94,10 @@ public:
         kDisableNVPR                   = 0x1,
         kUseInstanced                  = 0x2,
         kAllowSRGBWithoutDecodeControl = 0x4,
+        kAvoidStencilBuffers           = 0x8,
 
-        kRequireNVPRSupport            = 0x8,
-        kRequireSRGBSupport            = 0x10
+        kRequireNVPRSupport            = 0x10,
+        kRequireSRGBSupport            = 0x20,
     };
 
     static bool IsRenderingContext(ContextType type) {