Make GrContext cache the gpu paths

Creating paths for nv_path_rendering is costly. Try to reduce this
cost by caching paths based on the SkPath "hash" (i.e. SkPathRef
generation id) and stroke properties.

Adds the paths to GrContext::fTextureCache instance. Later this should
be renamed and the GrContext API should reflect the nature of the cache
better.

R=bsalomon@google.com, mtklein@google.com

Author: kkinnunen@nvidia.com

Review URL: https://codereview.chromium.org/26557003

git-svn-id: http://skia.googlecode.com/svn/trunk@12083 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 23 insertions, 0 deletions

diff --git a/src/gpu/GrPath.cpp b/src/gpu/GrPath.cpp
index afd223902f..f928dffaa8 100644
--- a/src/gpu/GrPath.cpp
+++ b/src/gpu/GrPath.cpp
@@ -8,3 +8,26 @@
 #include "GrPath.h"
 
 SK_DEFINE_INST_COUNT(GrPath)
+
+GrResourceKey GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke) {
+    static const GrResourceKey::ResourceType gPathResourceType = GrResourceKey::GenerateResourceType();
+    static const GrCacheID::Domain gPathDomain = GrCacheID::GenerateDomain();
+
+    GrCacheID::Key key;
+    uint32_t* keyData = key.fData32;
+    keyData[0] = path.getGenerationID();
+
+    SK_COMPILE_ASSERT(SkPaint::kJoinCount <= 3, cap_shift_will_be_wrong);
+    keyData[1] = stroke.needToApply();
+    if (0 != keyData[1]) {
+        keyData[1] |= stroke.getJoin() << 1;
+        keyData[1] |= stroke.getCap() << 3;
+        keyData[2] = static_cast<uint32_t>(stroke.getMiter());
+        keyData[3] = static_cast<uint32_t>(stroke.getWidth());
+    } else {
+        keyData[2] = 0;
+        keyData[3] = 0;
+    }
+
+    return GrResourceKey(GrCacheID(gPathDomain, key), gPathResourceType, 0);
+}