Update blurred rrect mask filter creation method to also handle caching

src/effects/SkBlurMaskFilter.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlurMaskFilter.h"
 #include "SkBlurMask.h"
 #include "SkGpuBlurUtils.h"
@@ skipping 994 matching lines @@
 
     SkRRect             fRRect;
     float               fSigma;
     GrTextureAccess     fNinePatchAccess;
 
     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 
     typedef GrFragmentProcessor INHERITED;
 };
 
-static sk_sp<GrTexture> make_rrect_blur_mask(GrContext* context,
-                                             const SkRRect& rrect,
-                                             float sigma,
-                                             bool doAA) {
-    SkRRect rrectToDraw;
-    SkISize size;
-    SkScalar xs[4], ys[4];
-    int numXs, numYs;
+static sk_sp<GrTexture> find_or_create_rrect_blur_mask(GrContext* context,
+                                                       const SkRRect& rrectToDraw,
+                                                       const SkISize& size,
+                                                       float xformedSigma,
+                                                       bool doAA) {
+    static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
+    GrUniqueKey key;
+    GrUniqueKey::Builder builder(&key, kDomain, 9);
+    builder[0] = 3*SkScalarCeilToInt(xformedSigma-1/6.0f);

[bsalomon, 2016/08/15 13:55:23]

Why 3*?

[robertphillips, 2016/08/15 17:41:37]

We/SVG requires that we include 3*sigma of the shadow.

[bsalomon, 2016/08/15 17:57:56]

Right but does it matter for the key?

[robertphillips, 2016/08/15 18:30:38]

Nope - removed.

 
-    SkBlurMaskFilter::ComputeBlurredRRectParams(rrect, sigma, &rrectToDraw, &size,
-                                                xs, &numXs, ys, &numYs);
+    int index = 1;
+    for (auto c : { SkRRect::kUpperLeft_Corner,  SkRRect::kUpperRight_Corner,
+                    SkRRect::kLowerRight_Corner, SkRRect::kLowerLeft_Corner }) {
+        SkASSERT(SkScalarIsInt(rrectToDraw.radii(c).fX) && SkScalarIsInt(rrectToDraw.radii(c).fY));
+        builder[index++] = SkScalarCeilToInt(rrectToDraw.radii(c).fX);

[bsalomon, 2016/08/15 13:55:23]

Is the idea to handle non-circular? Right now I think the x and y radii are the
same right? Is ceiling chosen for any particular reason over round?

[robertphillips, 2016/08/15 17:41:37]

The code will soon be able to handle non-simple-circular rrects. If it is
nine-patchable it will be nine-patched and cached. You are correct that right
now the upstream code limits us to simple circular.

No particular reason for ceil vs. round. Since they've been integerized they
should land in the same place.

+        builder[index++] = SkScalarCeilToInt(rrectToDraw.radii(c).fY);
+    }
+    builder.finish();
 
-    // TODO: this could be approx but the texture coords will need to be updated
-    sk_sp<GrDrawContext> dc(context->makeDrawContext(SkBackingFit::kExact,
-                                                     size.fWidth, size.fHeight,
-                                                     kAlpha_8_GrPixelConfig, nullptr));
-    if (!dc) {
-        return nullptr;
-    }
+    sk_sp<GrTexture> mask(context->textureProvider()->findAndRefTextureByUniqueKey(key));
+    if (!mask) {
+        // TODO: this could be approx but the texture coords will need to be updated
+        sk_sp<GrDrawContext> dc(context->makeDrawContext(SkBackingFit::kExact,
+                                                         size.fWidth, size.fHeight,
+                                                         kAlpha_8_GrPixelConfig, nullptr));
+        if (!dc) {
+            return nullptr;
+        }
                 
-    GrPaint grPaint;
-    grPaint.setAntiAlias(doAA);
+        GrPaint grPaint;
+        grPaint.setAntiAlias(doAA);
 
-    dc->clear(nullptr, 0x0, true);
-    dc->drawRRect(GrNoClip(), grPaint, SkMatrix::I(), rrectToDraw, GrStyle::SimpleFill());
+        dc->clear(nullptr, 0x0, true);
+        dc->drawRRect(GrNoClip(), grPaint, SkMatrix::I(), rrectToDraw, GrStyle::SimpleFill());
 
-    sk_sp<GrTexture> tex(dc->asTexture());
-    sk_sp<GrDrawContext> dc2(SkGpuBlurUtils::GaussianBlur(context,
-                                                          tex.get(),
-                                                          nullptr,
-                                                          SkIRect::MakeWH(size.fWidth,
-                                                                          size.fHeight),
-                                                          nullptr,
-                                                          sigma, sigma, SkBackingFit::kExact));
-    if (!dc2) {
-        return nullptr;
+        sk_sp<GrTexture> srcTexture(dc->asTexture());
+        sk_sp<GrDrawContext> dc2(SkGpuBlurUtils::GaussianBlur(context,
+                                                              srcTexture.get(),
+                                                              nullptr,
+                                                              SkIRect::MakeWH(size.fWidth,
+                                                                              size.fHeight),
+                                                              nullptr,
+                                                              xformedSigma, xformedSigma,
+                                                              SkBackingFit::kExact));
+        if (!dc2) {
+            return nullptr;
+        }
+
+        mask = dc2->asTexture();
+        SkASSERT(mask);
+        context->textureProvider()->assignUniqueKeyToTexture(key, mask.get());
     }
 
-    return dc2->asTexture();
+    return mask;
 }
 
-sk_sp<GrFragmentProcessor> GrRRectBlurEffect::Make(GrContext* context, float sigma,
-                                                   const SkRRect& rrect) {
-    if (rrect.isCircle()) {
+sk_sp<GrFragmentProcessor> GrRRectBlurEffect::Make(GrContext* context,
+                                                   float xformedSigma,
+                                                   const SkRRect& devRRect) {
+    if (devRRect.isCircle()) {
         return GrCircleBlurFragmentProcessor::Make(context->textureProvider(),
-                                                   rrect.rect(), sigma);
+                                                   devRRect.rect(), xformedSigma);
     }
 
     // TODO: loosen this up
-    if (!rrect.isSimpleCircular()) {
+    if (!devRRect.isSimpleCircular()) {
         return nullptr;
     }
 
     // Make sure we can successfully ninepatch this rrect -- the blur sigma has to be
     // sufficiently small relative to both the size of the corner radius and the
     // width (and height) of the rrect.
+    SkRRect rrectToDraw;
+    SkISize size;
+    SkScalar ignored[4];
+    int ignoredSize;
 
-    unsigned int blurRadius = 3*SkScalarCeilToInt(sigma-1/6.0f);
-    unsigned int cornerRadius = SkScalarCeilToInt(rrect.getSimpleRadii().x());
-    if (cornerRadius + blurRadius > rrect.width()/2 ||
-        cornerRadius + blurRadius > rrect.height()/2) {
+    bool ninePatchable = SkBlurMaskFilter::ComputeBlurredRRectParams(devRRect, xformedSigma,
+                                                                     &rrectToDraw, &size,
+                                                                     ignored, &ignoredSize,
+                                                                     ignored, &ignoredSize);
+    if (!ninePatchable) {
         return nullptr;
     }
 
-    static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
-    GrUniqueKey key;
-    GrUniqueKey::Builder builder(&key, kDomain, 2);
-    builder[0] = blurRadius;
-    builder[1] = cornerRadius;
-    builder.finish();
+    sk_sp<GrTexture> mask(find_or_create_rrect_blur_mask(context, rrectToDraw, size,
+                                                         xformedSigma, true));
+    if (!mask) {
+        return nullptr;
+    }
 
-    sk_sp<GrTexture> blurNinePatchTexture(
-                                context->textureProvider()->findAndRefTextureByUniqueKey(key));
-
-    if (!blurNinePatchTexture) {
-        blurNinePatchTexture = make_rrect_blur_mask(context, rrect, sigma, true);
-        if (!blurNinePatchTexture) {
-            return nullptr;
-        }
-        context->textureProvider()->assignUniqueKeyToTexture(key, blurNinePatchTexture.get());
-    }
-    return sk_sp<GrFragmentProcessor>(new GrRRectBlurEffect(sigma, rrect, blurNinePatchTexture.get()));
+    return sk_sp<GrFragmentProcessor>(new GrRRectBlurEffect(xformedSigma,
+                                                            devRRect,
+                                                            mask.get()));
 }
 
 void GrRRectBlurEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     inout->mulByUnknownSingleComponent();
 }
 
 GrRRectBlurEffect::GrRRectBlurEffect(float sigma, const SkRRect& rrect, GrTexture *ninePatchTexture)
     : fRRect(rrect),
       fSigma(sigma),
       fNinePatchAccess(ninePatchTexture) {
@@ skipping 321 matching lines @@
     } else {
         str->append("None");
     }
     str->append("))");
 }
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkBlurMaskFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBlurMaskFilterImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END