Add SkSpecialImage::makeTextureImage entry point

This is calved off of: https://codereview.chromium.org/1785643003 (Switch SkBlurImageFilter over to new onFilterImage interface)

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1813813002

Committed: https://skia.googlesource.com/skia/+/05849018c85403a34b88819db1c4bcf713b70a2b

Review URL: https://codereview.chromium.org/1813813002

3 files changed, 62 insertions, 2 deletions

diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 1a4c876d61..4ae839c3d4 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -596,7 +596,18 @@ SkSpecialImage* SkImageFilter::filterInput(int index,
         return SkRef(src);
     }
 
-    return input->filterImage(src, this->mapContext(ctx), offset);
+    SkAutoTUnref<SkSpecialImage> result(input->filterImage(src, this->mapContext(ctx), offset));
+
+#if SK_SUPPORT_GPU
+    if (src->peekTexture() && result && !result->peekTexture()) {
+        // Keep the result on the GPU - this is still required for some
+        // image filters that don't support GPU in all cases
+        GrContext* context = src->peekTexture()->getContext();
+        return result->makeTextureImage(src->internal_getProxy(), context).release();
+    }
+#endif
+
+    return result.release();
 }
 
 #if SK_SUPPORT_GPU
diff --git a/src/core/SkSpecialImage.cpp b/src/core/SkSpecialImage.cpp
index e90c655a58..991e163515 100644
--- a/src/core/SkSpecialImage.cpp
+++ b/src/core/SkSpecialImage.cpp
@@ -4,10 +4,16 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file
  */
+#include "SkSpecialImage.h"
+
+#if SK_SUPPORT_GPU
+#include "GrTexture.h"
+#include "GrTextureParams.h"
+#include "SkGr.h"
+#endif
 
 #include "SkCanvas.h"
 #include "SkImage_Base.h"
-#include "SkSpecialImage.h"
 #include "SkSpecialSurface.h"
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -42,6 +48,38 @@ static inline const SkSpecialImage_Base* as_SIB(const SkSpecialImage* image) {
     return static_cast<const SkSpecialImage_Base*>(image);
 }
 
+sk_sp<SkSpecialImage> SkSpecialImage::makeTextureImage(SkImageFilter::Proxy* proxy,
+                                                       GrContext* context) {
+#if SK_SUPPORT_GPU
+    if (!context) {
+        return nullptr;
+    }
+    if (GrTexture* peek = as_SIB(this)->peekTexture()) {
+        return peek->getContext() == context ? sk_sp<SkSpecialImage>(SkRef(this)) : nullptr;
+    }
+
+    SkBitmap bmp;
+    if (!this->internal_getBM(&bmp)) {
+        return nullptr;
+    }
+
+    SkAutoTUnref<GrTexture> resultTex(
+        GrRefCachedBitmapTexture(context, bmp, GrTextureParams::ClampNoFilter()));
+    if (!resultTex) {
+        return nullptr;
+    }
+
+    SkAlphaType at = this->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+
+    return SkSpecialImage::MakeFromGpu(proxy,
+                                       SkIRect::MakeWH(resultTex->width(), resultTex->height()),
+                                       this->uniqueID(),
+                                       resultTex, at);
+#else
+    return nullptr;
+#endif
+}
+
 void SkSpecialImage::draw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint) const {
     return as_SIB(this)->onDraw(canvas, x, y, paint);
 }
diff --git a/src/core/SkSpecialImage.h b/src/core/SkSpecialImage.h
index 1a01a5abc7..47ad6ccab7 100644
--- a/src/core/SkSpecialImage.h
+++ b/src/core/SkSpecialImage.h
@@ -14,12 +14,16 @@
 // remove this when internal_getProxy goes away (see skbug.com/4965)
 #include "SkImageFilter.h"
 
+#include "SkImageInfo.h" // for SkAlphaType
+
+class GrContext;
 class GrTexture;
 class SkBitmap;
 class SkCanvas;
 class SkImage;
 struct SkImageInfo;
 class SkPaint;
+class SkPixmap;
 class SkSpecialSurface;
 
 enum {
@@ -51,6 +55,13 @@ public:
     virtual size_t getSize() const = 0;
 
     /**
+     *  Ensures that a special image is backed by a texture (when GrContext is non-null). If no
+     *  transformation is required, the returned image may be the same as this special image.
+     *  If this special image is from a different GrContext, this will fail.
+     */
+    sk_sp<SkSpecialImage> makeTextureImage(SkImageFilter::Proxy*, GrContext*);
+
+    /**
      *  Draw this SpecialImage into the canvas.
      */
     void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const;