Add dm via-option rtblend- to test using Runtime Blends.

Change-Id: I46844754a86ae44b61747b7244edf6cc1fd73d61
Bug: skia:12080
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/429102
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

BUILD.gn

@@ -2104,7 +2104,9 @@ if (skia_enable_tools) {
         "dm/DM.cpp",
         "dm/DMGpuTestProcs.cpp",
         "dm/DMJsonWriter.cpp",
+        "dm/DMJsonWriter.h",
         "dm/DMSrcSink.cpp",
+        "dm/DMSrcSink.h",
       ]
       deps = [
         ":common_flags_aa",

dm/DM.cpp

@@ -1032,6 +1032,7 @@ static Sink* create_via(const SkString& tag, Sink* wrapped) {
 #endif
     VIA("serialize", ViaSerialization,     wrapped);
     VIA("pic",       ViaPicture,           wrapped);
+    VIA("rtblend",   ViaRuntimeBlend,      wrapped);
 
     if (FLAGS_matrix.count() == 4) {
         SkMatrix m;

dm/DMSrcSink.cpp

@@ -30,6 +30,7 @@
 #include "include/private/SkTLogic.h"
 #include "include/third_party/skcms/skcms.h"
 #include "include/utils/SkNullCanvas.h"
+#include "include/utils/SkPaintFilterCanvas.h"
 #include "include/utils/SkRandom.h"
 #include "modules/skottie/utils/SkottieUtils.h"
 #include "src/codec/SkCodecImageGenerator.h"
@@ -50,6 +51,7 @@
 #include "tools/DDLPromiseImageHelper.h"
 #include "tools/DDLTileHelper.h"
 #include "tools/Resources.h"
+#include "tools/RuntimeBlendUtils.h"
 #include "tools/debugger/DebugCanvas.h"
 #include "tools/gpu/BackendSurfaceFactory.h"
 #include "tools/gpu/MemoryCache.h"
@@ -1560,8 +1562,8 @@ Result GPUSink::onDraw(const Src& src, SkBitmap* dst, SkWStream*, SkString* log,
     if (FLAGS_preAbandonGpuContext) {
         factory.abandonContexts();
     }
-    SkCanvas* canvas = surface->getCanvas();
-    Result result = src.draw(direct, canvas);
+
+    Result result = src.draw(direct, surface->getCanvas());
     if (!result.isOk()) {
         return result;
     }
@@ -2265,6 +2267,35 @@ Result ViaPicture::draw(const Src& src, SkBitmap* bitmap, SkWStream* stream, SkS
 
 /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
+Result ViaRuntimeBlend::draw(const Src& src,
+                             SkBitmap* bitmap,
+                             SkWStream* stream,
+                             SkString* log) const {
+    class RuntimeBlendFilterCanvas : public SkPaintFilterCanvas {
+    public:
+        RuntimeBlendFilterCanvas(SkCanvas* canvas) : INHERITED(canvas) { }
+
+    protected:
+        bool onFilter(SkPaint& paint) const override {
+            if (skstd::optional<SkBlendMode> mode = paint.asBlendMode()) {
+                paint.setBlender(GetRuntimeBlendForBlendMode(*mode));
+            }
+            return true;
+        }
+
+    private:
+        using INHERITED = SkPaintFilterCanvas;
+    };
+
+    return draw_to_canvas(fSink.get(), bitmap, stream, log, src.size(),
+                          [&](GrDirectContext* context, SkCanvas* canvas) {
+        RuntimeBlendFilterCanvas runtimeBlendCanvas{canvas};
+        return src.draw(context, &runtimeBlendCanvas);
+    });
+}
+
+/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
 #ifdef TEST_VIA_SVG
 #include "include/svg/SkSVGCanvas.h"
 #include "modules/svg/include/SkSVGDOM.h"

dm/DMSrcSink.h

@@ -625,6 +625,12 @@ public:
     Result draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
+class ViaRuntimeBlend : public Via {
+public:
+    explicit ViaRuntimeBlend(Sink* sink) : Via(sink) {}
+    Result draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
+};
+
 class ViaSVG : public Via {
 public:
     explicit ViaSVG(Sink* sink) : Via(sink) {}