Coverage counting path renderer

Initial implementation of a GPU path renderer that draws antialiased
paths by counting coverage in an offscreen buffer.

Initially disabled until it has had time to soak.

Bug: skia:
Change-Id: I003d8cfdf8dc62641581b5ea2dc4f0aa00108df6
Reviewed-on: https://skia-review.googlesource.com/21541
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/tools/flags/SkCommonFlagsPathRenderer.h b/tools/flags/SkCommonFlagsPathRenderer.h
index 12755dcc06..ac293a1e79 100644
--- a/tools/flags/SkCommonFlagsPathRenderer.h
+++ b/tools/flags/SkCommonFlagsPathRenderer.h
@@ -40,6 +40,8 @@ inline GrContextOptions::GpuPathRenderers get_named_pathrenderers_flags(const ch
         return GpuPathRenderers::kAALinearizing;
     } else if (!strcmp(name, "small")) {
         return GpuPathRenderers::kSmall;
+    } else if (!strcmp(name, "ccpr")) {
+        return GpuPathRenderers::kCoverageCounting;
     } else if (!strcmp(name, "tess")) {
         return GpuPathRenderers::kTessellating;
     } else if (!strcmp(name, "grdefault")) {
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 29e5b70cb8..6753b6b63e 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -37,6 +37,8 @@
 
 #include "imgui.h"
 
+#include "ccpr/GrCoverageCountingPathRenderer.h"
+
 #include <stdlib.h>
 #include <map>
 
@@ -262,6 +264,7 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
         gPathRendererNames[GpuPathRenderers::kStencilAndCover] = "NV_path_rendering";
         gPathRendererNames[GpuPathRenderers::kMSAA] = "Sample shading";
         gPathRendererNames[GpuPathRenderers::kSmall] = "Small paths (cached sdf or alpha masks)";
+        gPathRendererNames[GpuPathRenderers::kCoverageCounting] = "Coverage counting";
         gPathRendererNames[GpuPathRenderers::kTessellating] = "Tessellating";
         gPathRendererNames[GpuPathRenderers::kDefault] = "Original Ganesh path renderer";
         gPathRendererNames[GpuPathRenderers::kNone] = "Software masks";
@@ -1069,6 +1072,9 @@ void Viewer::drawImGui(SkCanvas* canvas) {
                         prButton(GpuPathRenderers::kNone);
                     } else {
                         prButton(GpuPathRenderers::kAll);
+                        if (GrCoverageCountingPathRenderer::IsSupported(*ctx->caps())) {
+                            prButton(GpuPathRenderers::kCoverageCounting);
+                        }
                         prButton(GpuPathRenderers::kSmall);
                         prButton(GpuPathRenderers::kTessellating);
                         prButton(GpuPathRenderers::kNone);
@@ -1305,6 +1311,9 @@ void Viewer::updateUIState() {
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kNone]);
     } else {
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kAll]);
+        if (GrCoverageCountingPathRenderer::IsSupported(*ctx->caps())) {
+            prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kCoverageCounting]);
+        }
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kSmall]);
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kTessellating]);
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kNone]);