Wrap NV_path_rendering API with GrGLPathRendering

Adds a GrGLPathRendering class that wraps the NV_path_rendering
extension and manages its various API versions. It also provides
backup implementations when certain NVpr methods from later API
versions are not present on the current system.

BUG=skia:
R=bungeman@google.com, bsalomon@google.com, kkinnunen@nvidia.com

Author: cdalton@nvidia.com

Review URL: https://codereview.chromium.org/444223002

1 files changed, 19 insertions, 10 deletions

diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index e9ba32ed24..c192611f50 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -56,6 +56,10 @@ const GrGLInterface* GrGLInterfaceRemoveNVPR(const GrGLInterface* interface) {
     newInterface->fFunctions.fCoverStrokePath = NULL;
     newInterface->fFunctions.fCoverFillPathInstanced = NULL;
     newInterface->fFunctions.fCoverStrokePathInstanced = NULL;
+    newInterface->fFunctions.fStencilThenCoverFillPath = NULL;
+    newInterface->fFunctions.fStencilThenCoverStrokePath = NULL;
+    newInterface->fFunctions.fStencilThenCoverFillPathInstanced = NULL;
+    newInterface->fFunctions.fStencilThenCoverStrokePathInstanced = NULL;
     newInterface->fFunctions.fProgramPathFragmentInputGen = NULL;
     return newInterface;
 }
@@ -467,18 +471,23 @@ bool GrGLInterface::validate() const {
             NULL == fFunctions.fCoverFillPath ||
             NULL == fFunctions.fCoverStrokePath ||
             NULL == fFunctions.fCoverFillPathInstanced ||
-            NULL == fFunctions.fCoverStrokePathInstanced ||
-            NULL == fFunctions.fStencilThenCoverFillPath ||
-            NULL == fFunctions.fStencilThenCoverStrokePath ||
-            NULL == fFunctions.fStencilThenCoverFillPathInstanced ||
-            NULL == fFunctions.fStencilThenCoverStrokePathInstanced) {
+            NULL == fFunctions.fCoverStrokePathInstanced) {
             RETURN_FALSE_INTERFACE
         }
-        // Currently ProgramPathFragmentInputGen is not used on
-        // OpenGL, rather PathTexGen is.
-        if ((kGL_GrGLStandard == fStandard && NULL == fFunctions.fPathTexGen) ||
-            (kGLES_GrGLStandard == fStandard && NULL == fFunctions.fProgramPathFragmentInputGen)) {
-            RETURN_FALSE_INTERFACE
+        if (kGL_GrGLStandard == fStandard) {
+            // Some methods only exist on desktop
+            if (NULL == fFunctions.fPathTexGen) {
+                RETURN_FALSE_INTERFACE
+            }
+        } else {
+            // All additions through v1.3 exist on GLES
+            if (NULL == fFunctions.fStencilThenCoverFillPath ||
+                NULL == fFunctions.fStencilThenCoverStrokePath ||
+                NULL == fFunctions.fStencilThenCoverFillPathInstanced ||
+                NULL == fFunctions.fStencilThenCoverStrokePathInstanced ||
+                NULL == fFunctions.fProgramPathFragmentInputGen) {
+                RETURN_FALSE_INTERFACE
+            }
         }
     }