Add a GrPathRange class

include/gpu/GrTypes.h

Index: include/gpu/GrTypes.h
diff --git a/include/gpu/GrTypes.h b/include/gpu/GrTypes.h
index 425c136fa6013f5c8d444c87faa4bd3b0e62b132..b4a08eb9f265b7aec7ef78b77e960ff8ffc80371 100644
--- a/include/gpu/GrTypes.h
+++ b/include/gpu/GrTypes.h
@@ -202,6 +202,37 @@ static inline bool GrIsPrimTypeTris(GrPrimitiveType type) {
 }
 
 /**
+* Transform formats used for paths.
+*/
+enum GrTransformFormat {
+    kNone_GrTransformFormat,        //!< []
+    kTranslateX_GrTransformFormat,  //!< [kMTransX]
+    kTranslateY_GrTransformFormat,  //!< [kMTransY]
+    kTranslate_GrTransformFormat,   //!< [kMTransX, kMTransY]
+    kAffine_GrTransformFormat,      //!< [kMScaleX, kMSkewX, kMTransX, kMSkewY, kMScaleY, kMTransY]
+
+    kLast_GrTransformFormat = kAffine_GrTransformFormat
+};
+
+static inline int GrTransformSize(GrTransformFormat format) {

[bsalomon, 2014/07/17 17:27:28]

Can we call it Type rather than Format?

Also, maybe PathTransformType since we're only using it for paths and we have
GrCoordTransform?

Should we put this inside GrDrawTarget?

[Chris Dalton, 2014/07/17 18:15:19]

My motivation for calling it Format was because it describes the format of a
float* array of transforms: 'drawPaths(..., transforms, transformsFormat, ...)',
but then again, the parameter is named Type in nvpr :). I guess don't have a
strong preference.

I'll add Path to the name.

I thought GrTypes would be a good spot because it's alongside other enums that
basically map GLenums, complete with helper functions. But it is a bit weird
that it's in the include/ directory and there are no public APIs that use it.
Are all the other enums in this file used publicly? Were you thinking of moving
it to a nested enum within GrDrawTarget?

+    switch (format) {
+        case kNone_GrTransformFormat:
+            return 0;
+        case kTranslateX_GrTransformFormat:
+        case kTranslateY_GrTransformFormat:
+            return 1;
+        case kTranslate_GrTransformFormat:
+            return 2;
+        case kAffine_GrTransformFormat:
+            return 6;
+
+        default:
+            SkFAIL("Unknown transform format");
+            return 0;
+    }
+}
+
+/**
  * Coeffecients for alpha-blending.
  */
 enum GrBlendCoeff {