Remove SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE

This was rebaselined and removed from Chrome long ago.
Planning to fix more bugs in the Convexicator, but want
to get this out of the way first.

Change-Id: I4f299d56a81be509a861d1e9c9f0e48a47170096
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209322
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

gm/convex_all_line_paths.cpp

diff --git a/gm/convex_all_line_paths.cpp b/gm/convex_all_line_paths.cpp
index 1b607ff..38ee7b3 100644
--- a/gm/convex_all_line_paths.cpp
+++ b/gm/convex_all_line_paths.cpp
@@ -55,13 +55,9 @@
 const SkPoint gPoints4[] = {
     { -6.0f, -50.0f },
     { 4.0f, -50.0f },
-#if SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE == 0
     { 5.0f, -25.0f },  // remove if collinear diagonal points are not concave
-#endif
     { 6.0f,   0.0f },
-#if SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE == 0
     { 5.0f,  25.0f },  // remove if collinear diagonal points are not concave
-#endif
     { 4.0f,  50.0f },
     { -4.0f,  50.0f }
 };

src/core/SkPath.cpp

diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index 6655ff1..29693a0 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -2698,16 +2698,7 @@
         largest = SkTMax(largest, -smallest);
 
         if (almost_equal(largest, largest + cross)) {
-#if SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE
-    // colinear diagonals are not allowed; they aren't numerically stable
-    #define COLINEAR_POINT_DIR_CHANGE kConcave_DirChange
-#else
-    // colinear diagonals are allowed; we can survive dealing with 'close enough'
-    #define COLINEAR_POINT_DIR_CHANGE kStraight_DirChange
-#endif
-
-            SkScalar dot = lastVec.dot(curVec);
-            return dot < 0 ? kBackwards_DirChange : COLINEAR_POINT_DIR_CHANGE;
+            return lastVec.dot(curVec) < 0 ? kBackwards_DirChange : kStraight_DirChange;
         }
         return 1 == SkScalarSignAsInt(cross) ? kRight_DirChange : kLeft_DirChange;
     }

src/core/SkPathPriv.h

diff --git a/src/core/SkPathPriv.h b/src/core/SkPathPriv.h
index ff2fdc1..855efae 100644
--- a/src/core/SkPathPriv.h
+++ b/src/core/SkPathPriv.h
@@ -10,14 +10,6 @@
 
 #include "SkPath.h"
 
-#define SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE 0
-
-#if SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE
-    #define COLINEAR_DIAGONAL_CONVEXITY kConcave_Convexity
-#else
-    #define COLINEAR_DIAGONAL_CONVEXITY kConvex_Convexity
-#endif
-
 class SkPathPriv {
 public:
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK

tests/PathTest.cpp

diff --git a/tests/PathTest.cpp b/tests/PathTest.cpp
index 7ce1ee3..e55cb44 100644
--- a/tests/PathTest.cpp
+++ b/tests/PathTest.cpp
@@ -1348,16 +1348,10 @@
     tinyConvexPolygon.lineTo(600.134891f, 800.137724f);
     tinyConvexPolygon.close();
     tinyConvexPolygon.getConvexity();
-    check_convexity(reporter, tinyConvexPolygon, SkPath::COLINEAR_DIAGONAL_CONVEXITY);
-#if SK_TREAT_COLINEAR_DIAGONAL_POINTS_AS_CONCAVE
-    // colinear diagonal points cause convexicator to give up, so CheapComputeFirstDirection
-    // makes its best guess
-    check_direction(reporter, tinyConvexPolygon, SkPathPriv::kCW_FirstDirection);
-#else
+    check_convexity(reporter, tinyConvexPolygon, SkPath::kConvex_Convexity);
     // lines are close enough to straight that polygon collapses to line that does not
     // enclose area, so has unknown first direction
     check_direction(reporter, tinyConvexPolygon, SkPathPriv::kUnknown_FirstDirection);
-#endif
 
     SkPath  platTriangle;
     platTriangle.moveTo(0, 0);
@@ -1485,7 +1479,7 @@
     SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
     stroke.setStrokeStyle(2 * SK_Scalar1);
     stroke.applyToPath(&strokedSin, strokedSin);
-    check_convexity(reporter, strokedSin, SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    check_convexity(reporter, strokedSin, SkPath::kConvex_Convexity); // !!!
     check_direction(reporter, strokedSin, kDontCheckDir);
 
     // http://crbug.com/412640
@@ -1519,7 +1513,7 @@
     doubleback.lineTo(1, 1);
     check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
     doubleback.lineTo(2, 2);
-    check_convexity(reporter, doubleback, SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
     doubleback.reset();
     doubleback.lineTo(1, 0);
     check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
@@ -1529,7 +1523,7 @@
     check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
     doubleback.reset();
     doubleback.quadTo(1, 1, 2, 2);
-    check_convexity(reporter, doubleback, SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
     doubleback.reset();
     doubleback.quadTo(1, 0, 2, 0);
     check_convexity(reporter, doubleback, SkPath::kConvex_Convexity);
@@ -1592,7 +1586,7 @@
 
     path.reset();
     path.quadTo(100, 100, 50, 50); // This from GM:convexpaths
-    check_convexity(reporter, path, SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    check_convexity(reporter, path, SkPath::kConvex_Convexity);
 
     static const struct {
         const char*                 fPathStr;
@@ -3727,10 +3721,10 @@
     // diagonal colinear points make arc convex
     // TODO: one way to keep it concave would be to introduce interpolated on curve points
     // between control points and computing the on curve point at scan conversion time
-    REPORTER_ASSERT(reporter, p.getConvexity() == SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    REPORTER_ASSERT(reporter, p.getConvexity() == SkPath::kConvex_Convexity);
     REPORTER_ASSERT(reporter, SkPathPriv::CheapIsFirstDirection(p, SkPathPriv::kCW_FirstDirection));
     p.setConvexity(SkPath::kUnknown_Convexity);
-    REPORTER_ASSERT(reporter, p.getConvexity() == SkPath::COLINEAR_DIAGONAL_CONVEXITY);
+    REPORTER_ASSERT(reporter, p.getConvexity() == SkPath::kConvex_Convexity);
 }
 
 static inline SkScalar oval_start_index_to_angle(unsigned start) {