Remove Sk4fGradientInterval::fZeroRamp

It's cheap enough to compute when needed, and we don't need it in hot
loops anyway.
Change-Id: Ib0242f98f8bee31bff939cfdc7356d51525092e4
Reviewed-on: https://skia-review.googlesource.com/15764
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

3 files changed, 9 insertions, 19 deletions

diff --git a/src/effects/gradients/Sk4fGradientBase.cpp b/src/effects/gradients/Sk4fGradientBase.cpp
index 81442df048..e20f5f4702 100644
--- a/src/effects/gradients/Sk4fGradientBase.cpp
+++ b/src/effects/gradients/Sk4fGradientBase.cpp
@@ -120,8 +120,7 @@ void addMirrorIntervals(const SkColor colors[],
 Sk4fGradientInterval::Sk4fGradientInterval(const Sk4f& c0, SkScalar t0,
                                            const Sk4f& c1, SkScalar t1)
     : fT0(t0)
-    , fT1(t1)
-    , fZeroRamp((c0 == c1).allTrue()) {
+    , fT1(t1) {
     SkASSERT(t0 != t1);
     // Either p0 or p1 can be (-)inf for synthetic clamp edge intervals.
     SkASSERT(SkScalarIsFinite(t0) || SkScalarIsFinite(t1));
@@ -129,8 +128,8 @@ Sk4fGradientInterval::Sk4fGradientInterval(const Sk4f& c0, SkScalar t0,
     const auto dt = t1 - t0;
 
     // Clamp edge intervals are always zero-ramp.
-    SkASSERT(SkScalarIsFinite(dt) || fZeroRamp);
-    SkASSERT(SkScalarIsFinite(t0) || fZeroRamp);
+    SkASSERT(SkScalarIsFinite(dt) || (c0 == c1).allTrue());
+    SkASSERT(SkScalarIsFinite(t0) || (c0 == c1).allTrue());
     const Sk4f   dc = SkScalarIsFinite(dt) ? (c1 - c0) / dt : 0;
     const Sk4f bias = c0 - (SkScalarIsFinite(t0) ? t0 * dc : 0);
 
diff --git a/src/effects/gradients/Sk4fGradientBase.h b/src/effects/gradients/Sk4fGradientBase.h
index fcdcd9e8c7..9209a90637 100644
--- a/src/effects/gradients/Sk4fGradientBase.h
+++ b/src/effects/gradients/Sk4fGradientBase.h
@@ -33,7 +33,6 @@ struct Sk4fGradientInterval {
     //   C = fCb + t * fCg;
     SkPM4f   fCb, fCg;
     SkScalar fT0, fT1;
-    bool     fZeroRamp;
 };
 
 class Sk4fGradientIntervalBuffer {
diff --git a/src/effects/gradients/Sk4fLinearGradient.cpp b/src/effects/gradients/Sk4fLinearGradient.cpp
index fe900e8d03..49b98fd86e 100644
--- a/src/effects/gradients/Sk4fLinearGradient.cpp
+++ b/src/effects/gradients/Sk4fLinearGradient.cpp
@@ -351,16 +351,10 @@ private:
     void compute_interval_props(SkScalar t) {
         SkASSERT(in_range(t, fInterval->fT0, fInterval->fT1));
 
-        fZeroRamp     = fIsVertical || fInterval->fZeroRamp;
-        fCc           = DstTraits<dstType, premul>::load(fInterval->fCb);
-
-        if (fInterval->fZeroRamp) {
-            fDcDx = 0;
-        } else {
-            const Sk4f dC = DstTraits<dstType, premul>::load(fInterval->fCg);
-            fCc           = fCc + dC * Sk4f(t);
-            fDcDx         = dC * fDx;
-        }
+        const Sk4f dc = DstTraits<dstType, premul>::load(fInterval->fCg);
+                  fCc = DstTraits<dstType, premul>::load(fInterval->fCb) + dc * Sk4f(t);
+                fDcDx = dc * fDx;
+            fZeroRamp = fIsVertical || (dc == 0).allTrue();
     }
 
     void init_average_props() {
@@ -377,10 +371,8 @@ private:
             //
             //   Avg += C * (t1 - t0)
             //
-            auto c = DstTraits<dstType, premul>::load(i->fCb);
-            if (!i->fZeroRamp) {
-                c = c + DstTraits<dstType, premul>::load(i->fCg) * (i->fT0 + i->fT1) * 0.5f;
-            }
+            const auto c = DstTraits<dstType, premul>::load(i->fCb)
+                         + DstTraits<dstType, premul>::load(i->fCg) * (i->fT0 + i->fT1) * 0.5f;
             fCc = fCc + c * (i->fT1 - i->fT0);
         }
     }