From 653c12d773def4d25cbdb78072b84404a5d80957 Mon Sep 17 00:00:00 2001
From: fmalita <fmalita@chromium.org>
Date: Sat, 30 Jan 2016 10:06:46 -0800
Subject: [PATCH] Add sampler bias for the nofilter/translate specializations

Convert SkBitmapProcState::setupForTranslate() to use
SkBitmapProcStateAutoMapper.  This adds bias for the translate procs:
Clamp_S32_D32_nofilter_trans_shaderproc,
Repeat_S32_D32_nofilter_trans_shaderproc

Since the original impl checks for int overflow, extend
SkBitmapProcStateAutoMapper to detect this condition.

BUG=chromium:581870
R=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1642273002

Review URL: https://codereview.chromium.org/1642273002
---
 src/core/SkBitmapProcState.cpp | 20 ++++++++++++++++----
 src/core/SkBitmapProcState.h   | 14 ++++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/core/SkBitmapProcState.cpp b/src/core/SkBitmapProcState.cpp
index 3c3f3a54b7..c4b29392f1 100644
--- a/src/core/SkBitmapProcState.cpp
+++ b/src/core/SkBitmapProcState.cpp
@@ -586,24 +586,36 @@ static void DoNothing_shaderproc(const void*, int x, int y,
 }
 
 bool SkBitmapProcState::setupForTranslate() {
+#ifdef SK_SUPPORT_LEGACY_SAMPLER_BIAS
     SkPoint pt;
     fInvProc(fInvMatrix, SK_ScalarHalf, SK_ScalarHalf, &pt);
 
+    const SkScalar too_big = SkIntToScalar(1 << 30);
+    if (SkScalarAbs(pt.fX) > too_big || SkScalarAbs(pt.fY) > too_big) {
+        return false;
+    }
+
+    fFilterOneX = SkScalarFloorToInt(pt.fX);
+    fFilterOneY = SkScalarFloorToInt(pt.fY);
+#else
+    SkBitmapProcStateAutoMapper mapper(*this, 0, 0);
+
     /*
      *  if the translate is larger than our ints, we can get random results, or
      *  worse, we might get 0x80000000, which wreaks havoc on us, since we can't
      *  negate it.
      */
-    const SkScalar too_big = SkIntToScalar(1 << 30);
-    if (SkScalarAbs(pt.fX) > too_big || SkScalarAbs(pt.fY) > too_big) {
+    if (mapper.isOverflow()) {
         return false;
     }
 
     // Since we know we're not filtered, we re-purpose these fields allow
     // us to go from device -> src coordinates w/ just an integer add,
     // rather than running through the inverse-matrix
-    fFilterOneX = SkScalarFloorToInt(pt.fX);
-    fFilterOneY = SkScalarFloorToInt(pt.fY);
+    fFilterOneX = SkFractionalIntToInt(mapper.x());
+    fFilterOneY = SkFractionalIntToInt(mapper.y());
+#endif
+
     return true;
 }
 
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h
index 3f1d699cf2..5e680befd2 100644
--- a/src/core/SkBitmapProcState.h
+++ b/src/core/SkBitmapProcState.h
@@ -206,13 +206,27 @@ public:
         const SkFixed biasY = (s.fInvMatrix.getScaleY() > 0);
         fX = SkScalarToFractionalInt(pt.x()) - SkFixedToFractionalInt(biasX);
         fY = SkScalarToFractionalInt(pt.y()) - SkFixedToFractionalInt(biasY);
+
+        /*
+         *  (see SkBitmapProcState::setupForTranslate, which is the only user of this flag)
+         *
+         *  if the translate is larger than our ints, we can get random results, or
+         *  worse, we might get 0x80000000, which wreaks havoc on us, since we can't
+         *  negate it.
+         */
+        const SkScalar too_big = SkIntToScalar(1 << 30);
+        fOverflow = SkScalarAbs(pt.x() - SkFixedToScalar(biasX)) > too_big
+                 || SkScalarAbs(pt.y() - SkFixedToScalar(biasY)) > too_big;
     }
 
     SkFractionalInt x() const { return fX; }
     SkFractionalInt y() const { return fY; }
 
+    bool isOverflow() const { return fOverflow; }
+
 private:
     SkFractionalInt fX, fY;
+    bool            fOverflow;
 };
 
 #endif