some utils for rect and matrix

BUG=skia:

Review URL: https://codereview.chromium.org/1003813003

10 files changed, 56 insertions, 42 deletions

diff --git a/include/core/SkMatrix.h b/include/core/SkMatrix.h
index da7838b781..a272051067 100644
--- a/include/core/SkMatrix.h
+++ b/include/core/SkMatrix.h
@@ -457,6 +457,12 @@ public:
         this->getMapXYProc()(*this, x, y, result);
     }
 
+    SkPoint mapXY(SkScalar x, SkScalar y) const {
+        SkPoint result;
+        this->getMapXYProc()(*this, x, y, &result);
+        return result;
+    }
+
     /** Apply this matrix to the array of vectors specified by src, and write
         the transformed vectors into the array of vectors specified by dst.
         This is similar to mapPoints, but ignores any translation in the matrix.
@@ -480,6 +486,17 @@ public:
         this->mapVectors(vecs, vecs, count);
     }
 
+    void mapVector(SkScalar dx, SkScalar dy, SkVector* result) const {
+        SkVector vec = { dx, dy };
+        this->mapVectors(result, &vec, 1);
+    }
+
+    SkVector mapVector(SkScalar dx, SkScalar dy) const {
+        SkVector vec = { dx, dy };
+        this->mapVectors(&vec, &vec, 1);
+        return vec;
+    }
+
     /** Apply this matrix to the src rectangle, and write the transformed
         rectangle into dst. This is accomplished by transforming the 4 corners
         of src, and then setting dst to the bounds of those points.
diff --git a/include/core/SkRect.h b/include/core/SkRect.h
index 8d68c97feb..5c806a963b 100644
--- a/include/core/SkRect.h
+++ b/include/core/SkRect.h
@@ -162,17 +162,24 @@ struct SK_API SkIRect {
     /**
      *  Return a new IRect, built as an offset of this rect.
      */
-    SkIRect makeOffset(int dx, int dy) const {
+    SkIRect makeOffset(int32_t dx, int32_t dy) const {
         return MakeLTRB(fLeft + dx, fTop + dy, fRight + dx, fBottom + dy);
     }
 
     /**
      *  Return a new IRect, built as an inset of this rect.
      */
-    SkIRect makeInset(int dx, int dy) const {
+    SkIRect makeInset(int32_t dx, int32_t dy) const {
         return MakeLTRB(fLeft + dx, fTop + dy, fRight - dx, fBottom - dy);
     }
 
+    /**
+     *  Return a new Rect, built as an outset of this rect.
+     */
+    SkIRect makeOutset(int32_t dx, int32_t dy) const {
+        return MakeLTRB(fLeft - dx, fTop - dy, fRight + dx, fBottom + dy);
+    }
+
     /** Offset set the rectangle by adding dx to its left and right,
         and adding dy to its top and bottom.
     */
@@ -608,7 +615,7 @@ struct SK_API SkRect {
     SkRect makeOffset(SkScalar dx, SkScalar dy) const {
         return MakeLTRB(fLeft + dx, fTop + dy, fRight + dx, fBottom + dy);
     }
-
+    
     /**
      *  Return a new Rect, built as an inset of this rect.
      */
@@ -616,6 +623,13 @@ struct SK_API SkRect {
         return MakeLTRB(fLeft + dx, fTop + dy, fRight - dx, fBottom - dy);
     }
 
+    /**
+     *  Return a new Rect, built as an outset of this rect.
+     */
+    SkRect makeOutset(SkScalar dx, SkScalar dy) const {
+        return MakeLTRB(fLeft - dx, fTop - dy, fRight + dx, fBottom + dy);
+    }
+
     /** Offset set the rectangle by adding dx to its left and right,
         and adding dy to its top and bottom.
     */
diff --git a/include/gpu/GrCoordTransform.h b/include/gpu/GrCoordTransform.h
index 09f4ac9dfa..4d96cd9c97 100644
--- a/include/gpu/GrCoordTransform.h
+++ b/include/gpu/GrCoordTransform.h
@@ -125,7 +125,7 @@ public:
     static inline SkMatrix MakeDivByTextureWHMatrix(const GrTexture* texture) {
         SkASSERT(texture);
         SkMatrix mat;
-        mat.setIDiv(texture->width(), texture->height());
+        (void)mat.setIDiv(texture->width(), texture->height());
         return mat;
     }
 
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index bd4e40e9f1..ef268bfed3 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -2181,11 +2181,7 @@ static bool compute_bounds(const SkPath& devPath, const SkIRect* clipBounds,
     }
 
     //  init our bounds from the path
-    {
-        SkRect pathBounds = devPath.getBounds();
-        pathBounds.inset(-SK_ScalarHalf, -SK_ScalarHalf);
-        pathBounds.roundOut(bounds);
-    }
+    *bounds = devPath.getBounds().makeOutset(SK_ScalarHalf, SK_ScalarHalf).roundOut();
 
     SkIPoint margin = SkIPoint::Make(0, 0);
     if (filter) {
@@ -2204,7 +2200,6 @@ static bool compute_bounds(const SkPath& devPath, const SkIRect* clipBounds,
     // (possibly) trim the bounds to reflect the clip
     // (plus whatever slop the filter needs)
     if (clipBounds) {
-        SkIRect tmp = *clipBounds;
         // Ugh. Guard against gigantic margins from wacky filters. Without this
         // check we can request arbitrary amounts of slop beyond our visible
         // clip, and bring down the renderer (at least on finite RAM machines
@@ -2212,9 +2207,8 @@ static bool compute_bounds(const SkPath& devPath, const SkIRect* clipBounds,
         // quality of large filters like blurs, and the corresponding memory
         // requests.
         static const int MAX_MARGIN = 128;
-        tmp.inset(-SkMin32(margin.fX, MAX_MARGIN),
-                  -SkMin32(margin.fY, MAX_MARGIN));
-        if (!bounds->intersect(tmp)) {
+        if (!bounds->intersect(clipBounds->makeOutset(SkMin32(margin.fX, MAX_MARGIN),
+                                                      SkMin32(margin.fY, MAX_MARGIN)))) {
             return false;
         }
     }
diff --git a/src/core/SkRRect.cpp b/src/core/SkRRect.cpp
index f2927644da..d8b4a20d88 100644
--- a/src/core/SkRRect.cpp
+++ b/src/core/SkRRect.cpp
@@ -453,9 +453,8 @@ bool SkRRect::transform(const SkMatrix& matrix, SkRRect* dst) const {
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkRRect::inset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
-    SkRect r = fRect;
+    const SkRect r = fRect.makeInset(dx, dy);
 
-    r.inset(dx, dy);
     if (r.isEmpty()) {
         dst->setEmpty();
         return;
diff --git a/src/core/SkRasterizer.cpp b/src/core/SkRasterizer.cpp
index 3a7af95555..ab9e011761 100644
--- a/src/core/SkRasterizer.cpp
+++ b/src/core/SkRasterizer.cpp
@@ -27,8 +27,7 @@ bool SkRasterizer::rasterize(const SkPath& fillPath, const SkMatrix& matrix,
         if (!filter->filterMask(&dstM, srcM, matrix, &margin)) {
             return false;
         }
-        storage = *clipBounds;
-        storage.inset(-margin.fX, -margin.fY);
+        storage = clipBounds->makeOutset(margin.fX, margin.fY);
         clipBounds = &storage;
     }
 
diff --git a/src/core/SkScan_Antihair.cpp b/src/core/SkScan_Antihair.cpp
index d0341510a9..a3305e2dc8 100644
--- a/src/core/SkScan_Antihair.cpp
+++ b/src/core/SkScan_Antihair.cpp
@@ -625,7 +625,7 @@ void SkScan::AntiHairLineRgn(const SkPoint& pt0, const SkPoint& pt1,
             since the 1/2 pixel boundary is important to the antihair blitter,
             we don't want to risk numerical fate by chopping on that edge.
          */
-        clipBounds.inset(-SK_Scalar1, -SK_Scalar1);
+        clipBounds.outset(SK_Scalar1, SK_Scalar1);
 
         if (!SkLineClipper::IntersectLine(pts, clipBounds, pts)) {
             return;
diff --git a/src/core/SkScan_Hairline.cpp b/src/core/SkScan_Hairline.cpp
index 7ca54eac33..bd597b3d68 100644
--- a/src/core/SkScan_Hairline.cpp
+++ b/src/core/SkScan_Hairline.cpp
@@ -267,9 +267,7 @@ static void hair_path(const SkPath& path, const SkRasterClip& rclip,
     const SkRegion* clip = NULL;
 
     {
-        SkIRect ibounds;
-        path.getBounds().roundOut(&ibounds);
-        ibounds.inset(-1, -1);
+        const SkIRect ibounds = path.getBounds().roundOut().makeOutset(1, 1);
 
         if (rclip.quickReject(ibounds)) {
             return;
@@ -379,7 +377,7 @@ void SkScan::HairLine(const SkPoint& p0, const SkPoint& p1,
         SkRect r;
         r.set(p0.fX, p0.fY, p1.fX, p1.fY);
         r.sort();
-        r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
+        r.outset(SK_ScalarHalf, SK_ScalarHalf);
 
         SkAAClipBlitterWrapper wrap;
         if (!clip.quickContains(r.roundOut())) {
@@ -398,14 +396,11 @@ void SkScan::AntiHairLine(const SkPoint& p0, const SkPoint& p1,
     } else {
         const SkRegion* clipRgn = NULL;
         SkRect r;
-        SkIRect ir;
         r.set(p0.fX, p0.fY, p1.fX, p1.fY);
         r.sort();
-        r.roundOut(&ir);
-        ir.inset(-1, -1);
 
         SkAAClipBlitterWrapper wrap;
-        if (!clip.quickContains(ir)) {
+        if (!clip.quickContains(r.roundOut().makeOutset(1, 1))) {
             wrap.init(clip, blitter);
             blitter = wrap.getBlitter();
             clipRgn = &wrap.getRgn();
diff --git a/src/effects/SkPerlinNoiseShader.cpp b/src/effects/SkPerlinNoiseShader.cpp
index 3c1bf2fd03..fa46cbd44a 100644
--- a/src/effects/SkPerlinNoiseShader.cpp
+++ b/src/effects/SkPerlinNoiseShader.cpp
@@ -78,16 +78,14 @@ struct SkPerlinNoiseShader::PaintingData {
                  SkScalar baseFrequencyX, SkScalar baseFrequencyY,
                  const SkMatrix& matrix)
     {
-        SkVector wavelength = SkVector::Make(SkScalarInvert(baseFrequencyX),
-                                             SkScalarInvert(baseFrequencyY));
-        matrix.mapVectors(&wavelength, 1);
-        fBaseFrequency.fX = SkScalarInvert(wavelength.fX);
-        fBaseFrequency.fY = SkScalarInvert(wavelength.fY);
-        SkVector sizeVec = SkVector::Make(SkIntToScalar(tileSize.fWidth),
-                                          SkIntToScalar(tileSize.fHeight));
-        matrix.mapVectors(&sizeVec, 1);
-        fTileSize.fWidth = SkScalarRoundToInt(sizeVec.fX);
-        fTileSize.fHeight = SkScalarRoundToInt(sizeVec.fY);
+        SkVector vec[2] = {
+            { SkScalarInvert(baseFrequencyX),   SkScalarInvert(baseFrequencyY)  },
+            { SkIntToScalar(tileSize.fWidth),   SkIntToScalar(tileSize.fHeight) },
+        };
+        matrix.mapVectors(vec, 2);
+
+        fBaseFrequency.set(SkScalarInvert(vec[0].fX), SkScalarInvert(vec[0].fY));
+        fTileSize.set(SkScalarRoundToInt(vec[1].fX), SkScalarRoundToInt(vec[1].fY));
         this->init(seed);
         if (!fTileSize.isEmpty()) {
             this->stitch();
diff --git a/src/fonts/SkTestScalerContext.cpp b/src/fonts/SkTestScalerContext.cpp
index fc1f9456e2..769f4ea66f 100644
--- a/src/fonts/SkTestScalerContext.cpp
+++ b/src/fonts/SkTestScalerContext.cpp
@@ -214,9 +214,8 @@ protected:
     void generateAdvance(SkGlyph* glyph) SK_OVERRIDE {
         fFace->getAdvance(glyph);
 
-        SkVector advance;
-        fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
-                      SkFixedToScalar(glyph->fAdvanceY), &advance);
+        const SkVector advance = fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
+                                               SkFixedToScalar(glyph->fAdvanceY));
         glyph->fAdvanceX = SkScalarToFixed(advance.fX);
         glyph->fAdvanceY = SkScalarToFixed(advance.fY);
     }
@@ -224,9 +223,8 @@ protected:
     void generateMetrics(SkGlyph* glyph) SK_OVERRIDE {
         fFace->getMetrics(glyph);
 
-        SkVector advance;
-        fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
-                      SkFixedToScalar(glyph->fAdvanceY), &advance);
+        const SkVector advance = fMatrix.mapXY(SkFixedToScalar(glyph->fAdvanceX),
+                                               SkFixedToScalar(glyph->fAdvanceY));
         glyph->fAdvanceX = SkScalarToFixed(advance.fX);
         glyph->fAdvanceY = SkScalarToFixed(advance.fY);