Rename SkMatrix::get(Max|Min)Stretch to get(Min|Max)Scale

R=reed@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/295713002

git-svn-id: http://skia.googlecode.com/svn/trunk@14798 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkMatrix.h b/include/core/SkMatrix.h
index e225336..d52ab67 100644
--- a/include/core/SkMatrix.h
+++ b/include/core/SkMatrix.h
@@ -563,20 +563,20 @@
     SK_TO_STRING_NONVIRT()
 
     /**
-     * Calculates the minimum stretching factor of the matrix. If the matrix has
+     * Calculates the minimum scaling factor of the matrix. If the matrix has
      * perspective -1 is returned.
      *
-     * @return minumum strecthing factor
+     * @return minumum scale factor
      */
-    SkScalar getMinStretch() const;
+    SkScalar getMinScale() const;
 
     /**
-     * Calculates the maximum stretching factor of the matrix. If the matrix has
+     * Calculates the maximum scale factor of the matrix. If the matrix has
      * perspective -1 is returned.
      *
-     * @return maximum strecthing factor
+     * @return maximum scale factor
      */
-    SkScalar getMaxStretch() const;
+    SkScalar getMaxScale() const;
 
     /**
      *  Return a reference to a const identity matrix
diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index d726a46..3ac26f0 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -385,11 +385,11 @@
 // Note that this will return -1 if either matrix is perspective.
 static SkScalar get_combined_min_stretch(const SkMatrix& viewMatrix, const SkMatrix& localMatrix) {
     if (localMatrix.isIdentity()) {
-        return viewMatrix.getMinStretch();
+        return viewMatrix.getMinScale();
     } else {
         SkMatrix combined;
         combined.setConcat(viewMatrix, localMatrix);
-        return combined.getMinStretch();
+        return combined.getMinScale();
     }
 }
 
diff --git a/src/core/SkMatrix.cpp b/src/core/SkMatrix.cpp
index 0929440..483c6c8 100644
--- a/src/core/SkMatrix.cpp
+++ b/src/core/SkMatrix.cpp
@@ -1456,8 +1456,8 @@
     kMax_MinOrMax
 };
 
-template <MinOrMax MIN_OR_MAX> SkScalar get_stretch_factor(SkMatrix::TypeMask typeMask,
-                                                           const SkScalar m[9]) {
+template <MinOrMax MIN_OR_MAX> SkScalar get_scale_factor(SkMatrix::TypeMask typeMask,
+                                                         const SkScalar m[9]) {
     if (typeMask & SkMatrix::kPerspective_Mask) {
         return -1;
     }
@@ -1510,12 +1510,12 @@
     return SkScalarSqrt(chosenRoot);
 }
 
-SkScalar SkMatrix::getMinStretch() const {
-    return get_stretch_factor<kMin_MinOrMax>(this->getType(), fMat);
+SkScalar SkMatrix::getMinScale() const {
+    return get_scale_factor<kMin_MinOrMax>(this->getType(), fMat);
 }
 
-SkScalar SkMatrix::getMaxStretch() const {
-    return get_stretch_factor<kMax_MinOrMax>(this->getType(), fMat);
+SkScalar SkMatrix::getMaxScale() const {
+    return get_scale_factor<kMax_MinOrMax>(this->getType(), fMat);
 }
 
 static void reset_identity_matrix(SkMatrix* identity) {
diff --git a/src/gpu/GrPathUtils.cpp b/src/gpu/GrPathUtils.cpp
index 5fead5d..81921e3 100644
--- a/src/gpu/GrPathUtils.cpp
+++ b/src/gpu/GrPathUtils.cpp
@@ -14,8 +14,8 @@
                                           const SkMatrix& viewM,
                                           const SkRect& pathBounds) {
     // In order to tesselate the path we get a bound on how much the matrix can
-    // stretch when mapping to screen coordinates.
-    SkScalar stretch = viewM.getMaxStretch();
+    // scale when mapping to screen coordinates.
+    SkScalar stretch = viewM.getMaxScale();
     SkScalar srcTol = devTol;
 
     if (stretch < 0) {
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 854839d..cddf50a 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1184,7 +1184,7 @@
             break;
         case SkPaint::kMedium_FilterLevel:
             tileFilterPad = 1;
-            if (fContext->getMatrix().getMinStretch() < SK_Scalar1) {
+            if (fContext->getMatrix().getMinScale() < SK_Scalar1) {
                 textureFilterMode = GrTextureParams::kMipMap_FilterMode;
             } else {
                 // Don't trigger MIP level generation unnecessarily.
@@ -1193,7 +1193,7 @@
             break;
         case SkPaint::kHigh_FilterLevel:
             // Minification can look bad with the bicubic effect.
-            if (fContext->getMatrix().getMinStretch() >= SK_Scalar1) {
+            if (fContext->getMatrix().getMinScale() >= SK_Scalar1) {
                 // We will install an effect that does the filtering in the shader.
                 textureFilterMode = GrTextureParams::kNone_FilterMode;
                 tileFilterPad = GrBicubicEffect::kFilterTexelPad;
diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index a670eae..c4d1c27 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -1725,7 +1725,7 @@
             vmi.mapRect(&bounds);
             // theoretically could set bloat = 0, instead leave it because of matrix inversion
             // precision.
-            SkScalar bloat = drawState->getViewMatrix().getMaxStretch() * SK_ScalarHalf;
+            SkScalar bloat = drawState->getViewMatrix().getMaxScale() * SK_ScalarHalf;
             bounds.outset(bloat, bloat);
         } else {
             avmr.setIdentity(drawState);
@@ -1818,7 +1818,7 @@
             vmi.mapRect(&bounds);
             // theoretically could set bloat = 0, instead leave it because of matrix inversion
             // precision.
-            SkScalar bloat = drawState->getViewMatrix().getMaxStretch() * SK_ScalarHalf;
+            SkScalar bloat = drawState->getViewMatrix().getMaxScale() * SK_ScalarHalf;
             bounds.outset(bloat, bloat);
         } else {
             avmr.setIdentity(drawState);
diff --git a/tests/MatrixTest.cpp b/tests/MatrixTest.cpp
index ab406fb..1897554 100644
--- a/tests/MatrixTest.cpp
+++ b/tests/MatrixTest.cpp
@@ -119,44 +119,44 @@
     REPORTER_ASSERT(reporter, memcmp(buffer, buffer2, size1) == 0);
 }
 
-static void test_matrix_min_max_stretch(skiatest::Reporter* reporter) {
+static void test_matrix_min_max_scale(skiatest::Reporter* reporter) {
     SkMatrix identity;
     identity.reset();
-    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMinStretch());
-    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxStretch());
+    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMinScale());
+    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxScale());
 
     SkMatrix scale;
     scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
-    REPORTER_ASSERT(reporter, SK_Scalar1 * 2 == scale.getMinStretch());
-    REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxStretch());
+    REPORTER_ASSERT(reporter, SK_Scalar1 * 2 == scale.getMinScale());
+    REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxScale());
 
     SkMatrix rot90Scale;
     rot90Scale.setRotate(90 * SK_Scalar1);
     rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
-    REPORTER_ASSERT(reporter, SK_Scalar1 / 4 == rot90Scale.getMinStretch());
-    REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxStretch());
+    REPORTER_ASSERT(reporter, SK_Scalar1 / 4 == rot90Scale.getMinScale());
+    REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxScale());
 
     SkMatrix rotate;
     rotate.setRotate(128 * SK_Scalar1);
-    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMinStretch() ,SK_ScalarNearlyZero));
-    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMaxStretch(), SK_ScalarNearlyZero));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMinScale() ,SK_ScalarNearlyZero));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMaxScale(), SK_ScalarNearlyZero));
 
     SkMatrix translate;
     translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
-    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMinStretch());
-    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxStretch());
+    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMinScale());
+    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxScale());
 
     SkMatrix perspX;
     perspX.reset();
     perspX.setPerspX(SkScalarToPersp(SK_Scalar1 / 1000));
-    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinStretch());
-    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxStretch());
+    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinScale());
+    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxScale());
 
     SkMatrix perspY;
     perspY.reset();
     perspY.setPerspY(SkScalarToPersp(-SK_Scalar1 / 500));
-    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMinStretch());
-    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxStretch());
+    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMinScale());
+    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxScale());
 
     SkMatrix baseMats[] = {scale, rot90Scale, rotate,
                            translate, perspX, perspY};
@@ -175,20 +175,20 @@
             mat.postConcat(mats[x]);
         }
 
-        SkScalar minStretch = mat.getMinStretch();
-        SkScalar maxStretch = mat.getMaxStretch();
-        REPORTER_ASSERT(reporter, (minStretch < 0) == (maxStretch < 0));
-        REPORTER_ASSERT(reporter, (maxStretch < 0) == mat.hasPerspective());
+        SkScalar minScale = mat.getMinScale();
+        SkScalar maxScale = mat.getMaxScale();
+        REPORTER_ASSERT(reporter, (minScale < 0) == (maxScale < 0));
+        REPORTER_ASSERT(reporter, (maxScale < 0) == mat.hasPerspective());
 
         if (mat.hasPerspective()) {
             m -= 1; // try another non-persp matrix
             continue;
         }
 
-        // test a bunch of vectors. All should be scaled by between minStretch and maxStretch
+        // test a bunch of vectors. All should be scaled by between minScale and maxScale
         // (modulo some error) and we should find a vector that is scaled by almost each.
-        static const SkScalar gVectorStretchTol = (105 * SK_Scalar1) / 100;
-        static const SkScalar gClosestStretchTol = (97 * SK_Scalar1) / 100;
+        static const SkScalar gVectorScaleTol = (105 * SK_Scalar1) / 100;
+        static const SkScalar gCloseScaleTol = (97 * SK_Scalar1) / 100;
         SkScalar max = 0, min = SK_ScalarMax;
         SkVector vectors[1000];
         for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
@@ -202,8 +202,8 @@
         mat.mapVectors(vectors, SK_ARRAY_COUNT(vectors));
         for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
             SkScalar d = vectors[i].length();
-            REPORTER_ASSERT(reporter, SkScalarDiv(d, maxStretch) < gVectorStretchTol);
-            REPORTER_ASSERT(reporter, SkScalarDiv(minStretch, d) < gVectorStretchTol);
+            REPORTER_ASSERT(reporter, SkScalarDiv(d, maxScale) < gVectorScaleTol);
+            REPORTER_ASSERT(reporter, SkScalarDiv(minScale, d) < gVectorScaleTol);
             if (max < d) {
                 max = d;
             }
@@ -211,8 +211,8 @@
                 min = d;
             }
         }
-        REPORTER_ASSERT(reporter, SkScalarDiv(max, maxStretch) >= gClosestStretchTol);
-        REPORTER_ASSERT(reporter, SkScalarDiv(minStretch, min) >= gClosestStretchTol);
+        REPORTER_ASSERT(reporter, SkScalarDiv(max, maxScale) >= gCloseScaleTol);
+        REPORTER_ASSERT(reporter, SkScalarDiv(minScale, min) >= gCloseScaleTol);
     }
 }
 
@@ -779,7 +779,7 @@
     mat2.set(SkMatrix::kMSkewX, SK_ScalarNaN);
     REPORTER_ASSERT(reporter, !are_equal(reporter, mat, mat2));
 
-    test_matrix_min_max_stretch(reporter);
+    test_matrix_min_max_scale(reporter);
     test_matrix_is_similarity(reporter);
     test_matrix_recttorect(reporter);
     test_matrix_decomposition(reporter);