Blur refactoring

src/effects/SkEmbossMaskFilter.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkEmbossMaskFilter.h"
 #include "SkBlurMaskFilter.h"
 #include "SkBlurMask.h"
 #include "SkEmbossMask.h"
 #include "SkFlattenableBuffers.h"
 #include "SkString.h"
 
 static inline int pin2byte(int n) {
     if (n < 0) {
         n = 0;
     } else if (n > 0xFF) {
         n = 0xFF;
     }
     return n;
 }
 
 SkMaskFilter* SkBlurMaskFilter::CreateEmboss(const SkScalar direction[3],
                                              SkScalar ambient, SkScalar specular,
                                              SkScalar blurRadius) {
+    return SkBlurMaskFilter::CreateEmboss(SkBlurMask::ConvertRadiusToSigma(blurRadius),
+                                          direction, ambient, specular);
+}
+
+SkMaskFilter* SkBlurMaskFilter::CreateEmboss(SkScalar blurSigma, const SkScalar direction[3],
+                                             SkScalar ambient, SkScalar specular) {
     if (direction == NULL) {
         return NULL;
     }
 
     // ambient should be 0...1 as a scalar
     int am = pin2byte(SkScalarToFixed(ambient) >> 8);
 
     // specular should be 0..15.99 as a scalar
     int sp = pin2byte(SkScalarToFixed(specular) >> 12);
 
     SkEmbossMaskFilter::Light   light;
 
     memcpy(light.fDirection, direction, sizeof(light.fDirection));
     light.fAmbient = SkToU8(am);
     light.fSpecular = SkToU8(sp);
 
-    return SkNEW_ARGS(SkEmbossMaskFilter, (light, blurRadius));
+    return SkNEW_ARGS(SkEmbossMaskFilter, (blurSigma, light));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static void normalize(SkScalar v[3]) {
     SkScalar mag = SkScalarSquare(v[0]) + SkScalarSquare(v[1]) + SkScalarSquare(v[2]);
     mag = SkScalarSqrt(mag);
 
     for (int i = 0; i < 3; i++) {
         v[i] = SkScalarDiv(v[i], mag);
     }
 }
 
-SkEmbossMaskFilter::SkEmbossMaskFilter(const Light& light, SkScalar blurRadius)
-        : fLight(light), fBlurRadius(blurRadius) {
+SkEmbossMaskFilter::SkEmbossMaskFilter(SkScalar blurSigma, const Light& light)
+        : fBlurSigma(blurSigma), fLight(light) {
     normalize(fLight.fDirection);
 }
 
+SkEmbossMaskFilter::SkEmbossMaskFilter(const Light& light, SkScalar blurRadius)
+        : fLight(light) {
+    normalize(fLight.fDirection);
+
+    fBlurSigma = SkBlurMask::ConvertRadiusToSigma(blurRadius);
+}
+
 SkMask::Format SkEmbossMaskFilter::getFormat() const {
     return SkMask::k3D_Format;
 }
 
 bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
-                            const SkMatrix& matrix, SkIPoint* margin) const {
-    SkScalar radius = matrix.mapRadius(fBlurRadius);
+                                    const SkMatrix& matrix, SkIPoint* margin) const {
+    SkScalar sigma = matrix.mapRadius(fBlurSigma);
 
-    if (!SkBlurMask::Blur(dst, src, radius, SkBlurMask::kInner_Style,
-                          SkBlurMask::kLow_Quality)) {
+    if (!SkBlurMask::BoxBlur(dst, src, sigma, SkBlurMask::kInner_Style,
+                             SkBlurMask::kLow_Quality)) {
         return false;
     }
 
     dst->fFormat = SkMask::k3D_Format;
     if (margin) {
-        margin->set(SkScalarCeil(radius), SkScalarCeil(radius));
+        margin->set(SkScalarCeil(3*sigma), SkScalarCeil(3*sigma));
     }
 
     if (src.fImage == NULL) {
         return true;
     }
 
     // create a larger buffer for the other two channels (should force fBlur to do this for us)
 
     {
         uint8_t* alphaPlane = dst->fImage;
@@ skipping 24 matching lines @@
     memcpy(dst->fImage, src.fImage, src.computeImageSize());
 
     return true;
 }
 
 SkEmbossMaskFilter::SkEmbossMaskFilter(SkFlattenableReadBuffer& buffer)
         : SkMaskFilter(buffer) {
     SkASSERT(buffer.getArrayCount() == sizeof(Light));
     buffer.readByteArray(&fLight);
     SkASSERT(fLight.fPad == 0); // for the font-cache lookup to be clean
-    fBlurRadius = buffer.readScalar();
+    fBlurSigma = buffer.readScalar();
+#ifndef DELETE_THIS_CODE_WHEN_SKPS_ARE_REBUILT_AT_V13_AND_ALL_OTHER_INSTANCES_TOO
+    // Fixing this must be done in two stages. When the skps are recaptured in V13,
+    // remove the ConvertRadiusToSigma but retain the absolute value. 
+    // At the same time, switch the code in flatten to write a positive value.
+    // When the skps are captured in V14 the absolute value can be removed.
+    if (fBlurSigma > 0) {
+        fBlurSigma = SkBlurMask::ConvertRadiusToSigma(fBlurSigma);
+    } else {
+        fBlurSigma = -fBlurSigma;
+    }
+#endif
 }
 
 void SkEmbossMaskFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     Light tmpLight = fLight;
     tmpLight.fPad = 0;    // for the font-cache lookup to be clean
     buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
-    buffer.writeScalar(fBlurRadius);
+    buffer.writeScalar(-fBlurSigma);
 }
 
 #ifdef SK_DEVELOPER
 void SkEmbossMaskFilter::toString(SkString* str) const {
     str->append("SkEmbossMaskFilter: (");
 
     str->append("direction: (");
     str->appendScalar(fLight.fDirection[0]);
     str->append(", ");
     str->appendScalar(fLight.fDirection[1]);
     str->append(", ");
     str->appendScalar(fLight.fDirection[2]);
     str->append(") ");
 
     str->appendf("ambient: %d specular: %d ",
         fLight.fAmbient, fLight.fSpecular);
 
-    str->append("blurRadius: ");
-    str->appendScalar(fBlurRadius);
+    str->append("blurSigma: ");
+    str->appendScalar(fBlurSigma);
     str->append(")");
 }
 #endif