Revert of Update feSpotLight to match spec (patchset #2 id:20001 of https://codereview.chromium.org/1403403003/ )
Reason for revert:
re-land once layout test have been disabled (so they can be rebased)
Original issue's description:
> Update feSpotLight to match spec
>
> This change updates feSpotLight to match the spec via two changes:
>
> 1) specularExponent is ignored if the spotlight has no coneAngle (GPU
> bug only). This change updates the GPU path so that it matches the
> CPU path and the spec in this regard.
>
> 2) specularExponent is clamped to the 1-128 range. The spec does not
> specify a clamp for the specularExponent attribute of feSpotLight.
> Note that the spec *does* specify this clamp for the
> specularExponent attribute of feSpecularLighting. It looks like we
> incorrectly applied this to both specularExponent attributes.
>
> This change (along with a parallel change in Blink) allows us to pass
> the SVG filter effects conformance test here:
> http://www.w3.org/Graphics/SVG/Test/20110816/harness/htmlObject/filters-light-01-f.html
>
> Additionally, this brings our behavior in line with Safari and Edge’s
> behavior on this filter.
>
> Two new cases were added to gm/lighting.cpp to catch these issues:
> - The existing spotlight case exercised the path where our specular
> exponent was between 1-128 and had a limiting cone angle.
> - The first new spotlight case exercises the path where our specular
> exponent is between 1-128 and we do not have a limiting cone angle.
> - The second new spotlight case exercises the path where the specular
> exponent is not within the 1-128 range, to ensure that we don’t
> incorrectly clip to this range.
>
> BUG=472849
>
> Committed: https://skia.googlesource.com/skia/+/c84ccb070258db2803a9e8f532bfe7239a737063
TBR=senorblanco@google.com,senorblanco@chromium.org,bsalomon@google.com,ericrk@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=472849
Review URL: https://codereview.chromium.org/1417463006
diff --git a/src/effects/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index f0f2c66..199bb4d 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -682,7 +682,7 @@
class SkImageFilterLight : public SkRefCnt {
public:
-
+
enum LightType {
kDistant_LightType,
@@ -819,8 +819,8 @@
// Use X scale and Y scale on Z and average the result
SkPoint locationZ = SkPoint::Make(fLocation.fZ, fLocation.fZ);
matrix.mapVectors(&locationZ, 1);
- SkPoint3 location = SkPoint3::Make(location2.fX,
- location2.fY,
+ SkPoint3 location = SkPoint3::Make(location2.fX,
+ location2.fY,
SkScalarAve(locationZ.fX, locationZ.fY));
return new SkPointLight(location, color());
}
@@ -854,7 +854,7 @@
: INHERITED(color),
fLocation(location),
fTarget(target),
- fSpecularExponent(specularExponent)
+ fSpecularExponent(SkScalarPin(specularExponent, kSpecularExponentMin, kSpecularExponentMax))
{
fS = target - location;
fast_normalize(&fS);
@@ -984,6 +984,9 @@
}
private:
+ static const SkScalar kSpecularExponentMin;
+ static const SkScalar kSpecularExponentMax;
+
SkPoint3 fLocation;
SkPoint3 fTarget;
SkScalar fSpecularExponent;
@@ -995,6 +998,11 @@
typedef SkImageFilterLight INHERITED;
};
+// According to the spec, the specular term should be in the range [1, 128] :
+// http://www.w3.org/TR/SVG/filters.html#feSpecularLightingSpecularExponentAttribute
+const SkScalar SkSpotLight::kSpecularExponentMin = 1.0f;
+const SkScalar SkSpotLight::kSpecularExponentMax = 128.0f;
+
///////////////////////////////////////////////////////////////////////////////
void SkImageFilterLight::flattenLight(SkWriteBuffer& buffer) const {
@@ -1985,7 +1993,7 @@
lightColorBody.appendf("\t\treturn %s * scale * (cosAngle - %s) * %s;\n",
color, cosOuter, coneScale);
lightColorBody.appendf("\t}\n");
- lightColorBody.appendf("\treturn %s * scale;\n", color);
+ lightColorBody.appendf("\treturn %s;\n", color);
GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
fsBuilder->emitFunction(kVec3f_GrSLType,
"lightColor",