int shY = SkClampMax(y + yOffset, light.getShadowMap()->height() - 1);
int shDepth = 0;
+ int shDepthsq = 0;
// pixmaps that point to things have nonzero heights
if (fShadowMapPixels[l].height() > 0) {
SkColor shColor(pix);
shDepth = SkColorGetB(shColor);
+ shDepthsq = SkColorGetG(shColor) * 256;
} else {
// Make lights w/o a shadow map receive the full light contribution
shDepth = pvDepth;
}
- if (pvDepth >= shDepth) {
- // assume object normals are pointing straight up
- totalLight.fX += light.dir().fZ * light.color().fX;
- totalLight.fY += light.dir().fZ * light.color().fY;
- totalLight.fZ += light.dir().fZ * light.color().fZ;
+ SkScalar lightProb = 1.0f;
+ if (pvDepth < shDepth) {
+ if (lightShader.fShadowParams.fType ==
+ SkShadowParams::ShadowType::kVariance_ShadowType) {
+ int variance = SkMaxScalar(shDepthsq - shDepth * shDepth,
+ lightShader.fShadowParams.fMinVariance);
+ int d = pvDepth - shDepth;
+
+ lightProb = (SkScalar) variance / ((SkScalar) (variance + d * d));
+
+ SkScalar bias = lightShader.fShadowParams.fBiasingConstant;
+
+ lightProb = SkMaxScalar((lightProb - bias) / (1.0f - bias), 0.0f);
+ } else {
+ lightProb = 0.0f;
+ }
}
+
+ // assume object normals are pointing straight up
+ totalLight.fX += light.dir().fZ * light.color().fX * lightProb;
+ totalLight.fY += light.dir().fZ * light.color().fY * lightProb;
+ totalLight.fZ += light.dir().fZ * light.color().fZ * lightProb;
} else {
totalLight += light.color();
}