void AbstractOnGpuComparator::filter(Rendering::RenderingContext & context, TexRef_t src, TexRef_t dst) {
if (!filterValid) {
shaderFilterH->setUniform(context, Uniform("filterSize", filterSize));
shaderFilterV->setUniform(context, Uniform("filterSize", filterSize));
// std::cerr << getTypeName() << " Filter: " << (filterType == GAUSS ? "Gauss" : "Box") << " (" << filterSize << ") : " << "[";
std::vector<float> values;
if (filterType == GAUSS) {
// old formula was filterSize * 1.5, which was too big.
// older value used for some measurements in 2013's papers: 0.3
const double sigma = 0.3 * (filterSize - 1) + 0.8;
// sqrtOfTwoTimesPi = std::sqrt(2.0 * pi)
const double sqrtOfTwoTimesPi = 2.506628274631000502415765284811045253006986740609938316629923;
const double a = 1.0 / (sigma * sqrtOfTwoTimesPi);
double sum = 0.0;
for (int i = 0; i <= filterSize; i++) {
const double v = a * std::exp(-((i * i) / (2.0 * sigma * sigma)));
values.push_back(v);
sum += (i == 0 ? v : 2 * v);
}
for (int i = 0; i <= filterSize; i++) {
values[i] /= sum;
}
}
else if (filterType == BOX) {
for (int i = 0; i <= filterSize; i++) {
float v = 1.0f / (filterSize * 2.0f + 1.0f);
values.push_back(v);
}
}
else
WARN("the roof is on fire");
// for(const auto & x : values)
// std::cerr << x << " ";
// std::cerr << "\b]" << std::endl;
while (values.size() < 16)
values.push_back(0.0f);
shaderFilterH->setUniform(context, Uniform("filterValues", values));
shaderFilterV->setUniform(context, Uniform("filterValues", values));
filterValid = true;
}
Reference<TexRef> tmp = new TexRef(Vec2i(src->get()->getWidth(), src->get()->getHeight()));
context.pushAndSetShader(shaderFilterH.get());
context.pushAndSetTexture(0, src->get());
fbo->attachColorTexture(context, tmp->get());
Rendering::drawFullScreenRect(context);
context.setShader(shaderFilterV.get());
context.setTexture(0, tmp->get());
fbo->attachColorTexture(context, dst.isNull() ? src->get() : dst->get());
Rendering::drawFullScreenRect(context);
fbo->detachColorTexture(context);
context.popTexture(0);
context.popShader();
}
