+ // We only have 16 taps to work with on each side, and we want that to
+ // reach out to about 2.5*sigma. Bump up the mipmap levels (giving us
+ // box blurs) until we have what we need.
+ unsigned mipmap_width = input_width, mipmap_height = input_height;
+ float adjusted_radius = radius;
+ while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > num_taps / 2) {
+ // Find the next mipmap size (round down, minimum 1 pixel).
+ mipmap_width = max(mipmap_width / 2, 1u);
+ mipmap_height = max(mipmap_height / 2, 1u);
+
+ // Approximate when mipmap sizes are odd, but good enough.
+ adjusted_radius = radius * float(mipmap_width) / float(input_width);
+ }
+
+ bool ok = hpass->set_float("radius", adjusted_radius);
+ ok |= hpass->set_int("width", mipmap_width);
+ ok |= hpass->set_int("height", mipmap_height);
+ ok |= hpass->set_int("virtual_width", mipmap_width);
+ ok |= hpass->set_int("virtual_height", mipmap_height);
+ ok |= hpass->set_int("num_taps", num_taps);
+
+ ok |= vpass->set_float("radius", adjusted_radius);
+ ok |= vpass->set_int("width", mipmap_width);
+ ok |= vpass->set_int("height", mipmap_height);
+ ok |= vpass->set_int("virtual_width", input_width);
+ ok |= vpass->set_int("virtual_height", input_height);
+ ok |= vpass->set_int("num_taps", num_taps);
+
+ assert(ok);
+}
+
+bool BlurEffect::set_float(const string &key, float value) {
+ if (key == "radius") {
+ radius = value;
+ update_radius();
+ return true;
+ }
+ return false;
+}
+
+bool BlurEffect::set_int(const string &key, int value) {
+ if (key == "num_taps") {
+ if (value < 2 || value % 2 != 0) {
+ return false;
+ }
+ num_taps = value;
+ update_radius();
+ return true;
+ }
+ return false;
+}
+
+SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
+ : parent(parent),
+ num_taps(16),
+ radius(3.0f),
+ direction(HORIZONTAL),
+ width(1280),
+ height(720),
+ uniform_samples(NULL)
+{
+ register_float("radius", &radius);