#define NUM_TAPS 16
BlurEffect::BlurEffect()
- : radius(3.0f)
+ : radius(3.0f),
+ input_width(1280),
+ input_height(720)
{
- hpass = new SingleBlurPassEffect();
+ // The first blur pass will forward resolution information to us.
+ hpass = new SingleBlurPassEffect(this);
hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL);
- vpass = new SingleBlurPassEffect();
+ vpass = new SingleBlurPassEffect(NULL);
vpass->set_int("direction", SingleBlurPassEffect::VERTICAL);
update_radius();
graph->replace_receiver(self, hpass_node);
graph->replace_sender(self, vpass_node);
self->disabled = true;
+}
+
+// We get this information forwarded from the first blur pass,
+// since we are not part of the chain ourselves.
+void BlurEffect::inform_input_size(unsigned input_num, unsigned width, unsigned height)
+{
+ assert(input_num == 0);
+ assert(width != 0);
+ assert(height != 0);
+ input_width = width;
+ input_height = height;
+ update_radius();
}
void BlurEffect::update_radius()
// 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.
- //
- // TODO: Consider the actual width and height (they influence mipmap
- // sizes subtly).
- unsigned base_mipmap_level = 0;
+ unsigned mipmap_width = input_width, mipmap_height = input_height;
float adjusted_radius = radius;
- while (adjusted_radius * 1.5f > NUM_TAPS / 2) {
- ++base_mipmap_level;
- adjusted_radius /= 2.0f;
+ 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 = std::max(mipmap_width / 2, 1u);
+ mipmap_height = std::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", 1280 / (1 << base_mipmap_level)); // FIXME
- ok |= hpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME
+ ok |= hpass->set_int("width", mipmap_width);
+ ok |= hpass->set_int("height", mipmap_height);
ok |= vpass->set_float("radius", adjusted_radius);
- ok |= vpass->set_int("width", 1280 / (1 << base_mipmap_level)); // FIXME
- ok |= vpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME
+ ok |= vpass->set_int("width", mipmap_width);
+ ok |= vpass->set_int("height", mipmap_height);
assert(ok);
}
return false;
}
-SingleBlurPassEffect::SingleBlurPassEffect()
- : radius(3.0f),
+SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
+ : parent(parent),
+ radius(3.0f),
direction(HORIZONTAL),
width(1280),
height(720)
virtual bool needs_mipmaps() const { return true; }
virtual bool needs_srgb_primaries() const { return false; }
+ virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height);
+
virtual std::string output_fragment_shader() {
assert(false);
}
float radius;
SingleBlurPassEffect *hpass, *vpass;
+ unsigned input_width, input_height;
};
class SingleBlurPassEffect : public Effect {
public:
- SingleBlurPassEffect();
+ // If parent is non-NULL, calls to inform_input_size will be forwarded
+ // so that it can make reasonable decisions for both blur passes.
+ SingleBlurPassEffect(BlurEffect *parent);
virtual std::string effect_type_id() const { return "SingleBlurPassEffect"; }
std::string output_fragment_shader();
virtual bool needs_mipmaps() const { return true; }
virtual bool needs_srgb_primaries() const { return false; }
+ virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height) {
+ if (parent != NULL) {
+ parent->inform_input_size(input_num, width, height);
+ }
+ }
virtual bool changes_output_size() const { return true; }
virtual void get_output_size(unsigned *width, unsigned *height) const {
enum Direction { HORIZONTAL = 0, VERTICAL = 1 };
private:
+ BlurEffect *parent;
float radius;
Direction direction;
int width, height;