ResampleEffect::ResampleEffect()
: input_width(1280),
- input_height(720)
+ input_height(720),
+ offset_x(0.0f), offset_y(0.0f),
+ zoom_x(1.0f), zoom_y(1.0f),
+ zoom_center_x(0.5f), zoom_center_y(0.5f)
{
register_int("width", &output_width);
register_int("height", &output_height);
ok |= vpass->set_int("output_height", output_height);
assert(ok);
+
+ // The offset added due to zoom may have changed with the size.
+ update_offset_and_zoom();
+}
+
+void ResampleEffect::update_offset_and_zoom()
+{
+ bool ok = true;
+
+ // Zoom from the right origin. (zoom_center is given in normalized coordinates,
+ // i.e. 0..1.)
+ float extra_offset_x = zoom_center_x * (1.0f - 1.0f / zoom_x) * input_width;
+ float extra_offset_y = (1.0f - zoom_center_y) * (1.0f - 1.0f / zoom_y) * input_height;
+
+ ok |= hpass->set_float("offset", extra_offset_x + offset_x);
+ ok |= vpass->set_float("offset", extra_offset_y - offset_y); // Compensate for the bottom-left origin.
+ ok |= hpass->set_float("zoom", zoom_x);
+ ok |= vpass->set_float("zoom", zoom_y);
+
+ assert(ok);
}
bool ResampleEffect::set_float(const string &key, float value) {
return true;
}
if (key == "top") {
- // Compensate for the bottom-left origin.
- return vpass->set_float("offset", -value);
+ offset_y = value;
+ update_offset_and_zoom();
+ return true;
}
if (key == "left") {
- return hpass->set_float("offset", value);
+ offset_x = value;
+ update_offset_and_zoom();
+ return true;
+ }
+ if (key == "zoom_x") {
+ if (value <= 0.0f) {
+ return false;
+ }
+ zoom_x = value;
+ update_offset_and_zoom();
+ return true;
+ }
+ if (key == "zoom_y") {
+ if (value <= 0.0f) {
+ return false;
+ }
+ zoom_y = value;
+ update_offset_and_zoom();
+ return true;
+ }
+ if (key == "zoom_center_x") {
+ zoom_center_x = value;
+ update_offset_and_zoom();
+ return true;
+ }
+ if (key == "zoom_center_y") {
+ zoom_center_y = value;
+ update_offset_and_zoom();
+ return true;
}
return false;
}
input_width(1280),
input_height(720),
offset(0.0),
+ zoom(1.0),
last_input_width(-1),
last_input_height(-1),
last_output_width(-1),
last_output_height(-1),
- last_offset(0.0 / 0.0) // NaN.
+ last_offset(0.0 / 0.0), // NaN.
+ last_zoom(0.0 / 0.0) // NaN.
{
register_int("direction", (int *)&direction);
register_int("input_width", &input_width);
register_int("output_width", &output_width);
register_int("output_height", &output_height);
register_float("offset", &offset);
+ register_float("zoom", &zoom);
glGenTextures(1, &texnum);
}
// the first such loop, and then ask the card to repeat the texture for us.
// This is both easier on the texture cache and lowers our CPU cost for
// generating the kernel somewhat.
- num_loops = gcd(src_size, dst_size);
+ float scaling_factor;
+ if (fabs(zoom - 1.0f) < 1e-6) {
+ num_loops = gcd(src_size, dst_size);
+ scaling_factor = float(dst_size) / float(src_size);
+ } else {
+ // If zooming is enabled (ie., zoom != 1), we turn off the looping.
+ // We _could_ perhaps do it for rational zoom levels (especially
+ // things like 2:1), but it doesn't seem to be worth it, given that
+ // the most common use case would seem to be varying the zoom
+ // from frame to frame.
+ num_loops = 1;
+ scaling_factor = zoom * float(dst_size) / float(src_size);
+ }
slice_height = 1.0f / num_loops;
unsigned dst_samples = dst_size / num_loops;
// Anyhow, in this case we clearly need to look at more source pixels
// to compute the destination pixel, and how many depend on the scaling factor.
// Thus, the kernel width will vary with how much we scale.
- float radius_scaling_factor = min(float(dst_size) / float(src_size), 1.0f);
+ float radius_scaling_factor = min(scaling_factor, 1.0f);
int int_radius = lrintf(LANCZOS_RADIUS / radius_scaling_factor);
int src_samples = int_radius * 2 + 1;
float *weights = new float[dst_samples * src_samples * 2];
for (unsigned y = 0; y < dst_samples; ++y) {
// Find the point around which we want to sample the source image,
// compensating for differing pixel centers as the scale changes.
- float center_src_y = (y + 0.5f) * float(src_size) / float(dst_size) - 0.5f;
+ float center_src_y = (y + 0.5f) / scaling_factor - 0.5f;
int base_src_y = lrintf(center_src_y);
// Now sample <int_radius> pixels on each side around that point.
// Normalize so that the sum becomes one. Note that we do it twice;
// this sometimes helps a tiny little bit when we have many samples.
+#if 0
for (int normalize_pass = 0; normalize_pass < 2; ++normalize_pass) {
double sum = 0.0;
for (int i = 0; i < src_bilinear_samples; ++i) {
fp16_to_fp64(bilinear_weights_fp16_ptr[i * 2 + 0]) / sum);
}
}
+#endif
}
// Encode as a two-component texture. Note the GL_REPEAT.
input_height != last_input_height ||
output_width != last_output_width ||
output_height != last_output_height ||
- offset != last_offset) {
+ offset != last_offset ||
+ zoom != last_zoom) {
update_texture(glsl_program_num, prefix, sampler_num);
last_input_width = input_width;
last_input_height = input_height;
last_output_width = output_width;
last_output_height = output_height;
last_offset = offset;
+ last_zoom = zoom;
}
glActiveTexture(GL_TEXTURE0 + *sampler_num);
projects / movit / blobdiff