assert(false);
}
-
// For many resamplings (e.g. 640 -> 1280), we will end up with the same
// set of samples over and over again in a loop. Thus, we can compute only
// the first such loop, and then ask the card to repeat the texture for us.
weights[(y * src_samples + i) * 2 + 0] = weight * radius_scaling_factor;
weights[(y * src_samples + i) * 2 + 1] = (src_y + 0.5) / float(src_size);
}
+
}
// Now make use of the bilinear filtering in the GPU to reduce the number of samples
src_samples,
src_samples - src_bilinear_samples);
assert(int(src_samples) - int(num_samples_saved) == src_bilinear_samples);
+
+ // 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.
+ for (int normalize_pass = 0; normalize_pass < 2; ++normalize_pass) {
+ float sum = 0.0;
+ for (int i = 0; i < src_bilinear_samples; ++i) {
+ sum += bilinear_weights[(y * src_bilinear_samples + i) * 2 + 0];
+ }
+ for (int i = 0; i < src_bilinear_samples; ++i) {
+ bilinear_weights[(y * src_bilinear_samples + i) * 2 + 0] /= sum;
+ }
+ }
}
// Encode as a two-component texture. Note the GL_REPEAT.