assert(false);
}
- ScalingWeights weights = calculate_scaling_weights(src_size, dst_size, zoom, offset);
+ ScalingWeights weights = calculate_bilinear_scaling_weights(src_size, dst_size, zoom, offset);
src_bilinear_samples = weights.src_bilinear_samples;
num_loops = weights.num_loops;
slice_height = 1.0f / weights.num_loops;
tex.update(weights.src_bilinear_samples, weights.dst_samples, internal_format, GL_RG, type, pixels);
}
+namespace {
+
ScalingWeights calculate_scaling_weights(unsigned src_size, unsigned dst_size, float zoom, float offset)
{
// Only needed if run from outside ResampleEffect.
}
}
+ ScalingWeights ret;
+ ret.src_bilinear_samples = src_samples;
+ ret.dst_samples = dst_samples;
+ ret.num_loops = num_loops;
+ ret.bilinear_weights_fp16 = nullptr;
+ ret.bilinear_weights_fp32 = move(weights);
+ return ret;
+}
+
+} // namespace
+
+ScalingWeights calculate_bilinear_scaling_weights(unsigned src_size, unsigned dst_size, float zoom, float offset)
+{
+ ScalingWeights ret = calculate_scaling_weights(src_size, dst_size, zoom, offset);
+ unique_ptr<Tap<float>[]> weights = move(ret.bilinear_weights_fp32);
+ const int src_samples = ret.src_bilinear_samples;
+
// Now make use of the bilinear filtering in the GPU to reduce the number of samples
// we need to make. Try fp16 first; if it's not accurate enough, we go to fp32.
// Our tolerance level for total error is a bit higher than the one for invididual
// samples, since one would assume overall errors in the shape don't matter as much.
const float max_error = 2.0f / (255.0f * 255.0f);
unique_ptr<Tap<fp16_int_t>[]> bilinear_weights_fp16;
- int src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, dst_samples, &bilinear_weights_fp16);
+ int src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, ret.dst_samples, &bilinear_weights_fp16);
unique_ptr<Tap<float>[]> bilinear_weights_fp32 = nullptr;
double max_sum_sq_error_fp16 = 0.0;
- for (unsigned y = 0; y < dst_samples; ++y) {
+ for (unsigned y = 0; y < ret.dst_samples; ++y) {
double sum_sq_error_fp16 = compute_sum_sq_error(
weights.get() + y * src_samples, src_samples,
bilinear_weights_fp16.get() + y * src_bilinear_samples, src_bilinear_samples,
if (max_sum_sq_error_fp16 > max_error) {
bilinear_weights_fp16.reset();
- src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, dst_samples, &bilinear_weights_fp32);
+ src_bilinear_samples = combine_many_samples(weights.get(), src_size, src_samples, ret.dst_samples, &bilinear_weights_fp32);
}
- ScalingWeights ret;
ret.src_bilinear_samples = src_bilinear_samples;
- ret.dst_samples = dst_samples;
- ret.num_loops = num_loops;
ret.bilinear_weights_fp16 = move(bilinear_weights_fp16);
ret.bilinear_weights_fp32 = move(bilinear_weights_fp32);
return ret;