anulax
/
stb
1
0
Fork 0
Code Issues Pull Requests Packages project_board Releases Wiki Activity

unroll vertical_upsample inner loop, and reverse loop nesting to minimize work

Browse Source
master
Sean Barrett ago%!(EXTRA string=11 years)
parent 9c2ae9bdb8
commit 7a8c9196d1
1 changed files with 76 additions and 15 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 67
      stb_image_resize.h

67
stb_image_resize.h
Unescape View File

@ -1703,6 +1703,7 @@ static void stbir__resample_vertical_upsample(stbir__info* stbir_info, int n, in
float* encode_buffer = stbir_info->encode_buffer; float* encode_buffer = stbir_info->encode_buffer;
int decode = STBIR__DECODE(type, colorspace); int decode = STBIR__DECODE(type, colorspace);
int coefficient_width = stbir_info->vertical_coefficient_width; int coefficient_width = stbir_info->vertical_coefficient_width;
int coefficient_counter;
int contributor = n; int contributor = n;
float* ring_buffer = stbir_info->ring_buffer; float* ring_buffer = stbir_info->ring_buffer;
@ -1723,22 +1724,82 @@ static void stbir__resample_vertical_upsample(stbir__info* stbir_info, int n, in
memset(encode_buffer, 0, output_w * sizeof(float) * channels); memset(encode_buffer, 0, output_w * sizeof(float) * channels);
coefficient_counter = 0;
switch (channels) {
case 1:
for (k = n0; k <= n1; k++)
{
int coefficient_index = coefficient_counter++;
float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length);
float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
for (x = 0; x < output_w; x++) for (x = 0; x < output_w; x++)
{ {
int in_pixel_index = x * channels; int in_pixel_index = x * channels;
int coefficient_counter = 0; encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
}
}
break;
case 2:
for (k = n0; k <= n1; k++) for (k = n0; k <= n1; k++)
{ {
int coefficient_index = coefficient_counter++; int coefficient_index = coefficient_counter++;
float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length); float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length);
float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
for (x = 0; x < output_w; x++)
{
int in_pixel_index = x * channels;
encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
}
}
break;
case 3:
for (k = n0; k <= n1; k++)
{
int coefficient_index = coefficient_counter++;
float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length);
float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
for (x = 0; x < output_w; x++)
{
int in_pixel_index = x * channels;
encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient;
}
}
break;
case 4:
for (k = n0; k <= n1; k++)
{
int coefficient_index = coefficient_counter++;
float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length);
float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
for (x = 0; x < output_w; x++)
{
int in_pixel_index = x * channels;
encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient;
encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient;
encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient;
encode_buffer[in_pixel_index + 3] += ring_buffer_entry[in_pixel_index + 3] * coefficient;
}
}
break;
default:
for (k = n0; k <= n1; k++)
{
int coefficient_index = coefficient_counter++;
float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_pixel_width, ring_buffer_length);
float coefficient = vertical_coefficients[coefficient_group + coefficient_index];
for (x = 0; x < output_w; x++)
{
int in_pixel_index = x * channels;
int c; int c;
for (c = 0; c < channels; c++) for (c = 0; c < channels; c++)
encode_buffer[in_pixel_index + c] += ring_buffer_entry[in_pixel_index + c] * coefficient; encode_buffer[in_pixel_index + c] += ring_buffer_entry[in_pixel_index + c] * coefficient;
} }
} }
break;
}
stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, encode_buffer, channels, alpha_channel, decode); stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, encode_buffer, channels, alpha_channel, decode);
} }

Write Preview
Loading…
Cancel
Save