From 3a3e06029e4836d86ea7e5e7b7e5da413a78a843 Mon Sep 17 00:00:00 2001 From: Jorge Rodriguez Date: Tue, 29 Jul 2014 12:11:03 -0700 Subject: [PATCH] This is definitely faster than the function pointer solution. --- stb_resample.h | 79 +++++++++------------------------------------------------- 1 file changed, 12 insertions(+), 67 deletions(-) diff --git a/stb_resample.h b/stb_resample.h index 792092f..3e15400 100644 --- a/stb_resample.h +++ b/stb_resample.h @@ -699,62 +699,6 @@ static float* stbr__add_empty_ring_buffer_entry(stbr__info* stbr_info, int n) return ring_buffer; } -typedef void(*stbr__output_decode_coefficients)(float* output_buffer, int out_texel_index, float* decode_buffer, int decode_texel_index, int channels, float coefficient); - -static void stbr__output_decode_coefficients_1(float* output_buffer, int out_texel_index, float* input_buffer, int input_texel_index, int channels, float coefficient) -{ - STBR_DEBUG_ASSERT(channels == 1); - - output_buffer[out_texel_index] += input_buffer[input_texel_index] * coefficient; -} - -static void stbr__output_decode_coefficients_2(float* output_buffer, int out_texel_index, float* input_buffer, int input_texel_index, int channels, float coefficient) -{ - STBR_DEBUG_ASSERT(channels == 2); - - output_buffer[out_texel_index ] += input_buffer[input_texel_index ] * coefficient; - output_buffer[out_texel_index + 1] += input_buffer[input_texel_index + 1] * coefficient; -} - -static void stbr__output_decode_coefficients_3(float* output_buffer, int out_texel_index, float* input_buffer, int input_texel_index, int channels, float coefficient) -{ - STBR_DEBUG_ASSERT(channels == 3); - - output_buffer[out_texel_index ] += input_buffer[input_texel_index ] * coefficient; - output_buffer[out_texel_index + 1] += input_buffer[input_texel_index + 1] * coefficient; - output_buffer[out_texel_index + 2] += input_buffer[input_texel_index + 2] * coefficient; -} - -static void stbr__output_decode_coefficients_4(float* output_buffer, int out_texel_index, float* input_buffer, int input_texel_index, int channels, float coefficient) -{ - STBR_DEBUG_ASSERT(channels == 4); - - output_buffer[out_texel_index ] += input_buffer[input_texel_index ] * coefficient; - output_buffer[out_texel_index + 1] += input_buffer[input_texel_index + 1] * coefficient; - output_buffer[out_texel_index + 2] += input_buffer[input_texel_index + 2] * coefficient; - output_buffer[out_texel_index + 3] += input_buffer[input_texel_index + 3] * coefficient; -} - -static void stbr__output_decode_coefficients_n(float* output_buffer, int out_texel_index, float* input_buffer, int input_texel_index, int channels, float coefficient) -{ - int c; - for (c = 0; c < channels; c++) - output_buffer[out_texel_index + c] += input_buffer[input_texel_index + c] * coefficient; -} - -static stbr__output_decode_coefficients stbr__get_output_decode_coefficients_function(int channels) -{ - if (channels == 1) - return &stbr__output_decode_coefficients_1; - else if (channels == 2) - return &stbr__output_decode_coefficients_2; - else if (channels == 3) - return &stbr__output_decode_coefficients_3; - else if (channels == 4) - return &stbr__output_decode_coefficients_4; - - return &stbr__output_decode_coefficients_n; -} static void stbr__resample_horizontal_upsample(stbr__info* stbr_info, int n, float* output_buffer) { @@ -766,8 +710,6 @@ static void stbr__resample_horizontal_upsample(stbr__info* stbr_info, int n, flo stbr__contributors* horizontal_contributors = stbr_info->horizontal_contributors; float* horizontal_coefficients = stbr_info->horizontal_coefficients; - stbr__output_decode_coefficients output_decode_coefficients_fn = stbr__get_output_decode_coefficients_function(channels); - for (x = 0; x < output_w; x++) { int n0 = horizontal_contributors[x].n0; @@ -789,7 +731,9 @@ static void stbr__resample_horizontal_upsample(stbr__info* stbr_info, int n, flo int in_texel_index = k * channels; float coefficient = horizontal_coefficients[coefficient_index]; - output_decode_coefficients_fn(output_buffer, out_texel_index, decode_buffer, in_texel_index, channels, coefficient); + int c; + for (c = 0; c < channels; c++) + output_buffer[out_texel_index + c] += decode_buffer[in_texel_index + c] * coefficient; } } } @@ -807,8 +751,6 @@ static void stbr__resample_horizontal_downsample(stbr__info* stbr_info, int n, f int filter_texel_margin = stbr__get_filter_texel_margin(stbr_info->filter); int max_x = input_w + filter_texel_margin * 2; - stbr__output_decode_coefficients output_decode_coefficients_fn = stbr__get_output_decode_coefficients_function(channels); - STBR_DEBUG_ASSERT(!stbr__use_width_upsampling(stbr_info)); for (x = 0; x < max_x; x++) @@ -830,7 +772,9 @@ static void stbr__resample_horizontal_downsample(stbr__info* stbr_info, int n, f int out_texel_index = k * channels; float coefficient = horizontal_coefficients[coefficient_index]; - output_decode_coefficients_fn(output_buffer, out_texel_index, decode_buffer, in_texel_index, channels, coefficient); + int c; + for (c = 0; c < channels; c++) + output_buffer[out_texel_index + c] += decode_buffer[in_texel_index + c] * coefficient; } } } @@ -1039,7 +983,6 @@ static void stbr__resample_vertical_upsample(stbr__info* stbr_info, int n, int i int output_row_index = n * stbr_info->output_stride_bytes; - stbr__output_decode_coefficients output_decode_coefficients_fn = stbr__get_output_decode_coefficients_function(channels); stbr__encode_scanline_channels encode_channels_fn = stbr__get_encode_channels_function(channels); stbr__encode_scanline_type_colorspace encode_type_colorspace_fn = stbr__get_encode_type_colorspace_function(stbr_info->type, stbr_info->colorspace); @@ -1063,7 +1006,9 @@ static void stbr__resample_vertical_upsample(stbr__info* stbr_info, int n, int i float* ring_buffer_entry = stbr__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, kernel_texel_width, ring_buffer_length); float coefficient = vertical_coefficients[coefficient_index]; - output_decode_coefficients_fn(encode_buffer, 0, ring_buffer_entry, in_texel_index, channels, coefficient); + int c; + for (c = 0; c < channels; c++) + encode_buffer[c] += ring_buffer_entry[in_texel_index + c] * coefficient; } encode_channels_fn(output_data, out_texel_index, encode_buffer, 0, channels, encode_type_colorspace_fn); @@ -1094,8 +1039,6 @@ static void stbr__resample_vertical_downsample(stbr__info* stbr_info, int n, int int n1 = vertical_contributors->n1; int max_n = stbr__min(n1, output_h - 1); - stbr__output_decode_coefficients output_decode_coefficients_fn = stbr__get_output_decode_coefficients_function(channels); - STBR_DEBUG_ASSERT(!stbr__use_height_upsampling(stbr_info)); STBR_DEBUG_ASSERT(n0 >= in_first_scanline); STBR_DEBUG_ASSERT(n1 <= in_last_scanline); @@ -1113,7 +1056,9 @@ static void stbr__resample_vertical_downsample(stbr__info* stbr_info, int n, int { int in_texel_index = x * channels; - output_decode_coefficients_fn(ring_buffer_entry, in_texel_index, horizontal_buffer, in_texel_index, channels, coefficient); + int c; + for (c = 0; c < channels; c++) + ring_buffer_entry[in_texel_index + c] += horizontal_buffer[in_texel_index + c] * coefficient; } } }