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Fix upsampling, avoid dereferencing in an inner loop.

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This commit is contained in:
Jorge Rodriguez 2014-07-24 22:54:35 -07:00
parent dbb7480f12
commit 178e301ea4
1 changed files with 6 additions and 4 deletions
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10
stb_resample.h
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@ -285,6 +285,7 @@ static void stbr__calculate_coefficients_upsample(stbr__info* stbr_info, int in_
int i; int i;
float total_filter = 0; float total_filter = 0;
float filter_scale; float filter_scale;
stbr_filter filter = stbr_info->filter;
STBR_DEBUG_ASSERT(in_last_texel - in_first_texel <= stbr_info->kernel_texel_width); STBR_DEBUG_ASSERT(in_last_texel - in_first_texel <= stbr_info->kernel_texel_width);
STBR_DEBUG_ASSERT(in_first_texel >= 0); STBR_DEBUG_ASSERT(in_first_texel >= 0);
@ -296,7 +297,7 @@ static void stbr__calculate_coefficients_upsample(stbr__info* stbr_info, int in_
for (i = 0; i <= in_last_texel - in_first_texel; i++) for (i = 0; i <= in_last_texel - in_first_texel; i++)
{ {
float in_texel_center = (float)(i + in_first_texel) + 0.5f; float in_texel_center = (float)(i + in_first_texel) + 0.5f;
total_filter += coefficient_group[i] = stbr__filter_info_table[stbr_info->filter].kernel(in_center_of_out - in_texel_center); total_filter += coefficient_group[i] = stbr__filter_info_table[filter].kernel(in_center_of_out - in_texel_center);
} }
STBR_DEBUG_ASSERT(total_filter > 0); STBR_DEBUG_ASSERT(total_filter > 0);
@ -312,6 +313,7 @@ static void stbr__calculate_coefficients_upsample(stbr__info* stbr_info, int in_
static void stbr__calculate_coefficients_downsample(stbr__info* stbr_info, float scale_ratio, int out_first_texel, int out_last_texel, float out_center_of_in, int n, stbr__contributors* contributor, float* coefficient_group) static void stbr__calculate_coefficients_downsample(stbr__info* stbr_info, float scale_ratio, int out_first_texel, int out_last_texel, float out_center_of_in, int n, stbr__contributors* contributor, float* coefficient_group)
{ {
int i; int i;
stbr_filter filter = stbr_info->filter;
STBR_DEBUG_ASSERT(out_last_texel - out_first_texel <= stbr_info->kernel_texel_width); STBR_DEBUG_ASSERT(out_last_texel - out_first_texel <= stbr_info->kernel_texel_width);
STBR_DEBUG_ASSERT(out_first_texel >= 0); STBR_DEBUG_ASSERT(out_first_texel >= 0);
@ -323,7 +325,7 @@ static void stbr__calculate_coefficients_downsample(stbr__info* stbr_info, float
for (i = 0; i <= out_last_texel - out_first_texel; i++) for (i = 0; i <= out_last_texel - out_first_texel; i++)
{ {
float in_texel_center = (float)(i + out_first_texel) + 0.5f; float in_texel_center = (float)(i + out_first_texel) + 0.5f;
coefficient_group[i] = stbr__filter_info_table[stbr_info->filter].kernel(out_center_of_in - in_texel_center) * scale_ratio; coefficient_group[i] = stbr__filter_info_table[filter].kernel(out_center_of_in - in_texel_center) * scale_ratio;
} }
} }
@ -575,7 +577,7 @@ static void stbr__resample_vertical_upsample(stbr__info* stbr_info, int n, int i
STBR_UNIMPLEMENTED(stbr_info->type != STBR_TYPE_UINT8); STBR_UNIMPLEMENTED(stbr_info->type != STBR_TYPE_UINT8);
STBR_UNIMPLEMENTED("stbr__calculate_coefficients(stbr_info, in_first_scanline, in_last_scanline, in_center_of_out, n, vertical_contributors, vertical_coefficients)"); stbr__calculate_coefficients_upsample(stbr_info, in_first_scanline, in_last_scanline, in_center_of_out, n, vertical_contributors, vertical_coefficients);
int n0 = vertical_contributors->n0; int n0 = vertical_contributors->n0;
int n1 = vertical_contributors->n1; int n1 = vertical_contributors->n1;
@ -680,7 +682,7 @@ static void stbr__buffer_loop_upsample(stbr__info* stbr_info)
float in_center_of_out = 0; // Center of the current out scanline in the in scanline space float in_center_of_out = 0; // Center of the current out scanline in the in scanline space
int in_first_scanline = 0, in_last_scanline = 0; int in_first_scanline = 0, in_last_scanline = 0;
STBR_UNIMPLEMENTED("stbr__calculate_sample_range(y, out_scanlines_radius, scale_ratio, &in_first_scanline, &in_last_scanline, &in_center_of_out)"); stbr__calculate_sample_range_upsample(y, out_scanlines_radius, scale_ratio, &in_first_scanline, &in_last_scanline, &in_center_of_out);
STBR_DEBUG_ASSERT(in_last_scanline - in_first_scanline <= stbr_info->kernel_texel_width); STBR_DEBUG_ASSERT(in_last_scanline - in_first_scanline <= stbr_info->kernel_texel_width);
STBR_DEBUG_ASSERT(in_first_scanline >= 0); STBR_DEBUG_ASSERT(in_first_scanline >= 0);