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inline stbir__encode_pixel into stbir__encode_scanline

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This commit is contained in:
Sean Barrett 2014-09-01 19:29:28 -07:00
parent aee30095c7
commit 952c26e626
1 changed files with 88 additions and 42 deletions
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78
stb_image_resize.h
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@ -1160,75 +1160,131 @@ static float* stbir__get_ring_buffer_scanline(int get_scanline, float* ring_buff
}
static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* output_buffer, int output_pixel_index, float* encode_buffer, int encode_pixel_index, int channels, int alpha_channel, int decode)
// @OPTIMIZE: embed stbir__encode_pixel and move switch out of per-pixel loop
static void stbir__encode_scanline(stbir__info* stbir_info, int num_pixels, void *output_buffer, float *encode_buffer, int channels, int alpha_channel, int decode)
{
int x;
int n;
float divide_alpha = 1;
if (!(stbir_info->flags&STBIR_FLAG_PREMULTIPLIED_ALPHA)) {
// stbir__encode_pixel(stbir_info, output_buffer, x*channels, encode_buffer, x*channels, channels, alpha_channel, decode);
if (!(stbir_info->flags&STBIR_FLAG_PREMULTIPLIED_ALPHA))
{
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
float alpha = encode_buffer[encode_pixel_index + alpha_channel];
float reciprocal_alpha = alpha ? 1.0f / alpha : 0;
// @TODO: if final alpha=0, we actually want to have ignored alpha... set alpha to sRGB_to_linear(1/255)/(2^24) so floats will discard it?
for (n = 0; n < channels; n++)
if (n != alpha_channel)
encode_buffer[encode_pixel_index + n] *= reciprocal_alpha;
}
}
switch (decode)
{
case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_LINEAR):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned char*)output_buffer)[output_pixel_index + n] = (unsigned char)(stbir__saturate(encode_buffer[encode_pixel_index + n]) * 255);
}
break;
case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_SRGB):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned char*)output_buffer)[output_pixel_index + n] = stbir__linear_to_srgb_uchar(encode_buffer[encode_pixel_index + n]);
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
((unsigned char*)output_buffer)[output_pixel_index + alpha_channel] = (unsigned char)(stbir__saturate(encode_buffer[encode_pixel_index + alpha_channel]) * 255);
}
break;
case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_LINEAR):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned short*)output_buffer)[output_pixel_index + n] = (unsigned short)(stbir__saturate(encode_buffer[encode_pixel_index + n]) * 65535);
}
break;
case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_SRGB):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned short*)output_buffer)[output_pixel_index + n] = (unsigned short)(stbir__linear_to_srgb(stbir__saturate(encode_buffer[encode_pixel_index + n])) * 65535);
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
((unsigned short*)output_buffer)[output_pixel_index + alpha_channel] = (unsigned char)(stbir__saturate(encode_buffer[encode_pixel_index + alpha_channel]) * 255);
}
break;
case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_LINEAR):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned int*)output_buffer)[output_pixel_index + n] = (unsigned int)(((double)stbir__saturate(encode_buffer[encode_pixel_index + n])) * 4294967295);
}
break;
case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_SRGB):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((unsigned int*)output_buffer)[output_pixel_index + n] = (unsigned int)(((double)stbir__linear_to_srgb(stbir__saturate(encode_buffer[encode_pixel_index + n]))) * 4294967295);
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
((unsigned int*)output_buffer)[output_pixel_index + alpha_channel] = (unsigned int)(((double)stbir__saturate(encode_buffer[encode_pixel_index + alpha_channel])) * 4294967295);
}
break;
case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_LINEAR):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((float*)output_buffer)[output_pixel_index + n] = encode_buffer[encode_pixel_index + n];
}
break;
case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_SRGB):
for (x=0; x < num_pixels; ++x)
{
int output_pixel_index = x*channels;
int encode_pixel_index = x*channels;
for (n = 0; n < channels; n++)
((float*)output_buffer)[output_pixel_index + n] = stbir__linear_to_srgb(encode_buffer[encode_pixel_index + n]);
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
((float*)output_buffer)[output_pixel_index + alpha_channel] = encode_buffer[encode_pixel_index + alpha_channel];
}
break;
default:
@ -1237,16 +1293,6 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
}
}
// @OPTIMIZE: embed stbir__encode_pixel and move switch out of per-pixel loop
static void stbir__encode_scanline(stbir__info* stbir_info, int num_pixels, void *output_buffer, float *encode_buffer, int channels, int alpha_channel, int decode)
{
int x;
for (x=0; x < num_pixels; ++x)
{
stbir__encode_pixel(stbir_info, output_buffer, x*channels, encode_buffer, x*channels, channels, alpha_channel, decode);
}
}
static void stbir__resample_vertical_upsample(stbir__info* stbir_info, int n, int in_first_scanline, int in_last_scanline, float in_center_of_out)
{
int x, k;