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

rename alpha gamma flag

Browse Source
master
Sean Barrett ago%!(EXTRA string=11 years)
parent 07c35180f7
commit 24c540e1b0
1 changed files with 18 additions and 17 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 35
      stb_image_resize.h

35
stb_image_resize.h
Unescape View File

@ -70,7 +70,7 @@ typedef uint32_t stbir_uint32;
// * alpha channel is treated identically to other channels.
// * colorspace is linear or sRGB as specified by function name
// * returned result is 1 for success or 0 in case of an error.
// In the case of an error an assert with be triggered, #define STBIR_ASSERT() to see it.
// #define STBIR_ASSERT() to trigger an assert on parameter validation errors.
// * Memory required grows approximately linearly with input and output size, but with
// discontinuities at input_w == output_w and input_h == output_h.
// * These functions use a "default" resampling filter defined at compile time. To change the filter,
@ -86,15 +86,16 @@ STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , i
int num_channels);
//
// The following functions interpret image data as gamma-corrected sRGB.
// Specify STBIR_ALPHA_CHANNEL_NONE if you have no alpha channel,
// or otherwise provide the index of the alpha channel. By default,
// alpha channel is linear even if colors are sRGB.
// or otherwise provide the index of the alpha channel. Flags value
// of 0 will probably do the right thing if you're not sure what
// the flags mean.
#define STBIR_ALPHA_CHANNEL_NONE -1
#define STBIR_ALPHA_CHANNEL_NONE -1
#define STBIR_FLAG_PREMULTIPLIED_ALPHA (1 << 0) // If this flag is not set, the specified alpha channel will be multiplied into all other channels before resampling, then divided back out after.
#define STBIR_FLAG_GAMMA_CORRECT_ALPHA (1 << 1) // The specified alpha channel should be handled as gamma-corrected value even when doing sRGB operations.
#define STBIR_FLAG_PREMULTIPLIED_ALPHA (1 << 0) // If this flag is not set, the specified alpha channel will be multiplied into all other channels before resampling, then divided back out after.
#define STBIR_FLAG_ALPHA_USES_COLORSPACE (1 << 1) // The specified alpha channel should be handled as gamma-corrected value even when doing sRGB operations.
STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
@ -870,7 +871,7 @@ static void stbir__decode_scanline(stbir__info* stbir_info, int n)
for (c = 0; c < channels; c++)
decode_buffer[decode_pixel_index + c] = stbir__srgb_uchar_to_linear_float[((const unsigned char*)input_data)[input_pixel_index + c]];
if (!(stbir_info->flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA))
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned char*)input_data)[input_pixel_index + alpha_channel]) / 255;
}
break;
@ -893,7 +894,7 @@ static void stbir__decode_scanline(stbir__info* stbir_info, int n)
for (c = 0; c < channels; c++)
decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((float)((const unsigned short*)input_data)[input_pixel_index + c]) / 65535);
if (!(stbir_info->flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA))
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned short*)input_data)[input_pixel_index + alpha_channel]) / 65535;
}
break;
@ -916,7 +917,7 @@ static void stbir__decode_scanline(stbir__info* stbir_info, int n)
for (c = 0; c < channels; c++)
decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear((float)(((double)((const unsigned int*)input_data)[input_pixel_index + c]) / 4294967295));
if (!(stbir_info->flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA))
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
decode_buffer[decode_pixel_index + alpha_channel] = (float)(((double)((const unsigned int*)input_data)[input_pixel_index + alpha_channel]) / 4294967295);
}
break;
@ -939,7 +940,7 @@ static void stbir__decode_scanline(stbir__info* stbir_info, int n)
for (c = 0; c < channels; c++)
decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((const float*)input_data)[input_pixel_index + c]);
if (!(stbir_info->flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA))
if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE))
decode_buffer[decode_pixel_index + alpha_channel] = ((const float*)input_data)[input_pixel_index + alpha_channel];
}
@ -1152,7 +1153,7 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
for (n = 0; n < channels; n++)
((unsigned char*)output_buffer)[output_pixel_index + n] = stbir__linear_uchar_to_srgb_uchar[(unsigned char)(stbir__saturate(encode_buffer[encode_pixel_index + n]) * 255)];
if (!(stbir_info->flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA))
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;
@ -1166,7 +1167,7 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
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_GAMMA_CORRECT_ALPHA))
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;
@ -1180,7 +1181,7 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
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_GAMMA_CORRECT_ALPHA))
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;
@ -1194,7 +1195,7 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
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_GAMMA_CORRECT_ALPHA))
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;
@ -1564,9 +1565,9 @@ static int stbir__resize_allocated(stbir__info *stbir_info,
return 0;
if (alpha_channel < 0)
flags = STBIR_FLAG_GAMMA_CORRECT_ALPHA; // this shouldn't be necessary in the long run, but safety for now
flags = STBIR_FLAG_ALPHA_USES_COLORSPACE; // this shouldn't be necessary in the long run, but safety for now
if (!(flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA) || !(flags&STBIR_FLAG_PREMULTIPLIED_ALPHA))
if (!(flags&STBIR_FLAG_ALPHA_USES_COLORSPACE) || !(flags&STBIR_FLAG_PREMULTIPLIED_ALPHA))
STBIR_ASSERT(alpha_channel >= 0 && alpha_channel < channels);
if (alpha_channel >= channels)

Write Preview
Loading…
Cancel
Save