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tweak new API

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This commit is contained in:
Sean Barrett 2014-08-31 09:45:29 -07:00
parent 84520de6c4
commit 07c35180f7
1 changed files with 33 additions and 25 deletions
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58
stb_image_resize.h
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@ -81,14 +81,26 @@ STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int inp
unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
int num_channels);
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,
int num_channels);
STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
float *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
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.
#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.
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,
int num_channels, int alpha_channel, int flags);
typedef enum
{
STBIR_EDGE_CLAMP = 1,
@ -100,7 +112,7 @@ typedef enum
// This function adds the ability to specify how requests to sample off the edge of the image are handled.
STBIRDEF int stbir_resize_uint8_srgb_edgemode(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,
int num_channels,
int num_channels, int alpha_channel, int flags,
stbir_edge edge_wrap_mode);
//////////////////////////////////////////////////////////////////////////////
@ -109,7 +121,7 @@ STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels
//
// This extends the easy-to-use API as follows:
//
// * Alpha-channel can be processed separately
// * Alpha-channel can be processed separately
// * If alpha_channel is not STBIR_ALPHA_CHANNEL_NONE
// * Alpha channel will not be gamma corrected (unless flags&STBIR_FLAG_GAMMA_CORRECT)
// * Filters can be weighted by alpha channel (if flags&STBIR_FLAG_NONPREMUL_ALPHA)
@ -128,9 +140,6 @@ typedef enum
STBIR_FILTER_MITCHELL = 5,
} stbir_filter;
#define STBIR_FLAG_NONPREMUL_ALPHA (1 << 0) // 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.
typedef enum
{
STBIR_COLORSPACE_LINEAR,
@ -159,7 +168,6 @@ STBIRDEF int stbir_resize_float_generic( const float *input_pixels , int
stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space,
void *alloc_context);
#define STBIR_ALPHA_CHANNEL_NONE -1
//////////////////////////////////////////////////////////////////////////////
@ -942,7 +950,7 @@ static void stbir__decode_scanline(stbir__info* stbir_info, int n)
break;
}
if (stbir_info->flags & STBIR_FLAG_NONPREMUL_ALPHA)
if (!(stbir_info->flags & STBIR_FLAG_PREMULTIPLIED_ALPHA))
{
for (x = -stbir__get_filter_pixel_margin_horizontal(stbir_info); x < max_x; x++)
{
@ -1125,7 +1133,7 @@ static stbir__inline void stbir__encode_pixel(stbir__info* stbir_info, void* out
int n;
float divide_alpha = 1;
if (stbir_info->flags&STBIR_FLAG_NONPREMUL_ALPHA) {
if (!(stbir_info->flags&STBIR_FLAG_PREMULTIPLIED_ALPHA)) {
float alpha = encode_buffer[encode_pixel_index + alpha_channel];
float reciprocal_alpha = alpha ? 1.0f / alpha : 0;
for (n = 0; n < channels; n++)
@ -1558,7 +1566,7 @@ static int stbir__resize_allocated(stbir__info *stbir_info,
if (alpha_channel < 0)
flags = STBIR_FLAG_GAMMA_CORRECT_ALPHA; // this shouldn't be necessary in the long run, but safety for now
if (!(flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA) || (flags&STBIR_FLAG_NONPREMUL_ALPHA))
if (!(flags&STBIR_FLAG_GAMMA_CORRECT_ALPHA) || !(flags&STBIR_FLAG_PREMULTIPLIED_ALPHA))
STBIR_ASSERT(alpha_channel >= 0 && alpha_channel < channels);
if (alpha_channel >= channels)
@ -1786,16 +1794,6 @@ STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int inp
STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR);
}
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,
int num_channels)
{
return stbir_resize_arbitrary2(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
output_pixels, output_w, output_h, output_stride_in_bytes,
0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB);
}
STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes,
float *output_pixels, int output_w, int output_h, int output_stride_in_bytes,
int num_channels)
@ -1806,14 +1804,24 @@ STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , i
STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR);
}
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,
int num_channels, int alpha_channel, int flags)
{
return stbir_resize_arbitrary2(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
output_pixels, output_w, output_h, output_stride_in_bytes,
0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB);
}
STBIRDEF int stbir_resize_uint8_srgb_edgemode(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,
int num_channels,
int num_channels, int alpha_channel, int flags,
stbir_edge edge_wrap_mode)
{
return stbir_resize_arbitrary2(NULL, input_pixels, input_w, input_h, input_stride_in_bytes,
output_pixels, output_w, output_h, output_stride_in_bytes,
0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT,
edge_wrap_mode, edge_wrap_mode, STBIR_COLORSPACE_SRGB);
}