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[libpng16] More edits to libpng.3 and libpng-manual.txt

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This commit is contained in:
Glenn Randers-Pehrson 2015-07-25 08:30:12 -05:00
parent 59a82b40b0
commit 262c396666
2 changed files with 46 additions and 58 deletions
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52
libpng-manual.txt
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@ -3847,12 +3847,12 @@ appropriate "_SUPPORTED" macro, one of:
PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel
PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 0x04 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP 0x08 image data is color-mapped
PNG_FORMAT_FLAG_BGR 0x10 BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST 0x20 alpha channel comes first
PNG_FORMAT_FLAG_ALPHA format with an alpha channel
PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST alpha channel comes first
Supported formats are as follows. Future versions of libpng may support more
formats; for compatibility with older versions simply check if the format
@ -3861,15 +3861,15 @@ of the components of the pixels of the image.
First the single byte (sRGB) formats:
PNG_FORMAT_GRAY 0
PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_GRAY
PNG_FORMAT_GA
PNG_FORMAT_AG
PNG_FORMAT_RGB
PNG_FORMAT_BGR
PNG_FORMAT_RGBA
PNG_FORMAT_ARGB
PNG_FORMAT_BGRA
PNG_FORMAT_ABGR
Then the linear 2-byte formats. When naming these "Y" is used to
indicate a luminance (gray) channel. The component order within the pixel
@ -3878,26 +3878,22 @@ components in the linear format. The components are 16-bit integers in
the native byte order for your platform, and there is no provision for
swapping the bytes to a different endian condition.
PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
PNG_FORMAT_LINEAR_Y
PNG_FORMAT_LINEAR_Y_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_LINEAR_RGB
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
PNG_FORMAT_LINEAR_RGB_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|
PNG_FORMAT_FLAG_ALPHA)
With color-mapped formats the image data is one byte for each pixel. The byte
is an index into the color-map which is formatted as above. To obtain a
color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
to one of the above definitions, or you can use one of the definitions below.
#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
PNG_FORMAT_RGB_COLORMAP
PNG_FORMAT_BGR_COLORMAP
PNG_FORMAT_RGBA_COLORMAP
PNG_FORMAT_ARGB_COLORMAP
PNG_FORMAT_BGRA_COLORMAP
PNG_FORMAT_ABGR_COLORMAP
PNG_IMAGE macros
@ -3942,14 +3938,12 @@ they can be used in #if tests.
PNG_IMAGE_COLORMAP_SIZE(fmt)
The size of the color-map required by the format; this is the size of the
color-map buffer passed to the png_image_{read,write}_colormap APIs, it is
color-map buffer passed to the png_image_{read,write}_colormap APIs. It is
a fixed number determined by the format so can easily be allocated on the
stack if necessary.
Corresponding information about the pixels
PNG_IMAGE_PIXEL_(test,fmt)
PNG_IMAGE_PIXEL_CHANNELS(fmt)
The number of separate channels (components) in a pixel; 1 for a
color-mapped image.

52
libpng.3
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@ -4355,12 +4355,12 @@ appropriate "_SUPPORTED" macro, one of:
PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel
PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 0x04 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP 0x08 image data is color-mapped
PNG_FORMAT_FLAG_BGR 0x10 BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST 0x20 alpha channel comes first
PNG_FORMAT_FLAG_ALPHA format with an alpha channel
PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST alpha channel comes first
Supported formats are as follows. Future versions of libpng may support more
formats; for compatibility with older versions simply check if the format
@ -4369,15 +4369,15 @@ of the components of the pixels of the image.
First the single byte (sRGB) formats:
PNG_FORMAT_GRAY 0
PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
PNG_FORMAT_GRAY
PNG_FORMAT_GA
PNG_FORMAT_AG
PNG_FORMAT_RGB
PNG_FORMAT_BGR
PNG_FORMAT_RGBA
PNG_FORMAT_ARGB
PNG_FORMAT_BGRA
PNG_FORMAT_ABGR
Then the linear 2-byte formats. When naming these "Y" is used to
indicate a luminance (gray) channel. The component order within the pixel
@ -4386,26 +4386,22 @@ components in the linear format. The components are 16-bit integers in
the native byte order for your platform, and there is no provision for
swapping the bytes to a different endian condition.
PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
PNG_FORMAT_LINEAR_Y
PNG_FORMAT_LINEAR_Y_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_LINEAR_RGB
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
PNG_FORMAT_LINEAR_RGB_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|
PNG_FORMAT_FLAG_ALPHA)
With color-mapped formats the image data is one byte for each pixel. The byte
is an index into the color-map which is formatted as above. To obtain a
color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
to one of the above definitions, or you can use one of the definitions below.
#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
PNG_FORMAT_RGB_COLORMAP
PNG_FORMAT_BGR_COLORMAP
PNG_FORMAT_RGBA_COLORMAP
PNG_FORMAT_ARGB_COLORMAP
PNG_FORMAT_BGRA_COLORMAP
PNG_FORMAT_ABGR_COLORMAP
PNG_IMAGE macros
@ -4450,14 +4446,12 @@ they can be used in #if tests.
PNG_IMAGE_COLORMAP_SIZE(fmt)
The size of the color-map required by the format; this is the size of the
color-map buffer passed to the png_image_{read,write}_colormap APIs, it is
color-map buffer passed to the png_image_{read,write}_colormap APIs. It is
a fixed number determined by the format so can easily be allocated on the
stack if necessary.
Corresponding information about the pixels
PNG_IMAGE_PIXEL_(test,fmt)
PNG_IMAGE_PIXEL_CHANNELS(fmt)
The number of separate channels (components) in a pixel; 1 for a
color-mapped image.