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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_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel PNG_FORMAT_FLAG_ALPHA format with an alpha channel
PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 0x04 2-byte channels else 1-byte PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP 0x08 image data is color-mapped PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
PNG_FORMAT_FLAG_BGR 0x10 BGR colors, else order is RGB PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST 0x20 alpha channel comes first PNG_FORMAT_FLAG_AFIRST alpha channel comes first
Supported formats are as follows. Future versions of libpng may support more Supported formats are as follows. Future versions of libpng may support more
formats; for compatibility with older versions simply check if the format 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: First the single byte (sRGB) formats:
PNG_FORMAT_GRAY 0 PNG_FORMAT_GRAY
PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA PNG_FORMAT_GA
PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_AG
PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR PNG_FORMAT_RGB
PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) PNG_FORMAT_BGR
PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) PNG_FORMAT_RGBA
PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_ARGB
PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) PNG_FORMAT_BGRA
PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_ABGR
Then the linear 2-byte formats. When naming these "Y" is used to Then the linear 2-byte formats. When naming these "Y" is used to
indicate a luminance (gray) channel. The component order within the pixel 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 the native byte order for your platform, and there is no provision for
swapping the bytes to a different endian condition. 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_LINEAR_Y_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_LINEAR_RGB PNG_FORMAT_LINEAR_RGB
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
PNG_FORMAT_LINEAR_RGB_ALPHA 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 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 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 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. 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) PNG_FORMAT_RGB_COLORMAP
#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_BGR_COLORMAP
#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_RGBA_COLORMAP
#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_ARGB_COLORMAP
#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_BGRA_COLORMAP
#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_ABGR_COLORMAP
PNG_IMAGE macros PNG_IMAGE macros
@ -3942,14 +3938,12 @@ they can be used in #if tests.
PNG_IMAGE_COLORMAP_SIZE(fmt) PNG_IMAGE_COLORMAP_SIZE(fmt)
The size of the color-map required by the format; this is the size of the 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 a fixed number determined by the format so can easily be allocated on the
stack if necessary. stack if necessary.
Corresponding information about the pixels Corresponding information about the pixels
PNG_IMAGE_PIXEL_(test,fmt)
PNG_IMAGE_PIXEL_CHANNELS(fmt) PNG_IMAGE_PIXEL_CHANNELS(fmt)
The number of separate channels (components) in a pixel; 1 for a The number of separate channels (components) in a pixel; 1 for a
color-mapped image. 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_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel PNG_FORMAT_FLAG_ALPHA format with an alpha channel
PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale
PNG_FORMAT_FLAG_LINEAR 0x04 2-byte channels else 1-byte PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte
PNG_FORMAT_FLAG_COLORMAP 0x08 image data is color-mapped PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
PNG_FORMAT_FLAG_BGR 0x10 BGR colors, else order is RGB PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB
PNG_FORMAT_FLAG_AFIRST 0x20 alpha channel comes first PNG_FORMAT_FLAG_AFIRST alpha channel comes first
Supported formats are as follows. Future versions of libpng may support more Supported formats are as follows. Future versions of libpng may support more
formats; for compatibility with older versions simply check if the format 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: First the single byte (sRGB) formats:
PNG_FORMAT_GRAY 0 PNG_FORMAT_GRAY
PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA PNG_FORMAT_GA
PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_AG
PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR PNG_FORMAT_RGB
PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) PNG_FORMAT_BGR
PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) PNG_FORMAT_RGBA
PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_ARGB
PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) PNG_FORMAT_BGRA
PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) PNG_FORMAT_ABGR
Then the linear 2-byte formats. When naming these "Y" is used to Then the linear 2-byte formats. When naming these "Y" is used to
indicate a luminance (gray) channel. The component order within the pixel 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 the native byte order for your platform, and there is no provision for
swapping the bytes to a different endian condition. 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_LINEAR_Y_ALPHA
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
PNG_FORMAT_LINEAR_RGB PNG_FORMAT_LINEAR_RGB
(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
PNG_FORMAT_LINEAR_RGB_ALPHA 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 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 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 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. 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) PNG_FORMAT_RGB_COLORMAP
#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_BGR_COLORMAP
#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_RGBA_COLORMAP
#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_ARGB_COLORMAP
#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_BGRA_COLORMAP
#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP) PNG_FORMAT_ABGR_COLORMAP
PNG_IMAGE macros PNG_IMAGE macros
@ -4450,14 +4446,12 @@ they can be used in #if tests.
PNG_IMAGE_COLORMAP_SIZE(fmt) PNG_IMAGE_COLORMAP_SIZE(fmt)
The size of the color-map required by the format; this is the size of the 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 a fixed number determined by the format so can easily be allocated on the
stack if necessary. stack if necessary.
Corresponding information about the pixels Corresponding information about the pixels
PNG_IMAGE_PIXEL_(test,fmt)
PNG_IMAGE_PIXEL_CHANNELS(fmt) PNG_IMAGE_PIXEL_CHANNELS(fmt)
The number of separate channels (components) in a pixel; 1 for a The number of separate channels (components) in a pixel; 1 for a
color-mapped image. color-mapped image.