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Diffstat (limited to 'shared/pixel-formats.h')
| -rw-r--r-- | shared/pixel-formats.h | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/shared/pixel-formats.h b/shared/pixel-formats.h new file mode 100644 index 0000000..8df5b45 --- /dev/null +++ b/shared/pixel-formats.h @@ -0,0 +1,373 @@ +/* + * Copyright © 2016, 2019 Collabora, Ltd. + * Copyright (c) 2018 DisplayLink (UK) Ltd. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Author: Daniel Stone <daniels@collabora.com> + */ + +#include <inttypes.h> +#include <stdbool.h> +#include <pixman.h> + +/** + * Contains information about pixel formats, mapping format codes from + * wl_shm and drm_fourcc.h (which are deliberately identical, but for the + * special cases of WL_SHM_ARGB8888 and WL_SHM_XRGB8888) into various + * sets of information. Helper functions are provided for dealing with these + * raw structures. + */ +struct pixel_format_info { + /** DRM/wl_shm format code */ + uint32_t format; + + /** The DRM format name without the DRM_FORMAT_ prefix. */ + const char *drm_format_name; + + /** If true, is only for internal use and should not be advertised to + * clients to allow them to create buffers of this format. */ + bool hide_from_clients; + + /** If non-zero, number of planes in base (non-modified) format. */ + int num_planes; + + /** If format contains alpha channel, opaque equivalent of format, + * i.e. alpha channel replaced with X. */ + uint32_t opaque_substitute; + + /** How the format should be sampled, expressed in terms of tokens + * from the EGL_WL_bind_wayland_display extension. If not set, + * assumed to be either RGB or RGBA, depending on whether or not + * the format contains an alpha channel. The samplers may still + * return alpha even for opaque formats; users must manually set + * the alpha channel to 1.0 (or ignore it) if the format is + * opaque. */ + uint32_t sampler_type; + + /** GL internal format; to be used when creating FBO renderbuffers */ + int gl_internalformat; + + /** GL format, if data can be natively/directly uploaded. Note that + * whilst DRM formats are little-endian unless explicitly specified, + * (i.e. DRM_FORMAT_ARGB8888 is stored BGRA as sequential bytes in + * memory), GL uses the sequential byte order, so that format maps to + * GL_BGRA_EXT plus GL_UNSIGNED_BYTE. To add to the confusion, the + * explicitly-sized types (e.g. GL_UNSIGNED_SHORT_5_5_5_1) read in + * machine-endian order, so for these types, the correspondence + * depends on endianness. */ + int gl_format; + + /** GL data type, if data can be natively/directly uploaded. */ + int gl_type; + + /** Pixman data type, if it agrees exactly with the wl_shm format */ + pixman_format_code_t pixman_format; + + /** If set, this format can be used with the legacy drmModeAddFB() + * function (not AddFB2), using this and the bpp member. */ + int addfb_legacy_depth; + + /** Number of bits required to store a single pixel, for + * single-planar formats. */ + int bpp; + + /** Horizontal subsampling; if non-zero, divide the width by this + * member to obtain the number of columns in the source buffer for + * secondary planes only. Stride is not affected by horizontal + * subsampling. */ + int hsub; + + /** Vertical subsampling; if non-zero, divide the height by this + * member to obtain the number of rows in the source buffer for + * secondary planes only. */ + int vsub; + + /* Ordering of chroma components. */ + enum { + ORDER_UV = 0, + ORDER_VU, + } chroma_order; + + /* If packed YUV (num_planes == 1), ordering of luma/chroma + * components. */ + enum { + ORDER_LUMA_CHROMA = 0, + ORDER_CHROMA_LUMA, + } luma_chroma_order; + + /** How many significant bits each channel has, or zero if N/A. */ + struct { + int r; + int g; + int b; + int a; + } bits; + + /** How channel bits are interpreted, fixed (uint) or floating-point */ + enum { + PIXEL_COMPONENT_TYPE_FIXED = 0, + PIXEL_COMPONENT_TYPE_FLOAT, + } component_type; +}; + +/** + * Get pixel format information for a DRM format code + * + * Given a DRM format code, return a pixel format info structure describing + * the properties of that format. + * + * @param format DRM format code to get info for + * @returns A pixel format structure (must not be freed), or NULL if the + * format could not be found + */ +const struct pixel_format_info * +pixel_format_get_info(uint32_t format); + +/** + * Get pixel format information for a SHM format code + * + * Given a SHM format code, return a DRM pixel format info structure describing + * the properties of that format. + * + * @param format SHM format code to get info for. + * @returns A pixel format structure (must not be freed), or NULL if the + * format could not be found. + */ +const struct pixel_format_info * +pixel_format_get_info_shm(uint32_t format); + +/** + * Get pixel format information by table index + * + * Given a 0-based index in the format table, return the corresponding + * DRM pixel format info structure. + * + * @param index Index of the pixel format in the table + * @returns A pixel format structure (must not be freed), or NULL if the + * index is out of range. + */ +const struct pixel_format_info * +pixel_format_get_info_by_index(unsigned int index); + +/** + * Return the size of the pixel format table + * + * @returns The number of entries in the pixel format table + */ +unsigned int +pixel_format_get_info_count(void); + +/** + * Get pixel format information for a named DRM format + * + * Given a DRM format name, return a pixel format info structure describing + * the properties of that format. + * + * The DRM format name is the preprocessor token name from drm_fourcc.h + * without the DRM_FORMAT_ prefix. The search is also case-insensitive. + * Both "xrgb8888" and "XRGB8888" searches will find DRM_FORMAT_XRGB8888 + * for example. + * + * @param drm_format_name DRM format name to get info for (not NULL) + * @returns A pixel format structure (must not be freed), or NULL if the + * name could not be found + */ +const struct pixel_format_info * +pixel_format_get_info_by_drm_name(const char *drm_format_name); + +/** + * Get pixel format information for a Pixman format code + * + * Given a Pixman format code, return a pixel format info structure describing + * the properties of that format. + * + * @param pixman_format Pixman format code to get info for + * @returns A pixel format structure (must not be freed), or NULL if the + * format could not be found + */ +const struct pixel_format_info * +pixel_format_get_info_by_pixman(pixman_format_code_t pixman_format); + +/** + * Get number of planes used by a pixel format + * + * Given a pixel format info structure, return the number of planes + * required for a buffer. Note that this is not necessarily identical to + * the number of samplers required to be bound, as two views into a single + * plane are sometimes required. + * + * @param format Pixel format info structure + * @returns Number of planes required for the format + */ +unsigned int +pixel_format_get_plane_count(const struct pixel_format_info *format); + +/** + * Determine if a pixel format is opaque or contains alpha + * + * Returns whether or not the pixel format is opaque, or contains a + * significant alpha channel. Note that the suggested EGL sampler type may + * still sample undefined data into the alpha channel; users must consider + * alpha as 1.0 if the format is opaque, and not rely on the sampler to + * return this when sampling from the alpha channel. + * + * @param format Pixel format info structure + * @returns True if the format is opaque, or false if it has significant alpha + */ +bool +pixel_format_is_opaque(const struct pixel_format_info *format); + +/** + * Get compatible opaque equivalent for a format + * + * Given a pixel format info structure, return a format which is wholly + * compatible with the input format, but opaque, ignoring the alpha channel. + * If an alpha format is provided, but the content is known to all be opaque, + * then this can be used as a substitute to avoid blending. + * + * If the input format is opaque, this function will return the input format. + * + * @param format Pixel format info structure + * @returns A pixel format info structure for the compatible opaque substitute + */ +const struct pixel_format_info * +pixel_format_get_opaque_substitute(const struct pixel_format_info *format); + +/** + * For an opaque format, get the equivalent format with alpha instead of an + * ignored channel + * + * This is the opposite lookup from pixel_format_get_opaque_substitute(). + * Finds the format whose opaque substitute is the given format. + * + * If the input format is not opaque or does not have ignored (X) bits, then + * the search cannot find a match. + * + * @param format DRM format code to search for + * @returns A pixel format info structure for the pixel format whose opaque + * substitute is the argument, or NULL if no match. + */ +const struct pixel_format_info * +pixel_format_get_info_by_opaque_substitute(uint32_t format); + +/** + * Return the horizontal subsampling factor for a given plane + * + * When horizontal subsampling is effective, a sampler bound to a secondary + * plane must bind the sampler with a smaller effective width. This function + * returns the subsampling factor to use for the given plane. + * + * @param format Pixel format info structure + * @param plane Zero-indexed plane number + * @returns Horizontal subsampling factor for the given plane + */ +unsigned int +pixel_format_hsub(const struct pixel_format_info *format, + unsigned int plane); + +/** + * Return the vertical subsampling factor for a given plane + * + * When vertical subsampling is effective, a sampler bound to a secondary + * plane must bind the sampler with a smaller effective height. This function + * returns the subsampling factor to use for the given plane. + * + * @param format Pixel format info structure + * @param plane Zero-indexed plane number + * @returns Vertical subsampling factor for the given plane + */ +unsigned int +pixel_format_vsub(const struct pixel_format_info *format, + unsigned int plane); + +/** + * Return the effective sampling width for a given plane + * + * When horizontal subsampling is effective, a sampler bound to a secondary + * plane must bind the sampler with a smaller effective width. This function + * returns the effective width to use for the sampler, i.e. dividing by hsub. + * + * If horizontal subsampling is not in effect, this will be equal to the + * width. + * + * @param format Pixel format info structure + * @param plane Zero-indexed plane number + * @param width Width of the buffer + * @returns Effective width for sampling + */ +unsigned int +pixel_format_width_for_plane(const struct pixel_format_info *format, + unsigned int plane, + unsigned int width); + +/** + * Return the effective sampling height for a given plane + * + * When vertical subsampling is in effect, a sampler bound to a secondary + * plane must bind the sampler with a smaller effective height. This function + * returns the effective height to use for the sampler, i.e. dividing by vsub. + * + * If vertical subsampling is not in effect, this will be equal to the height. + * + * @param format Pixel format info structure + * @param plane Zero-indexed plane number + * @param height Height of the buffer + * @returns Effective width for sampling + */ +unsigned int +pixel_format_height_for_plane(const struct pixel_format_info *format, + unsigned int plane, + unsigned int height); +/** + * Return a human-readable format modifier. Comprised from the modifier name, + * the vendor name, and the original encoded value in hexadecimal, using + * 'VENDOR_NAME_MODIFIER_NAME (modifier_encoded_value)' pattern. In case the + * modifier name (and the vendor name) isn't found, this returns the original + * encoded value, as a string value. + * + * @param modifier the modifier in question + * @returns a malloc'ed string, caller responsible for freeing after use. + */ +char * +pixel_format_get_modifier(uint64_t modifier); + +/** + * Return the wl_shm format code + * + * @param info Pixel format info structure + * @returns The wl_shm format code for this pixel format. + */ +uint32_t +pixel_format_get_shm_format(const struct pixel_format_info *info); + +/** + * Get pixel format array for an array of DRM format codes + * + * Given an array of DRM format codes, return an array of corresponding pixel + * format info pointers. + * + * @param formats Array of DRM format codes to get info for + * @param formats_count Number of entries in formats. + * @returns An array of pixel format info pointers, or NULL if any format could + * not be found. Must be freed by the caller. + */ +const struct pixel_format_info ** +pixel_format_get_array(const uint32_t *formats, unsigned int formats_count); |