netsurf/desktop/bitmap.h

148 lines
4.0 KiB
C

/*
* Copyright 2022 Michael Drake <tlsa@nesturf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Internal core bitmap interface.
*/
#ifndef _NETSURF_DESKTOP_BITMAP_H_
#define _NETSURF_DESKTOP_BITMAP_H_
#include <nsutils/endian.h>
#include "netsurf/types.h"
#include "netsurf/bitmap.h"
/** Pixel format: colour component order. */
struct bitmap_colour_layout {
uint8_t r; /**< Byte offset within pixel to red component. */
uint8_t g; /**< Byte offset within pixel to green component. */
uint8_t b; /**< Byte offset within pixel to blue component. */
uint8_t a; /**< Byte offset within pixel to alpha component. */
};
/** The client bitmap format. */
extern bitmap_fmt_t bitmap_fmt;
/** The client bitmap colour channel layout. */
extern struct bitmap_colour_layout bitmap_layout;
/**
* Convert a bitmap pixel to a NetSurf colour (0xAARRGGBB).
*
* The bitmap must be in the client format.
*
* \param[in] Pointer to a pixel in the bitmap's pixel data.
* \return The corresponding NetSurf colour.
*/
static inline colour bitmap_pixel_to_colour(const uint8_t *pixel)
{
return (pixel[bitmap_layout.r] << 0) |
(pixel[bitmap_layout.g] << 8) |
(pixel[bitmap_layout.b] << 16) |
(pixel[bitmap_layout.a] << 24);
}
/**
* Sanitise bitmap pixel component layout.
*
* Map endian-dependant layouts to byte-wise layout for the host.
*
* \param[in] layout Layout to convert.
* \return sanitised layout.
*/
static inline enum bitmap_layout bitmap_sanitise_bitmap_layout(
enum bitmap_layout layout)
{
bool le = endian_host_is_le();
switch (layout) {
case BITMAP_LAYOUT_RGBA8888:
layout = (le) ? BITMAP_LAYOUT_A8B8G8R8
: BITMAP_LAYOUT_R8G8B8A8;
break;
case BITMAP_LAYOUT_BGRA8888:
layout = (le) ? BITMAP_LAYOUT_A8R8G8B8
: BITMAP_LAYOUT_B8G8R8A8;
break;
case BITMAP_LAYOUT_ARGB8888:
layout = (le) ? BITMAP_LAYOUT_B8G8R8A8
: BITMAP_LAYOUT_A8R8G8B8;
break;
case BITMAP_LAYOUT_ABGR8888:
layout = (le) ? BITMAP_LAYOUT_R8G8B8A8
: BITMAP_LAYOUT_A8B8G8R8;
break;
default:
break;
}
return layout;
}
/**
* Convert bitmap from one format to another.
*
* Note that both formats should be sanitised.
*
* \param[in] bitmap The bitmap to convert.
* \param[in] from The current bitmap format specifier.
* \param[in] to The bitmap format to convert to.
*/
void bitmap_format_convert(void *bitmap,
const bitmap_fmt_t *from,
const bitmap_fmt_t *to);
/**
* Convert a bitmap to the client bitmap format.
*
* \param[in] bitmap The bitmap to convert.
* \param[in] current_fmt The current bitmap format specifier.
*/
static inline void bitmap_format_to_client(
void *bitmap,
const bitmap_fmt_t *current_fmt)
{
bitmap_fmt_t from = *current_fmt;
from.layout = bitmap_sanitise_bitmap_layout(from.layout);
if (from.layout != bitmap_fmt.layout || from.pma != bitmap_fmt.pma) {
bitmap_format_convert(bitmap, &from, &bitmap_fmt);
}
}
/**
* Convert a bitmap to the client bitmap format.
*
* \param[in] bitmap The bitmap to convert.
* \param[in] target_fmt The target bitmap format specifier.
*/
static inline void bitmap_format_from_client(
void *bitmap,
const bitmap_fmt_t *target_fmt)
{
bitmap_fmt_t to = *target_fmt;
to.layout = bitmap_sanitise_bitmap_layout(to.layout);
if (to.layout != bitmap_fmt.layout || to.pma != bitmap_fmt.pma) {
bitmap_format_convert(bitmap, &bitmap_fmt, &to);
}
}
#endif