weston/tests/color_util.h
Pekka Paalanen 53b1268018 tests/color_util: refactor into color_float_apply_matrix()
Make process_pixel_using_pipeline() slightly easier to read by
extracting a meaningful function.

Pure refactoring, no behavioral changes.

Compared to previous, flip the scalar multiplication around, so that it
matches the mathematical order of matrix-vector multiplication.

Also document the layout conventions for lcmsVEC3 and lcmsMAT3. These
follow the convention used in LittleCMS for cmsVEC3 and cmsMAT3, and are
necessary to understand to review the matrix-vector multiplication for
correctness.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
2022-06-03 10:22:25 +00:00

108 lines
2.9 KiB
C

/*
* Copyright 2020 Collabora, Ltd.
* Copyright 2021 Advanced Micro Devices, Inc.
*
* 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.
*/
#pragma once
#include <stdint.h>
#include <stdbool.h>
enum color_chan_index {
COLOR_CHAN_R = 0,
COLOR_CHAN_G,
COLOR_CHAN_B,
COLOR_CHAN_NUM
};
/* column vector when used in linear algebra */
struct color_float {
union {
float rgb[COLOR_CHAN_NUM];
struct {
float r, g, b;
};
};
float a;
};
/* column vector */
struct lcmsVEC3 {
float n[3];
};
struct lcmsMAT3 {
/* array of columns */
struct lcmsVEC3 v[3];
};
enum transfer_fn {
TRANSFER_FN_SRGB_EOTF,
TRANSFER_FN_SRGB_EOTF_INVERSE,
TRANSFER_FN_ADOBE_RGB_EOTF,
TRANSFER_FN_ADOBE_RGB_EOTF_INVERSE,
TRANSFER_FN_POWER2_4_EOTF,
TRANSFER_FN_POWER2_4_EOTF_INVERSE,
};
/*
* A helper to lay out a matrix in the natural writing order in code
* instead of needing to transpose in your mind every time you read it.
* The matrix is laid out as written:
* ⎡ a11 a12 a13 ⎤
* ⎢ a21 a22 a23 ⎥
* ⎣ a31 a32 a33 ⎦
* where the first digit is row and the second digit is column.
*/
#define LCMSMAT3(a11, a12, a13, \
a21, a22, a23, \
a31, a32, a33) ((struct lcmsMAT3) \
{ /* Each vector is a column => looks like a transpose */ \
.v[0] = { .n = { a11, a21, a31} }, \
.v[1] = { .n = { a12, a22, a32} }, \
.v[2] = { .n = { a13, a23, a33} }, \
})
void
sRGB_linearize(struct color_float *cf);
void
sRGB_delinearize(struct color_float *cf);
struct color_float
a8r8g8b8_to_float(uint32_t v);
bool
find_tone_curve_type(enum transfer_fn fn, int *type, double params[5]);
void
process_pixel_using_pipeline(enum transfer_fn pre_curve,
const struct lcmsMAT3 *mat,
enum transfer_fn post_curve,
const struct color_float *in,
struct color_float *out);
struct color_float
color_float_apply_matrix(const struct lcmsMAT3 *mat, struct color_float c);