weston/tests/color-icc-output-test.c

928 lines
27 KiB
C

/*
* Copyright 2021 Advanced Micro Devices, Inc.
* Copyright 2020, 2022 Collabora, 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.
*/
#include "config.h"
#include <math.h>
#include <string.h>
#include <stdio.h>
#include <linux/limits.h>
#include <lcms2.h>
#include "weston-test-client-helper.h"
#include "weston-test-fixture-compositor.h"
#include "color_util.h"
#include "image-iter.h"
#include "lcms_util.h"
struct lcms_pipeline {
/**
* Color space name
*/
const char *color_space;
/**
* Chromaticities for output profile
*/
cmsCIExyYTRIPLE prim_output;
/**
* tone curve enum
*/
enum transfer_fn pre_fn;
/**
* Transform matrix from sRGB to target chromaticities in prim_output
*/
struct lcmsMAT3 mat;
/**
* matrix from prim_output to XYZ, for example matrix conversion
* sRGB->XYZ, adobeRGB->XYZ, bt2020->XYZ
*/
struct lcmsMAT3 mat2XYZ;
/**
* tone curve enum
*/
enum transfer_fn post_fn;
};
static const int WINDOW_WIDTH = 256;
static const int WINDOW_HEIGHT = 24;
static cmsCIExyY wp_d65 = { 0.31271, 0.32902, 1.0 };
enum profile_type {
PTYPE_MATRIX_SHAPER,
PTYPE_CLUT,
};
/*
* Using currently destination gamut bigger than source.
* Using https://www.colour-science.org/ we can extract conversion matrix:
* import colour
* colour.matrix_RGB_to_RGB(colour.RGB_COLOURSPACES['sRGB'], colour.RGB_COLOURSPACES['Adobe RGB (1998)'], None)
* colour.matrix_RGB_to_RGB(colour.RGB_COLOURSPACES['sRGB'], colour.RGB_COLOURSPACES['ITU-R BT.2020'], None)
*/
const struct lcms_pipeline pipeline_sRGB = {
.color_space = "sRGB",
.prim_output = {
.Red = { 0.640, 0.330, 1.0 },
.Green = { 0.300, 0.600, 1.0 },
.Blue = { 0.150, 0.060, 1.0 }
},
.pre_fn = TRANSFER_FN_SRGB_EOTF,
.mat = LCMSMAT3(1.0, 0.0, 0.0,
0.0, 1.0, 0.0,
0.0, 0.0, 1.0),
.mat2XYZ = LCMSMAT3(0.436037, 0.385124, 0.143039,
0.222482, 0.716913, 0.060605,
0.013922, 0.097078, 0.713899),
.post_fn = TRANSFER_FN_SRGB_EOTF_INVERSE
};
const struct lcms_pipeline pipeline_adobeRGB = {
.color_space = "adobeRGB",
.prim_output = {
.Red = { 0.640, 0.330, 1.0 },
.Green = { 0.210, 0.710, 1.0 },
.Blue = { 0.150, 0.060, 1.0 }
},
.pre_fn = TRANSFER_FN_SRGB_EOTF,
.mat = LCMSMAT3( 0.715127, 0.284868, 0.000005,
0.000001, 0.999995, 0.000004,
-0.000003, 0.041155, 0.958848),
.mat2XYZ = LCMSMAT3(0.609740, 0.205279, 0.149181,
0.311111, 0.625681, 0.063208,
0.019469, 0.060879, 0.744552),
.post_fn = TRANSFER_FN_ADOBE_RGB_EOTF_INVERSE
};
const struct lcms_pipeline pipeline_BT2020 = {
.color_space = "bt2020",
.prim_output = {
.Red = { 0.708, 0.292, 1.0 },
.Green = { 0.170, 0.797, 1.0 },
.Blue = { 0.131, 0.046, 1.0 }
},
.pre_fn = TRANSFER_FN_SRGB_EOTF,
.mat = LCMSMAT3(0.627402, 0.329292, 0.043306,
0.069095, 0.919544, 0.011360,
0.016394, 0.088028, 0.895578),
/* this is equivalent to BT.1886 with zero black level */
.post_fn = TRANSFER_FN_POWER2_4_EOTF_INVERSE,
};
struct setup_args {
struct fixture_metadata meta;
int ref_image_index;
const struct lcms_pipeline *pipeline;
/**
* Two-norm color error tolerance in units of 1.0/255, computed in
* output electrical space.
*
* Tolerance depends more on the 1D LUT used for the
* inv EOTF than the tested 3D LUT size:
* 9x9x9, 17x17x17, 33x33x33, 127x127x127
*
* TODO: when we add power-law in the curve enumeration
* in GL-renderer, then we should fix the tolerance
* as the error should reduce a lot.
*/
float tolerance;
/**
* 3DLUT dimension size
*/
int dim_size;
enum profile_type type;
/** Two-norm error limit for cLUT DToB->BToD roundtrip */
float clut_roundtrip_tolerance;
/**
* VCGT tag exponents for each channel. If any is zeroed, we ignore
* the VCGT tag.
*/
double vcgt_exponents[COLOR_CHAN_NUM];
};
static const struct setup_args my_setup_args[] = {
/* name, ref img, pipeline, tolerance, dim, profile type, clut tolerance, vcgt_exponents */
{ { "sRGB->sRGB MAT" }, 0, &pipeline_sRGB, 0.0, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->sRGB MAT VCGT" }, 3, &pipeline_sRGB, 0.8, 0, PTYPE_MATRIX_SHAPER, 0.0000, {1.1, 1.2, 1.3} },
{ { "sRGB->adobeRGB MAT" }, 1, &pipeline_adobeRGB, 1.4, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->adobeRGB MAT VCGT" }, 4, &pipeline_adobeRGB, 1.0, 0, PTYPE_MATRIX_SHAPER, 0.0000, {1.1, 1.2, 1.3} },
{ { "sRGB->BT2020 MAT" }, 2, &pipeline_BT2020, 4.5, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->sRGB CLUT" }, 0, &pipeline_sRGB, 0.0, 17, PTYPE_CLUT, 0.0005 },
{ { "sRGB->sRGB CLUT VCGT" }, 3, &pipeline_sRGB, 0.9, 17, PTYPE_CLUT, 0.0005, {1.1, 1.2, 1.3} },
{ { "sRGB->adobeRGB CLUT" }, 1, &pipeline_adobeRGB, 1.8, 17, PTYPE_CLUT, 0.0065 },
{ { "sRGB->adobeRGB CLUT VCGT" }, 4, &pipeline_adobeRGB, 1.1, 17, PTYPE_CLUT, 0.0065, {1.1, 1.2, 1.3} },
};
static void
test_roundtrip(uint8_t r, uint8_t g, uint8_t b, cmsPipeline *pip,
struct rgb_diff_stat *stat)
{
struct color_float in = { .rgb = { r / 255.0, g / 255.0, b / 255.0 } };
struct color_float out = {};
cmsPipelineEvalFloat(in.rgb, out.rgb, pip);
rgb_diff_stat_update(stat, &in, &out, &in);
}
/*
* Roundtrip verification tests that converting device -> PCS -> device
* results in the original color values close enough.
*
* This ensures that the two pipelines are probably built correctly, and we
* do not have problems with unexpected value clamping or with representing
* (inverse) EOTF curves.
*/
static void
roundtrip_verification(cmsPipeline *DToB, cmsPipeline *BToD, float tolerance)
{
unsigned r, g, b;
struct rgb_diff_stat stat = {};
cmsPipeline *pip;
pip = cmsPipelineDup(DToB);
cmsPipelineCat(pip, BToD);
/*
* Inverse-EOTF is known to have precision problems near zero, so
* sample near zero densely, the rest can be more sparse to run faster.
*/
for (r = 0; r < 256; r += (r < 15) ? 1 : 8) {
for (g = 0; g < 256; g += (g < 15) ? 1 : 8) {
for (b = 0; b < 256; b += (b < 15) ? 1 : 8)
test_roundtrip(r, g, b, pip, &stat);
}
}
cmsPipelineFree(pip);
rgb_diff_stat_print(&stat, "DToB->BToD roundtrip", 8);
assert(stat.two_norm.max < tolerance);
}
static cmsInt32Number
sampler_matrix(const float src[], float dst[], void *cargo)
{
const struct lcmsMAT3 *mat = cargo;
struct color_float in = { .r = src[0], .g = src[1], .b = src[2] };
struct color_float cf;
unsigned i;
cf = color_float_apply_matrix(mat, in);
for (i = 0; i < COLOR_CHAN_NUM; i++)
dst[i] = cf.rgb[i];
return 1;
}
static cmsStage *
create_cLUT_from_matrix(cmsContext context_id, const struct lcmsMAT3 *mat, int dim_size)
{
cmsStage *cLUT_stage;
assert(dim_size);
cLUT_stage = cmsStageAllocCLutFloat(context_id, dim_size, 3, 3, NULL);
cmsStageSampleCLutFloat(cLUT_stage, sampler_matrix, (void *)mat, 0);
return cLUT_stage;
}
static void
vcgt_tag_add_to_profile(cmsContext context_id, cmsHPROFILE profile,
const double vcgt_exponents[COLOR_CHAN_NUM])
{
cmsToneCurve *vcgt_tag_curves[COLOR_CHAN_NUM];
unsigned int i;
if (!should_include_vcgt(vcgt_exponents))
return;
for (i = 0; i < COLOR_CHAN_NUM; i++)
vcgt_tag_curves[i] = cmsBuildGamma(context_id, vcgt_exponents[i]);
assert(cmsWriteTag(profile, cmsSigVcgtTag, vcgt_tag_curves));
cmsFreeToneCurveTriple(vcgt_tag_curves);
}
/*
* Originally the cLUT profile test attempted to use the AToB/BToA tags. Those
* come with serious limitations though: at most uint16 representation for
* values in a LUT which means LUT entry precision is limited and range is
* [0.0, 1.0]. This poses difficulties such as:
* - for AToB, the resulting PCS XYZ values may need to be > 1.0
* - for BToA, it is easy to fall outside of device color volume meaning that
* out-of-range values are needed in the 3D LUT
* Working around these could require offsetting and scaling of values
* before and after the 3D LUT, and even that may not always be possible.
*
* DToB/BToD tags do not have most of these problems, because there pipelines
* use float32 representation throughout. We have much more precision, and
* we can mostly use negative and greater than 1.0 values. LUT elements
* still clamp their input to [0.0, 1.0] before applying the LUT. This type of
* pipeline is called multiProcessElement (MPE).
*
* MPE also allows us to represent curves in a few analytical forms. These are
* just enough to represent the EOTF curves we have and their inverses, but
* they do not allow encoding extended EOTF curves or their inverses
* (defined for all real numbers by extrapolation, and mirroring for negative
* inputs). Using MPE curves we avoid the precision problems that arise from
* attempting to represent an inverse-EOTF as a LUT. For the precision issue,
* see: https://gitlab.freedesktop.org/pq/color-and-hdr/-/merge_requests/9
*
* MPE is not a complete remedy, because 3D LUT inputs are still always clamped
* to [0.0, 1.0]. Therefore a 3D LUT cannot represent the inverse of a matrix
* that can produce negative or greater than 1.0 values without further tricks
* (scaling and offsetting) in the pipeline. Rather than implementing that
* complication, we decided to just not test with such matrices. Therefore
* BT.2020 color space is not used in the cLUT test. AdobeRGB is enough.
*/
static cmsHPROFILE
build_lcms_clut_profile_output(cmsContext context_id,
const struct setup_args *arg)
{
enum transfer_fn inv_eotf_fn = arg->pipeline->post_fn;
enum transfer_fn eotf_fn = transfer_fn_invert(inv_eotf_fn);
cmsHPROFILE hRGB;
cmsPipeline *DToB0, *BToD0;
cmsStage *stage;
cmsStage *stage_inv_eotf;
cmsStage *stage_eotf;
struct lcmsMAT3 mat2XYZ_inv;
lcmsMAT3_invert(&mat2XYZ_inv, &arg->pipeline->mat2XYZ);
hRGB = cmsCreateProfilePlaceholder(context_id);
cmsSetProfileVersion(hRGB, 4.3);
cmsSetDeviceClass(hRGB, cmsSigDisplayClass);
cmsSetColorSpace(hRGB, cmsSigRgbData);
cmsSetPCS(hRGB, cmsSigXYZData);
SetTextTags(hRGB, L"cLut profile");
stage_eotf = build_MPE_curve_stage(context_id, eotf_fn);
stage_inv_eotf = build_MPE_curve_stage(context_id, inv_eotf_fn);
/*
* Pipeline from PCS (optical) to device (electrical)
*/
BToD0 = cmsPipelineAlloc(context_id, 3, 3);
stage = create_cLUT_from_matrix(context_id, &mat2XYZ_inv, arg->dim_size);
cmsPipelineInsertStage(BToD0, cmsAT_END, stage);
cmsPipelineInsertStage(BToD0, cmsAT_END, cmsStageDup(stage_inv_eotf));
cmsWriteTag(hRGB, cmsSigBToD0Tag, BToD0);
cmsLinkTag(hRGB, cmsSigBToD1Tag, cmsSigBToD0Tag);
cmsLinkTag(hRGB, cmsSigBToD2Tag, cmsSigBToD0Tag);
cmsLinkTag(hRGB, cmsSigBToD3Tag, cmsSigBToD0Tag);
/*
* Pipeline from device (electrical) to PCS (optical)
*/
DToB0 = cmsPipelineAlloc(context_id, 3, 3);
cmsPipelineInsertStage(DToB0, cmsAT_END, cmsStageDup(stage_eotf));
stage = create_cLUT_from_matrix(context_id, &arg->pipeline->mat2XYZ, arg->dim_size);
cmsPipelineInsertStage(DToB0, cmsAT_END, stage);
cmsWriteTag(hRGB, cmsSigDToB0Tag, DToB0);
cmsLinkTag(hRGB, cmsSigDToB1Tag, cmsSigDToB0Tag);
cmsLinkTag(hRGB, cmsSigDToB2Tag, cmsSigDToB0Tag);
cmsLinkTag(hRGB, cmsSigDToB3Tag, cmsSigDToB0Tag);
vcgt_tag_add_to_profile(context_id, hRGB, arg->vcgt_exponents);
roundtrip_verification(DToB0, BToD0, arg->clut_roundtrip_tolerance);
cmsPipelineFree(BToD0);
cmsPipelineFree(DToB0);
cmsStageFree(stage_eotf);
cmsStageFree(stage_inv_eotf);
return hRGB;
}
static cmsHPROFILE
build_lcms_matrix_shaper_profile_output(cmsContext context_id,
const struct setup_args *arg)
{
cmsToneCurve *arr_curves[3];
cmsHPROFILE hRGB;
int type_inverse_tone_curve;
double inverse_tone_curve_param[5];
assert(find_tone_curve_type(arg->pipeline->post_fn, &type_inverse_tone_curve,
inverse_tone_curve_param));
/*
* We are creating output profile and therefore we can use the following:
* calling semantics:
* cmsBuildParametricToneCurve(type_inverse_tone_curve, inverse_tone_curve_param)
* The function find_tone_curve_type sets the type of curve positive if it
* is tone curve and negative if it is inverse. When we create an ICC
* profile we should use a tone curve, the inversion is done by LCMS
* when the profile is used for output.
*/
arr_curves[0] = arr_curves[1] = arr_curves[2] =
cmsBuildParametricToneCurve(context_id,
(-1) * type_inverse_tone_curve,
inverse_tone_curve_param);
assert(arr_curves[0]);
hRGB = cmsCreateRGBProfileTHR(context_id, &wp_d65,
&arg->pipeline->prim_output, arr_curves);
assert(hRGB);
vcgt_tag_add_to_profile(context_id, hRGB, arg->vcgt_exponents);
cmsFreeToneCurve(arr_curves[0]);
return hRGB;
}
static cmsHPROFILE
build_lcms_profile_output(cmsContext context_id, const struct setup_args *arg)
{
switch (arg->type) {
case PTYPE_MATRIX_SHAPER:
return build_lcms_matrix_shaper_profile_output(context_id, arg);
case PTYPE_CLUT:
return build_lcms_clut_profile_output(context_id, arg);
}
return NULL;
}
static char *
build_output_icc_profile(const struct setup_args *arg)
{
char *profile_name = NULL;
cmsHPROFILE profile = NULL;
char *wd;
int ret;
bool saved;
wd = realpath(".", NULL);
assert(wd);
if (arg->type == PTYPE_MATRIX_SHAPER)
ret = asprintf(&profile_name, "%s/matrix-shaper-test-%s.icm", wd,
arg->pipeline->color_space);
else
ret = asprintf(&profile_name, "%s/cLUT-test-%s.icm", wd,
arg->pipeline->color_space);
assert(ret > 0);
profile = build_lcms_profile_output(NULL, arg);
assert(profile);
saved = cmsSaveProfileToFile(profile, profile_name);
assert(saved);
cmsCloseProfile(profile);
free(wd);
return profile_name;
}
static void
test_lcms_error_logger(cmsContext context_id,
cmsUInt32Number error_code,
const char *text)
{
testlog("LittleCMS error: %s\n", text);
}
static enum test_result_code
fixture_setup(struct weston_test_harness *harness, const struct setup_args *arg)
{
struct compositor_setup setup;
char *file_name;
cmsSetLogErrorHandler(test_lcms_error_logger);
compositor_setup_defaults(&setup);
setup.renderer = WESTON_RENDERER_GL;
setup.backend = WESTON_BACKEND_HEADLESS;
setup.width = WINDOW_WIDTH;
setup.height = WINDOW_HEIGHT;
setup.shell = SHELL_TEST_DESKTOP;
setup.logging_scopes = "log,color-lcms-profiles,color-lcms-transformations,color-lcms-optimizer";
file_name = build_output_icc_profile(arg);
if (!file_name)
return RESULT_HARD_ERROR;
weston_ini_setup(&setup,
cfgln("[core]"),
cfgln("output-decorations=true"),
cfgln("color-management=true"),
cfgln("[output]"),
cfgln("name=headless"),
cfgln("icc_profile=%s", file_name));
free(file_name);
return weston_test_harness_execute_as_client(harness, &setup);
}
DECLARE_FIXTURE_SETUP_WITH_ARG(fixture_setup, my_setup_args, meta);
static void
gen_ramp_rgb(pixman_image_t *image, int bitwidth, int width_bar)
{
static const int hue[][COLOR_CHAN_NUM] = {
{ 1, 1, 1 }, /* White */
{ 1, 1, 0 }, /* Yellow */
{ 0, 1, 1 }, /* Cyan */
{ 0, 1, 0 }, /* Green */
{ 1, 0, 1 }, /* Magenta */
{ 1, 0, 0 }, /* Red */
{ 0, 0, 1 }, /* Blue */
};
const int num_hues = ARRAY_LENGTH(hue);
struct image_header ih = image_header_from(image);
float val_max;
int x, y;
int hue_index;
int chan;
float value;
unsigned char r, g, b;
uint32_t *pixel;
float n_steps = width_bar - 1;
val_max = (1 << bitwidth) - 1;
for (y = 0; y < ih.height; y++) {
hue_index = (y * num_hues) / (ih.height - 1);
hue_index = MIN(hue_index, num_hues - 1);
pixel = image_header_get_row_u32(&ih, y);
for (x = 0; x < ih.width; x++, pixel++) {
struct color_float rgb = { .rgb = { 0, 0, 0 } };
value = (float)x / (float)(ih.width - 1);
if (width_bar > 1)
value = floor(value * n_steps) / n_steps;
for (chan = 0; chan < COLOR_CHAN_NUM; chan++) {
if (hue[hue_index][chan])
rgb.rgb[chan] = value;
}
sRGB_delinearize(&rgb);
r = round(rgb.r * val_max);
g = round(rgb.g * val_max);
b = round(rgb.b * val_max);
*pixel = (255U << 24) | (r << 16) | (g << 8) | b;
}
}
}
static bool
process_pipeline_comparison(const struct buffer *src_buf,
const struct buffer *shot_buf,
const struct setup_args * arg)
{
FILE *dump = NULL;
#if 0
/*
* This file can be loaded in Octave for visualization. Find the script
* in tests/visualization/weston_plot_rgb_diff_stat.m and call it with
*
* weston_plot_rgb_diff_stat('opaque_pixel_conversion-f05-dump.txt')
*/
dump = fopen_dump_file(arg->meta.name);
#endif
struct image_header ih_src = image_header_from(src_buf->image);
struct image_header ih_shot = image_header_from(shot_buf->image);
int y, x;
struct color_float pix_src;
struct color_float pix_src_pipeline;
struct color_float pix_shot;
struct rgb_diff_stat diffstat = { .dump = dump };
bool ok;
/* no point to compare different images */
assert(ih_src.width == ih_shot.width);
assert(ih_src.height == ih_shot.height);
for (y = 0; y < ih_src.height; y++) {
uint32_t *row_ptr = image_header_get_row_u32(&ih_src, y);
uint32_t *row_ptr_shot = image_header_get_row_u32(&ih_shot, y);
for (x = 0; x < ih_src.width; x++) {
pix_src = a8r8g8b8_to_float(row_ptr[x]);
pix_shot = a8r8g8b8_to_float(row_ptr_shot[x]);
process_pixel_using_pipeline(arg->pipeline->pre_fn,
&arg->pipeline->mat,
arg->pipeline->post_fn,
arg->vcgt_exponents,
&pix_src, &pix_src_pipeline);
rgb_diff_stat_update(&diffstat,
&pix_src_pipeline, &pix_shot,
&pix_src);
}
}
ok = diffstat.two_norm.max <= arg->tolerance / 255.0f;
testlog("%s %s %s tolerance %f %s\n", __func__,
ok ? "SUCCESS" : "FAILURE",
arg->meta.name, arg->tolerance,
arg->type == PTYPE_MATRIX_SHAPER ? "matrix-shaper" : "cLUT");
rgb_diff_stat_print(&diffstat, __func__, 8);
if (dump)
fclose(dump);
return ok;
}
/*
* Test that opaque client pixels produce the expected output when converted
* from the implicit sRGB input to ICC profile described output.
*
* The groundtruth conversion comes from the struct lcms_pipeline definitions.
* The first error source is converting those to ICC files. The second error
* source is Weston.
*
* This tests particularly the chain of input-to-blend followed by
* blend-to-output categories of color transformations.
*/
TEST(opaque_pixel_conversion)
{
int seq_no = get_test_fixture_index();
const struct setup_args *arg = &my_setup_args[seq_no];
const int width = WINDOW_WIDTH;
const int height = WINDOW_HEIGHT;
const int bitwidth = 8;
const int width_bar = 32;
struct client *client;
struct buffer *buf;
struct buffer *shot;
struct wl_surface *surface;
bool match;
client = create_client_and_test_surface(0, 0, width, height);
assert(client);
surface = client->surface->wl_surface;
buf = create_shm_buffer_a8r8g8b8(client, width, height);
gen_ramp_rgb(buf->image, bitwidth, width_bar);
wl_surface_attach(surface, buf->proxy, 0, 0);
wl_surface_damage(surface, 0, 0, width, height);
wl_surface_commit(surface);
shot = capture_screenshot_of_output(client, NULL);
assert(shot);
match = verify_image(shot->image, "shaper_matrix", arg->ref_image_index,
NULL, seq_no);
assert(process_pipeline_comparison(buf, shot, arg));
assert(match);
buffer_destroy(shot);
buffer_destroy(buf);
client_destroy(client);
}
static struct color_float
convert_to_blending_space(const struct lcms_pipeline *pip,
struct color_float cf)
{
/* Blending space is the linearized output space,
* or simply output space without the non-linear encoding
*/
cf = color_float_apply_curve(pip->pre_fn, cf);
return color_float_apply_matrix(&pip->mat, cf);
}
static void
compare_blend(const struct lcms_pipeline *pip,
const double vcgt_exponents[COLOR_CHAN_NUM],
struct color_float bg,
struct color_float fg,
const struct color_float *shot,
struct rgb_diff_stat *diffstat)
{
struct color_float ref;
unsigned i;
/* convert sources to straight alpha */
assert(bg.a == 1.0f);
fg = color_float_unpremult(fg);
bg = convert_to_blending_space(pip, bg);
fg = convert_to_blending_space(pip, fg);
/* blend */
for (i = 0; i < COLOR_CHAN_NUM; i++)
ref.rgb[i] = (1.0f - fg.a) * bg.rgb[i] + fg.a * fg.rgb[i];
/* non-linear encoding for output */
ref = color_float_apply_curve(pip->post_fn, ref);
if (should_include_vcgt(vcgt_exponents))
for (i = 0; i < COLOR_CHAN_NUM; i++)
ref.rgb[i] = pow(ref.rgb[i], vcgt_exponents[i]);
rgb_diff_stat_update(diffstat, &ref, shot, &fg);
}
/* Alpha blending test pattern parameters */
static const int ALPHA_STEPS = 256;
static const int BLOCK_WIDTH = 1;
static void *
get_middle_row(struct buffer *buf)
{
struct image_header ih = image_header_from(buf->image);
assert(ih.width >= BLOCK_WIDTH * ALPHA_STEPS);
assert(ih.height >= BLOCK_WIDTH);
return image_header_get_row_u32(&ih, (BLOCK_WIDTH - 1) / 2);
}
static bool
check_blend_pattern(struct buffer *bg_buf,
struct buffer *fg_buf,
struct buffer *shot_buf,
const struct setup_args *arg)
{
FILE *dump = NULL;
#if 0
/*
* This file can be loaded in Octave for visualization. Find the script
* in tests/visualization/weston_plot_rgb_diff_stat.m and call it with
*
* weston_plot_rgb_diff_stat('output_icc_alpha_blend-f01-dump.txt', 255, 8)
*/
dump = fopen_dump_file(arg->meta.name);
#endif
uint32_t *bg_row = get_middle_row(bg_buf);
uint32_t *fg_row = get_middle_row(fg_buf);
uint32_t *shot_row = get_middle_row(shot_buf);
struct rgb_diff_stat diffstat = { .dump = dump };
int x;
for (x = 0; x < BLOCK_WIDTH * ALPHA_STEPS; x++) {
struct color_float bg = a8r8g8b8_to_float(bg_row[x]);
struct color_float fg = a8r8g8b8_to_float(fg_row[x]);
struct color_float shot = a8r8g8b8_to_float(shot_row[x]);
compare_blend(arg->pipeline, arg->vcgt_exponents, bg, fg, &shot, &diffstat);
}
rgb_diff_stat_print(&diffstat, "Blending", 8);
if (dump)
fclose(dump);
/* Test success condition: */
return diffstat.two_norm.max < 1.5f / 255.0f;
}
static uint32_t
premult_color(uint32_t a, uint32_t r, uint32_t g, uint32_t b)
{
uint32_t c = 0;
c |= a << 24;
c |= (a * r / 255) << 16;
c |= (a * g / 255) << 8;
c |= a * b / 255;
return c;
}
static void
fill_alpha_pattern(struct buffer *buf)
{
struct image_header ih = image_header_from(buf->image);
int y;
assert(ih.pixman_format == PIXMAN_a8r8g8b8);
assert(ih.width == BLOCK_WIDTH * ALPHA_STEPS);
for (y = 0; y < ih.height; y++) {
uint32_t *row = image_header_get_row_u32(&ih, y);
uint32_t step;
for (step = 0; step < (uint32_t)ALPHA_STEPS; step++) {
uint32_t alpha = step * 255 / (ALPHA_STEPS - 1);
uint32_t color;
int i;
color = premult_color(alpha, 0, 255 - alpha, 255);
for (i = 0; i < BLOCK_WIDTH; i++)
*row++ = color;
}
}
}
/*
* Test that alpha blending is correct when an output ICC profile is installed.
*
* The background is a constant color. On top of that, there is an
* alpha-blended gradient with ramps in both alpha and color. Sub-surface
* ensures the correct positioning and stacking.
*
* The gradient consists of ALPHA_STEPS number of blocks. Block size is
* BLOCK_WIDTH x BLOCK_WIDTH and a block has a uniform color.
*
* In the blending result over x axis:
* - red goes from 1.0 to 0.0, monotonic
* - green is not monotonic
* - blue goes from 0.0 to 1.0, monotonic
*
* The test has sRGB encoded input pixels (non-linear). These are converted to
* linear light (optical) values in output color space, blended, and converted
* to non-linear (electrical) values according to the output ICC profile.
*
* Specifically, this test exercises the linearization of output ICC profiles,
* retrieve_eotf_and_output_inv_eotf().
*/
TEST(output_icc_alpha_blend)
{
const int width = BLOCK_WIDTH * ALPHA_STEPS;
const int height = BLOCK_WIDTH;
const pixman_color_t background_color = {
.red = 0xffff,
.green = 0x8080,
.blue = 0x0000,
.alpha = 0xffff
};
int seq_no = get_test_fixture_index();
const struct setup_args *arg = &my_setup_args[seq_no];
struct client *client;
struct buffer *bg;
struct buffer *fg;
struct wl_subcompositor *subco;
struct wl_surface *surf;
struct wl_subsurface *sub;
struct buffer *shot;
bool match;
client = create_client();
subco = bind_to_singleton_global(client, &wl_subcompositor_interface, 1);
/* background window content */
bg = create_shm_buffer_a8r8g8b8(client, width, height);
fill_image_with_color(bg->image, &background_color);
/* background window, main surface */
client->surface = create_test_surface(client);
client->surface->width = width;
client->surface->height = height;
client->surface->buffer = bg; /* pass ownership */
surface_set_opaque_rect(client->surface,
&(struct rectangle){ 0, 0, width, height });
/* foreground blended content */
fg = create_shm_buffer_a8r8g8b8(client, width, height);
fill_alpha_pattern(fg);
/* foreground window, sub-surface */
surf = wl_compositor_create_surface(client->wl_compositor);
sub = wl_subcompositor_get_subsurface(subco, surf, client->surface->wl_surface);
/* sub-surface defaults to position 0, 0, top-most, synchronized */
wl_surface_attach(surf, fg->proxy, 0, 0);
wl_surface_damage(surf, 0, 0, width, height);
wl_surface_commit(surf);
/* attach, damage, commit background window */
move_client(client, 0, 0);
shot = capture_screenshot_of_output(client, NULL);
assert(shot);
match = verify_image(shot->image, "output_icc_alpha_blend", arg->ref_image_index,
NULL, seq_no);
assert(check_blend_pattern(bg, fg, shot, arg));
assert(match);
buffer_destroy(shot);
wl_subsurface_destroy(sub);
wl_surface_destroy(surf);
buffer_destroy(fg);
wl_subcompositor_destroy(subco);
client_destroy(client); /* destroys bg */
}
/*
* Test that output decorations have the expected colors.
*
* This is the only way to test input-to-output category of color
* transformations. They are used only for output decorations and some other
* debug-like features. The input color space is hardcoded to sRGB in the
* compositor.
*
* Because the output decorations are drawn with Cairo, we do not have an
* easy access to the ground-truth image and so do not check the results
* against a reference formula.
*/
TEST(output_icc_decorations)
{
int seq_no = get_test_fixture_index();
const struct setup_args *arg = &my_setup_args[seq_no];
struct client *client;
struct buffer *shot;
pixman_image_t *img;
bool match;
client = create_client();
shot = client_capture_output(client, client->output,
WESTON_CAPTURE_V1_SOURCE_FULL_FRAMEBUFFER);
img = image_convert_to_a8r8g8b8(shot->image);
match = verify_image(img, "output-icc-decorations",
arg->ref_image_index, NULL, seq_no);
assert(match);
pixman_image_unref(img);
buffer_destroy(shot);
client_destroy(client);
}