wlroots/render/color_lcms2.c
Simon Ser 3665b53e29 render/color: replace COLOR_TRANSFORM_LUT_3D with COLOR_TRANSFORM_LCMS2
Converting the LCMS2 transform to a 3D LUT early causes issues:

- It's a lossy process, the consumer will not be able to pick a
  3D LUT size on their own.
- It requires unnecessary conversions and allocations: an intermediate
  3D LUT is allocated, but the renderer already allocates one.
- It makes it harder to support arbitrary color transforms in the
  renderer, because each type needs to be handled differently.

Instead, expose a function to evaluate a color transform, and use
that to build the 3D LUT in the renderer.
2025-06-16 09:06:10 +00:00

113 lines
2.9 KiB
C

#include <assert.h>
#include <lcms2.h>
#include <stdlib.h>
#include <wlr/util/log.h>
#include <wlr/render/color.h>
#include "render/color.h"
struct wlr_color_transform_lcms2 {
struct wlr_color_transform base;
cmsContext ctx;
cmsHTRANSFORM lcms;
};
static const cmsCIExyY srgb_whitepoint = { 0.3127, 0.3291, 1 };
static const cmsCIExyYTRIPLE srgb_primaries = {
.Red = { 0.64, 0.33, 1 },
.Green = { 0.3, 0.6, 1 },
.Blue = { 0.15, 0.06, 1},
};
static void handle_lcms_error(cmsContext ctx, cmsUInt32Number code, const char *text) {
wlr_log(WLR_ERROR, "[lcms] %s", text);
}
struct wlr_color_transform *wlr_color_transform_init_linear_to_icc(
const void *data, size_t size) {
struct wlr_color_transform_lcms2 *tx = NULL;
cmsContext ctx = cmsCreateContext(NULL, NULL);
if (ctx == NULL) {
wlr_log(WLR_ERROR, "cmsCreateContext failed");
return NULL;
}
cmsSetLogErrorHandlerTHR(ctx, handle_lcms_error);
cmsHPROFILE icc_profile = cmsOpenProfileFromMemTHR(ctx, data, size);
if (icc_profile == NULL) {
wlr_log(WLR_ERROR, "cmsOpenProfileFromMemTHR failed");
goto error_ctx;
}
if (cmsGetDeviceClass(icc_profile) != cmsSigDisplayClass) {
wlr_log(WLR_ERROR, "ICC profile must have the Display device class");
goto error_icc_profile;
}
cmsToneCurve *linear_tone_curve = cmsBuildGamma(ctx, 1);
if (linear_tone_curve == NULL) {
wlr_log(WLR_ERROR, "cmsBuildGamma failed");
goto error_icc_profile;
}
cmsToneCurve *linear_tf[] = {
linear_tone_curve,
linear_tone_curve,
linear_tone_curve,
};
cmsHPROFILE srgb_profile = cmsCreateRGBProfileTHR(ctx, &srgb_whitepoint,
&srgb_primaries, linear_tf);
cmsFreeToneCurve(linear_tone_curve);
if (srgb_profile == NULL) {
wlr_log(WLR_ERROR, "cmsCreateRGBProfileTHR failed");
goto error_icc_profile;
}
cmsHTRANSFORM lcms_tr = cmsCreateTransformTHR(ctx,
srgb_profile, TYPE_RGB_FLT, icc_profile, TYPE_RGB_FLT,
INTENT_RELATIVE_COLORIMETRIC, 0);
cmsCloseProfile(srgb_profile);
cmsCloseProfile(icc_profile);
if (lcms_tr == NULL) {
wlr_log(WLR_ERROR, "cmsCreateTransformTHR failed");
goto error_ctx;
}
tx = calloc(1, sizeof(*tx));
if (!tx) {
cmsDeleteTransform(lcms_tr);
goto error_ctx;
}
wlr_color_transform_init(&tx->base, COLOR_TRANSFORM_LCMS2);
tx->ctx = ctx;
tx->lcms = lcms_tr;
return &tx->base;
error_icc_profile:
cmsCloseProfile(icc_profile);
error_ctx:
cmsDeleteContext(ctx);
return NULL;
}
void color_transform_lcms2_finish(struct wlr_color_transform_lcms2 *tr) {
cmsDeleteTransform(tr->lcms);
cmsDeleteContext(tr->ctx);
}
struct wlr_color_transform_lcms2 *color_transform_lcms2_from_base(
struct wlr_color_transform *tr) {
assert(tr->type == COLOR_TRANSFORM_LCMS2);
struct wlr_color_transform_lcms2 *lcms2 = wl_container_of(tr, lcms2, base);
return lcms2;
}
void color_transform_lcms2_eval(struct wlr_color_transform_lcms2 *tr,
float out[static 3], const float in[static 3]) {
cmsDoTransform(tr->lcms, in, out, 1);
}