Merge branch 'color-pipeline' into 'master'

Draft: Apply output color transform in KMS

See merge request wlroots/wlroots!5083

backend/drm/atomic.c

@@ -6,6 +6,7 @@
 #include <wlr/util/box.h>
 #include <wlr/util/log.h>
 #include <xf86drmMode.h>
+#include "backend/drm/color.h"
 #include "backend/drm/drm.h"
 #include "backend/drm/fb.h"
 #include "backend/drm/iface.h"
@@ -153,6 +154,31 @@ static bool create_gamma_lut_blob(struct wlr_drm_backend *drm,
 	return true;
 }
 
+static bool create_ctm_blob(struct wlr_drm_backend *drm,
+		const float *matrix, uint32_t *blob_id) {
+	if (matrix == NULL) {
+		*blob_id = 0;
+		return true;
+	}
+
+	// Convert to S31.32 sign-magnitude fixed floating-point encoding
+	struct drm_color_ctm ctm = {0};
+	for (size_t i = 0; i < 9; i++) {
+		uint64_t v = fabs(matrix[i]) * ((uint64_t)1 << 32);
+		if (matrix[i] < 0) {
+			v |= (uint64_t)1 << 63;
+		}
+		ctm.matrix[i] = v;
+	}
+
+	if (drmModeCreatePropertyBlob(drm->fd, &ctm, sizeof(ctm), blob_id) != 0) {
+		wlr_log_errno(WLR_ERROR, "Unable to create CTM property blob");
+		return false;
+	}
+
+	return true;
+}
+
 bool create_fb_damage_clips_blob(struct wlr_drm_backend *drm,
 		int width, int height, const pixman_region32_t *damage, uint32_t *blob_id) {
 	pixman_region32_t clipped;
@@ -331,28 +357,39 @@ bool drm_atomic_connector_prepare(struct wlr_drm_connector_state *state, bool mo
 	}
 
 	uint32_t gamma_lut = crtc->gamma_lut;
+	uint32_t ctm = crtc->ctm;
 	if (state->base->committed & WLR_OUTPUT_STATE_COLOR_TRANSFORM) {
-		size_t dim = 0;
+		size_t lut_dim = 0;
 		uint16_t *lut = NULL;
-		if (state->base->color_transform != NULL) {
+		const float *matrix = NULL;
-			struct wlr_color_transform_lut_3x1d *tr =
+		if (state->crtc_color_transform != NULL) {
-				color_transform_lut_3x1d_from_base(state->base->color_transform);
+			lut_dim = state->crtc_color_transform->lut_3x1d->dim;
-			dim = tr->dim;
+			lut = state->crtc_color_transform->lut_3x1d->lut_3x1d;
-			lut = tr->lut_3x1d;
+			if (state->crtc_color_transform->has_matrix) {
+				matrix = state->crtc_color_transform->matrix;
+			}
 		}
 
 		// Fallback to legacy gamma interface when gamma properties are not
 		// available (can happen on older Intel GPUs that support gamma but not
 		// degamma).
 		if (crtc->props.gamma_lut == 0) {
-			if (!drm_legacy_crtc_set_gamma(drm, crtc, dim, lut)) {
+			if (!drm_legacy_crtc_set_gamma(drm, crtc, lut_dim, lut)) {
 				return false;
 			}
 		} else {
-			if (!create_gamma_lut_blob(drm, dim, lut, &gamma_lut)) {
+			if (!create_gamma_lut_blob(drm, lut_dim, lut, &gamma_lut)) {
 				return false;
 			}
 		}
+
+		if (matrix != NULL && crtc->props.ctm == 0) {
+			wlr_log(WLR_DEBUG, "CRTC %"PRIu32" doesn't support CTM", crtc->id);
+			return false;
+		}
+		if (!create_ctm_blob(drm, matrix, &ctm)) {
+			return false;
+		}
 	}
 
 	uint32_t fb_damage_clips = 0;
@@ -395,6 +432,7 @@ bool drm_atomic_connector_prepare(struct wlr_drm_connector_state *state, bool mo
 
 	state->mode_id = mode_id;
 	state->gamma_lut = gamma_lut;
+	state->ctm = ctm;
 	state->fb_damage_clips = fb_damage_clips;
 	state->primary_in_fence_fd = in_fence_fd;
 	state->vrr_enabled = vrr_enabled;
@@ -414,6 +452,7 @@ void drm_atomic_connector_apply_commit(struct wlr_drm_connector_state *state) {
 	crtc->own_mode_id = true;
 	commit_blob(drm, &crtc->mode_id, state->mode_id);
 	commit_blob(drm, &crtc->gamma_lut, state->gamma_lut);
+	commit_blob(drm, &crtc->ctm, state->ctm);
 	commit_blob(drm, &conn->hdr_output_metadata, state->hdr_output_metadata);
 
 	conn->output.adaptive_sync_status = state->vrr_enabled ?
@@ -440,6 +479,7 @@ void drm_atomic_connector_rollback_commit(struct wlr_drm_connector_state *state)
 
 	rollback_blob(drm, &crtc->mode_id, state->mode_id);
 	rollback_blob(drm, &crtc->gamma_lut, state->gamma_lut);
+	rollback_blob(drm, &crtc->ctm, state->ctm);
 	rollback_blob(drm, &conn->hdr_output_metadata, state->hdr_output_metadata);
 
 	destroy_blob(drm, state->fb_damage_clips);
@@ -544,6 +584,9 @@ static void atomic_connector_add(struct atomic *atom,
 		if (crtc->props.gamma_lut != 0) {
 			atomic_add(atom, crtc->id, crtc->props.gamma_lut, state->gamma_lut);
 		}
+		if (crtc->props.ctm != 0) {
+			atomic_add(atom, crtc->id, crtc->props.ctm, state->ctm);
+		}
 		if (crtc->props.vrr_enabled != 0) {
 			atomic_add(atom, crtc->id, crtc->props.vrr_enabled, state->vrr_enabled);
 		}

backend/drm/color.c

@@ -0,0 +1,177 @@
+#include <stdlib.h>
+
+#include "backend/drm/color.h"
+#include "backend/drm/drm.h"
+#include "render/color.h"
+#include "util/matrix.h"
+
+enum wlr_drm_crtc_color_transform_stage {
+	WLR_DRM_CRTC_COLOR_TRANSFORM_MATRIX,
+	WLR_DRM_CRTC_COLOR_TRANSFORM_LUT_3X1D,
+};
+
+static struct wlr_color_transform_lut_3x1d *create_identity_3x1dlut(size_t dim) {
+	if (dim == 0) {
+		return NULL;
+	}
+	uint16_t *lut = malloc(dim * sizeof(lut[0]));
+	if (lut == NULL) {
+		return NULL;
+	}
+	for (size_t i = 0; i < dim; i++) {
+		float x = (float)i / (dim - 1);
+		lut[i] = (uint16_t)roundf(UINT16_MAX * x);
+	}
+	struct wlr_color_transform *out = wlr_color_transform_init_lut_3x1d(dim, lut, lut, lut);
+	free(lut);
+	return color_transform_lut_3x1d_from_base(out);
+}
+
+static bool set_stage(enum wlr_drm_crtc_color_transform_stage *current,
+		enum wlr_drm_crtc_color_transform_stage next) {
+	// Enforce that we fill the pipeline in order: first CTM then GAMMA_LUT
+	if (*current > next) {
+		return false;
+	}
+	*current = next;
+	return true;
+}
+
+static bool drm_crtc_color_transform_init_lut_3x1d(struct wlr_drm_crtc_color_transform *out,
+		enum wlr_drm_crtc_color_transform_stage *stage, size_t dim) {
+	if (!set_stage(stage, WLR_DRM_CRTC_COLOR_TRANSFORM_LUT_3X1D)) {
+		return false;
+	}
+	if (out->lut_3x1d != NULL) {
+		return true;
+	}
+	out->lut_3x1d = create_identity_3x1dlut(dim);
+	return out->lut_3x1d != NULL;
+}
+
+static bool drm_crtc_color_transform_convert(struct wlr_drm_crtc_color_transform *out,
+		struct wlr_color_transform *in, enum wlr_drm_crtc_color_transform_stage *stage,
+		size_t lut_3x1d_dim) {
+	switch (in->type) {
+	case COLOR_TRANSFORM_INVERSE_EOTF:;
+		struct wlr_color_transform_inverse_eotf *inv_eotf =
+			wlr_color_transform_inverse_eotf_from_base(in);
+
+		if (!drm_crtc_color_transform_init_lut_3x1d(out, stage, lut_3x1d_dim)) {
+			return false;
+		}
+
+		for (size_t i = 0; i < 3; i++) {
+			for (size_t j = 0; j < lut_3x1d_dim; j++) {
+				size_t offset = i * lut_3x1d_dim + j;
+				float v = (float)out->lut_3x1d->lut_3x1d[offset] / UINT16_MAX;
+				v = wlr_color_transfer_function_eval_inverse_eotf(inv_eotf->tf, v);
+				out->lut_3x1d->lut_3x1d[offset] = (uint16_t)roundf(UINT16_MAX * v);
+			}
+		}
+
+		return true;
+	case COLOR_TRANSFORM_LUT_3X1D:;
+		struct wlr_color_transform_lut_3x1d *lut_3x1d =
+			color_transform_lut_3x1d_from_base(in);
+		if (lut_3x1d->dim != lut_3x1d_dim) {
+			return false;
+		}
+
+		if (!drm_crtc_color_transform_init_lut_3x1d(out, stage, lut_3x1d_dim)) {
+			return false;
+		}
+
+		// TODO: we loose precision when the input color transform is a lone 3×1D LUT
+		for (size_t i = 0; i < 3 * lut_3x1d->dim; i++) {
+			out->lut_3x1d->lut_3x1d[i] *= lut_3x1d->lut_3x1d[i];
+		}
+
+		return true;
+	case COLOR_TRANSFORM_MATRIX:;
+		struct wlr_color_transform_matrix *matrix = wl_container_of(in, matrix, base);
+		if (!set_stage(stage, WLR_DRM_CRTC_COLOR_TRANSFORM_MATRIX)) {
+			return false;
+		}
+		wlr_matrix_multiply(out->matrix, matrix->matrix, out->matrix);
+		out->has_matrix = true;
+		return true;
+	case COLOR_TRANSFORM_LCMS2:
+		return false; // unsupported
+	case COLOR_TRANSFORM_PIPELINE:;
+		struct wlr_color_transform_pipeline *pipeline = wl_container_of(in, pipeline, base);
+
+		for (size_t i = 0; i < pipeline->len; i++) {
+			if (!drm_crtc_color_transform_convert(out, pipeline->transforms[i], stage, lut_3x1d_dim)) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+	abort(); // unreachable
+}
+
+static void addon_destroy(struct wlr_addon *addon) {
+	struct wlr_drm_crtc_color_transform *tr = wl_container_of(addon, tr, addon);
+	if (tr->lut_3x1d != NULL) {
+		wlr_color_transform_unref(&tr->lut_3x1d->base);
+	}
+	free(tr);
+}
+
+static const struct wlr_addon_interface addon_impl = {
+	.name = "wlr_drm_crtc_color_transform",
+	.destroy = addon_destroy,
+};
+
+static struct wlr_drm_crtc_color_transform *drm_crtc_color_transform_create(
+		struct wlr_drm_backend *backend, struct wlr_drm_crtc *crtc,
+		struct wlr_color_transform *base) {
+	struct wlr_drm_crtc_color_transform *tr = calloc(1, sizeof(*tr));
+	if (tr == NULL) {
+		return NULL;
+	}
+
+	tr->base = base;
+	wlr_addon_init(&tr->addon, &base->addons, crtc, &addon_impl);
+	wlr_matrix_identity(tr->matrix);
+
+	size_t lut_3x1d_dim = drm_crtc_get_gamma_lut_size(backend, crtc);
+	enum wlr_drm_crtc_color_transform_stage stage = WLR_DRM_CRTC_COLOR_TRANSFORM_MATRIX;
+	tr->failed = !drm_crtc_color_transform_convert(tr, base, &stage, lut_3x1d_dim);
+
+	return tr;
+}
+
+struct wlr_drm_crtc_color_transform *drm_crtc_color_transform_import(
+		struct wlr_drm_backend *backend, struct wlr_drm_crtc *crtc,
+		struct wlr_color_transform *base) {
+	struct wlr_drm_crtc_color_transform *tr;
+	struct wlr_addon *addon = wlr_addon_find(&base->addons, crtc, &addon_impl);
+	if (addon != NULL) {
+		tr = wl_container_of(addon, tr, addon);
+	} else {
+		tr = drm_crtc_color_transform_create(backend, crtc, base);
+		if (tr == NULL) {
+			return NULL;
+		}
+	}
+
+	if (tr->failed) {
+		// We failed to convert the color transform to a 3×1D LUT. Keep the
+		// addon attached so that we remember that this color transform cannot
+		// be imported next time a commit contains it.
+		return NULL;
+	}
+
+	wlr_color_transform_ref(tr->base);
+	return tr;
+}
+
+void drm_crtc_color_transform_unref(struct wlr_drm_crtc_color_transform *tr) {
+	if (tr == NULL) {
+		return;
+	}
+	wlr_color_transform_unref(tr->base);
+}

backend/drm/drm.c

@@ -20,6 +20,7 @@
 #include <wlr/util/transform.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
+#include "backend/drm/color.h"
 #include "backend/drm/drm.h"
 #include "backend/drm/fb.h"
 #include "backend/drm/iface.h"
@@ -390,6 +391,9 @@ void finish_drm_resources(struct wlr_drm_backend *drm) {
 		if (crtc->gamma_lut) {
 			drmModeDestroyPropertyBlob(drm->fd, crtc->gamma_lut);
 		}
+		if (crtc->ctm) {
+			drmModeDestroyPropertyBlob(drm->fd, crtc->ctm);
+		}
 	}
 
 	free(drm->crtcs);
@@ -707,6 +711,7 @@ static void drm_connector_state_finish(struct wlr_drm_connector_state *state) {
 	drm_fb_clear(&state->primary_fb);
 	drm_fb_clear(&state->cursor_fb);
 	wlr_drm_syncobj_timeline_unref(state->wait_timeline);
+	drm_crtc_color_transform_unref(state->crtc_color_transform);
 }
 
 static bool drm_connector_state_update_primary_fb(struct wlr_drm_connector *conn,
@@ -858,11 +863,15 @@ static bool drm_connector_prepare(struct wlr_drm_connector_state *conn_state, bo
 		}
 	}
 
-	if ((state->committed & WLR_OUTPUT_STATE_COLOR_TRANSFORM) && state->color_transform != NULL &&
+	if ((state->committed & WLR_OUTPUT_STATE_COLOR_TRANSFORM) && state->color_transform != NULL) {
-			state->color_transform->type != COLOR_TRANSFORM_LUT_3X1D) {
+		assert(conn_state->crtc_color_transform == NULL);
-		wlr_drm_conn_log(conn, WLR_DEBUG,
+		conn_state->crtc_color_transform = drm_crtc_color_transform_import(conn->backend,
-			"Only 3x1D LUT color transforms are supported");
+			conn->crtc, state->color_transform);
-		return false;
+		if (conn_state->crtc_color_transform == NULL) {
+			wlr_drm_conn_log(conn, WLR_DEBUG,
+				"Failed to import color transform");
+			return false;
+		}
 	}
 
 	if ((state->committed & WLR_OUTPUT_STATE_IMAGE_DESCRIPTION) &&

backend/drm/legacy.c

@@ -3,6 +3,7 @@
 #include <wlr/util/log.h>
 #include <xf86drm.h>
 #include <xf86drmMode.h>
+#include "backend/drm/color.h"
 #include "backend/drm/drm.h"
 #include "backend/drm/fb.h"
 #include "backend/drm/iface.h"
@@ -128,11 +129,9 @@ static bool legacy_crtc_commit(const struct wlr_drm_connector_state *state,
 	if (state->base->committed & WLR_OUTPUT_STATE_COLOR_TRANSFORM) {
 		size_t dim = 0;
 		uint16_t *lut = NULL;
-		if (state->base->color_transform != NULL) {
+		if (state->crtc_color_transform != NULL) {
-			struct wlr_color_transform_lut_3x1d *tr =
+			dim = state->crtc_color_transform->lut_3x1d->dim;
-				color_transform_lut_3x1d_from_base(state->base->color_transform);
+			lut = state->crtc_color_transform->lut_3x1d->lut_3x1d;
-			dim = tr->dim;
-			lut = tr->lut_3x1d;
 		}
 
 		if (!drm_legacy_crtc_set_gamma(drm, crtc, dim, lut)) {

backend/drm/libliftoff.c

@@ -328,6 +328,9 @@ static bool add_connector(drmModeAtomicReq *req,
 		if (crtc->props.gamma_lut != 0) {
 			ok = ok && add_prop(req, crtc->id, crtc->props.gamma_lut, state->gamma_lut);
 		}
+		if (crtc->props.ctm != 0) {
+			ok = ok && add_prop(req, crtc->id, crtc->props.ctm, state->ctm);
+		}
 		if (crtc->props.vrr_enabled != 0) {
 			ok = ok && add_prop(req, crtc->id, crtc->props.vrr_enabled, state->vrr_enabled);
 		}

backend/drm/meson.build

@@ -38,6 +38,7 @@ wlr_files += pnpids_c
 wlr_files += files(
 	'atomic.c',
 	'backend.c',
+	'color.c',
 	'drm.c',
 	'fb.c',
 	'legacy.c',

backend/drm/properties.c

@@ -40,6 +40,7 @@ static const struct prop_info connector_info[] = {
 static const struct prop_info crtc_info[] = {
 #define INDEX(name) (offsetof(struct wlr_drm_crtc_props, name) / sizeof(uint32_t))
 	{ "ACTIVE", INDEX(active) },
+	{ "CTM", INDEX(ctm) },
 	{ "GAMMA_LUT", INDEX(gamma_lut) },
 	{ "GAMMA_LUT_SIZE", INDEX(gamma_lut_size) },
 	{ "MODE_ID", INDEX(mode_id) },

include/backend/drm/color.h

@@ -0,0 +1,25 @@
+#ifndef BACKEND_DRN_COLOR_H
+#define BACKEND_DRN_COLOR_H
+
+#include <wlr/util/addon.h>
+
+struct wlr_drm_backend;
+struct wlr_drm_crtc;
+struct wlr_color_transform;
+
+struct wlr_drm_crtc_color_transform {
+	struct wlr_color_transform *base;
+	struct wlr_addon addon; // wlr_color_transform.addons
+	bool failed;
+	struct wlr_color_transform_lut_3x1d *lut_3x1d;
+	float matrix[9];
+	bool has_matrix;
+};
+
+struct wlr_drm_crtc_color_transform *drm_crtc_color_transform_import(
+	struct wlr_drm_backend *backend, struct wlr_drm_crtc *crtc,
+	struct wlr_color_transform *base);
+
+void drm_crtc_color_transform_unref(struct wlr_drm_crtc_color_transform *tr);
+
+#endif

include/backend/drm/drm.h

@@ -15,6 +15,8 @@
 #include "backend/drm/properties.h"
 #include "backend/drm/renderer.h"
 
+struct wlr_drm_crtc_color_transform;
+
 struct wlr_drm_viewport {
 	struct wlr_fbox src_box;
 	struct wlr_box dst_box;
@@ -74,6 +76,7 @@ struct wlr_drm_crtc {
 	bool own_mode_id;
 	uint32_t mode_id;
 	uint32_t gamma_lut;
+	uint32_t ctm;
 
 	// Legacy only
 	int legacy_gamma_size;
@@ -152,9 +155,12 @@ struct wlr_drm_connector_state {
 	struct wlr_drm_syncobj_timeline *wait_timeline;
 	uint64_t wait_point;
 
+	struct wlr_drm_crtc_color_transform *crtc_color_transform;
+
 	// used by atomic
 	uint32_t mode_id;
 	uint32_t gamma_lut;
+	uint32_t ctm;
 	uint32_t fb_damage_clips;
 	int primary_in_fence_fd, out_fence_fd;
 	bool vrr_enabled;

include/backend/drm/properties.h

@@ -35,6 +35,7 @@ struct wlr_drm_crtc_props {
 	uint32_t vrr_enabled;
 	uint32_t gamma_lut;
 	uint32_t gamma_lut_size;
+	uint32_t ctm;
 
 	// atomic-modesetting only
 

include/render/color.h

@@ -108,4 +108,9 @@ void wlr_color_primaries_to_xyz(const struct wlr_color_primaries *primaries, flo
 void wlr_color_transfer_function_get_default_luminance(enum wlr_color_transfer_function tf,
 	struct wlr_color_luminances *lum);
 
+/**
+ * Apply a color transfer function's EOTF⁻¹ operation.
+ */
+float wlr_color_transfer_function_eval_inverse_eotf(enum wlr_color_transfer_function tf, float x);
+
 #endif

render/color.c

@@ -188,7 +188,7 @@ static float bt1886_eval_inverse_eotf(float x) {
 	return powf(x / a, 1.0 / 2.4) - b;
 }
 
-static float transfer_function_eval_inverse_eotf(
+float wlr_color_transfer_function_eval_inverse_eotf(
 		enum wlr_color_transfer_function tf, float x) {
 	switch (tf) {
 	case WLR_COLOR_TRANSFER_FUNCTION_SRGB:
@@ -209,7 +209,7 @@ static void color_transform_inverse_eotf_eval(
 		struct wlr_color_transform_inverse_eotf *tr,
 		float out[static 3], const float in[static 3]) {
 	for (size_t i = 0; i < 3; i++) {
-		out[i] = transfer_function_eval_inverse_eotf(tr->tf, in[i]);
+		out[i] = wlr_color_transfer_function_eval_inverse_eotf(tr->tf, in[i]);
 	}
 }