From d4b4a3e57e23e97386c7aa91e62ad368a76d5337 Mon Sep 17 00:00:00 2001
From: Alexander Orzechowski <alex@ozal.ski>
Date: Sat, 24 Aug 2024 18:52:17 -0400
Subject: [PATCH] render/color: Add wlr_color_transform_create_from_gamma_lut

---
 include/wlr/render/color.h |  7 +++++++
 render/color.c             | 30 ++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/include/wlr/render/color.h b/include/wlr/render/color.h
index 43d9154be..619e07acf 100644
--- a/include/wlr/render/color.h
+++ b/include/wlr/render/color.h
@@ -10,6 +10,7 @@
 #define WLR_RENDER_COLOR_H
 
 #include <stdbool.h>
+#include <stdint.h>
 #include <sys/types.h>
 
 /**
@@ -52,4 +53,10 @@ struct wlr_color_transform *wlr_color_transform_ref(struct wlr_color_transform *
  */
 void wlr_color_transform_unref(struct wlr_color_transform *tr);
 
+/**
+ * Creates a color transform based on a gamma ramp.
+ */
+struct wlr_color_transform *wlr_color_transform_create_from_gamma_lut(
+	size_t ramp_size, const uint16_t *r, const uint16_t *g, const uint16_t *b);
+
 #endif
diff --git a/render/color.c b/render/color.c
index 403a6532b..d7b4d7691 100644
--- a/render/color.c
+++ b/render/color.c
@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <stdlib.h>
+#include <string.h>
 #include <wlr/render/color.h>
 #include "render/color.h"
 
@@ -49,6 +50,35 @@ void wlr_color_transform_unref(struct wlr_color_transform *tr) {
 	}
 }
 
+struct wlr_color_transform *wlr_color_transform_create_from_gamma_lut(
+		size_t ramp_size, const uint16_t *r, const uint16_t *g, const uint16_t *b) {
+	uint16_t *data = malloc(3 * ramp_size * sizeof(uint16_t));
+	if (!data) {
+		return NULL;
+	}
+
+	struct wlr_color_transform_lut3x1d *tx = calloc(1, sizeof(*tx));
+	if (!tx) {
+		free(data);
+		return NULL;
+	}
+
+	tx->base.type = COLOR_TRANSFORM_LUT_3x1D;
+	tx->base.ref_count = 1;
+	wlr_addon_set_init(&tx->base.addons);
+
+	tx->r = data;
+	tx->g = data + ramp_size;
+	tx->b = data + ramp_size * 2;
+	tx->ramp_size = ramp_size;
+
+	memcpy(tx->r, r, ramp_size * sizeof(uint16_t));
+	memcpy(tx->g, g, ramp_size * sizeof(uint16_t));
+	memcpy(tx->b, b, ramp_size * sizeof(uint16_t));
+
+	return &tx->base;
+}
+
 struct wlr_color_transform_lut3d *wlr_color_transform_lut3d_from_base(
 		struct wlr_color_transform *tr) {
 	assert(tr->type == COLOR_TRANSFORM_LUT_3D);