From 0bdd1133e483c7e584060a4b7d4b9331da950d9a Mon Sep 17 00:00:00 2001
From: Lubosz Sarnecki <lubosz.sarnecki@collabora.com>
Date: Fri, 26 Jun 2020 13:03:19 +0200
Subject: [PATCH] u/json: Add u_json_get_vec3_array.

As seen in Vive driver.
---
 src/xrt/auxiliary/util/u_json.c | 37 +++++++++++++++++++++++++++++++++
 src/xrt/auxiliary/util/u_json.h |  8 +++++++
 2 files changed, 45 insertions(+)

diff --git a/src/xrt/auxiliary/util/u_json.c b/src/xrt/auxiliary/util/u_json.c
index 44162066a..26eaa9e1f 100644
--- a/src/xrt/auxiliary/util/u_json.c
+++ b/src/xrt/auxiliary/util/u_json.c
@@ -146,6 +146,43 @@ u_json_get_vec3(const cJSON *json, struct xrt_vec3 *out_vec3)
 	return true;
 }
 
+bool
+u_json_get_vec3_array(const cJSON *json, struct xrt_vec3 *out_vec3)
+{
+	assert(out_vec3 != NULL);
+
+	if (!json) {
+		return false;
+	}
+	if (!cJSON_IsArray(json)) {
+		return false;
+	}
+
+	float array[3];
+
+	if (cJSON_GetArraySize(json) != 3) {
+		return false;
+	}
+
+	const cJSON *item = NULL;
+	size_t i = 0;
+	cJSON_ArrayForEach(item, json)
+	{
+		assert(cJSON_IsNumber(item));
+		array[i] = (float)item->valuedouble;
+		++i;
+		if (i == 3) {
+			break;
+		}
+	}
+
+	out_vec3->x = array[0];
+	out_vec3->y = array[1];
+	out_vec3->z = array[2];
+
+	return true;
+}
+
 bool
 u_json_get_quat(const cJSON *json, struct xrt_quat *out_quat)
 {
diff --git a/src/xrt/auxiliary/util/u_json.h b/src/xrt/auxiliary/util/u_json.h
index 94c2a1740..e402e3e37 100644
--- a/src/xrt/auxiliary/util/u_json.h
+++ b/src/xrt/auxiliary/util/u_json.h
@@ -77,6 +77,14 @@ u_json_get_double(const cJSON *json, double *out_double);
 bool
 u_json_get_vec3(const cJSON *json, struct xrt_vec3 *out_vec3);
 
+/*!
+ * @brief Parse a vec3 from a JSON array.
+ *
+ * @return true if successful, false if not.
+ */
+bool
+u_json_get_vec3_array(const cJSON *json, struct xrt_vec3 *out_vec3);
+
 /*!
  * @brief Parse a quaternion from a JSON object.
  *