From b75eeac03d2a6903d31430aa16ffb4b9d0dc69cb Mon Sep 17 00:00:00 2001
From: Andri Yngvason <andri@yngvason.is>
Date: Sun, 5 Sep 2021 00:39:35 +0000
Subject: [PATCH] Add API function for creating nvnc_fb from an pre-allocated
 buffer

---
 include/fb.h      |  3 ++-
 include/neatvnc.h |  2 ++
 src/fb.c          | 31 ++++++++++++++++++++++++-------
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/include/fb.h b/include/fb.h
index 24444ca..2c80d56 100644
--- a/include/fb.h
+++ b/include/fb.h
@@ -19,6 +19,7 @@
 #include <unistd.h>
 #include <stdint.h>
 #include <stdatomic.h>
+#include <stdbool.h>
 
 #include "neatvnc.h"
 #include "common.h"
@@ -31,12 +32,12 @@ struct nvnc_fb {
 	void* release_context;
 	void* addr;
 	enum nvnc_fb_flags flags;
-	size_t size;
 	uint16_t width;
 	uint16_t height;
 	int32_t stride;
 	uint32_t fourcc_format;
 	uint64_t fourcc_modifier;
+	bool is_external;
 };
 
 void nvnc_fb_hold(struct nvnc_fb* fb);
diff --git a/include/neatvnc.h b/include/neatvnc.h
index d10e5c9..f5af6bb 100644
--- a/include/neatvnc.h
+++ b/include/neatvnc.h
@@ -83,6 +83,8 @@ int nvnc_enable_auth(struct nvnc* self, const char* privkey_path,
 
 struct nvnc_fb* nvnc_fb_new(uint16_t width, uint16_t height,
                             uint32_t fourcc_format, uint16_t stride);
+struct nvnc_fb* nvnc_fb_from_buffer(void* buffer, uint16_t width,
+		uint16_t height, uint32_t fourcc_format, int32_t stride);
 
 void nvnc_fb_ref(struct nvnc_fb* fb);
 void nvnc_fb_unref(struct nvnc_fb* fb);
diff --git a/src/fb.c b/src/fb.c
index 789d6b9..bd15f82 100644
--- a/src/fb.c
+++ b/src/fb.c
@@ -40,15 +40,11 @@ struct nvnc_fb* nvnc_fb_new(uint16_t width, uint16_t height,
 	fb->height = height;
 	fb->fourcc_format = fourcc_format;
 	fb->stride = stride;
-	fb->size = width * stride * 4; /* Assume 4 byte format for now */
 
+	size_t size = width * stride * 4; /* Assume 4 byte format for now */
 	size_t alignment = MAX(4, sizeof(void*));
-	size_t aligned_size = ALIGN_UP(fb->size, alignment);
+	size_t aligned_size = ALIGN_UP(size, alignment);
 
-	/* fb could be allocated in single allocation, but I want to reserve
-	 * the possiblity to create an fb with a pixel buffer passed from the
-	 * user.
-	 */
 	fb->addr = aligned_alloc(alignment, aligned_size);
 	if (!fb->addr) {
 		free(fb);
@@ -58,6 +54,25 @@ struct nvnc_fb* nvnc_fb_new(uint16_t width, uint16_t height,
 	return fb;
 }
 
+EXPORT
+struct nvnc_fb* nvnc_fb_from_buffer(void* buffer, uint16_t width, uint16_t height,
+                            uint32_t fourcc_format, int32_t stride)
+{
+	struct nvnc_fb* fb = calloc(1, sizeof(*fb));
+	if (!fb)
+		return NULL;
+
+	fb->ref = 1;
+	fb->addr = buffer;
+	fb->is_external = true;
+	fb->width = width;
+	fb->height = height;
+	fb->fourcc_format = fourcc_format;
+	fb->stride = stride;
+
+	return fb;
+}
+
 EXPORT
 enum nvnc_fb_flags nvnc_fb_get_flags(const struct nvnc_fb* fb)
 {
@@ -112,7 +127,9 @@ static void nvnc__fb_free(struct nvnc_fb* fb)
 	if (cleanup)
 		cleanup(fb->common.userdata);
 
-	free(fb->addr);
+	if (!fb->is_external)
+		free(fb->addr);
+
 	free(fb);
 }