apps: cam: sdl_texture: Add `SDLTexture1Plane`

`SDLTextureYUYV` uses `SDL_PIXELFORMAT_YUY2`, which is a single plane
format. To support other single plane formats, replace `SDLTextureYUYV`
with `SDLTexture1Plane` that can be instantiated with an arbitrary SDL
pixel format and that uses `SDL_UpdateTexture()` to update the texture
using exactly a single plane.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/apps/cam/sdl_texture_1plane.cpp b/src/apps/cam/sdl_texture_1plane.cpp
new file mode 100644
index 00000000..b97015bc
--- /dev/null
+++ b/src/apps/cam/sdl_texture_1plane.cpp
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2025, Ideas on Board Oy
+ *
+ * SDL single plane textures
+ */
+
+#include "sdl_texture_1plane.h"
+
+#include <assert.h>
+
+void SDLTexture1Plane::update(libcamera::Span<const libcamera::Span<const uint8_t>> data)
+{
+	assert(data.size() == 1);
+	assert(data[0].size_bytes() == std::size_t(rect_.h) * std::size_t(stride_));
+	SDL_UpdateTexture(ptr_, nullptr, data[0].data(), stride_);
+}