[RFC PATCH v1 2/5] apps: cam: sdl_texture: Add single plane generic texture

[Barnabás Pőcze]

Add the `SDLTexture1Plane` type 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 at ideasonboard.com>
---
 src/apps/cam/sdl_texture_1plane.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 src/apps/cam/sdl_texture_1plane.h

diff --git a/src/apps/cam/sdl_texture_1plane.h b/src/apps/cam/sdl_texture_1plane.h
new file mode 100644
index 000000000..ded35c589
--- /dev/null
+++ b/src/apps/cam/sdl_texture_1plane.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <assert.h>
+
+#include "sdl_texture.h"
+
+class SDLTexture1Plane final : public SDLTexture
+{
+public:
+	using SDLTexture::SDLTexture;
+
+	void update(libcamera::Span<const libcamera::Span<const uint8_t>> data) override
+	{
+		assert(data.size() == 1);
+		assert(data[0].size_bytes() == std::size_t(rect_.h * stride_));
+		SDL_UpdateTexture(ptr_, nullptr, data[0].data(), stride_);
+	}
+};
-- 
2.49.0