[gpu.resource] added new api function resource_read. also added undoc…

…umented NYI api functions buffer_resize and image_resize, which error out currently if you try to call them

include/tz/gpu/resource.hpp

@@ -203,6 +203,15 @@ namespace tz::gpu
 	 * 		- If the image was created with @ref image_type::depth or @ref image_type::floats, then each pixel should be 4 bytes - a single signed 32-bit float.
 	 */
 	void resource_write(resource_handle res, std::span<const std::byte> new_data);
+	/**
+	 * @ingroup tz_gpu_resource
+	 * @brief Retrieves the current data within a resource.
+	 *
+	 * You aren't allowed to read from @ref tz::gpu::window_resource.
+	 */
+	std::span<const std::byte> resource_read(resource_handle res);
+	void buffer_resize(resource_handle bufh, std::size_t new_size_bytes);
+	void image_resize(resource_handle imgh, unsigned int new_width, unsigned int new_height);
 	/**
 	 * @ingroup tz_gpu_resource
 	 * @brief Write indices into a buffer resource.

src/tz/gpu/rhi_vulkan.cpp

@@ -902,6 +902,26 @@ namespace tz::gpu
 		impl_write_single_resource(resh);
 	}
 
+	std::span<const std::byte> resource_read(resource_handle resh)
+	{
+		auto& res = resources[resh.peek()];
+		return res.data;
+	}
+
+	void buffer_resize(resource_handle bufh, std::size_t new_size_bytes)
+	{
+		(void)bufh;
+		(void)new_size_bytes;
+		tz_error("buffer resize NYI");
+	}
+
+	void image_resize(resource_handle imgh, unsigned int new_width, unsigned int new_height)
+	{
+		(void)imgh;
+		(void)new_width; (void)new_height;
+		tz_error("image resize NYI");
+	}
+
 	void index_buffer_write(resource_handle index_buffer, std::span<const index_t> indices)
 	{
 		resource_write(index_buffer, std::as_bytes(indices));