wlr_texture: Introduce wlr_texture_read_pixels

include/wlr/render/interface.h

@@ -52,6 +52,8 @@ void wlr_renderer_init(struct wlr_renderer *renderer,
 struct wlr_texture_impl {
 	bool (*update_from_buffer)(struct wlr_texture *texture,
 		struct wlr_buffer *buffer, const pixman_region32_t *damage);
+	bool (*read_pixels)(struct wlr_texture *texture,
+		const struct wlr_texture_read_pixels_options *options);
 	void (*destroy)(struct wlr_texture *texture);
 };
 

include/wlr/render/wlr_texture.h

@@ -13,6 +13,7 @@
 #include <stdint.h>
 #include <wayland-server-core.h>
 #include <wlr/render/dmabuf.h>
+#include <wlr/util/box.h>
 
 struct wlr_buffer;
 struct wlr_renderer;
@@ -25,6 +26,22 @@ struct wlr_texture {
 	struct wlr_renderer *renderer;
 };
 
+struct wlr_texture_read_pixels_options {
+	/** Memory location to read pixels into */
+	void *data;
+	/** Format used for writing the pixel data */
+	uint32_t format;
+	/** Stride in bytes for the data */
+	uint32_t stride;
+	/** Destination offsets */
+	uint32_t dst_x, dst_y;
+	/** Source box of the texture to read from. If empty, the full texture is assumed. */
+	const struct wlr_box src_box;
+};
+
+bool wlr_texture_read_pixels(struct wlr_texture *texture,
+	const struct wlr_texture_read_pixels_options *options);
+
 /**
  * Create a new texture from raw pixel data. `stride` is in bytes. The returned
  * texture is mutable.

render/wlr_texture.c

@@ -26,6 +26,15 @@ void wlr_texture_destroy(struct wlr_texture *texture) {
 	}
 }
 
+bool wlr_texture_read_pixels(struct wlr_texture *texture,
+		const struct wlr_texture_read_pixels_options *options) {
+	if (!texture->impl->read_pixels) {
+		return false;
+	}
+
+	return texture->impl->read_pixels(texture, options);
+}
+
 struct wlr_texture *wlr_texture_from_pixels(struct wlr_renderer *renderer,
 		uint32_t fmt, uint32_t stride, uint32_t width, uint32_t height,
 		const void *data) {