wlr_texture: Introduce wlr_texture_read_pixels_options helpers

include/wlr/render/interface.h

@@ -93,4 +93,10 @@ float wlr_render_texture_options_get_alpha(const struct wlr_render_texture_optio
 void wlr_render_rect_options_get_box(const struct wlr_render_rect_options *options,
 	const struct wlr_buffer *buffer, struct wlr_box *box);
 
+void wlr_texture_read_pixels_options_get_src_box(
+	const struct wlr_texture_read_pixels_options *options,
+	const struct wlr_texture *texture, struct wlr_box *box);
+void *wlr_texture_read_pixel_options_get_data(
+	const struct wlr_texture_read_pixels_options *options);
+
 #endif

render/wlr_texture.c

@@ -4,6 +4,7 @@
 #include <string.h>
 #include <wlr/render/interface.h>
 #include <wlr/render/wlr_texture.h>
+#include "render/pixel_format.h"
 #include "types/wlr_buffer.h"
 
 void wlr_texture_init(struct wlr_texture *texture, struct wlr_renderer *renderer,
@@ -26,6 +27,31 @@ void wlr_texture_destroy(struct wlr_texture *texture) {
 	}
 }
 
+void wlr_texture_read_pixels_options_get_src_box(
+		const struct wlr_texture_read_pixels_options *options,
+		const struct wlr_texture *texture, struct wlr_box *box) {
+	if (wlr_box_empty(&options->src_box)) {
+		*box = (struct wlr_box){
+			.x = 0,
+			.y = 0,
+			.width = texture->width,
+			.height = texture->height,
+		};
+		return;
+	}
+
+	*box = options->src_box;
+}
+
+void *wlr_texture_read_pixel_options_get_data(
+		const struct wlr_texture_read_pixels_options *options) {
+	const struct wlr_pixel_format_info *fmt = drm_get_pixel_format_info(options->format);
+
+	return (char *)options->data +
+		pixel_format_info_min_stride(fmt, options->dst_x) +
+		options->dst_y * options->stride;
+}
+
 bool wlr_texture_read_pixels(struct wlr_texture *texture,
 		const struct wlr_texture_read_pixels_options *options) {
 	if (!texture->impl->read_pixels) {