screencopy: add support for frame flags

1 files changed, 20 insertions, 8 deletions

diff --git a/render/gles2/renderer.c b/render/gles2/renderer.c
index 05426fa9..0c57bfa1 100644
--- a/render/gles2/renderer.c
+++ b/render/gles2/renderer.c
@@ -250,9 +250,9 @@ static int gles2_get_dmabuf_modifiers(struct wlr_renderer *wlr_renderer,
 }
 
 static bool gles2_read_pixels(struct wlr_renderer *wlr_renderer,
-		enum wl_shm_format wl_fmt, uint32_t stride, uint32_t width,
-		uint32_t height, uint32_t src_x, uint32_t src_y, uint32_t dst_x,
-		uint32_t dst_y, void *data) {
+		enum wl_shm_format wl_fmt, uint32_t *flags, uint32_t stride,
+		uint32_t width, uint32_t height, uint32_t src_x, uint32_t src_y,
+		uint32_t dst_x, uint32_t dst_y, void *data) {
 	gles2_get_renderer_in_context(wlr_renderer);
 
 	const struct wlr_gles2_pixel_format *fmt = get_gles2_format_from_wl(wl_fmt);
@@ -266,12 +266,24 @@ static bool gles2_read_pixels(struct wlr_renderer *wlr_renderer,
 	// Make sure any pending drawing is finished before we try to read it
 	glFinish();
 
-	// Unfortunately GLES2 doesn't support GL_PACK_*, so we have to read
-	// the lines out row by row
 	unsigned char *p = data + dst_y * stride;
-	for (size_t i = src_y; i < src_y + height; ++i) {
-		glReadPixels(src_x, src_y + height - i - 1, width, 1, fmt->gl_format,
-			fmt->gl_type, p + i * stride + dst_x * fmt->bpp / 8);
+	uint32_t pack_stride = width * fmt->bpp / 8;
+	if (pack_stride == stride && dst_x == 0 && flags != NULL) {
+		// Under these particular conditions, we can read the pixels with only
+		// one glReadPixels call
+		glReadPixels(src_x, src_y, width, height, fmt->gl_format,
+			fmt->gl_type, p);
+		*flags = WLR_RENDERER_READ_PIXELS_Y_INVERT;
+	} else {
+		// Unfortunately GLES2 doesn't support GL_PACK_*, so we have to read
+		// the lines out row by row
+		for (size_t i = src_y; i < src_y + height; ++i) {
+			glReadPixels(src_x, src_y + height - i - 1, width, 1, fmt->gl_format,
+				fmt->gl_type, p + i * stride + dst_x * fmt->bpp / 8);
+		}
+		if (flags != NULL) {
+			*flags = 0;
+		}
 	}
 
 	POP_GLES2_DEBUG;