screen-share: use pixman_image_composite32 instead of pixman_blt

The function pixman_blt may return false in case there is no
accelerated blit function available. In this case the remote shared
screen stays black.

This has been observed on Weston compiled for aarch64. In currrent
pixman 0.38.4 there is no accelerated pixman_blt function for
aarch64 available.

Use pixman_image_composite32 instead which is guaranteed to have a
working fallback implementation.

Fixes: #253
Signed-off-by: Stefan Agner <stefan@agner.ch>

diff --git a/compositor/screen-share.c b/compositor/screen-share.c
index b65f84115b4b920bcc2b3e094291cd86347f6f08..d3f115ecf14c09e632cf2c1c996e87f18294f67e 100644 (file)
--- a/compositor/screen-share.c
+++ b/compositor/screen-share.c
@@ -820,7 +820,8 @@ shared_output_repainted(struct wl_listener *listener, void *data)
        int32_t x, y, width, height, stride;
        int i, nrects, do_yflip, y_orig;
        pixman_box32_t *r;
-       uint32_t *cache_data;
+       pixman_image_t *damaged_image;
+       pixman_transform_t transform;
 
        width = so->output->current_mode->width;
        height = so->output->current_mode->height;
@@ -863,7 +864,6 @@ shared_output_repainted(struct wl_listener *listener, void *data)
 
        do_yflip = !!(so->output->compositor->capabilities & WESTON_CAP_CAPTURE_YFLIP);
 
-       cache_data = pixman_image_get_data(so->cache_image);
        r = pixman_region32_rectangles(&damage, &nrects);
        for (i = 0; i < nrects; ++i) {
                x = r[i].x1;
@@ -880,13 +880,34 @@ shared_output_repainted(struct wl_listener *listener, void *data)
                        so->output, PIXMAN_a8r8g8b8, so->tmp_data,
                        x, y_orig, width, height);
 
+               damaged_image = pixman_image_create_bits(PIXMAN_a8r8g8b8,
+                                                        width, height,
+                                                        so->tmp_data,
+                               (PIXMAN_FORMAT_BPP(PIXMAN_a8r8g8b8) / 8) * width);
+               if (!damaged_image)
+                       goto err_pixman_init;
+
                if (do_yflip) {
-                       pixman_blt(so->tmp_data, cache_data, -width, stride,
-                                  32, 32, 0, 1 - height, x, y, width, height);
-               } else {
-                       pixman_blt(so->tmp_data, cache_data, width, stride,
-                                  32, 32, 0, 0, x, y, width, height);
+                       pixman_transform_init_scale(&transform,
+                                                   pixman_fixed_1,
+                                                   pixman_fixed_minus_1);
+
+                       pixman_transform_translate(&transform, NULL,
+                                                  0,
+                                                  pixman_int_to_fixed(height));
+
+                       pixman_image_set_transform(damaged_image, &transform);
                }
+
+               pixman_image_composite32(PIXMAN_OP_SRC,
+                                        damaged_image,
+                                        NULL,
+                                        so->cache_image,
+                                        0, 0,
+                                        0, 0,
+                                        x, y,
+                                        width, height);
+               pixman_image_unref(damaged_image);
        }
 
        so->cache_dirty = 1;