screenshooter: Properly handle multiple outputs.

src/compositor-drm.c

@@ -1047,6 +1047,20 @@ drm_set_dpms(struct weston_output *output_base, enum dpms_enum level)
 	drmModeFreeConnector(connector);
 }
 
+static void
+drm_output_read_pixels(struct weston_output *output_base, void *data)
+{
+	struct drm_output *output = (struct drm_output *) output_base;
+	struct drm_compositor *compositor =
+		(struct drm_compositor *) output->base.compositor;
+
+	eglMakeCurrent(compositor->base.display, output->egl_surface,
+			output->egl_surface, compositor->base.context);
+
+	glReadPixels(0, 0, output_base->current->width, output_base->current->height,
+				GL_BGRA_EXT, GL_UNSIGNED_BYTE, data);
+}
+
 static int
 create_output_for_connector(struct drm_compositor *ec,
 			    drmModeRes *resources,
@@ -1154,6 +1168,7 @@ create_output_for_connector(struct drm_compositor *ec,
 	output->base.repaint = drm_output_repaint;
 	output->base.destroy = drm_output_destroy;
 	output->base.assign_planes = drm_assign_planes;
+	output->base.read_pixels = drm_output_read_pixels;
 	output->base.set_dpms = drm_set_dpms;
 
 	return 0;

src/compositor-wayland.c

@@ -377,6 +377,20 @@ wayland_output_destroy(struct weston_output *output_base)
 	return;
 }
 
+static void
+wayland_output_read_pixels(struct weston_output *output_base, void *data)
+{
+	struct wayland_output *output = (struct wayland_output *) output_base;
+	struct wayland_compositor *compositor =
+		(struct wayland_compositor *) output->base.compositor;
+
+	eglMakeCurrent(compositor->base.display, output->egl_surface,
+			output->egl_surface, compositor->base.context);
+
+	glReadPixels(0, 0, output_base->current->width, output_base->current->height,
+				GL_BGRA_EXT, GL_UNSIGNED_BYTE, data);
+}
+
 static int
 wayland_compositor_create_output(struct wayland_compositor *c,
 				 int width, int height)
@@ -444,6 +458,7 @@ wayland_compositor_create_output(struct wayland_compositor *c,
 	output->base.repaint = wayland_output_repaint;
 	output->base.destroy = wayland_output_destroy;
 	output->base.assign_planes = NULL;
+	output->base.read_pixels = wayland_output_read_pixels;
 	output->base.set_backlight = NULL;
 	output->base.set_dpms = NULL;
 

src/compositor-x11.c

@@ -344,6 +344,20 @@ x11_output_set_icon(struct x11_compositor *c,
 	pixman_image_unref(image);
 }
 
+static void
+x11_output_read_pixels(struct weston_output *output_base, void *data)
+{
+	struct x11_output *output = (struct x11_output *) output_base;
+	struct x11_compositor *compositor =
+		(struct x11_compositor *) output->base.compositor;
+
+	eglMakeCurrent(compositor->base.display, output->egl_surface,
+			output->egl_surface, compositor->base.context);
+
+	glReadPixels(0, 0, output_base->current->width, output_base->current->height,
+				GL_BGRA_EXT, GL_UNSIGNED_BYTE, data);
+}
+
 static int
 x11_compositor_create_output(struct x11_compositor *c, int x, int y,
 			     int width, int height, int fullscreen)
@@ -454,6 +468,7 @@ x11_compositor_create_output(struct x11_compositor *c, int x, int y,
 	output->base.repaint = x11_output_repaint;
 	output->base.destroy = x11_output_destroy;
 	output->base.assign_planes = NULL;
+	output->base.read_pixels = x11_output_read_pixels;
 	output->base.set_backlight = NULL;
 	output->base.set_dpms = NULL;
 

src/compositor.h

@@ -96,6 +96,7 @@ struct weston_output {
 			pixman_region32_t *damage);
 	void (*destroy)(struct weston_output *output);
 	void (*assign_planes)(struct weston_output *output);
+	void (*read_pixels)(struct weston_output *output, void *data);
 
 	/* backlight values are on 0-255 range, where higher is brighter */
 	uint32_t backlight_current;

src/screenshooter.c

@@ -32,7 +32,7 @@ struct screenshooter {
 	struct weston_compositor *ec;
 	struct wl_global *global;
 	struct wl_client *client;
-	struct weston_process screenshooter_process;
+	struct weston_process process;
 };
 
 static void
@@ -44,7 +44,7 @@ screenshooter_shoot(struct wl_client *client,
 	struct weston_output *output = output_resource->data;
 	struct wl_buffer *buffer = buffer_resource->data;
 	uint8_t *tmp, *d, *s;
-	int32_t stride, i;
+	int32_t buffer_stride, output_stride, i;
 
 	if (!wl_buffer_is_shm(buffer))
 		return;
@@ -53,24 +53,25 @@ screenshooter_shoot(struct wl_client *client,
 	    buffer->height < output->current->height)
 		return;
 
-	stride = wl_shm_buffer_get_stride(buffer);
-	tmp = malloc(stride * buffer->height);
+	buffer_stride = wl_shm_buffer_get_stride(buffer);
+	output_stride = output->current->width * 4;
+	tmp = malloc(output_stride * output->current->height);
 	if (tmp == NULL) {
 		wl_resource_post_no_memory(resource);
 		return;
 	}
 
 	glPixelStorei(GL_PACK_ALIGNMENT, 1);
-	glReadPixels(0, 0, output->current->width, output->current->height,
-		     GL_BGRA_EXT, GL_UNSIGNED_BYTE, tmp);
+	output->read_pixels(output, tmp);
 
-	d = wl_shm_buffer_get_data(buffer);
-	s = tmp + stride * (buffer->height - 1);
+	d = wl_shm_buffer_get_data(buffer) + output->y * buffer_stride +
+							output->x * 4;
+	s = tmp + output_stride * (output->current->height - 1);
 
-	for (i = 0; i < buffer->height; i++) {
-		memcpy(d, s, stride);
-		d += stride;
-		s -= stride;
+	for (i = 0; i < output->current->height; i++) {
+		memcpy(d, s, output_stride);
+		d += buffer_stride;
+		s -= output_stride;
 	}
 
 	free(tmp);
@@ -101,7 +102,7 @@ static void
 screenshooter_sigchld(struct weston_process *process, int status)
 {
 	struct screenshooter *shooter =
-		container_of(process, struct screenshooter, screenshooter_process);
+		container_of(process, struct screenshooter, process);
 
 	shooter->client = NULL;
 }
@@ -116,7 +117,7 @@ screenshooter_binding(struct wl_input_device *device, uint32_t time,
 
 	if (!shooter->client)
 		shooter->client = weston_client_launch(shooter->ec,
-					&shooter->screenshooter_process,
+					&shooter->process,
 					screenshooter_exe, screenshooter_sigchld);
 }