commit d2329237af197429492ec27d22a4ba4f121dbc10
author Gerd Hoffmann <kraxel@redhat.com> Mon Sep 09 09:39:11 2019 +0200
committer Gerd Hoffmann <kraxel@redhat.com> Tue Sep 17 13:42:02 2019 +0200
tree a8bfaa3bb76ecc3f4d96faff146eab22be92e973
parent 89ea03a7dc83ca36b670ba7f787802791fcb04b1

ui/egl: fix framebuffer reads

Fix egl_fb_read() to use the (destination) surface size instead of the
(source) framebuffer source for glReadPixels.  Pass the DisplaySurface
instead of the pixeldata pointer to egl_fb_read() to make this possible.

With that in place framebuffer reads work fine even if the surface and
framebuffer sizes don't match, so we can remove the guest-triggerable
asserts in egl_scanout_flush().

Buglink: https://bugzilla.redhat.com//show_bug.cgi?id=1749659
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20190909073911.24787-1-kraxel@redhat.com

ui/egl-helpers.c

diff --git a/ui/egl-helpers.c b/ui/egl-helpers.c
index edc53f6..7c530c2 100644
--- a/ui/egl-helpers.c
+++ b/ui/egl-helpers.c
@@ -102,12 +102,12 @@
                       GL_COLOR_BUFFER_BIT, GL_LINEAR);
 }
 
-void egl_fb_read(void *dst, egl_fb *src)
+void egl_fb_read(DisplaySurface *dst, egl_fb *src)
 {
     glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);
     glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
-    glReadPixels(0, 0, src->width, src->height,
-                 GL_BGRA, GL_UNSIGNED_BYTE, dst);
+    glReadPixels(0, 0, surface_width(dst), surface_height(dst),
+                 GL_BGRA, GL_UNSIGNED_BYTE, surface_data(dst));
 }
 
 void egl_texture_blit(QemuGLShader *gls, egl_fb *dst, egl_fb *src, bool flip)