Hi,
> Subject: [PATCH 8/9] ui/gtk-gl-area: Render guest content with padding in
> fixed-scale mode
>
> In fixed-scale mode (zoom-to-fit=false), we expect that scale should not
> change, meaning that if window size is larger than guest surface, padding is
# @zoom-to-fit: Zoom guest display to fit into the host window. When
# turned off the host window will be resized instead. In case the
# display device can notify the guest on window resizes
# (virtio-gpu) this will default to "on", assuming the guest will
# resize the display to match the window size then. Otherwise it
# defaults to "off". (Since 3.1)
Current definition says the host window should be resized to fit the
size of the guest surface instead. Wouldn't padding accommodate this?
> supposed to be added to preserve the scale. However, in OpenGL mode
> (gl=on), guest surface is always painted to the whole canvas without any
> padding. This change tries to fix this bug by adding appropriate padding
> when drawing surfaces.
>
> Signed-off-by: Weifeng Liu <weifeng.li...@gmail.com>
> ---
> ui/gtk-gl-area.c | 33 ++++++++++++++++++++++++++++++++-
> 1 file changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/ui/gtk-gl-area.c b/ui/gtk-gl-area.c index db93cd6204..8151cc413c
> 100644
> --- a/ui/gtk-gl-area.c
> +++ b/ui/gtk-gl-area.c
> @@ -44,7 +44,9 @@ void gd_gl_area_draw(VirtualConsole *vc) #endif
> int pw, ph, gs, y1, y2;
> int ww, wh;
> + int ww_surface, wh_surface;
> int fbw, fbh;
> + int wx_offset, wy_offset;
>
> if (!vc->gfx.gls) {
> return;
> @@ -61,6 +63,17 @@ void gd_gl_area_draw(VirtualConsole *vc)
>
> gd_update_scale(vc, ww, wh, fbw, fbh);
>
> + ww_surface = fbw * vc->gfx.scale_x;
> + wh_surface = fbh * vc->gfx.scale_y;
> +
> + wx_offset = wy_offset = 0;
> + if (ww > ww_surface) {
> + wx_offset = (ww - ww_surface) / 2;
> + }
> + if (wh > wh_surface) {
> + wy_offset = (wh - wh_surface) / 2;
> + }
> +
> if (vc->gfx.scanout_mode) {
> if (!vc->gfx.guest_fb.framebuffer) {
> return;
> @@ -79,11 +92,29 @@ void gd_gl_area_draw(VirtualConsole *vc)
> glBindFramebuffer(GL_READ_FRAMEBUFFER, vc-
> >gfx.guest_fb.framebuffer);
> /* GtkGLArea sets GL_DRAW_FRAMEBUFFER for us */
>
> + if (wx_offset > 0) {
> + glEnable(GL_SCISSOR_TEST);
> + glScissor(0, 0, wx_offset * gs, wh * gs);
> + glClear(GL_COLOR_BUFFER_BIT);
> + glScissor((ww - wx_offset) * gs, 0, wx_offset * gs, wh * gs);
> + glClear(GL_COLOR_BUFFER_BIT);
> + glDisable(GL_SCISSOR_TEST);
> + }
> + if (wy_offset > 0) {
> + glEnable(GL_SCISSOR_TEST);
> + glScissor(0, 0, ww * gs, wy_offset * gs);
> + glClear(GL_COLOR_BUFFER_BIT);
> + glScissor(0, (wh - wy_offset) * gs, ww * gs, wy_offset * gs);
> + glClear(GL_COLOR_BUFFER_BIT);
> + glDisable(GL_SCISSOR_TEST);
> + }
> +
> glViewport(0, 0, pw, ph);
> y1 = vc->gfx.y0_top ? 0 : vc->gfx.h;
> y2 = vc->gfx.y0_top ? vc->gfx.h : 0;
> glBlitFramebuffer(0, y1, vc->gfx.w, y2,
> - 0, 0, pw, ph,
> + wx_offset * gs, wy_offset * gs,
> + (ww - wx_offset) * gs, (wh - wy_offset) * gs,
> GL_COLOR_BUFFER_BIT, GL_NEAREST); #ifdef
> CONFIG_GBM
> if (dmabuf) {
> --
> 2.49.0
>
Thanks
