Hi

On Wed, Dec 22, 2021 at 4:11 AM Alexander Orzechowski <
orzechowski.alexander@gmail.com> wrote:

> gtk/gl was incorrectly always rendering as if the 'Zoom to Fit' was
> always checked even if it wasn't. This is now using logic closer
> to what is being used for the existing cairo code paths.
>
> Signed-off-by: Alexander Orzechowski <orzechowski.alexander@gmail.com>
>

This is definitely an improvement for me (on hidpi), but I have some
questions and I don't have much interest in working on qemu GTK3 code.

(fwiw, I hope the future will be around the gtk4 widget I work on at
https://gitlab.com/marcandre.lureau/qemu-display/)

The 2nd patch should come after this one imho, to avoid intermediary extra
regressions.

---
>  ui/gtk-gl-area.c | 34 +++++++++++++++++++++++++++++-----
>  1 file changed, 29 insertions(+), 5 deletions(-)
>
> diff --git a/ui/gtk-gl-area.c b/ui/gtk-gl-area.c
> index 01e4e74ee3..f4f2dac882 100644
> --- a/ui/gtk-gl-area.c
> +++ b/ui/gtk-gl-area.c
> @@ -41,16 +41,40 @@ void gd_gl_area_draw(VirtualConsole *vc)
>  #ifdef CONFIG_GBM
>      QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
>  #endif
> +    GtkDisplayState *s = vc->s;
>      int ww, wh, ws, y1, y2;
> +    int mx, my;
> +    int fbh, fbw;
>
>      if (!vc->gfx.gls) {
>          return;
>      }
>
>      gtk_gl_area_make_current(GTK_GL_AREA(vc->gfx.drawing_area));
> +
> +    fbw = surface_width(vc->gfx.ds);
> +    fbh = surface_height(vc->gfx.ds);
> +
>      ws =
> gdk_window_get_scale_factor(gtk_widget_get_window(vc->gfx.drawing_area));
> -    ww = gtk_widget_get_allocated_width(vc->gfx.drawing_area) * ws;
> -    wh = gtk_widget_get_allocated_height(vc->gfx.drawing_area) * ws;
> +    ww = gtk_widget_get_allocated_width(vc->gfx.drawing_area);
> +    wh = gtk_widget_get_allocated_height(vc->gfx.drawing_area);
> +
> +    if (s->full_screen) {
> +        vc->gfx.scale_x = (double)ww / fbw;
> +        vc->gfx.scale_y = (double)wh / fbh;
>

Why not keep aspect-ratio in full-screen?

(and hopefully the pointer follows the same size logic, as well as the
2d/cairo & gtk-x11/egl code paths..)

+    } else if (s->free_scale) {
> +        double sx, sy;
> +
> +        sx = (double)ww / fbw;
> +        sy = (double)wh / fbh;
> +
> +        vc->gfx.scale_x = vc->gfx.scale_y = MIN(sx, sy);
> +    }
> +
> +    fbw *= vc->gfx.scale_x * ws;
> +    fbh *= vc->gfx.scale_y * ws;
> +    mx = (ww * ws - fbw) / 2;
> +    my = (wh * ws - fbh) / 2;
>
>      if (vc->gfx.scanout_mode) {
>          if (!vc->gfx.guest_fb.framebuffer) {
> @@ -70,11 +94,11 @@ void gd_gl_area_draw(VirtualConsole *vc)
>          glBindFramebuffer(GL_READ_FRAMEBUFFER,
> vc->gfx.guest_fb.framebuffer);
>          /* GtkGLArea sets GL_DRAW_FRAMEBUFFER for us */
>
> -        glViewport(0, 0, ww, wh);
> +        glViewport(mx, my, fbw, fbh);
>          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, ww, wh,
> +                          mx, my, fbw + mx, fbh + my,
>                            GL_COLOR_BUFFER_BIT, GL_NEAREST);
>  #ifdef CONFIG_GBM
>          if (dmabuf) {
> @@ -98,7 +122,7 @@ void gd_gl_area_draw(VirtualConsole *vc)
>          }
>          gtk_gl_area_make_current(GTK_GL_AREA(vc->gfx.drawing_area));
>
> -        surface_gl_setup_viewport(vc->gfx.gls, vc->gfx.ds, ww, wh);
> +        glViewport(mx, my, fbw, fbh);
>

 We should be able to reuse and share the surface_gl_setup_viewport()
logic, no?

-- 
Marc-André Lureau