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 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.liu.z@gmail.com>
Message-ID: <20250511073337.876650-9-weifeng.liu.z@gmail.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
This commit is contained in:
Weifeng Liu 2025-05-11 15:33:18 +08:00 committed by Marc-André Lureau
parent a1b28f71f7
commit fdc09b028f

View file

@ -44,7 +44,9 @@ void gd_gl_area_draw(VirtualConsole *vc)
#endif #endif
int pw, ph, gs, y1, y2; int pw, ph, gs, y1, y2;
int ww, wh; int ww, wh;
int ww_surface, wh_surface;
int fbw, fbh; int fbw, fbh;
int wx_offset, wy_offset;
if (!vc->gfx.gls) { if (!vc->gfx.gls) {
return; return;
@ -61,6 +63,17 @@ void gd_gl_area_draw(VirtualConsole *vc)
gd_update_scale(vc, ww, wh, fbw, fbh); 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.scanout_mode) {
if (!vc->gfx.guest_fb.framebuffer) { if (!vc->gfx.guest_fb.framebuffer) {
return; return;
@ -79,11 +92,29 @@ void gd_gl_area_draw(VirtualConsole *vc)
glBindFramebuffer(GL_READ_FRAMEBUFFER, vc->gfx.guest_fb.framebuffer); glBindFramebuffer(GL_READ_FRAMEBUFFER, vc->gfx.guest_fb.framebuffer);
/* GtkGLArea sets GL_DRAW_FRAMEBUFFER for us */ /* 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); glViewport(0, 0, pw, ph);
y1 = vc->gfx.y0_top ? 0 : vc->gfx.h; y1 = vc->gfx.y0_top ? 0 : vc->gfx.h;
y2 = vc->gfx.y0_top ? vc->gfx.h : 0; y2 = vc->gfx.y0_top ? vc->gfx.h : 0;
glBlitFramebuffer(0, y1, vc->gfx.w, y2, 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); GL_COLOR_BUFFER_BIT, GL_NEAREST);
#ifdef CONFIG_GBM #ifdef CONFIG_GBM
if (dmabuf) { if (dmabuf) {