vo_opengl: support framebuffer invalidation

Not sure how much can be gained with this, as we can't use it properly
yet. For now, this is used only before rendering, which probably does
overwhelmingly nothing.

In the future, this should be used after temporary passes, which could
possibly reduce memory usage and even memory bandwidth usage, depending
on the drivers.

1 files changed, 15 insertions, 0 deletions

diff --git a/video/out/opengl/utils.c b/video/out/opengl/utils.c
index 199895e4ec..f8ed6eebaf 100644
--- a/video/out/opengl/utils.c
+++ b/video/out/opengl/utils.c
@@ -293,6 +293,7 @@ bool fbotex_change(struct fbotex *fbo, GL *gl, struct mp_log *log, int w, int h,
     if (fbo->rw == cw && fbo->rh == ch && fbo->iformat == iformat) {
         fbo->lw = w;
         fbo->lh = h;
+        fbotex_invalidate(fbo);
         return true;
     }
 
@@ -378,6 +379,20 @@ void fbotex_uninit(struct fbotex *fbo)
     }
 }
 
+// Mark framebuffer contents as unneeded.
+void fbotex_invalidate(struct fbotex *fbo)
+{
+    GL *gl = fbo->gl;
+
+    if (!fbo->fbo || !gl->InvalidateFramebuffer)
+        return;
+
+    gl->BindFramebuffer(GL_FRAMEBUFFER, fbo->fbo);
+    gl->InvalidateFramebuffer(GL_FRAMEBUFFER, 1,
+                              (GLenum[]){GL_COLOR_ATTACHMENT0});
+    gl->BindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
 // Standard parallel 2D projection, except y1 < y0 means that the coordinate
 // system is flipped, not the projection.
 void gl_transform_ortho(struct gl_transform *t, float x0, float x1,