vo_opengl: simplify mirroring and fix it if glBlitFramebuffer is used

The vp_w/vp_h variables and parameters were not really used anymore
(they were redundant with ra_tex w/h) - but vp_h was still used to
identify whether rendering should be done mirrored.

Simplify this by adding a fbodst struct (some bad naming), which
contains the render target texture, and some parameters how it should be
rendered to (for now only flipping). It would not be appropriate to make
this a member of ra_tex, so it's a separate struct.

Introduces a weird regression for the first frame rendered after
interpolation is toggled at runtime, but seems to work otherwise. This
is possibly due to the change that blit() now mirrors, instead of just
copying. (This is also why ra_fns.blit is changed.)

Fixes #4719.

1 files changed, 6 insertions, 6 deletions

diff --git a/video/out/opengl/ra.h b/video/out/opengl/ra.h
index e93061eb61..cf18b110a5 100644
--- a/video/out/opengl/ra.h
+++ b/video/out/opengl/ra.h
@@ -349,17 +349,17 @@ struct ra_fns {
 
     // Copy a sub-rectangle from one texture to another. The source/dest region
     // is always within the texture bounds. Areas outside the dest region are
-    // preserved. The formats of the textures will be losely compatible (this
-    // probably has to be defined strictly). The dst texture can be a swapchain
-    // framebuffer, but src can not. Only 2D textures are supported.
+    // preserved. The formats of the textures must be losely compatible. The
+    // dst texture can be a swapchain framebuffer, but src can not. Only 2D
+    // textures are supported.
     // Both textures must have tex->params.render_dst==true (even src, which is
     // an odd GL requirement).
-    // A rectangle with negative width or height means a flipped copy should be
-    // done. Coordinates are always in pixels.
+    // Rectangle with negative width/height lead to flipping, different src/dst
+    // sizes lead to point scaling. Coordinates are always in pixels.
     // Optional. Only available if RA_CAP_BLIT is set (if it's not set, the must
     // not be called, even if it's non-NULL).
     void (*blit)(struct ra *ra, struct ra_tex *dst, struct ra_tex *src,
-                 int dst_x, int dst_y, struct mp_rect *src_rc);
+                 struct mp_rect *dst_rc, struct mp_rect *src_rc);
 
     // Compile a shader and create a pipeline. This is a rare operation.
     // The params pointer and anything it points to must stay valid until