From 095038b1bc0e997846d00bfe32fd4eceeddbedb4 Mon Sep 17 00:00:00 2001
From: nanahi <130121847+na-na-hi@users.noreply.github.com>
Date: Fri, 16 Feb 2024 01:08:43 -0500
Subject: [PATCH] opengl/context_win: make --alpha runtime changeable

Same as d3d11, but since SetPixelFormat can be only called once,
cAlphaBits in PIXELFORMATDESCRIPTOR must be set to make this work.
---
 video/out/opengl/context_win.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/video/out/opengl/context_win.c b/video/out/opengl/context_win.c
index 17b1cb491a..a582e2834e 100644
--- a/video/out/opengl/context_win.c
+++ b/video/out/opengl/context_win.c
@@ -96,8 +96,7 @@ static bool create_dc(struct ra_ctx *ctx)
 
     pfd.iPixelType = PFD_TYPE_RGBA;
     pfd.cColorBits = 24;
-    if (ctx->opts.want_alpha)
-        pfd.cAlphaBits = 8;
+    pfd.cAlphaBits = 8;
     pfd.iLayerType = PFD_MAIN_PLANE;
     int pf = ChoosePixelFormat(hdc, &pfd);
 
@@ -373,11 +372,17 @@ static int wgl_control(struct ra_ctx *ctx, int *events, int request, void *arg)
     return ret;
 }
 
+static void wgl_update_render_opts(struct ra_ctx *ctx)
+{
+    vo_w32_set_transparency(ctx->vo, ctx->opts.want_alpha);
+}
+
 const struct ra_ctx_fns ra_ctx_wgl = {
-    .type           = "opengl",
-    .name           = "win",
-    .init           = wgl_init,
-    .reconfig       = wgl_reconfig,
-    .control        = wgl_control,
-    .uninit         = wgl_uninit,
+    .type               = "opengl",
+    .name               = "win",
+    .init               = wgl_init,
+    .reconfig           = wgl_reconfig,
+    .control            = wgl_control,
+    .update_render_opts = wgl_update_render_opts,
+    .uninit             = wgl_uninit,
 };