gl_common: factor context creation

Always create the context in mpgl_init(), instead of doing it when
mpgl_config_window() is called the first time. This is a small step
towards cleaning up the GL backend interface, and adding other things
like perhaps GLES support, or a callback-driven backend for libmpv.

4 files changed, 51 insertions, 50 deletions

diff --git a/video/out/gl_common.c b/video/out/gl_common.c
index 195ad72539..4d0a3c8dd4 100644
--- a/video/out/gl_common.c
+++ b/video/out/gl_common.c
@@ -930,7 +930,7 @@ static MPGLContext *init_backend(struct vo *vo, MPGLSetBackendFn set_backend,
     return ctx;
 }
 
-MPGLContext *mpgl_init(struct vo *vo, const char *backend_name)
+static MPGLContext *mpgl_create(struct vo *vo, const char *backend_name)
 {
     MPGLContext *ctx = NULL;
     int index = mpgl_find_backend(backend_name);
@@ -946,17 +946,22 @@ MPGLContext *mpgl_init(struct vo *vo, const char *backend_name)
     return ctx;
 }
 
-bool mpgl_config_window(struct MPGLContext *ctx, int gl_caps, int flags)
+MPGLContext *mpgl_init(struct vo *vo, const char *backend_name,
+                       int gl_caps, int vo_flags)
 {
+    MPGLContext *ctx = mpgl_create(vo, backend_name);
+    if (!ctx)
+        return NULL;
+
     gl_caps |= MPGL_CAP_GL;
 
     ctx->requested_gl_version = (gl_caps & MPGL_CAP_GL_LEGACY)
                                 ? MPGL_VER(2, 1) : MPGL_VER(3, 0);
 
-    if (ctx->config_window(ctx, flags)) {
+    if (ctx->config_window(ctx, vo_flags | VOFLAG_HIDDEN)) {
         int missing = (ctx->gl->mpgl_caps & gl_caps) ^ gl_caps;
         if (!missing)
-            return true;
+            return ctx;
 
         MP_WARN(ctx->vo, "Missing OpenGL features:");
         list_features(missing, ctx->vo->log, MSGL_WARN, false);
@@ -970,7 +975,13 @@ bool mpgl_config_window(struct MPGLContext *ctx, int gl_caps, int flags)
     }
 
     MP_ERR(ctx->vo, "OpenGL context creation failed!\n");
-    return false;
+    mpgl_uninit(ctx);
+    return NULL;
+}
+
+bool mpgl_reconfig_window(struct MPGLContext *ctx, int flags)
+{
+    return ctx->config_window(ctx, flags);
 }
 
 void mpgl_uninit(MPGLContext *ctx)
diff --git a/video/out/gl_common.h b/video/out/gl_common.h
index a8775ba09d..eb54ca41d2 100644
--- a/video/out/gl_common.h
+++ b/video/out/gl_common.h
@@ -136,9 +136,6 @@ typedef struct MPGLContext {
     void *priv;
 } MPGLContext;
 
-MPGLContext *mpgl_init(struct vo *vo, const char *backend_name);
-void mpgl_uninit(MPGLContext *ctx);
-
 void mpgl_lock(MPGLContext *ctx);
 void mpgl_unlock(MPGLContext *ctx);
 void mpgl_set_context(MPGLContext *ctx);
@@ -150,7 +147,12 @@ bool mpgl_is_thread_safe(MPGLContext *ctx);
 // gl_caps: bitfield of MPGL_CAP_* (required GL version and feature set)
 // flags: passed to the backend's create window function
 // Returns success.
-bool mpgl_config_window(struct MPGLContext *ctx, int gl_caps, int flags);
+MPGLContext *mpgl_init(struct vo *vo, const char *backend_name,
+                       int gl_caps, int vo_flags);
+void mpgl_uninit(MPGLContext *ctx);
+
+// flags: passed to the backend function
+bool mpgl_reconfig_window(struct MPGLContext *ctx, int flags);
 
 int mpgl_find_backend(const char *name);
 
diff --git a/video/out/vo_opengl.c b/video/out/vo_opengl.c
index 0c35ca3ee0..c7d274ec72 100644
--- a/video/out/vo_opengl.c
+++ b/video/out/vo_opengl.c
@@ -186,23 +186,6 @@ static int query_format(struct vo *vo, uint32_t format)
     return caps;
 }
 
-static bool config_window(struct gl_priv *p, int flags)
-{
-    if (p->renderer_opts->stereo_mode == GL_3D_QUADBUFFER)
-        flags |= VOFLAG_STEREO;
-
-    if (p->renderer_opts->alpha_mode == 1)
-        flags |= VOFLAG_ALPHA;
-
-    if (p->use_gl_debug)
-        flags |= VOFLAG_GL_DEBUG;
-
-    int mpgl_caps = MPGL_CAP_GL21 | MPGL_CAP_TEX_RG;
-    if (!p->allow_sw)
-        mpgl_caps |= MPGL_CAP_NO_SW;
-    return mpgl_config_window(p->glctx, mpgl_caps, flags);
-}
-
 static void video_resize_redraw_callback(struct vo *vo, int w, int h)
 {
     struct gl_priv *p = vo->priv;
@@ -216,7 +199,7 @@ static int reconfig(struct vo *vo, struct mp_image_params *params, int flags)
 
     mpgl_lock(p->glctx);
 
-    if (!config_window(p, flags)) {
+    if (!mpgl_reconfig_window(p->glctx, flags)) {
         mpgl_unlock(p->glctx);
         return -1;
     }
@@ -462,14 +445,26 @@ static int preinit(struct vo *vo)
     struct gl_priv *p = vo->priv;
     p->vo = vo;
 
-    p->glctx = mpgl_init(vo, p->backend);
+    int vo_flags = 0;
+
+    if (p->renderer_opts->stereo_mode == GL_3D_QUADBUFFER)
+        vo_flags |= VOFLAG_STEREO;
+
+    if (p->renderer_opts->alpha_mode == 1)
+        vo_flags |= VOFLAG_ALPHA;
+
+    if (p->use_gl_debug)
+        vo_flags |= VOFLAG_GL_DEBUG;
+
+    int mpgl_caps = MPGL_CAP_GL21 | MPGL_CAP_TEX_RG;
+    if (!p->allow_sw)
+        mpgl_caps |= MPGL_CAP_NO_SW;
+
+    p->glctx = mpgl_init(vo, p->backend, mpgl_caps, vo_flags);
     if (!p->glctx)
         goto err_out;
     p->gl = p->glctx->gl;
 
-    if (!config_window(p, VOFLAG_HIDDEN))
-        goto err_out;
-
     mpgl_set_context(p->glctx);
 
     if (p->gl->SwapInterval)
diff --git a/video/out/vo_opengl_old.c b/video/out/vo_opengl_old.c
index 91a14398d5..fb0831202e 100644
--- a/video/out/vo_opengl_old.c
+++ b/video/out/vo_opengl_old.c
@@ -1700,19 +1700,6 @@ static int initGl(struct vo *vo, uint32_t d_width, uint32_t d_height)
     return 1;
 }
 
-static bool config_window(struct vo *vo, int flags)
-{
-    struct gl_priv *p = vo->priv;
-
-    if (p->stereo_mode == GL_3D_QUADBUFFER)
-        flags |= VOFLAG_STEREO;
-
-    int mpgl_caps = MPGL_CAP_GL_LEGACY;
-    if (!p->allow_sw)
-        mpgl_caps |= MPGL_CAP_NO_SW;
-    return mpgl_config_window(p->glctx, mpgl_caps, flags);
-}
-
 static int reconfig(struct vo *vo, struct mp_image_params *params, int flags)
 {
     struct gl_priv *p = vo->priv;
@@ -1733,7 +1720,7 @@ static int reconfig(struct vo *vo, struct mp_image_params *params, int flags)
 
     uninitGl(vo);
 
-    if (!config_window(vo, flags))
+    if (!mpgl_reconfig_window(p->glctx, flags))
         return -1;
 
     initGl(vo, vo->dwidth, vo->dheight);
@@ -2085,16 +2072,22 @@ static int preinit(struct vo *vo)
         p->use_yuv = 2;
     }
 
-    p->glctx = mpgl_init(vo, p->backend_arg);
+    int vo_flags = 0;
+
+    if (p->stereo_mode == GL_3D_QUADBUFFER)
+        vo_flags |= VOFLAG_STEREO;
+
+    int mpgl_caps = MPGL_CAP_GL_LEGACY;
+    if (!p->allow_sw)
+        mpgl_caps |= MPGL_CAP_NO_SW;
+
+    p->glctx = mpgl_init(vo, p->backend_arg, mpgl_caps, vo_flags);
     if (!p->glctx)
         goto err_out;
     p->gl = p->glctx->gl;
 
-    if (p->use_yuv == -1) {
-        if (!config_window(vo, VOFLAG_HIDDEN))
-            goto err_out;
+    if (p->use_yuv == -1)
         autodetectGlExtensions(vo);
-    }
     MP_VERBOSE(vo, "Using %d as slice height "
                "(0 means image height).\n", p->slice_height);